Optimization Of Biodiesel Production Process

Published in: Mechanical

2,556 Views

Optimization of Biodiesel Production Process & CI Engine Performance.

Juned K / Navi Mumbai

10 years of teaching experience

Qualification: M.Tech (DR BATU LONERE MANGAON - 2015), Ph.D (Amity Mumbai Campus - 2023), B.Tech/B.E. (FINOLEX ACADEMY OF MANAGEMENT AND TECHNOLOGY RATNAGIRI - 2011)

Teaches: All Subjects, Hindi, Mathematics, Science, Accountancy, Arts Group, Physics, Biology, Chemistry, B.Sc Tuition, B.Tech Tuition, Drawing, Engineering Graphics, Mechanical, Mechanics, Production

Contact this Tutor

Optimization of Biodiesel Production Process & CI Engine Performance Using Mahua Biodiesel Chapter 1 Introduction 1.1 Background The term compressed-ignition (CI) is used all over the world to denote diesel oil engines. This includes two or four stroke engines with airless fuel injection. The combustion is initiated by injection of fuel to the highly compressed air. The concept of Compression Ignition (CI) Engines is credited to great German Engineer Rudolf Diesel. Great inventor of diesel engines Rudolf Diesel was born in Paris (1858-1913). In 1892, he proposed "compression of air alone until a sufficiently high temperature was attained to ignite the fuel which was to be injected at end of compression stroke" In his first experiment, he tried to inject coal dust into a cylinder containing air that has been already highly compressed. He was successful only to some extent. Later on he turned to liquid and achieved success after four years of extreme hard work. Later by end of journey of this great inventor, engine he invented and fuel used are known by his name called "Diesel Engine" for CI Engines [l]. One prominent key on liquid fuel was given by Rudolf Diesel. He used peanut oil as fuel for demonstration on CI Engine, and suggested it as an alternative fuel option. However, he quoted very true predicting fact as, 'the use of vegetable oil for engine fuels may seem insignificant today. But such oils may become, in course of time, as important as petroleum and the coal tar products of the present time"- Rudolf Diesel, 1912. After eight decades, the awareness about environment rose among the people to search for an alternative fuel that could burn with less pollution. Rudolf Diesel's prediction is becoming true today with more and more bio-diesel being used all over the world [2]. CI Engines are well known as better power source due to high thermal efficiency, fuel economy, higher compression ratio, lean air-fuel mixture operation, good reliability, higher performance, and fuel economy compared to Spark Ignition Engine. Owing to low fuel 1
consumption, CI Engines have become increasingly attractive for small Lorries, various agriculture machines and passenger cars [1, 3, 4]. Besides, CI Engines run on diesel, dual fuel such as LPG, CNG, bio-gas, producer gas, with diesel as pilot fuel, and alternative fuels like bio-diesel, its blend with diesel. Also, diesel, bio-diesel fuels are non-volatile, more viscous and self-lubricating [3]. However, biodiesel is emerging efficient and economical alternative fuel for diesel in CI Engines without any considerable modifications in existing engine [4]. 1.2 Global & Indian Energy Scenario Energy is critical input for socio-economic development for any country. Demand of energy is increasing day by day due to the fast industrial development, urbanization and increasing population. According to estimation of IEA (International Energy agency), the global demand for energy will be increased by 30% by 2030[5]. From past 25 years the energy supply s steadily increased but due to increasing consumption rate the reserve of crude oil and natural gas will diminish approximately after 41.8 and 60.3 years respectively. At present condition 88.6% of energy demand is fulfilled by the fossil fuels in which crude oil, coal and natural gas have 33.7%, 30.5%, 24.4% contribution respectively. Table 1.1 gives details about proved reserves, production and consumption of different energy resources for the year 2013 Table 1.1 Energy Scenario in 2013 [5] RESOURSE Natural (tcm) Coal (Mtone) gas Nuclear energy Hydroelectricity Renewable energy oil India World India World India World India World India World India PROVED RESOURSES 1.4(tcm) 185.7(tcm) 60600 891531 800 PRODUCTION 33.7(bcm) 3369.9(bcm) 228.8(MtOe) 3881.4 7.5 563.2 29.8 855.8 11.7 279.3 CONSUMPTION 51.4(bcm) 3347.6(bcm) 324.3 3826.7 7.5 563.2 29.8 855.8 11.7 279.3 175.2 2
World 238200 4132.9 4185.1 It can be concluded from these statistics that domestic crude oil can meet only about 24% of the demand, while the rest met by imported crude . Among the renewable energy resources biofuel plays an important role. In India for 2013 the biofuel production was 321 thousand tons of oil equivalents, for the world the production was 65348 thousand tons of oil equivalents [6]. 1.3 National Biofuel Policy National biofuel policy is the agenda decided by the government of India for biofuels. This policy provides guide lines regarding the strategy and approach, distribution and marketing, financing, research and development, quality standards etc. The prices of crude oil are increasing significantly from past few years with the increase in demand for transportation fuels. The domestic crude oil is able to meet only 24% of the demand, while rest is met from imported crude. Hence India has large concerns about the energy security. Hence it is necessary for India to be focused on the biofuels. The transporting sector is has been identified as the major polluting sector, biofuels have become compelling in view of tightening automobile vehicle emission standards. Biofuels are the potential means to stimulate rural development and create employment opportunities. 1.3.1 Vision and goals The policy aims at mainstreaming of biofuels. The policy will bring the accelerated development and promotion, cultivation, production and use of biofuels to increasingly substitute petrol and diesel. The goal of policy is to ensure that a minimum level of biofuel to become readily available in the market to meet the demand at given time. An indicative target of 20% blending of biofuel for both biodiesel and bioethanol are proposed. 1.3.2 Strategy and approach The focus for development of biofuels will be to utilize waste and degrade forest and non- forest land only for cultivation of shrubs and trees bearing non edible oil seed for production of biodiesel. In the future to, it would be ensured that the next generation of technology is 3
based on nonfood feedstock's. Cultivators, farmers and labors will be encouraged to take plantation that provides the feedstocks for biodiesel and bioethanol. Such plantation will be supported through minimum support price for the non-edible oil seed. Appropriate financial and fiscal measure will be considered from time to time to support the development and promotions of biofuel and their utilization in different. There are over 400 species of tree bearing non edible oil seed in the country. The potential of all these species will be exploited, depending on their techno economic viability for production of biodiesel. 1.3.3 Research & development Research & development will focus on plantations, biofuel processing and production technologies as well as maximizing efficiency of different end use applications of by-product. High priority will be given to indigenous R & D and technology development based on local feedstocks and needs. Intensive R & D work will be taken in a) Biofuel feedstock production based on sustainable biomass b) Advanced conversion technologies for first generation biofuels and emerging technology for second generation biofuels c) Technologies for end use applications including modification and development of engines for transportation sector[7] 1.4 Advantages of Biodiesels Review of literature available in the field of vegetable oil usage, many advantages is noticeable. The following are some of the advantages of using vegetable oil as l.c. engine in India: Vegetable oil is produced domestically which helps to reduce costly petroleum imports Development of the bio-diesel industry would strengthen the domestic, and particularly the rural, agricultural economy of agricultural based countries like India It is biodegradable and non-toxic It is a renewable fuel that can be made from agricultural crops and or other feed stocks that are considered as waste It has 80% heating value compared to that of diesel 4
It contains low aromatics It has a reasonable Cetane number and hence possesses less knocking tendency Low sulphur content and hence environment friendly Enhanced lubricity, thereby no major modification is required in the engine Personal safety is improved (flash point is 1000C higher than that of diesel) It is usable within the existing petroleum diesel infrastructure (with minor or no modification in the engine)[8,9,10]. 1.5 Challenges with Biodiesel The major challenges that face the use of vegetable oil as l.c. engine fuels are listed below: The price of vegetable oil is dependent on the feed stock price; Feed stock homogeneity, consistency and reliability are questionable; Homogeneity of the product depends on the supplier, feed stocks and production methods; Storage and handling is difficult (particularly stability in long term storage) Flash point in blends is unreliable Compatibility with l.c. engine material needs to be studied further Cold weather operation of the engine is not easy with vegetable oils Acceptance by engine manufacturers is another major difficulty Continuous availability of the vegetable oils needs to be assured before embarking on the major use of it in l.c. engines [8, 9, 10]. 1.6 Aim and Objectives of the Present Study The main aim of the study was to optimize the biodiesel production procedure and to optimize the engine performance of Mahua oil biodiesel using taguchi method. In order to achieve the aim following objectives were decided for project: • To decide range of various parameters for experimental study based on the literature review. • To study biodiesel production process through transesterification of Mahua Oil. • To study the effect of molar ratio, type of catalyst, reaction temperature and catalyst concentration on reaction. 5
• To study the effect of size of heterogeneous catalyst on reaction. • To conduct tests on engine for deciding optimum operating parameters like compression ratio, injector opening pressure, nozzle hole geometry etc. • Evaluate performance of CI engine fuelled with Mahua oil biodiesel and its blends with diesel. • To study the effect of additive in Mahua oil biodiesel on performance of diesel engine 1.7 Summary The world is facing the energy crisis hence it is necessary to find the different energy resources, due to this the use of non-renewable energy sources is new trend in the energy world. One of the alternative renewable energy resource options is the use of biodiesel. Concept of use of biodiesel is there from the invention of the diesel engine. But due the large prize, unavailability the concept was not developed. Government of India has taken an initiative to mainstream the biofuels. As India is very much dependent on the other countries for the supply of petroleum products, it raises the issue of energy security of the country. Hence it will be beneficial for country to use biofuels to become energy independent. In national biofuel policy, the use of edible oils for the use of biofuel production is prohibited. It is mentioned to focus on the local feedstocks for the biofuel production which gives direction to the research. It is necessary to find the potential of each and every available non edible oil seed so that demand of large amount of fuel can be satisfied in near future. The biodiesel have certain advantages over the conventional petroleum fuels such as they are biodegradable and nontoxic, they do not contain sulfur and they are safer to use. But there are various challenges to use the biodiesel as mainstream fuel such as properties of biodiesel are not consistent, cold weather operation is not easy and continuous availability is not possible. 6
N/A
Chapter 2 Literature Review 2.1 Biodiesel Feedstock Alternative diesel fuels made from natural, renewable sources such as vegetable oil and fats . The most commonly used oils for the production of Biodiesel are soybean, sunflower, palm, rapeseed, canola, cotton seed and Jatropha [1]. Feedstocks for biodiesel production can be traditionally categorized into three main groups • Vegetable oils (edible and non-edible), Animal fats • Waste cooking oils (used oily materials). Additionally, algal oils have been emerging in recent years as the fourth category of growing interest because of their high oil content and rapid biomass production. Different kinds of vegetable edible oils, depending upon the climate and soil conditions, are being used as the main conventionally feedstocks for biodiesel production such as rapeseed oil in Canada, edible and non-edible oily plants for land available. When deciding which type of oil crops should be grown, in addition to profits, their impact on the environment should also be taken into account. In relation to vegetable oils, animal fats such as tallow, white grease or lard, chicken fat and yellow grease are often priced favorably for conversion into biodiesel, providing an economic advantage. However, there is a limited amount of animal fats available, so they will never be able to meet the world's fuel needs. Besides, it is the fact that animal fats can create a big problem during the biodiesel production since they became solid wax at room temperature. Waste cooking oils could be a good choice as feedstocks for biodiesel production because they are either priceless or cheaper than virgin vegetable oils. Their amount can be great in each country and is dependent on the use of vegetable oils from which they are generated. But Waste cooking oils can be contaminated by many types of impurities from the cooking process (polymers, FFAs, etc.) and their conversion to biodiesel is complicated [11]. Biodiesel has been mainly produced from edible vegetable oils all over the world. More than 95% of global biodiesel production is made from edible vegetable oils. Global use of edible 8
oils increased faster, than its production. Industrialized countries with bio-fuels targets, such as the United States and the EU countries are unlikely to have the agricultural land base needed to meet their growing demand for current production of bio-fuels. Currently, biodiesel is mainly prepared from conventionally grown edible oils such as rapeseed, soybean, sunflower and palm thus leading to alleviate food versus fuel issue. Serious problems face the world food supply today. The rapidly growing world population and rising consumption of bio-fuels are increasing demand for both food and bio-fuels. This exaggerates both food and fuel shortages. The human population faces serious food shortages and malnutrition. Nearly 60% of humans in the world are currently malnourished, so the need for grains and other basic foods is critical. Growing crops for fuel squanders land, water, and energy resources vital for the production of food for people. Rapeseed and sunflower oils are used in the EU, palm oil predominates in biodiesel production in tropical countries, and soybean oil is the major feedstock in the United States. Rapeseed oil has 59% of total global biodiesel raw material sources, followed by soybean (25%), palm oil (10%), sunflower oil (5%), and other (1%)[12]. It is not feasible in India to use edible oil to such extend for biodiesel production because there is big gap between demand and supply of such oils. Using edible oil for biodiesel production means conversion of food in to fuel; hence the focus should be on non-edible vegetable oils. Government of India has also forbidden the use of edible oil for the biodiesel. Non-edible vegetable oils have certain advantages over the edible oils. Most of the Non- edible vegetable oil seeds are obtained from wild plants and they do not require any intense care. Non- edible vegetable oil seeds have very low cultivation cost. Their plants can be grown on the unproductive lands, degraded forests, by the side of the irrigation canals and roads. This may help to provide employment in rural and undeveloped areas of developed country [13]. 2.2 Non Edible Seeds The production of biodiesel from different non-edible oilseed crops has been extensively investigated over the last few years. Some of these non-edible oilseed crops include jatropha tree, karanja, tobacco seed, rice bran, mahua, neem, rubber seed, and microalgae. Karanja is medium sized green tree from the legumnosae family which has a yield of 9-99 kg of seeds per tree. Recently, Karanja has been recognized as an invaluable source of oil. Its seed has 25- 40% oil which when applied dual-step transesterification would result in a yield of 96.6-97% biodiesel. Karanja oil mainly contains oleic acid (44.5-71.3%), followed by linoleic acid 9
(10.8-18.3%) and stearic acids (2.4-8.9%)[2]. The important properties of Karanja lies within the limit set by ASTM standards and German biodiesel standards. The large cultivation of karanja could make the non-edible feedstock cheaper for biodiesel production [11]. Table 2.1 Various feedstocks of biodiesel depending upon its category Edible oil Soybeans Groundnut Wheat Oat Rice Sorghum Rapeseed Canola Sunflower Barley Coconut Cotton seed Non-edible oil Almond Babassu Brassica Cynara cardunculus Jatropha curcas Jatropha nana Jojoba oil Pongamia glabra Simarouba Undi Palm Karanja Tobacco seed Rubber plant Rice bran Sesame Salmon oil Animal oil Lard Tallow Poultry Fat Fish oil Other oil Bacteria Algae Fungi Micro algae Tarpenes Latexes Cooking Oil (Yellow Grease) Microalgae (Chlorellavulgaris) Polanga is a medium and large-sized evergreen sub-maritime tree .Polanga kernels have very high oil content (75%) and the oil contains approximately 71% of unsaturated fatty acids (essentially oleic and linoloeic acids). It is obtained by cold expression and yields refined, greenish yellow oil, similar to olive oil, with an aromatic odour and an insipid taste. The yield of biodiesel from the Polanga oil under the optimized conditions is found to be 89%. The Polanga biodiesel obtained by this process is suitable use in direct injection diesel engine. The viscosity of Polanga oil reduces substantially after transesterification. The density and viscosity of the Polanga oil methyl ester formed after triple stage transesterification and it is close to diesel oil. All the characterization tests of Polanga biodiesel demonstrated and found that most of the properties are in very close agreement with the diesel oil. Therefore, Polanga 10
biodiesel is a potential fuel for the application in compression ignition engines for complete replacement of diesel fuel without any modification of engine [11, 12]. Neem is a medium-sized evergreen tree from the Meliaceae family. The neem tree can grow in all kinds of soil, including saline, clay, dry, shallow, alkaline, and stony soils, and even in highly calcareous soil [1]. Neem seed contains 20—30 wt% oil, and its kernels contain 40 50% brown oil. Neem oil has high-unsaturated constituents, such as linoleic acid (6—16%) and oleic (25—54%) acid, and saturated oil like stearic acid (9 24%). It is observed that the viscosity of neem oil biodiesel blends (up to B50) is within ASTM specification limits whereas BIOO is marginally out of specifications. Calorific value of biodiesel blends is lower than mineral diesel because biodiesel is having approximately 12% lower calorific value compared to mineral diesel. Density of biodiesel is observed to be higher than mineral diesel. Cetane number of the neem oil biodiesel and mineral diesel were 51 and 48 respectively. Mahua is a large-sized evergreen or semi-evergreen tree from the Sapotaceae family. Mahua oil fat (solid at ambient temperature) has been used in skin care and in manufacturing soap or detergents. The mahua tree starts producing seeds 10 years after plantation and continues to do so up to 60 years. Its seed has an oil content of 35—50 wt.%. The mahua oil generally contains about 20% FFAs and a procedure for converting this mahua oil to biodiesel is very much required. Mahua oil contains approximately 41—51% oleic acid. Other fatty acids are also present in the oil, such as stearic (20.0—25.1%), palmitic (16.0— 28.2%), and linoleic acids (8.9-18.3%). Rubber seed oil comes from the Euphorbiaceae family. It is a forest-based tree largely produced in Malaysia, India, Thailand, and Indonesia. In the wild, plant height can reach up to 34 m. The tree requires heavy rainfall and non-frost climate condition. Rubber seed contains 50—60 wt. % oil, and its kernel contains 40—50 wt. % of brown oil. Rubber seed oil is high in unsaturated constituents, such as 39.6—40.5% linoleic acid, 17 24.6% oleic acid, and 16.3 26% linolenic acid. Linseed is an herbaceous annual-type plant that grows in countries such as India, Canada, Argentina, and some parts of Europe. Linseed contains 35—45 wt% oil and is high in unsaturated constituents, such as linoleic (13.29—14.93%), oleic (20.17—24.05%), and linolenic acids (46.10—51.12%). Other fatty acids found in linseed oil include saturated species such as stearic (5.47—5.63%) and palmitic (5.85 6.21%) acids [11, 13]. 11
Table 2.2 Production of non-edible oil seeds and biodiesel in India Species Castor Jatropha Mahua Sal Linseed Neem Pongamia (Karanja) Simarouba Glauca Oil fraction (%) 45-50 50-60 35—40 10-12 35—45 20-30 30—40 50-65 Oil tons/ha 0.5-1.0 2.0-3.0 1.0—4. O 1.0-2.0 0.5-1.0 2.0-3.0 2.0—4. O 2.0-2.5 Jojoba is native to the Mojave and Sonoran deserts of California, Arizona, and Mexico. Jojoba has been grown commercially for its oil, a liquid wax ester, extracted from the seed. The plant has been used to combat and prevent desertification in some parts of India. The seed contains approximately 40—50 wt. % oil with a fatty acid composition of 43.5—66% oleic acid and 25.2—34.4% linoleic acid. Tobacco belongs to the Solanaceae family, and it is cultivated in several countries worldwide, such as Turkey, Macedonia, North America, South America, India and Russia. The tree is commonly grown for leaf collection. The physical and chemical properties of tobacco oil are comparable with those of other vegetable oils, and tobacco is considered a new potential feedstock for biodiesel production . The seed contains approximately 35—49 wt. % oil with fatty acid composition of 69.49—75.58% of linoleic acid[14]. 2.3 Production of Biodiesel Many standardized procedures are available for the production of bio-diesel fuel oil. The commonly used methods for bio-fuel production are elaborated on below. 2.3.1 Blending Vegetable oil can be directly mixed with diesel fuel and may be used for running an engine. The blending of vegetable oil with diesel fuel were experimented successfully by various researchers. A diesel fleet was powered with a blend of 95% filtered used cooking oil and 5% diesel in 1982. In 1980, Caterpillar Brazil Company used pre-combustion chamber engines 12
with a mixture of 10% vegetable oil to maintain total power without any modification to the engine. A blend of 20% oil and 80% diesel was found to be successful. It has been proved that the use of 100% vegetable oil was also possible with some minor modifications in the fuel system. The high fuel caused the major problems associated with the use of pure vegetable oils as fuel viscosity in compression ignition engines. Micro-emulsification, pyrolysis and transesterification are the remedies used to solve the problems encountered due to high fuel viscosity[15,16]. 2.3.2 Micro-emulsification To solve the problem of high viscosity of vegetable oil, micro emulsions with solvents such as methanol, ethanol and butanol have been used. A micro emulsion is defined as the colloidal equilibrium dispersion of optically isotropic fluid microstructures with dimensions generally in the range of 1—150 nm formed spontaneously from two normally immiscible liquids and one or more ionic or non-ionic amphiphiles. These can improve spray characteristics by explosive vaporization of the low boiling constituents in the micelles. All micro emulsions with butanol, hexanol and octanol will meet the maximum viscosity limitation for diesel engines [15, 16]. 2.3.3 Cracking Cracking is the process of conversion of one substance into another by means of heat or with the aid of catalyst. It involves heating in the absence of air or oxygen and cleavage of chemical bonds to yield small molecules. The pyrolyzed material can be vegetable oils, animal fats, natural fatty acids and methyl esters of fatty acids. The pyrolysis of fats has been investigated for more than 100 years, especially in those areas of the world that lack deposits of petroleum. Since World War I, many investigators have studied the pyrolysis of vegetable oil to obtain products suitable for engine fuel application. Tung oil was saponified with lime and then thermally cracked to yield crude oil, which was refined to produce diesel fuel and small amounts of gasoline and kerosene [16, 17]. 2.3.4 Transesterification Transesterification is otherwise known as alcoholysis. It is the reaction off at or oil with an alcohol to form esters and glycerin. A catalyst is used to improve the reaction rate and yield. 13
Among the alcohols, methanol and ethanol are used commercially because of their low cost and their physical and chemical advantages. They quickly react with tri-glycerides and NaOH and are easily dissolved in them. To complete a transesterification process, 3:1 molar ratio of alcohol is needed. Enzymes, alkalis or acids can catalyze the reaction, i.e. lipases, NaOH and sulphuric acid, respectively. Among these, alkali transesterification is faster and hence it is used commercially. A mixture of vegetable oil and sodium hydroxide (used as catalyst) are heated and maintained at 650C for 1 h, while the solution is continuously stirred. Two distinct layers are formed, the lower layer is glycerin and the upper layer is ester. The upper layer (ester) is separated and moisture is removed from the ester by using calcium chloride. It is observed that 90% ester can be obtained from vegetable oils [15,16,17,18]. 2.4 Transesterification Using Different Catalysts The most widely used industrial method for the commercial production of biodiesel from vegetable oils/fats is a base catalyzed transesterification process using KOH or NaOH as the homogeneous catalyst and MeOH as the lower alcohol. The advantage of this process is production of methyl esters at very high yields under mild conditions and reaction generally takes about an hour for completion. But this method with homogeneous transesterification has certain disadvantages Production costs were high Process involved number of washing and purification steps in order to meet the stipulated quality. It is quite difficult to remove the traces the K/Na remaining in the product Separation of glycerine also posed technical challenges. The higher amount of water used in washing and consequent treatment of the resulting effluent added to the overall process cost of oil and problems of product separation The major drawback of homogeneous catalyst such as KOH and NaOH is hygroscopic nature and hazardous for the environment as compared to the heterogeneous catalyst [18]. Due to these issues a large number of alternative methods are being developed. These include supercritical process, enzymatic process and solid catalysts process. Supercritical process is also one of the promising methods for biodiesel production as this process is very fast and is carried out without catalyst. Enzyme based transesterification is also one of the option for 14
biodiesel production and is generally carried out at moderate temperature with high yields. Lipase enzymes are used for transesterification reaction and process can tolerate free fatty acid and water without soap formation and thereby making separation of biodiesel and glycerol easier. Enzymatic catalysts though highly promising but are rather slow. For a successful commercial catalyst, catalyst life, recyclability and lower cost are extremely important as these have a direct effect on overall cost of the process. Renewable biodiesel produced by an environmentally-friendly approach like enzymatic transesterification makes the whole process sustainable for future need of clean energy. Enzyme cost and its deactivation due to feed impurities are major hindrance for commercial viability of this process. Biodiesel synthesis using solid catalysts instead of homogeneous liquid catalyst could potentially lead to economical production costs because of reuse of the catalyst and offer the possibility for carrying out both transesterification and esterification simultaneously. Additional benefit with solid based catalyst is the lesser consumption of catalyst. for production of 8000 tons of biodiesel, 88 tons of sodium hydroxide may be required while only 5.7 tons of solid supported MgO is sufficient for production of 100,000 tons of biodiesel. One disadvantage with use of solid catalyst is the formation of three phases together with oil and alcohol, which leads to diffusion limitations thus decreasing the rate of the reaction biodiesel production [19,20]. Liu et al. Studied SrO metal oxide for transesterification of soybean oil. The conversion obtained was 95% at temperature of 650C, catalyst content of 3wt%, molar ratio of methanol to oil of 12:1 and reaction time of 30 min. Further, biodiesel yield was only slightly reduced when the SrO catalyst is subsequently reused for 10 cycles [21]. Liu et al. studied transesterification of soybean oil to biodiesel using CaO as a solid catalyst. The reaction was carried out using 12:1 M ratio of methanol to oil, 8wt% catalyst concentration at 650C. Biodiesel yield of 95% was obtained when reaction was carried out for 3 h. The authors also reported comparative activity of CaO with K2C03/cA1203 and KF/cA1203 catalysts. It was observed that CaO maintained sustained activity for longer time (20 cycles) after repeated use and biodiesel yield was also not affected, while K2C03/cA1203 and KF/cA1203 catalysts were not able to maintain activity and biodiesel yield also got affected after every use [22]. Veljkovic et al. described the kinetics of CaO heterogeneously catalyzed methanolysis of sunflower oil. They observed 98% yield in the transesterification with 6:1 M ratio of 15
sunflower oil to methanol, 1 wt% catalyst (based on oil wt.) at 600C within 2 h reaction time [23]. Granados et al. evaluated catalytic activity of activated calcium oxide was also for production of biodiesel by transesterification of sunflower oil in batch reactor at 13:1 methanol to oil molar ratio, 3 wt. % catalyst content at 600C. Under these conditions, reaction was complete in 100 min giving 94% conversion [24]. Benjapornkulaphong et al. compared the catalytic performance of A1203—supported alkali, alkali earth metal oxides and effect of calcination temperature on activity of different catalyst for transesterification of palm kernel oil and crude coconut oil with methanol. After 3 h of reaction time, at 600C with 65: 1 M ratio of alcohol/oil and 10 wt% catalyst content, the maximum conversion achieved was 94.3% from palm kernel oil whereas only 85% conversion was obtained in the case of crude coconut oil due to high acid value and moisture content of crude coconut oil than palm kernel oil. But when catalyst amount was increased from 15 to 20 wt%, the conversion of crude coconut oil also increased from 94% to 99.8%. Abhishek Guldhe et al studied the advances in synthesis of biodiesel via enzyme catalysis. Bio conversion of oils to biodiesel using the enzyme lipaseas catalyst is a greener approach to biodiesel production [25]. Lipases have been used at industrial level for a wide range of applications in food processing, pharmaceutical and cosmetics industry. With its ability to catalyze a variety of reactions, lipase is a suitable catalyst for transesterification of various feedstocks, even those with high acid value, which are considered slow quality feedstocks. Lipase catalysis offers the following benefits over chemical catalysis Lower energy requirement Pure quality of biodiesel and glycerol High product yield Easy recovery of products No waste water generation [26, 27]. The cost of lipase, comparatively longer reaction time and in habitation of lipase activity by short chain alcohol are the obstacles in further scaling-up of this process s to industrial production level. Screening of lipases from various sources is needed to find effective lipases for transesterification. Use of a combination of lipases with different specificities has been 16
proved to be an effective tool to achieve higher biodiesel yields. Lipases have shown greater stability and conversion ability in novel green solvents like ionic liquids. These green solvents could effectively displace toxic organic solvents to make the biodiesel production process safer. Even the biodiesel synthesis by lipase in solvent free synthesis and continuous process has shown great potential of scaling up of this technology to industrial scale. The enzymatic conversion method of biodiesel production is a promising alternative to conventional conversion methods. Enzyme catalysis addresses the environmental problems as well as ensures quality biodiesel yield for fulfilling the existing fuel demand [28, 29]. Ramachandran et al revived the recent developments for biodiesel production by ultrasonic assist transesterification using different heterogeneous catalyst. Heterogeneous catalytic reaction converts triglycerides in to methyl ester and glycerol as a byproduct slowly but produced biodiesel in a very feasible economic way due to the reusability of catalyst for both batch and continuous process and cost effective due to easy separation. Different heterogeneous catalytic transesterification for various feedstocks are summarized table 2.1 along with process conditions. The effectiveness of the heterogeneous catalytic reaction is based on the activity of the solid catalyst used. There are two types of heterogeneous catalyst used for biodiesel production such as base and acid catalyst . The reaction time and temperature is maintained in lower range for solid base catalytic transesterification reaction . The solid base catalyst is found to be more active when compared to acid catalyst. Generally, metal oxides group are studied for transesterification reaction. There are several metal oxides studied: magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), strontium oxide, titanium oxide, zinc oxide, mixed oxides catalysts and hydrotalcites. MgO, CaO, SrO and Bao are widely used as an alkaline earth metal. These are having well heterogeneous in nature. Calcium oxide is much attracted due to its availability and cost effective. They pointed out the main advantages of using solid acid catalyst as Esterification and transesterification occurs simultaneously They are in sensitive to free fatty acids content Eliminate the washing step in biodiesel process Easy separation of the catalyst from the reaction mixtures result in g in lower product contamination level Easy regeneration and recycling of catalyst and Reduction in corrosion problem, even with the presence of acid species[18] 17
Table 2.3 Different heterogeneous catalytic transesterification for various feedstocks Feedstock Sunflower oil Sunflower oil Soybean oil Soybean oil Palm oil Palm oil Palm oil Rape seed oil Waste cooking oil Jatropha oil Soybean oil Moringa oleifera oil Mixed waste ve etable oil Al Purified palmoilS04 Sunflower oil Cottonseed oil Croton me aloco us oil Yellow horn Catalyst Fe—Zn double metal cyanide (DMC) Zr02 supported La203 catal st ZnO loaded with S Zr02 CaO from eggshells CaO/A1203 KF/Ca-A1 h drotalcite KN03/CaO MgO/Ti02 M Al h drotalcite Sodium silicate S04 2/Sn02-Si02 Al (H S 04)3 S04 Zr02 S04 2Zr02/Si02 Carbon based solid acid S04 2/Sn02-Si02 Heteropolyacid (HPA) Optimum reaction condition T=170 IC, t=8h Cat.=2 wt%, IC, t=5h Cat.=5 wt%, T=65 IC, h MeOH/Oi1=20: 1 T=120 IC, h T=65 IC, h Cat.=l .3wt%, MeOH/Oi1=12.1, T-64.29 IC, h MeOH/Oi1=12.1, T=65 IC, h Cat.=l wt%, T=65 Cat.=10 wt%, T=170 IC, h Cat.=l T=45 IC, t=1.5 h Cat.=3 T=60 IC, h Cat.=3 T=150 IC, t=2.5 h Cat.=O.5 T=220 IC, t=50 min Cat.=O.5 T=250 IC, t=10 min Cat.=14.6 T=200 IC, h Cat.=O.2 T=220 IC, t=4.5 h Cat.=3 T=180 IC, h Cat.=l wt%, T=OO IC, t=10 min Yield (wt%) 92 84.9 94.7 98.6 98 98.64 97.98 98 91.6 95.2 -100 84 81 90 91.5 94.8 95 96.22 N. Saravanan et al studied the comparison of transesterification process with different alcohols using acid catalysts for mahua oil. They observed that if the material possesses high free fatty acid then acid catalyst gives better results. In this investigation, Mahua oil having 14% free fatty acid was transistorized to obtain biodiesel using acid catalysts 18
with different alcohols. The alcohols used were Methanol, Ethanol and Butanol. The process optimization was made based on the maximum ester yield. The results show that transesterification with butanol gives a better yield compared to methanol and ethanol. The transesterification results show that higher catalyst concentration by 6- 10% Vol. produces biodiesel with lower viscosity, lower specific gravity with a higher yield (short reaction time of 5 hours). The best process condition with butanol was found to be 6% Vol. of sulfuric acid with 150% excess butanol, which gave an yield of around 95.4% in a reaction time of 5 hours. The prepared biodiesels were tested as per the standard and were found to be satisfactory [29]. 2.5 Performance of Biodiesel: Combustion & Emission Characteristics Qi et al. have studied to characterize the effect of biodiesel produced from soybean crude oil on the combustion characteristics, performance and exhaust emissions of a diesel engine. The properties, performance, emissions and combustion characteristics of the engine fueled with biodiesel and diesel were compared. Based on the experimental results, it was found that the fuel properties of biodiesel are slightly different from those of diesel. The viscosity of biodiesel is evidently higher than that of diesel, especially at low temperatures. The specific gravity of the biodiesel is approximately 6.1% higher than that of diesel. The LHV of the biodiesel is approximately 10.2% lower than that of diesel. The flash point is higher than that of diesel. The acid value of biodiesel is 1.8 mg KOH/g. The biodiesel has a narrow boiling range, 95% of which is boiled off between 310 and 3600C. Due to the different properties of biodiesel and diesel, both fuels exhibit different combustion characteristics with the variation of engine loads. At lower engine loads, the peak cylinder pressure, the peak rate of pressure rise and the peak heat release rate are slightly higher for biodiesel. At higher engine loads, the peak cylinder pressures for both fuels are almost same, but the peak rate of pressure rise and peak heat release rate are lower for biodiesel. The crank angles at which the peak values occur are in advance for biodiesel. Combustion for biodiesel starts earlier owing to a shorter ignition delay and advanced injection time at all engine loads. The power output for biodiesel is almost the same as that for diesel under speed characteristic at full load. The BSFC for biodiesel is higher than that for diesel. The higher fuel consumption reflects its lower heating value. Both fuels give nearly identical BSEC. The emission of carbon monoxide, hydrocarbon, nitrogen oxides and smoke are averagely decreased under speed characteristic at 19
full load. The study tacitly suggests that biodiesel from soybean crude oil can be used as a substitute for diesel in diesel engine [30] Nabi et al. Investigated the production of biodiesel from nonedible Cotton Seed Oil (CSO) and performance study of diesel engine with diesel fuel and biodiesel mixtures. Biodiesel was prepared from CSO by transesterification process. A maximum of 77% BD production was found at 20% methanol and 0.5% NaOH at 550C reaction temperature. Biodiesel mixtures showed less CO, PM, smoke emissions than those of neat diesel fuel. NOX emission with biodiesel mixtures showed higher values when compared with neat diesel fuel. Compared to the neat diesel fuel, 10% biodiesel mixtures reduced PM, smoke emissions by 24% and 14%, respectively. Biodiesel mixtures (30%) reduced CO emissions by 24%, while 10% increase in the NOX emission was experienced with the same blend. The reason for reducing three emissions (PM, smoke and CO) and increasing NOX emission with biodiesel mixtures was mainly due to the presence of oxygen in their molecular structure. Also low aromatics in the biodiesel mixtures may be an additional reason for reducing these emissions. Thermal efficiency with biodiesel mixtures was slightly lower than that of neat diesel fuel due to lower heating value of the mixtures. However, volatility, higher viscosity, higher density may be additional reasons for efficiency reduction with biodiesel mixtures [31]. Sureshkumar et al. conducted the performance and emission analyses carried out in an unmodified diesel engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel. Engine tests have been conducted to get the comparative measures of brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC) and emissions such as CO, C02, HC, NOX to evaluate the behavior of PPME and diesel in varying proportions. It is found that there is slight increase in NOX emissions due to high temperature in the combustion chamber for biodiesel. The results reveal that blends of PPME with diesel up to 40% by volume (B40) provide better engine performance (BSFC and BSEC) and improved emission characteristics [32]. N. R. Banapurmath and P. G. Tewari., (2010) [16] investigated characteristics of a single cylinder CI Engines operated on ethanol-biodiesel blends. The variable load tests were conducted at three injection timings of 190, 230 and 270 and injection pressure varied from 205 to 280 bars. The break thermal efficiency values at all injection timing were lower for biodiesel, and biodiesel ethanol blends than diesel fuel. The decrease in brake thermal efficiency for Hong oil methyl ester (HOME) and Jatropha oil methyl ester (JOME) were 20
might be due to lower energy content of fuel, and higher viscosity of biodiesel. The ethanol blend with 15% ethanol shows better performance than 5% or 10% ethanol [32]. Moreover, the optimum injection timing for all fuels was found to 230 BTDC. The maximum brake thermal efficiency at this optimum injection timing value is 31.25%. However, at optimum injection timing it was found that with increase in blend ratio of ethanol in respective esters, an improvement in brake thermal efficiency. The blended fuel with ethanol showed better performance compared to neat biodiesel of Jatropha oil methyl ester operation Ethanol not only reduces petroleum/oil consumption in diesel engine but also increases oxygen content for alternative fuel. Ethanol has some obstacles to overcome such as separation of ethanol in diesel/biodiesel blends when blending ratio exceeds than 10%. In addition, it has corrosive effect on engine mechanical component as well as on rubber material of fuel pipe may cause jamming of fuel flow. They also reported that increase in smoke emission 17% was found compared to conventional diesel. Also, increase in HC, CO emissions were found to be 39.25 % & 40.78% respectively. Moreover, NOX emission was found to be reduced for 190 BTDC than 230 & 270 BTDC. As, injection pressure increases NOX increases whereas HC, CO decreases. Consequently, for Honge oil methyl ester 19 BTDC was found to be optimum [32]. Fangrui et al, (2010) [17] have been carried the experimental investigation to examine the performance-emission effect at different compression ratio, injection timing and injection pressure. Engine was used direct injection, air cooled, rated for 4.4 kW at 1500 rpm. It was found that combined increase of compression ratio; injection timing and injection pressure increases the BTE and reduces BSFC. The optimum operating condition was found as CR of 19:1 with IP of 240 bar and injection timing of 270BTDC. The tests were conducted for various blend 10%, 20%, 30% of pungam oil methyl ester. Their result proved that with increase in injection timing, compression ratio, injection pressure there was significant reduction in HC, CO, C02. The effect besides found more notable for bio-diesel than neat diesel. The reason might be due to increase in oxygen content, increased atomization, complete combustion, increased BTE, and reduced BSEC, The results shows that diesel has maximum rate of HC, it was 36 ppm among tested blends of Pungam biodiesel. CO was found to be 0.49% of volume for diesel and 0.42% volume for Pungam oil methyl ester 20% which was maintained due to more oxygen content. However, results of preceding researcher showed that due to advancement of injection timing, and pressure, NOX emission for biodiesel blend Pungam oil methyl ester 20% was increased very significantly. The NOX 21
value 1238 ppm found for Pungam oil methyl ester 20%, it was higher than that for diesel 1096 ppm. This promotes higher flame or combustion temperature results more NOX emission [33]. Also, researcher showed that, heat release rate with crank angle for different pungam biodiesel blends and diesel. The heat rejection rate reduces with increase in pungam methyl ester blends than diesel. The values of heat rejection rate for biodiesel was 81.6 and for diesel 102. However, the cumulative heat release rate showed that it reduces with increase in biodiesel blends than diesel. This might be due to higher exhaust gas temperature and NOX emission. The thermal efficiency of the engine was improved by increasing the concentration of the biodiesel in the blends and also the additional lubricity provided by biodiesel. The main reason for increasing the thermal efficiency with increase in injection pressure may be due to atomization. It was observed that BSFC of 0.273 kg/kW-hr were obtained for diesel and 0.272 kg/kW-hr for BD20. It was seen that the optimum blend of pungam oil methyl ester biodiesel may be 20% i.e. BD20 due to optimum BSFC and maximum brake power. However, BSEC was increased with increase in concentration of pungam methyl ester on diesel and decreased with increase in injection pressure [34]. N.R. Banapurmath et al described systematically, effect of nozzle geometry on the performance of CI Engines operated on vegetable oils. They used different vegetable oils such as honge oil, jatropha, neem, rice bran oil, sunflower oil, palm oil, soybean oils for study. Also, they considered three injector with different number of hole geometry. In additions, injection rate for selected oil was varied in order to study effects of spray characterizes. He concluded that, spray pattern of vegetable oil gets affected due to relative higher viscosity leading to larger fuel droplet. It was observed that, spray pattern of jatropha and honge oil was better compared to other fuel. Effect of injector nozzle geometry on the performance of CI Engines operate with vegetable oil and concluded that, smoke opacity, HC, CO and emission was comparatively higher than diesel. This was may be due to incomplete combustion prevailing for vegetable oil. Spray pattern for Jatropha and Honge oil was slightly better. NOX emission for all vegetable oil was comparatively lower than diesel fuel [35]. N.R. Banapurmath et al., performed studies of low heat rejection engine operated on vegetable oils and EGR system. It was revealed that, Low heat rejection operation with honge oil methyl ester & Neem oil methyl ester produces an improvement in BTE. The BTE values were 29.51% & 28.0% with low heat rejection compared to 28% & 27.01% without low heat 22
rejection. However, values for standard diesel were higher for both conditions i.e with and without low heat rejection. EGT was observed increases with increase in brake power. The lowest values were observed for standard diesel engine operation, however, highest values were observed for honge oil methyl ester & neem oil methyl ester under low heat rejection engine operation. Heat release rate was better for honge oil methyl ester when compared with Neem oil methyl ester oil operation, resulted in improved BTE. They reported that, low heat rejection engine operation reduced HC, Smoke, CO emissions due to improvement in pre- mixed combustion, combustion duration, and reduced ignition delay as well as heat release rate. However, NOX emission for low heat rejection operation for Honge oil methyl ester & Neem oil methyl ester was found to be increased. For example, NOX values for LHR operations for Honge oil methyl ester & Neem oil methyl ester were 1100 & 1200 ppm respectively compared to 990 ppm & 780 ppm respectively. Consequently, 10% EGR reduced 28% NOX emissions significantly [36]. N.R. Banapurmath et al studied the performance-emissions experiments with Honge, honge oil methyl ester & its blends. They mentioned that performance BTE of engine with honge oil methyl ester was improved by 6.0% compared to Honge oil. Also, BTE with B20 was found to be closest to diesel performance with reduced emissions compared to other biodiesel blends. Further, with honge oil methyl ester (HOME) & B20 operation peak pressure, maximum rate of pressure rise, pre-mixed heat release rate were higher in comparison with Honge oil operation. They concluded that, for CI Engines with honge oil operation gives more CO, HC, smoke emissions compared to honge oil methyl ester & its blends. Reduction in HC, CO, & smoke opacity in comparison to honge oil operations was found to be 17.72%, 23.68% & 13% respectively. Furthermore, NOX emissions were higher for honge oil methyl ester operation by 26.92% than honge oil and lower by 9% compared to diesel [37]. N.R. Banapurmath et al., reported experimental performance and emissions characteristics of CI Engines operated on Honge, Jatropha, sesame oil methyl esters. The different fatty acid methyl esters were operated independently and comparisons were carried to know better fuel source from performance-emissions aspect. The BTE with Honge biodiesel, Sesame biodiesel, & Jatropha biodiesel was 29.51%, 30.4% & 29% respectively. Increased ignition delay and combustion duration was observed for all the esters. This may be due to high viscosity and low volatility for fatty acid methyl ester. It was found that smoke, HC, CO emissions increase with increase in injection timing retardation. However, optimum was found to be 230 BTDC. This was so because at this injection timing proper mixing of air-fuel, complete combustion 23
and break thermal efficiency was found maximum. Moreover, with further increase in injection timing to 270 BTDC; smoke levels, HC, CO, will increase significantly due to fall in break thermal efficiency [38]. N. Reddy et al. have conducted experiments on a direct injection (DI), diesel engine using neat jatropha oil. Injection timing, injector opening pressure and injection rate were changed to study their influence on performance, emissions and combustion and are compared with total diesel operation. Results show that, for neat jatropha oil by increasing 15 bar in injector opening pressure and 30 in fuel injection advance, an improved brake thermal efficiency, the peak heat release rate were observed. N. Reddy et al., (2006) [22] have conducted experiments on a direct injection (DI), diesel engine using neat jatropha oil. Results show that, for neat jatropha oil by increasing 15 bar in injector opening pressure and 30 in fuel injection advance were reduced emissions (except NOx) were observed [39]. In addition, researcher showed that smoke opacity, HC, CO, for neat diesel fuel was lower than biodiesel or biodiesel blends with ethanol. This was so due to high viscosity of honge oil methyl ester /Jatropha oil methyl ester and low heating values which causes problem during combustion. However, as ethanol blend ratio in esters increases there was reduction in CO, HC, and smoke emission than neat Honge oil methyl ester / Jatropha oil methyl ester. But there was significant increase in NOX emission since blend of ethanol with biodiesel increases oxygen content of fuel mixture. This was eventually caused to increase in the flame temperature during combustion. .2.6 Performance of Mahua Biodiesel Agarwal et al. performed the work to investigate the performance and exhaust emission of Mahua oil blends in a four stroke diesel engine and compare it with diesel fuel. It was observed by them that all mahua oil blends (10, 20 and 30%) have almost similar thermal efficiency and are very close to the thermal efficiency of diesel fuel. It should be pointed out that 30% mahua oil blend is found to be most thermally efficient from their work. It was also found that smoke density is higher for mahua oil blends compared to diesel at lower loads. Smoke density increased with proportion of Mahua oil in blend with diesel [40]. Puhan et al. Performed a test of MO biodiesel (mahua oil methyl ester: MOME) with diesel fuel in a single cylinder direct injection CI engine and showed decrease (13%) in thermal efficiency. In the continuing work, Puhan tested MO biodiesel (mahua oil ethyl ester: MOEE) 24
with diesel fuel in a same engine with the previous study and showed the comparable thermal efficiency with diesel fuel. They pointed out that this is due to the chemical composition of MOEE, which promotes the combustion process. It should be pointed out that the viscosity of MOEE is slightly higher than that of MOVIE. Exhaust emissions of CO, HC, NON and smoke number were reduced around 58, 63, 12 and 70% respectively in case of MOEE and 30, 35, 4 and 11% respectively in case of MOME, compared to diesel. The amount of NOX produced for neat biodiesel of mahua oil was 50 ppm as compared to 44 ppm for diesel. This could be attributed to the increased gas temperature due to the oxygen content within biodiesel[41]. Saravanan et al. tested MO biodiesel was on a single cylinder CI engine by. The performance tests showed that power loss was around 13% combined with 20% increase in fuel consumption with MO biodiesel at full load. Emissions such as CO and HC were lower for MO biodiesel compared to diesel by 26% and 20% respectively. However, it should be noted that NOX emission was lesser by 4% for MO biodiesel compared to diesel[42]. Kapilan et al. conducted Engine tests with MO biodiesel were on a single cylinder CI engine at different injection opening pressures and loads. It was observed that the higher IOP of 20 MPa resulted in better BTE and engine efficiency of MO biodiesel is close to diesel. The engine performance with the MO biodiesel results in lower CO, HC and smoke emissions and slightly higher NO emission [43]. Raheman and Ghadge found that the differences of brake thermal efficiencies between diesel fuel and neat MO biodiesel were not significant at engine settings of compression ratio of 20:1 and injection timing of 408 bTDC. At full load conditions, the mean brake thermal efficiency of neat biodiesel of mahua oil was about 10.1% lower than that of diesel fuel while at lower loads, the variation was as high as 17.1% which could be attributed to the significantly lower efficiencies of neat biodiesel, especially at lower loads [44]. Godignur et al. tested the performance and emission characteristics of turbocharged DI CI engine fuelled with diesel, MO biodiesel and its blends at constant speed of 1500 rpm under variable load conditions. Their results indicated that with the increase of MO biodiesel in the blends CO, HC reduced remarkably, fuel consumption and NO emission of MO biodiesel increases slightly compared with diesel. BSEC decreases and thermal efficiency of engine slightly increases when operating on 20% MO biodiesel than that operating on diesel engine performance [45]. 25
2.7 Additives to Improve Performance Due to growth of population, energy consumption and global warming concerns, design and improvement of energy efficient and environmental friendly diesel engines have received substantial attention. A Vegetable oils and animal fats are not suitable direct replacements for diesel fuel in engines, boilers or cogeneration systems, due to their inappropriate physical properties such as longer molecule chains, lower pour points, lower vapor pressures, higher viscosities and higher flash points. These features cause poor atomization, poor vapor—air mixing, low pressure, and incomplete combustion and engine deposits. However, it is possible to reduce the viscosity of vegetable oil, improve the physical features of both vegetable oil and animal fat through dilution, pyrolysis, micro emulsion and esterification. In this regard, the various techniques have been employed such as fuel properties modification, engine design alteration, and exhaust gas treatment etc. The purpose of fuel properties modification is to improve the combustion to obtain low fuel consumption and emissions without requiring modifications to the engine, fuel injection or exhaust systems. Fuels containing bio- components present special challenge in use, for which a range of additives provide valuable benefits. The use of biodiesel has presented a hopeful alternative in the world. It is not only a renewable energy, but also it can reduce the dependence on conventional diesel fuel. In addition the use of additives can solve some technical problems generated by the use of biodiesel fuel. The range of benefits accruing from fuel additives is very significant and includes: Protection of fuel tanks, pipe lines and other from massively expensive corrosion. Protection of fuel system equipment in the diesel engine from catastrophic premature wear. Reduced pumping costs and energy use in long-distance fuel pipelines. Reduced refinery processing needed to meet diesel Cetane, octane and specifications. Cold flow improvement in middle distillates, maximizing use of bio fuel. Stability improvement to prolong storage life of fuels throughout the operating theatre. Fuel saving from optimized vehicle performance and economy. Emission reduction from fuel system cleanliness and combustion optimization [46]. Additives can be divided in terms of their point of application as indicated below: 26
2.7.1 Metal based additives To improve the property of diesel fuel, various types of metal based additives are added with biodiesel for reaching more complete combustion and reducing exhaust emissions. The principle of such additives action consists of a catalytic effect on the combustion of hydrocarbons. These metal based additives include platinum (Pt), platinum—cerium (Pt—Ce), cerium (Ce), cerium—iron (Ce—Fe), iron (Fe), barium, calcium, manganese (Mn) and copper. The reduction of exhaust emission while using additives may be due to the fact that the metals either react with water vapor to generate hydroxyl radicals or directly react with carbon atoms as a catalyst thereby releasing oxidation temperature. Usually, metal based additives are added as a metal— organic compound in the diesel engine and the metal is formed as nano particle. Particle traps are useful tools for reducing soot emissions. Nano metal oxide as fuel additives playing an important role to enhance the engine performance and exhaust emission of a diesel engine [46]. 2.7.2 Oxygenated additives Oxygenated additives are nothing more than fuel, contain oxygen. To enhance octane rating and combustion quality oxygenate additives are used. The oxygenate additives generally used are alcohol (ethanol, methanol, butanol and propanol etc.), ether (ethyl tertiary butyl ether, methyl tert-butyl ethe, diisopropyl ether, dimethyl ether, diethyl ether etc.) and ester (dicarboxylic acid esters and acetoacetic esters) functional group. Oxygenated additives are considered for minimizing the ignition temperature of biodiesel fuels. However, the decrease of smoke emissions of oxygenated additives depends on the oxygen content and molecular structure of the fuel. Consequently, the composition of biodiesel and the use of additives directly affect properties such as viscosity, density, and behavior at low temperatures, volatility, and the cetane number. Oxygenated additives assist fuel to inflame more efficiently as well as minimize atmospheric pollution. Oxygenated fuel allows the fuel in engine to burn more completely. Due to most of the fuel is burning, there are least amount of harmful chemicals rescued into the atmosphere. 2.7.3 Antioxidant additives 27
Antioxidant chemistry typically comprises hindered phenols, aromatic diamines or mixture of alkyl phenols and aromatic diamines. Oxidation of fuel, also termed instability, leads to deterioration, resulting in fuel darkening and the formation of gums and sediments. Antioxidants enhance biodiesel stability and inhibit its tendency to deteriorate in storage. Unsaturated fatty acid esters are existent in biodiesel, which make it much capable to the auto oxidation or oxidation starts if long time storage of biodiesel is done. After oxidation of biodiesel and its diesel blends the density, viscosity and acid value increased, as the iodine value diminished with rising storage time. Unstable species in biodiesel produce free radicals which combine with oxygen to produce further free radicals in the chain reaction and react with olefinic compounds to form gums. Unchecked, this oxidative chain reaction increase at an exponential rate producing increasing amount of free radicals and peroxide species. Antioxidant work by disrupting the chain propagating steps, by decomposing peroxides and by acting as free radical traps [46]. 2.7.4 Cold flow improver additives Cold flow improver additives for biodiesel fuel typically utilize vinyl eater co-polymer such as ethylene vinyl acetate (EVA). A range of different low molecular weight polymers with a variety of structure is employed to treat fuels from different crude sources with different hydrocarbon compositions. Other additive chemistries employed olefin-ester copolymers and dispersants which may be combined with EVA. Biodiesel has a higher pour point and cloud point than diesel fuel. The cold filter plugging point (CFPP) temperature is higher closely related to the actual cold weather operability of biodiesel. As temperature drop, crystal grow in size and begin to adhere to each other, forming large lattices of crystal, blocking fuel filters and feed lines, ultimate leading to power loss and possible engine shutdown. Use of cold flow improvers in middle distillates prevent these problem and permits a greater proportion of the crude barrel to be include in the diesel pool, resulting in a smaller output of lower value residual fuel and thereby reducing the overall cost of fuel production[46]. 2.8 Effect of Additives on Performance S.P. Venkatesan et al studied the Influence of an aqueous cerium oxide Nano fluid fuel additive on performance and emission characteristics of a compression ignition engine. Aqueous cerium oxide at the rate of 50cc per liter was dispersed into diesel and diesel— biodiesel using mechanical agitator and an ultrasonicator for preparing the test fuels. Cerium 28
oxide nanomaterials present in the aqueous cerium oxide exhibit higher catalytic activity because of their large contact surface area per unit volume and can react with water at high temperature to generate hydrogen and improve fuel combustion. Also, cerium oxide nanomaterials act as oxygen buffers causing simultaneous oxidation of hydrocarbons (HCs) as well as the reduction of oxides of nitrogen. The neat diesel and test fuels were tested in an engine without changing the engine system at 0%, 25%, 50%, 75% and 100% load condition and resulted in a considerable enhancement in the brake thermal efficiency, improved brake- specific fuel consumption and decreased concentration of HC, NOX and smoke in the exhaust emitted from the diesel engine due to incorporation of aqueous cerium oxide in the test fuels [47]. S. Kiran Kumar studied the Performance and Emission Analysis of Diesel Engine Using Fish Oil and Biodiesel Blends with Isobutanol as an Additive. Experiments were done on a 4- Stroke single cylinder diesel engine by varying percentage by volume of isobutanol in diesel- biodiesel blends. The effect of isobutanol on brake thermal efficiency, brake specific fuel consumption, cylinder pressure, heat release and exhaust emissions were studied. It was found that brake thermal efficiency is increased with increase in blend percentage both with 5% and 10% isobutanol. Addition of isobutanol shows negative impact on Brake specific fuel consumption (BSFC) which decreased with blend percentage while it increases with isobutanol percentage.CO emissions and smoke capacity decreased significantly while NOX emissions decreased marginally with the increase in isobutanol percentage[48]. Sinem Caynak et al studied Biodiesel production from pomace oil and improvement of its properties with synthetic manganese additive. This oil was obtained from pomace which is the waste of olive oil plants. Optimum producing conditions were determined experimentally. The maximum yield was obtained at 30% of methanol/oil ratio, 600C temperature for 60 min with NaOH catalyst. The properties of the biodiesel thus obtained were compared with diesel fuel requirements. An organic based Manganese additive improved the biodiesel properties. Doping the fuel at a ratio of 12 Imol/l oil methyl ester led to a 20.37% decrease in viscosity, 7 oc fall in the flash point and reduced the pour point from OOC to 150C. This blend of pomace oil methyl ester-diesel fuel with manganese additive was tested in a direct injection diesel engine. The maximum effect of the new fuel blend and diesel fuel on engine performance was obtained at 1400 rpm[49]. 29
M. Mofijur et al done Experimental study of additive added palm biodiesel in a compression ignition engine For this study four fuel sample including BO (100% diesel fuel), BIOO (100% palm biodiesel), B35 (35% palm biodiesel and diesel) and B35+1% (B35 with additives) was used in a multi cylinder compression ignition engine. Performance and emissions were investigated at various engine speeds of 1500 rpm to 4000 rpm at an interval of 250 rpm and with 50% throttle opening. To evaluate the performance characteristics brake power (BP), brake specific fuel consumption (BSFC) and exhaust temperature were tested whereas in case of emissions test nitrogen oxides (NOx), carbon monoxide (CO), total hydrocarbon (THC) and carbon dioxide (C02) were measured. The results showed that using 1% anti-oxidant additive with higher percentages (35%) of palm biodiesel blend gave 2.7% lower brake power but it significantly reduced exhaust emissions including NOX emissions than diesel fuel. Based on this study fuel "B35+l%" (35% biodiesel with 1% additives)[50]. 2.9 Summary There is variety of feedstock available for the production of biodiesel. In India major study has been done on the Jatropha and Karanja. It is observed that there are many potential options for biodiesel production. Studies on newer biodiesel such as rice bran, Jajoba, rubber, Mahua, Seasame, Neem oil and large amount of regional oil shown that the CI engine using biodiesels are working efficiently. Mahua seed is available in plenty of amount in our country; it can be large source of biodiesel. But very few studies are done on production of biodiesel with heterogeneous catalyst for transesterification. Heterogeneous catalysis has certain advantages over homogeneous catalysis. The disadvantages of homogeneous catalysis are its high cost, large number of steps, contamination of product, and use of water in large amount. All these disadvantages can be overcome by heterogynous catalyst. Transesterification using Lipase catalyst has advantages such as lower energy requirement, pure quality of glycerol, high product yield. But its high cost and longer reaction time are obstacle in use of Lipase catalyst. Mahua biodiesel gives poor results in terms of engine performance. Most researchers found that it has high BSFC and low BTE. However, some test conditions gave higher thermal efficiency. The following conclusions can be made by analyzing the different experimental observations: • A 20% biodiesel blend gives about 1 32.5% higher BTE at higher engine load condition than any other blend. 30
• BTE is reduced with the presence of a higher percentage of biodiesel in the fuel blend. • BSFC increases by 4.1% with the increased proportion of biodiesel in the fuel blend The biodiesel have some inappropriate properties such longer molecular chain, longer pour point , lower vapor pressure, high viscosity which causes poor atomization, poor vapor air mixing, low pressure and incomplete combustion and engine deposits. This problem can be solved by the use of additives. Additives are of two types as combustion improvement additives and property improvement additives. Metal based additives and oxygenated additives are combustion improvement additives. Most researchers have found that the additives have improved the properties and performance of the biodiesel. 31
Chapter 3 Experimental Set-up 3.1 Experimental Setup for Biodiesel Production The biodiesel production setup is developed with glass reactor, mechanical stirrer with motor and temperature indicator. The chemical agents and catalyst also require for biodiesel production will be as, methanol, H2S04 acidic catalyst for esterification, and KOH, NaOH, Zno as catalysts for transesterification. Table 3.1 Biodiesel production equipment with specifications. Sr. 1. 2. 3. 4. 5. 6. 7. 8. 9. Equipment/ Apparatus Heating mental (450 W) Three neck RBF (2 Ltr) Bends (2") Thermometer (1 IOOC) Electric motor with stirrer (240 V and 1000 RPM) Separating funnel with valve (ILtr.) Reflux condenser (12") Conical flask( 500ml) Water stream Need or specification For heat supplying to oil in Round Bottom Flask For carrying oil in heating mental for reaction For interconnections For measuring the temperature For stirring oil and maintaining the RPM For separating oil under gravity For water cooling to extract the methanol by distillation For preparing the catalyst For cooling the reflux condenser 3.2 CI Engine Test Set-up The engine tests are to be conducted on a single cylinder four-stroke, naturally aspirated, open chamber water-cooled CI engine. The engine is operated at a rated constant speed at 1500 rev/min and has a conventional fuel injection system figure. Shows the schematic diagram of the set-up and Figure. shows the overall view of the experimental set-up. The injector opening pressure and the static injection timing as specified by the manufacturer was 205 bar and 32
230BTDC respectively. The engine was provided with a toroidal combustion chamber with overhead valves operated through push rods. Eddy current dynamometer has been used for measurement of output. DYNAMOMETER EGR ENGINE Fig. 3.1 Schematic of engine set-up Cooling of the engine was accomplished by circulating water through the jackets on the engine block and cylinder head. A piezoelectric pressure transducer was mounted with the cylinder head surface to measure the cylinder pressure. EGR Set-up Fig 3.2 Overall view of engine-setup 33
ake and Model o. of Cylinders Orientation Cycle Ignition System ore X Stroke isplacement Volume Compression Ration rrangement of valves Combustion Chamber ated Power Cooling Medium Table 3.2 Specifications of the engine irioskar, TVI ne ertical Stroke ompression Ignition 87.5mm 11 Omm 660 cc 18:1 verhead pen Chamber (Direct Injection) 3.5 kW (7 HP) @ 1500 rpm ater cooled 34
Chapter 4 Optimization of Biodiesel Production Process 4.1 Physiochemical Properties of Mahua Oil Physical properties of Mahua oil were measured with the standard procedures. These properties are shown in the table 4.1. Fuel properties of Mahua oil are shown in table 4.6. Table 4.1 Physiochemical properties of Mahua oil Sr. No 1 2 3 4 5 6 7 Physical character Refractive Index at 400C Iodine Value Sa onification value Unsa onificable matter S ecific avit Kinematic Viscosity 400C (cst) color Value 1.452 74.2 201 2% 0.924 3.98 Greenish Yellow The fatty acid composition of Mahua oil was determined using a Gas Chromatograph is shown in the table 4.2. Molecular weight of Mahua Oil was calculated using fatty acid composition which was found to be 890. Table 4.2 Fatty acid composition of the Mahua oil Fatty acid Palmitic Stearic Oleic Linoleic Arachidic 4.2 Experimental Procedure Chemical Structure C16H3202 C18H3602 C18H3402 C18H3202 C20H4002 Percentage 19.7 21.3 42.4 13.1 1.8 A constant temperature silicon oil bath with a PID controller is used for the process with a three neck spherical gas reactor. Stirrer and water condenser were the accessories used along with oil bath. Additional R TD temperature sensor with accuracy of ±0.30C was used to ensure 35
the temperature indicated by the digital temperature indicator. First the mixture of the oil and methanol were heated to the required temperature and then the catalyst with methanol with the same temperature was poured into the reactor. RPM of stirrer were adjusted to the required number. EN14103 standard method was used to determine the yield of methyl ester. For that, sample of 0.5 ml from upper of layer mixture was centrifuged for regular interval. For further confirmation of conversion the same sample was analyzed using gas chromatograph. Both homogenous and heterogeneous transesterification processes were carried at atmospheric pressure. Esterification, transesterification, settling, gravity separation, warm water washing and drying are the stages of the process. Conical separator funnel is used to separate the biodiesel after the transesterification procedure. Glycerol, as it is heavier than biodiesel settles down at the bottom of the funnel. Further the biodiesel is washed with the water to remove the impurities. Gravity separation was used to remove the homogeneous catalyst. For that, distilled warm water and ester in the ratio of 1:2 were mixed, which forms two layers. Upper layer was of biodiesel and lower layer was of mixture of water and heavier catalyst impurities. Complete removal of the catalyst is indicated by pH of lower level, which must be equal to pH of distilled water. Until then, the procedure was repeated. For heterogeneous catalyst, esterification and transesterification takes place at same time. Removal heterogeneous catalyst was done with the simple centrifuge separation by eliminating washing procedure. 4.3 Optimization of Transesterification Reactions Design of experiment for optimization of Mahua oil transesterification process was done by using Taguchi method. Four factors namely oil to methanol ratio, catalyst, catalyst concentration (Wt%) and reaction temperature with four levels were used to design L16 orthogonal array. Levels of factor are shown in the table 4.3. The results obtained by the experiments were analyzed using ANOVA, which analyses the important of each factor for production of biodiesel. Experiments analyzed with ANOVA are shown in the table 4.4. The fuel properties of methyl ester synthesized from Mahua oil were determined are summarized in table 4.6. Total weight of methyl ester Yield (%) x 100%. Total weight of oil in the sample 36
Table 4.3 Levels of factors for biodiesel production Factors Oil/Methan01 Ratio [A] Catalyst Type [B] Catalyst Concentration (wt%) [C] Reaction temperature CC) [D] 1:08 KOH 1.5 56 Levels 1:12 1:16 NaOH mZnO 3.0 60 4.5 64 1:20 nZnO 6.0 68 Table 4.4 Design of Experimentation (DOE) Catalyst Oil/Methanol Catalyst Type [B] Concentration (wt%) Ratio [A] 1:08 1:08 1:08 1:08 1:12 1:12 1:12 1:12 1:16 1:16 1:16 1:16 1:20 1:20 1:20 1:20 KOH NaOH mZnO nZnO KOH NaOH mZnO nZnO KOH NaOH mZnO nZnO KOH NaOH mZnO nZnO [C] 3 6 1.5 4.5 6 3 4.5 1.5 1.5 4.5 3 6 4.5 1.5 6 3 Reaction temp. 56 60 64 68 64 68 56 60 68 64 60 56 60 56 68 64 4.4 Statistical Analysis The all runs of experiments were carried out three times in order to determine random errors. The standard deviation and arithmetical mean values were calculated for all results. The values of standard deviation of total fatty acid methyl ester were within the range of ±5%. The statistical technique was used for design of experiments (DOE) with orthogonal array L16 (4) 4. The results were analyzed by ANOVA. 37
4.5 Results and Discussions Present study has been done to study the suitability of the homogeneous and heterogeneous catalysts for transesterification. The effect of size of heterogeneous catalyst on the yield has also been studied. The transesterification process is optimized for the factors namely oil to methanol molar ratio, type of catalyst, concentration of catalyst (wt%) and reaction temperature. Table 4.5 Properties of diesel, Mahua oil and Mahua biodiesel Property S ecific ravit Kinematic viscosity @ 400 (cSt) Cloud Point CC)] Pour Point(OC) Flash Point(OC) Fire oint(OC) Calorific Value (MJ/k 4.5.1 Taguchi analysis Test Procedure c ASTM D445 ASTM D2500 ASTM D2500 ASTM D93 ASTM D93 ASTM D240 Diesel 0.839 3.18 6 68 103 44.8 Mangifera Indica Oil 0.924s 3.98 12 11 220 246 37.61 MOME 0.8712 4.62 8 -2 176 179 43.1 Table 4.6 Response table for means of yield Level 1 2 3 4 Delta Rank Catalyst Catalyst Ratio 67.00 68.73 75.00 76.5 9.50 3 76.25 72.82 58.18 79.99 21.81 1 Loadin 79.24 73.07 68.00 66.93 12.31 2 Reaction Tem erature 69.68 72.99 72.88 71.75 3.31 4 Taguchi analysis is performed to study the response of the factors for the yield. Taguchi analysis also provides ranking for the significance of the factors. As shown in the table it can be concluded that most important for the yield is the catalyst type which is followed by catalyst concentration, reaction temperature and oil to methanol ratio. 4.5.2 Effect of molar ratio Three mole of alcohol is required for one of triglyceride to produce three moles of fatty acid alkyl ester and one mole of glycerol in a stoichiometric transesterification reaction. 38
Stoichiometric esterification reaction requires one mole of FFA and one mole of alcohol to generate one mole of ester and one mole of water. Effects Oil to Methanol Molar ratio on Yield 73.0 72.5 72.0 71.5 71.0 70.5 70.0 69.5 1:12 1:16 Oil to Methanol Mohr Ratio 1:20 s. Fig 4.1. Effect of Oil-to-Methanol molar ratio Esterification and transesterification reactions are reversible hence excess of alcohol is required to shift the equilibrium towards the product side for completing the conversion. 1:8, 1:12, 1:16 and 1:20 were the oil to methanol molar ratios selected for the process. The mean yield of MOME at different molar ratio are shown in Figure 4.1. The yield first increases and then decreases with increase in oil to methanol molar ratio. The increase in the yield is because increase in methanol increases the probability of breaking bond between glycerol and trygyceroid. But excess of methanol increases the solubility of glycerin which reduces the separation of alcohol. Due to this glycerin remains in the solution which shifts the equilibrium toward left side of reaction causing reduction in yield. 4.5.3 Effect of catalyst type KOH, NaOH, mZnO and nZnO were the catalyst studied. The mean of yield obtained with this catalyst are shown in Fig. (KOH and NaOH are homogeneous catalysts, mZnO and nZno are heterogeneous catalysts). The highest yield was obtained with the nZnO. The NaOH catalyst has given the lowest yield. NaOH catalyst was more prone to soap formation with increase in the catalyst concentration. The results show that the size of heterogeneous catalyst effects significantly on the yield as nano ZnO has given more yield than micro ZnO. With reduction in size of catalyst increases the availability of more active site of catalyst. 39
Effects of type Catalyst 80 75 70 o 65 60 KOH mZnO NaOH nZnO CATALYST Fig 4.2 Effect of Catalysts Type 4.5.4 Effect of catalyst concentration The study was conducted for the catalyst concentration of 1.5, 3, 4.5 and 6 percent. The result obtained is shown in Figure with the mean yield. Yield decreases with increase in the catalyst concentration. For homogeneous catalysts, increase in the concentration increases the soap formation which reduces yield. High concentration of catalyst form emulsion and increases the viscosity, which is also responsible for the decrease in the yield. Hence 1.5% wt concentration of catalyst is found to be optimum. Effects of Catalyst Concentration 80 78 76 74 72 70 68 66 1.5 3.0 4.5 6.0 Catalyst Concentration Fig 4.3. Effect of catalyst concentration 40
4.5.5 Effect of reaction temperature. Effect of Reaction Temperature 76 74 72 70 68 66 56 60 64 68 REACTION TEMPERA n.RE Fig 4.4. Effect of reaction temperature The transesterification process was studied for reaction temperature 56, 60, 64 and 680C. The results obtained are shown in Figure. The maximum yield was obtained at 68 reaction temperature. It can be observed that yield increases with increase in temperature. Increase in yield from 60 to 64 is more rapid because 64 is the boiling temperature of methanol. Further the rate of increase of yield reduces with increase in the temperature. This is because formation of vapor increases volatilization of reaction. 4.6 Summary Optimization of the transesterification procedure of Mahua oil using homogeneous and heterogeneous catalyst is done. The parameters optimized for transesterification process are oil to methanol molar ratio, catalyst type, catalyst concentration and reaction temperature. Type of catalyst is found to be most significant factor for the yield which is followed by concentration of catalyst, reaction temperature and oil to methanol ratio. Size of catalyst is found to be effective as the yield increased with decreased in size of catalyst. Reaction is found to be optimum for nano ZnO catalyst, 1.5% catalyst concentration, 680C reaction temperature and 1 methanol ratio. Yield was 92% at optimum condition. 41
Chapter 5 Optimization of CI Engine Performance with Mahua Oil Biodiesel for Operating Variables including Additive 5.1 Array for Experiment Taguchi method was used to optimize the engine operating parameters. Orthogonal L16 array was used to design the experiment. The factors for which the engine is optimized are: compression ratio, injection pressure, nozzle, biodiesel fuel fraction and additive (ml/ltr). Four levels of each factor are considered hence L16 array was the suggested and most suitable array. Levels of each factor are shown in table 5.1 Table 5.1 Levels of factors for engine testing Parameters Compression Ratio Injection Pressure (Bar) Nozzle(Number of Holes) Fuel fraction(% volume) Additive(ml/ltr) 5.2 Fuel Fraction Used for the test Levels 16 330 1 15 o 17 310 2 30 3 17.5 290 3 50 6 18 270 4 100 9 Fuels used for the test include Mahua oil methyl ester and its blends. Biodiesel and diesel blends were prepared on the basis of percentage volume basis of diesel and biodiesel for net unit volume. The combination of B 15, B30, B50, and BIOO were selected for the optimization. As the additive is used to improve the combustion properties of fuel, high percentage of biodiesel were selected for the experiment. Properties of diesel and biodiesel are shown in table 5.2
Table 5.2 Design of experiment for engine testing Compression Ratio 16 16 16 16 17 17 17 17 17.5 17.5 17.5 17.5 18 18 18 18 Injection pressure 330 310 290 270 330 310 290 270 330 310 290 270 330 310 290 270 Nozzle Fuel Geometry fraction 15 30 50 100 50 100 15 30 100 50 30 15 30 15 100 50 Additive (ml/ltr) 3 6 9 9 6 3 3 9 6 6 9 3 5.3 Additive used for the test Additive used for improvement of performance of biodiesel is AA-93. The basic function of this additive is to improve the Cetane number of fuel. Table 5.3 Components of AA-93 additive Com onent 2-Eth lhex I nitrate Na htha ( etroleum), heav aromatic Petroleum na htha, li ht aromatic Pseudocumene 1,3,5-Trimeth Ibenzene Pro I benzene Na hthalene Cumene- X lenes (0-, m-, - isomers) 2-Eth 1 Eth I benzene CAS No 27247-96-7 64742-94-5 64742-95-6 95-63-6 108-67-8 103-65-1 91-20-3 98-82-8 1330-20-7 104-76-7 100-41-4 43
Along with Cetane number improvement it reduces gelling and clogging of filters and injector tip, inhibits the oxygen and reduces the corrosion,. This contains the ignition improvers that shorten the cranking time, reducing detonation and wear of the engine. It also has demulsifies that separate moisture from fuel to prevent poor engine performance. The components of additive with their CAS number (Chemical Abstract Service) are given in the table 5.3. 5.4 Result and Discussion The result obtained with L16 array is shown in table5.4. The result is for 100% loading of the engine. The result table shows the BTE, SFC, CO, HC, NO, K results for each test. These result were analyzed with ANOVA. The regression analysis is also done to form a linear model of the obtained results. The ranking of each factor is is also described by the response of each factor. Table 5.5 shows the results of test conducted with diesel with same physical parameters instead of biodiesel blends with additive. The results of diesel and biodiesel were compared and it is found that the results obtained with biodiesel are in the same range as that for diesel. The brake thermal efficiency of biodiesel is nearly the same as that of diesel. For some tests the results are better for biodiesel. The maximum difference is within 2%. The same is true for SFC also. The emission parameters are within range with the diesel. Hence it can be concluded that the Mahua biodiesel have given improved results with additive. Table 5.4 Results for L16 array of biodiesel with additive Test No 10 12 13 14 15 16 BTE 11.73 14.75 22.82 17.5 16.81 18.38 15.9 21.76 22.71 16.68 14.73 16.34 29.72 25.88 16.95 15.36 SFC co HC 29 128 66 183 35 32 232 73 61 184 50 85 257 55 55 62 C02 ( % vol) 4.3 5.8 6.7 8.3 5.5 6.5 7.5 6.6 6.6 7.9 6.1 5.7 5.5 6.1 Smoke K NO (ppm) (kg/kWh) ( % vol) 0.73 0.58 0.38 0.49 0.51 0.47 0.54 0.39 0.38 0.51 0.58 0.52 0.29 0.33 0.51 1.6 0.25 1.38 0.62 0.93 0.38 0.62 0.61 0.77 0.93 0.89 0.82 1.93 0.17 0.44 50 60 107 64 52 100 134 157 93 57 71 86 176 75 95 Constant 4.8 5.04 3.1 3.28 2.04 1.25 4.55 3.3 3.4 3.95 2.3 4.45 5.32 2.5 1.93 2.18 44
Table 5.5 Results for L16 array of diesel Test No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 BTE 12.16 15.61 24.71 17.25 16.2 14.02 14.6 23.7 23.93 17.95 12.15 17.14 17.21 24.67 19.09 13.12 SFC (kg/kWh) 0.7 0.55 0.35 0.5 0.53 0.61 0.54 0.36 0.36 48 0.71 0.5 0.5 0.35 0.45 0.65 co ( % vol) 0.16 1.1 0.24 0.67 0.92 0.36 0.98 0.26 0.25 0.49 0.27 0.77 0.65 0.13 0.46 1.21 HC (ppm) 11 158 47 140 114 20 161 38 39 120 17 73 111 29 57 C02 ( % vol) 4.3 6.8 4.6 5.8 6.5 6.9 5.8 4.6 4.6 5.7 4.8 6 5.8 4.3 5.8 6.5 NO (ppm) 36 74 130 66 76 58 83 118 136 81 41 79 74 126 80 47 Smoke K Constant 1 4.85 1.2 4.04 4.42 2.34 5.14 1.92 1.31 3.54 1.96 4.64 4.09 1.85 2.34 3.29 5.4.1 Effect of operating parameters on brake thermal efficiency The response obtained from each level of all factors is shown in the Table 5.6. A ranking is given for each parameter for its significance on the basis of its deviation from mean of response. It can be observed from the deviation that nozzle is most significant parameter for BTE which is followed by compression ratio, additive , fuel fraction and injection pressure. Table 5.6 Response for means of BTE Level 1 2 3 4 Delta Rank NOZZLE FUEL FRACTION 16.70 18.21 17.62 21.98 5.28 2 17.74 17.60 18.92 20.24 2.64 5 15.05 16.21 23.29 19.95 8.24 1 17.46 20.24 17.92 18.89 2.78 4 ADD 16.78 17.18 21.82 18.73 5.03 3 A multiple regression using least count is done to find the relation between the factors and BTE. The obtained equation is given as below = -39.2 + 2.18CR + 0.04421P + 2.1814 + 0.0052 FF + 0.350 ADD 45
The effect of each parameter is shown in Figure 5.1. It can be observed that 18 compression ratio is having highest BTE which reduces with reduction in CR. BTE continuously increases with increase in the injection pressure. Highest BTE is obtained with 330 bar injection pressure. Increase in efficiency is due to better atomization of fuel.3 hole nozzle is having highest BTE, while 1 hole nozzle is having lowest efficiency. BTE is highest for 30 percent blending of biodiesel. BTE increases with increasing biodiesel percentage, this is because, and biodiesel is having high oxygen percentage which helps in improving the combustion. Further addition of biodiesel decreases the calorific value of the fuel fraction which results in decrease in BTE. 6 ml/lit additive is having the highest brake thermal efficiency. Increase in additive also tends to increase in heat losses which ultimately reduce the BTE. Effece of Factors On BTHE (0/0) COMPRESSION RATIO NOZZLE 3 4 o 24 22 20 18 16 16.0 24 22 20 18 16 15 17.0 17.5 BLEND INJECTION PRESSURE 290 310 ADDITIVE 18.0 100 270 o 330 9 1 2 30 50 3 6 Fig 5.1 Effect of operating parameters on brake thermal efficiency 5.4.2 Effect of operating parameters on specific fuel consumption The response for each factor for SFC is shown in the table 5.7. It can be observed from the deviation of response from mean that nozzle is most significant parameter which is similar to 46
BTE. Second most significant parameter is additive which is followed by fuel fraction, injection pressure and compression ratio. The linear relation between the operating parameter and SFC formed using multiple regression least square method is shown below. SFC kWh) = 1.39 + 0.0507CR - 0.004241P - 0.132H - O.00045FF - 0.0178ADD Table 5.7 Response for means of SFC 0.6 0.4 Level 1 2 3 4 Delta Rank CR 0.5450 0.4775 0.4975 0.6825 0.2050 5 NOZZLE FUEL FRACTION 0.7500 0.5025 0.4725 0.4775 0.2775 4 0.8450 0.5300 0.3700 0.4575 0.4750 1 0.5300 0.4600 0.7500 0.4625 0.2900 3 ADD 0.5350 0.7750 0.4150 0.4775 0.3600 2 Effece of Factors On SFC (kg/ kWh) COMPRESSION RATIO INJECTION PRESSURE 290 310 ADDITIVE NOZZLE 0.8 0.7 0.5 16.0 0.8 0.7 0.6 0.5 0.4 15 17.0 17.5 BLEND 18.0 100 270 o 330 9 1 2 3 4 30 50 3 6 Fig 5.2 Effect of operating parameters on specific fuel consumption 47
The effect of operating parameters on mean of SFC is shown in figure 5.2. It can be observed that 17 and 17.5 compression ratios are having nearly the same lowest SFC. 18 compression ratio is having highest SFC. 270 bar injection pressure is having highest SFC which decreases with increase in pressure.330 bar is having lowest SFC.3 hole nozzle and 330 bar injection pressure are having lowest SFC because better penetration and atomization of fuel. The best results are obtained with 3 hole nozzle and 1 hole nozzle has given the worst results.30 and 100 percent are having nearly the same SFC. These results are similar to the BTE results. 6 ml/ ltr are having lowest SFC. 5.4.3 Effect of operating parameters on CO emission Ranking of factors for response of CO emission are given in table 5.8. Similar to BTE and SFC, nozzle is most effective parameter which is followed by fuel fraction, additive, compression ratio and injection pressure.CO emission are dependent on composition of fuel hence fuel fraction and additive play important role. Table 5.8 Response for means of CO emission Level 1 2 3 4 Delta Rank CR 0.7950 0.6525 0.8525 0.7575 0.2000 4 NOZZLE FUEL FRACTION 0.7125 0.7375 0.7750 0.8325 0.1200 5 0.5625 0.7550 0.5425 1.1975 0.6550 1 0.5600 1.2025 0.6050 0.6900 0.6425 2 ADD 0.5575 0.9100 0.9975 0.5925 0.4400 3 The equation obtained for CO by multiple regression analysis using least square method is as below CO = -0.27 + 0.003 + 0.001991P + 0.169H - 0.00129FF + 0.0064ADD The effect of factors on CO is shown in Figure 5.3. The 17 compression is having lowest CO emissions. 270 bar injection pressure is having lowest CO emission which increases with increase in pressure. The 3 hole nozzle is having lowest CO emissions.30 percent blending is having highest CO emissions even though it has high heat release rate. 48
Effects of Factors On CO ( % vol) COMPRESSION RATIO INJECTION PRESSURE NOZZLE 8 1.25 1.00 o. 75 0.50 16.0 1.25 1.00 o. 75 0.50 15 17.0 17.5 BLEND 18.0 100 270 o 290 310 ADDITIVE 330 9 1 2 3 4 30 50 3 6 Fig 5.3 Effect of Operating Parameters on CO emission 5.4.4 Effect of operating parameters on HC emission The ranking of factors for HC emission from deviation of response is shown in table 5.9. It can be observed that like other parameters the HC emission is also largely effected by nozzle. As HC emission is largely dependent on content of the fuel, the HC emission depends on blending which is followed by additives, compression ratio and injection pressure. Table 5.9 Response for means of HC emission Level 1 2 3 4 Delta Rank CR 101.50 93.00 95.00 107.25 14.25 4 NOZZLE FUEL FRACTION 100.75 100.75 99.75 95.50 5.25 5 43.25 75.75 63.75 214.00 170.75 1 100.25 127.00 86.75 82.75 44.25 2 ADD 85.25 120.75 110.00 80.75 40.00 3 The equation obtained for HC with multiple regression using least square method is follows 49
HC -9 + 1.7CR - 0.0841P + 50H - 0.344FF - 0.81ADD The effect of factors on the HC is shown in the Figure 5.4. It can be observed that all compression ratios are having nearly the same effect on HC emission. The same pattern is seen for injection pressure. The 1 hole nozzle is having very low hydrocarbon emission which increases with increases in number of holes. 30 percent blending is having the highest HC emission and the 100 percent loading is having lowest HC emission. 0 and 6 ml/ltr additive have given nearly the same HC emissions. Effece of Factors On HC (ppm) COMPRESSION RATIO O 200 150 100 50 16.0 200 150 100 50 15 INJECTION PRESSURE 290 310 ADDITIVE 1 NOZZLE 3 17.0 17.5 BLEND 18.0 100 270 o 330 9 2 4 30 50 3 6 Fig 5.4 Effect of Operating Parameters on HC emission 5.4.5 Effect of Operating Parameters on NO emission The response for factors for NO emission is given in table 5.10. It can be observed from the deviation of response from mean that nozzle is most significant factor which is followed by compression ratio, additive, fuel fraction and injection pressure. 50
Table 5.10 Response for means of NO emission Level 1 2 3 4 Delta Rank CR 89.50 87.50 94.50 108.00 20.50 2 NOZZLE BLEND ADD 101.75 93.25 95.25 89.25 12.50 5 63.50 67.50 152.00 96.50 88.50 1 99.25 84.25 98.25 97.75 15.00 4 88.00 103.00 87.50 101.00 15.50 3 The following equation shows the relation between the factors and NO emission. A multiple regression using least square method is used to find the relation. NO = -47 + 8.4CR - 0.1771P + 18.4H + 0.049FF + 0.78ADD Effects of Factors On NO (ppm) COMPRESSION RATIO 9 140 120 100 80 60 16.0 140 120 100 80 60 15 INJECTION PRESSURE 290 310 ADDITIVE 1 NOZZLE 3 17.0 17.5 BLEND 18.0 100 270 o 330 9 2 4 30 50 3 6 Fig 5.5 Effect of Operating Parameters on NO emission Figure 5.5 shows that no emissions increase with increase in compression ratio. This is due to better combustion due to increase in compression ratio. 17 Compression ratio is having lowest NO emissions. The injection pressure is not having much effect on the NO emission. 330 bar in injection pressure shows lowest emission. 51
The nozzle with 3 holes is having highest NO emission. The lowest emission are shown by 1 hole nozzle because it has poor combustion which results in low flame temperature. NO formation is primary function of flame temperature. Higher the flame temperature, higher will be the NO emissions. The 30 percent fuel fraction has shown the lowest NO emission. 0 and 6 ml/ ltr additives are having the same effect on NO emission which is lowest. 5.4.6 Effect of Operating Parameters on Smoke The response of factor for smoke is shown in the table5.11. Nozzle is most significant factor for smoke emission. Which is followed by fuel fraction, compression ratio, additive and injection pressure. Level 1 2 3 4 Delta Rank Table 5.11 Response for means of Smoke NOZZLE FUEL FRACTION 4.055 2.785 3.525 2.983 1.270 3 3.303 2.970 3.185 3.890 0.920 5 2.633 3.365 3.075 4.275 1.643 1 4.075 3.990 2.818 2.465 1.610 2 ADD 3.495 3.793 3.530 2.530 1.263 4 The resultant equation obtained with multiple regression using least square method is given below. K = 8.32 - 0.447CR + 0.009891P + 0.464H - O.0200FF - 0.105ADD Effect of operating parameters is shown in a figure 5.6. Formation of smoke is lowest for 17 compression ratio. This is nearly equal to smoke emissions caused by 18 compression ratio. The lowest smoke is found for 290 bar injection pressure which increases with increase in pressure. The 1 hole nozzle is having lowest smoke and it increases with increase in number of holes. The smoke decreases with increase in percentage of fuel fraction. This may be because percentage of oxygen increases with increase in biodiesel blending which results in reduction of smoke. The 9 ml/ ltr additive has shown the minimum smoke emission. 52
Effece of Factors On Smoke (HSU) COMPRESSION RATIO NOZZLE O 4.5 4.0 3.5 3.0 2.5 16.0 4.5 4.0 3.5 3.0 2.5 15 17.0 17.5 BLEND INJECTION PRESSURE 290 310 ADDITIVE 18.0 100 270 o 330 9 1 2 3 4 30 50 3 6 Fig 5.6 Effect of Operating Parameters on smoke emission 5.5 Summary Design of experiments was done by using Taguchi method for optimization of diesel engine for Mahua oil with additive. AA-93 additive was used for improvement of performance of diesel engine for mahua oil. The results obtained with Mahua oil biodiesel with additive were compared to that of diesel. It was found that Mahua biodiesel with additive has given nearly same results as those diesel readings. The diesel engine operating parameters was optimized are: compression ratio, injection pressure, nozzle, fuel fraction and additive with four levels of each factor by using L16 orthogonal array. The optimized engine conditions are; 18:1 compression ratio. 330bar injection pressure, 3 hole nozzle, 30 percent biodiesel fuel fraction and 6 ml/ltr additive content. The result obtained with optimize condition are given in table 5.12 Test No 1 Table 5.12 Results for optimum condition BTE 29.89 SFC (kg/kWh) 0.28 HC CO ( % vol) C02 ( % vol) NO (ppm) (ppm) 0.37 4.1 81 Smoke K Constant 1.52 53
Chapter 6 Conclusions The world is facing the energy crisis hence it is necessary to find the different energy resources, due to this the use of non-renewable energy sources is new trend in the energy world. One of the alternative renewable energy resource options is the use of biodiesel. Concept of use of biodiesel is there from the invention of the diesel engine. But due the large prize, unavailability the concept was not developed. Government of India has taken an initiative to mainstream the biofuels. Use of biofuels will be beneficial for country to become energy independent. In national biofuel policy, the use of edible oils for the use of biofuel production is prohibited. It is mentioned to focus on the local feedstocks for the biofuel production which gives direction to the research. Mahua seed is available in plenty of amount in our country; it can be large source of biodiesel. But very few studies are done on production of biodiesel with heterogeneous catalyst for transesterification. Heterogeneous catalysis has certain advantages over homogeneous catalysis. The disadvantages of homogeneous catalysis are its high cost, large number of steps, contamination of product, and use of water in large amount. All these disadvantages can be overcome by heterogynous catalyst. The biodiesel have some inappropriate properties such longer molecular chain, longer pour point , lower vapor pressure, high viscosity which causes poor atomization, poor vapor air mixing, low pressure and incomplete combustion and engine deposits. This problem can be solved by the use of additives. Additives are of two types as combustion improvement additives and property improvement additives. Metal based additives and oxygenated additives are combustion improvement additives. Optimization of transesterification process is done by using Taguchi method. The Parameters optimized were: oil to methanol ratio, type of catalyst, catalyst concentration and reaction temperature. Results obtained for response of each factor for yield showed that type of catalyst is most significant factor for the yield which is followed by concentration of catalyst, oil to methanol ratio and reaction temperature. Size of catalyst shows effect on yield because nano solid catalyst has given more yield than micro solid catalyst. Heterogeneous catalyst was having advantages over homogeneous catalyst like easy removal, elimination of washing 54
procedures. Reaction is found to be optimum for nano ZnO catalyst, 1.5% catalyst concentration, 680C reaction temperatures and 1:8 methanol ratio. 92% yield was obtained at optimum conditions. Operating parameters of diesel engine were optimized for the Mahua oil methyl ester with additive. AA-93 additive was to improve the combustion of biodiesel blends. L16 orthogonal array was selected for experiment with five factors and four levels. The operating parameters optimized are: compression ratio, injection pressure, nozzle geometry, biodiesel fuel fraction and additive amount. The results of combustion and emission were obtained and compared with the results of diesel for same parameters. It was found that Mahua oil with additive has given results similar to the diesel. Results obtained were analyzed using ANOVA. Optimum operating parameters are: 18 compression ratio, 330 bar injection pressure, 3 hole nozzle, 30% biodiesel fuel fraction and 6 ml/ltr additive amount. Further test was taken at optimum conditions. The obtained results are: 29.89% BTE, 0.28 SFC (kg/ kWh), 42 ppm HC, 4.1% vol C02, 81 ppm NON, 1.52 HSU smoke. At optimum conditions the engine performance is improved and emissions are reduced as compared to diesel. 55
1. 2. 3. 4. 5. 6. 7. 8. 9. References M. L. Mathur, R. P. Sharma, "A course in internal combustion engines " Dhanpatrai publications, 15th edition, 2005, pg 3-9, 252-254. A. K. Babu, D. Devaradjane, "Vegetable oils and their derivates as fuels for CI engines, an overview " SAE, 2003. V. Ganeshan, "Internal combustion engines ", Engine emission and their control, McGraw Hill, 3rd edition, 2008, pg. 471-500. B. Heywood "Fundamental of Internal Combustion Engines ", McGraw Hill International Editions, Automotive Technology series, 1988, pg. 87-1525. A. K Agrawal, S. K. Singh, S. Sinha, M. K. Shukla, "Effect of EGR on exhaust gas temperature and exhaust opacity in CI engines", Sadhana vol. 29, part 3, 2004, pg. 275- 284. www.energy.hw.ac.uk National Biofuel policy (2012) A.S. Ramadhas , S. Jayaraj, C. Muraleedharan, "Use ofvegetable oils as l.c. engine fuels A review ", Renewable Energy 29 (2004), pg 727-742 I.M. Atadashi, M.K. Aroua, A. Aziz, "High quality biodiesel and its diesel engine application: A review ", Renewable and Sustainable Energy Reviews, 2010, pg. 1999 2008 10. S . P . Singh , Dipti Singh , "Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review Renewable and Sustainable Energy Reviews 14 (2010), pg 200—216 11. Ashwani Kumar, Satyawati Sharma, "Potential non-edible oil resources as biodiesel feedstock: An Indian perspective ", Renewable and Sustainable Energy Reviews 15 (2011), pg 1791-1800 12. Jidon Janaun, Naoko Ellis, "Perspectives on biodiesel as a sustainable fuel", Renewable and Sustainable Energy Reviews 14 (2010), pg 1312—1320 13. M. Satyanarayana, C. Muraleedharan, "A comparative study of vegetable oil methyl esters (biodiesels) ", Energy 36 (2011), pg 2129-2137 14. A.K. Hossain, P.A. Davies, "Plant oils as fuels for compression ignition engines technical review and life-cycle analysis ", Renewable Energy (2009), pg 1—13 15. Mustafa Balat, Havva Balat, "Progress in biodiesel processing", Applied Energy 87 (2010), pg 1815-1835 56
16. Ivana B. Bankovi', Olivera S. Stamenkovi', Vlada B. Veljkovi', "Biodiesel production from non-edible plant oils" , Renewable and Sustainable Energy Reviews 16 (2012) , pg 3621- 3647 17. Fangrui Ma, Milford A. Hanna, "Biodiesel production: a review ", Bioresource Technology 70, pg (1999) 1-15 "Recent 18. K. Ramachandran, T.Suganya, N.Nagendra Gandhi, S.Renganathan developments for biodiesel production by ultrasonic assist transesterification using different heterogeneous catalyst: A review ", Renewable and Sustainable Energy Reviews 22 (2013), pg 410-418 19. Surbhi Semwal, Ajay K. Arora, Rajendra P. Badoni, Deepak K. Tuli, "Biodiesel production using heterogeneous catalysis Bioresource Technology 102 (2011), pg 2151-2161 20. Patricia Hernåndez-Hip61ito, Montserrat Garcia-Castillejos, Elena Martinez-Klimova, Nohemf Juårez-Flores, Antonio G6mez-Cortés, Tatiana E. Klimova, "Biodiesel production with nanoiubular sodium titanaie as a catalyst Catalysis Today 22(2014), pg 4— 11 21. Liu, X., He, H., Wang, Y., Zhu, S.. "Transesierificaiion of soybean oil to biodiesel using 22. Liu, X., He, H., Wang, Y., Zhu, S., Ziao, X., "Transesterification ofsoybean oil to biodiesel using Cal) as a solid base catalyst ", Fuel 87 (2007), pg 216—221 23. Veljkovic, Stamenkovic, O.S., Todorovic, z.B., Lazic, M.L., Skala, D.U., "Kinetics of sunflower oil methanolysis catalyzed by calcium oxide " , Fuel 88 (2009) pg 554—1562 24. Granados, M.L., Poves, M.D.Z., Alonso, D.M., Mariscal, R., Galisteo, F.c., Tost, R.M, "Biodiesel from sunflower oil by using activated calcium oxide ", Appl. Catal. B: Environ 73(2007), pg 317-326 25. Benjapornkulaphong, S., Ngamcharussrivichai, C. , Bunyakiat, K., "A1203 supported alkali earth metal oxides for transesterification of palm kernel oil and coconut oil". Chem. Eng. J. 145 (2008), pg 468-474 26. Abhishek Guldhe , Bhaskar Singh , Taurai Mutanda, Kugen Permaul , Faizal Bux, "Advance sinsynihesis of biodiesel via enzyme catalysis: Novel and sustainable approaches ", Renewable and Sustainable Energy Reviews 41 (2015), pg 1447—1464 27. T. Jeyarani, S. Yella Reddy, "Effect of enzymatic interesterification on physicochemical properties of mahua oil and kokum fat blend", Food Chemistry 123 (2010), pg 249 253 57
28. B. Singh, faizal bux, Y.C. sharma, "comparison of homogeneous and heterogeneous catalysis for synthesis of biodiesel from madhuca indica oil", chemical industry & chemical engineering quarterly 17 (2) (2011), pg 117-124 29. N. Saravanan, Sukumar Puhan , G. Nagarajan, N. Vedaraman, "An experimental comparison of transesierificaiion process with different alcohols using acid catalysts ' Biomass and bioenergy 34 ( 2010 ), pg 999 — 1005 30. Qi DH., Geng LM., Bian YZH., Liu J. "Combustion and performance evaluation of a diesel engine fueled with biodiesel produced from soybean crude oil. " , Renewable Energy 34 (2009), pg. 2706-2713. 31. Nabi Md. Nurun, Rahman Md. Mustafizur, Akhter Md. Shamim. "Biodiesel from cotton seed oil and its effect on engine performance and exhaust emissions. ", Applied Thermal Engineering 29 (2009), pp. 2265 2270. 32. Sureshkumar K., Velraj R., Ganesan R. "Performance and exhaust emission characteristics of a CI engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel. " Renewable Energy 33 (2008), pp. 2294—2302. 33. N. R Banapurmath, P.G. Tewari, "Performance, combustion, and emissions characteristics of a single-cylinder compression ignition engine operated on ethanol- biodiesel blendedfuel", Proc. 1MechE vol. 224, Power and Energy, 2010, pg. 533-543. 34. M. Venkatraman, G. Devaradjane "Effect of compression ratio, injection timing, and injection pressure on a DI diesel engine for better performance and emission fueled with diesel biodiesel blends ", Proc. IMechE vol. 224, Power and Energy (2010), pg 0976- 4259,. 35. N.R. Banapurmath, P.G. Tewari, Y.S. Yaliwal, "Effect of injection nozzle geometry on the performance of CI engine operated on vegetable oils", Proc. International conference of ERA, 2009, pg. 1120-1124. 36. N. R. Banapurmath, P. G. Tewari "Performance studies of low heat rejection engines operated on non volatile vegetable oils with exhaust gas recirculation" International Journal of sustainable engineering, Taylor & Francis Vol. 2, No.4, 2009, pg. 265-274. 37. N. R. Banapurmath, P.G. Tewari and R. S. Hosmath "Combustion and emission characteristics of a DI CI engine when operated on Honge oil, HOME and blends of HOME and diesel" International Journal of sustainable engineering, Taylor & Francis vol. 1 No. 2, 2008, pg. 80-93. 58
38. N. R. Banapurmath, P. G. Tewari and R. S. Hosmath "performance and emissions characteristics of DI CI engine operated on Honge, Jatropha, and Sesame oil methyl ester " Renewable energy, 2008, pg. 1982 — 1989. 39. N. Reddy, A. Ramesh, "Parametric studies for improving the performance of a jatropha oil-fuelled compression ignition engine ", Renewable Energy, 2006, pg. 1994—2016. 40. Agarwal D, Kumar L, Agarwal AK., "Performance evaluation of a vegetable oil fuelled compression ignition engine". Renewable Energy ( 2008) , 33 pg 1147—1156. 41. Puhan S, Vedaraman N, Sankaranarayanan S, Ram B VB. "Performance and emission study of Mahua oil (madhuca indica oil) ethyl ether in a 4-stroke natural aspirated direct injection diesel engine ". Renewable Energy 2005;30: pg 1269—1278. 42. Saravanan N, Nagarajan G, Puhan S. "Experimental investigation on a DI diesel engine fuelled with Madhuca indica ester and diesel blend". Biomass Bioenergy 43. Kapilan N, Babu TPA, Janardhan K, Reddy RP. "Effect of injector opening pressure on performance and emission characteristics of Mahua oil methyl ester in a DI diesel engine ". SAE paper 2009-01-2901; 2009. 44. Raheman H, Ghadge S V. "Performance of compression ignition engine with mahua (Madhuca indica) biodiesel". Fuel 2007;86: pg 2568-73. 45. Godiganur S, Murthy CHS, Reddy RP. "Cummins engine performance and emission tests using methyl ester mahua (Madhuca indica) oil diesel blends ", Renewable Energy 2009;34: pg 2172-2177. 46. H.K. Rashedul, H.H. Masjuki, M.A. Kalam, A.M. Ashraful, S.M. Ashrafur Rahman, S.A. Shahir, "The effect of additives on properties, performance and emission of biodiesel fuelled compression ignition engine ", Energy Conversion and Management 88 (2014) 348 364 47. S.P. Venkatesan, P.N. Kadiresh, , "Influence of an aqueous cerium oxide nanofluid fuel additive on performance and emission characteristics of a compression ignition engine International Journal of Ambient Energy, 2014 48. S. Kiran Kumar, "Performance and Emission Analysis of Diesel Engine Using Fish Oil And Biodiesel Blends With Isobutanol As An Additive ", American Journal of Engineering Research ,V01ume-02 (10), pg-322-329 49. Sinem Caynak, Metin Guru, Ahmet Bicer, Ali Keskin, Yakup Icingur, "Biodiesel production from pomace oil and improvement of its properties with synthetic manganese additive Fuel 88 (2009), pg.534 538. 59
50. M. Mofijur, H. H. Masjuki, M. A. Kalam, M. Shahabuddin, "Experimental study of additive added palm biodiesel in a compression ignition engine ", Energy Education Science and Technology Part A: Energy Science and Research 30 (2012), pg. 1-12 60

Need a Tutor or Coaching Class?

Post an enquiry and get instant responses from qualified and experienced tutors.

Post Requirement

Related Study Notes

Mechanical MQC

Mechanical

1,135 Views
Energy Conservation Measure

Mechanical

2,123 Views
Design Of Machine Elements I

Mechanical

2,588 Views
Mechanical MQC

Mechanical

1,118 Views
Differential In Automobiles

Mechanical

8,245 Views
Sources Of Energy

Mechanical, Physics

5,909 Views
Fluid Mechanics

Mechanical, Physics

2,058 Views
Mechanical MQC

Mechanical

3,854 Views
Mechanical MQC

Mechanical

1,284 Views
Metal Cutting(Manufacturing)

Mechanical

6,059 Views

Upload Study Notes

If you have your own Study Notes which you think can benefit others, please upload on LearnPick. For each approved Study Note you will get 100 Credit Points and 100 Activity Score which will increase your profile visibility.

Upload Now

We use cookies

Choose Country Code

Direction

Ask a Question

Report a Profile Issue

Optimization Of Biodiesel Production Process

Juned K / Navi Mumbai

Need a Tutor or Coaching Class?

Related Study Notes

Upload Study Notes