Performance evaluation of a vegetable oil fuelled compression ignition engine

doi:10.1016/j.renene.2007.06.017

Renewable Energy

Volume 33, Issue 6, June 2008, Pages 1147-1156

https://doi.org/10.1016/j.renene.2007.06.017 Get rights and content

Abstract

Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as linseed oil, mahua oil, rice bran oil, etc. are potentially effective diesel substitute. Vegetable oils have high-energy content. This study was carried out to investigate the performance and emission characteristics of linseed oil, mahua oil, rice bran oil and linseed oil methyl ester (LOME), in a stationary single cylinder, four-stroke diesel engine and compare it with mineral diesel. The linseed oil, mahua oil, rice bran oil and LOME were blended with diesel in different proportions. Baseline data for diesel fuel was collected. Engine tests were performed using all these blends of linseed, mahua, rice bran, and LOME. Straight vegetable oils posed operational and durability problems when subjected to long-term usage in CI engine. These problems are attributed to high viscosity, low volatility and polyunsaturated character of vegetable oils. However, these problems were not observed for LOME blends. Hence, process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. Economic analysis was also done in this study and it is found that use of vegetable oil and its derivative as diesel fuel substitutes has almost similar cost as that of mineral diesel.

Introduction

Energy demand is increasing due to ever increasing number of vehicles employing internal combustion engines. Also, world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Fossil fuels are limited resources; hence, search for renewable fuels is becoming more and more prominent for ensuring energy security and environmental protection. For the developing countries of the world, fuels of bio-origin can provide a feasible solution to the crisis. When Rudolf Diesel invented the diesel engine more than a century ago, he demonstrated the principle of compression ignition engine by employing peanut oil as fuel and suggested that vegetable oils would be the future fuel for diesel engines. However, petroleum was discovered later, which replaced vegetable oils as engine fuel due to its abundant supply. Thus, it is highly desired in present context to direct the research towards renewable fuels of bio-origin, which are environment friendly, provide improved performance, while being used as diesel substitute and must not be harmful to human health.

India is producing a host of non-edible oils such as linseed, castor, mahua, rice bran, karanji (Pongamia glabra), neem (Azadirachta indica), palash (Butea monosperma), kusum (Schlelchera trijuga), etc. Some of these oils produced even now are not being properly utilized, and it has been estimated that some other plant-based and forest derived oils have a much higher production potential [1]. Vegetable oils have comparable heat content, cetane number, heat of vaporization, and stoichiometric air/fuel ratio with mineral diesel. Heat values decrease with increasing un-saturation as a result of fewer hydrogen atoms in their molecular structure. The structure of typical vegetable oil molecule is given below:

Here R¹, R² and R³ represent straight chain alkyl groups. Free fatty acids are also found in vegetable oils. The large molecular sizes of the triglycerides results in the oils having higher viscosity and low volatility compared to mineral diesel. Proportion and location of double bonds affects cetane number of vegetable oils [1].

Problems associated with vegetable oils during engine tests can be classified into two broad groups, namely, operational and durability problems. Operational problems are related to starting ability, ignition, combustion and performance. Durability problems are related to deposit formation, carbonization of injector tip, ring sticking and lubricating oil dilution. It has been observed that the straight vegetable oils when used for long hours tend to choke the fuel filter because of high viscosity and insoluble present in the straight vegetable oils. The high viscosity, polyunsaturated character, and extremely low volatility of vegetable oils are responsible for the operational and durability problems associated with its utilization as fuels in diesel engines. High viscosity of vegetable oils causes poor fuel atomization, large droplet size and thus high spray jet penetration. The jet tends to be a solid stream instead of a spray of small droplets. As a result, the fuel is not distributed or mixed with the air required for burning in the combustion chamber. This result in poor combustion accompanied by loss of power and economy.

Blending, cracking/pyrolysis, emulsification or transesterification of vegetable oils may overcome these problems. Heating and blending of vegetable oils reduce the viscosity and improve volatility of vegetable oils but its molecular structure remains unchanged hence polyunsaturated character remains. Blending of vegetable oils with diesel, however, reduces the viscosity drastically (depending on level of blending) and the fuel handling system of engine can handle the vegetable oil-diesel blends without any problems. On the basis of experimental investigations, it is found that converting vegetable oils into simple esters is an effective way to overcome all the problems associated with the vegetable oils. Most of the conventional production methods for biodiesel use basic or acidic catalyst. A reaction time of 45 min to 1 h and reaction temperature of 55–65 °C are required for completion of reaction and formation of respective esters [1], [2], [3], [4], [5], [6], [7], [8], [9], [10].

Biodiesel consists of alkyl ester of fatty acids produced by the transesterification of vegetable oils. The use of biodiesel in diesel engines require no hardware modifications. In addition, biodiesel is a superior fuel than diesel because of lower sulfur content, higher flash point and lower aromatic content. Biodiesel fuelled engine emits fewer pollutants. Biodiesel can be used in its pure form or as a blend with diesel. It can also be used as a diesel fuel additive to improve its properties. Even a low percent blend, such as 2% biodiesel will provide sufficient lubricity for low sulfur diesel [11].

Saka and Kusdiana [2] prepared biodiesel using rapeseed oil and supercritical methanol to investigate the possibility of converting the triglycerides of the rapeseed oil to rapeseed oil methyl esters (ROME). Murayama et al. [3] evaluated waste vegetable oils as a feedstock for biodiesel production. This research was focused on the engine performance and emission characteristics of esterified vegetable oil, when used in a diesel engine. When blends of biodiesel and diesel are used in diesel engines, a significant reduction in hydrocarbons (HC) and particulate matter (PM) are observed but NO_x emissions are found to have increased. In general, engine performance and power remains unchanged [1], [4], [5], [6], [7], [12]. Akasaka et al. [4] found that under partial load conditions, soybean methyl ester (SME) addition increases PM emissions.

Agarwal [1], [6], [7] observed significant improvement in engine performance and emission characteristics for the biodiesel-fuelled engine compared to diesel-fuelled engine. Thermal efficiency of the engine improved, brake specific energy consumption reduced and a considerable reduction in the exhaust smoke opacity was observed. Prasad et al. [13] used non-edible oils such as Pongamia and Jatropha oils in low heat rejection (LHR) diesel engine. Esterification, preheating and increase in injection pressure have been tried for utilization of vegetable oils in diesel engines. The emission of smoke and NO_x has been found to increase.

Section snippets

Blending

Undoubtedly, transesterification is well-accepted and best method of utilizing vegetable oils in CI engine without any long-term operational and durability problems. However, this adds to the cost of production because of the chemical process involved. In rural and remote areas of developing countries, where grid power is not available, vegetable oils can play a vital role in decentralized power generation for irrigation and electrification purposes. In these remote areas, different types of

Transesterification

The formation of methyl esters by transesterification of vegetable oils requires 3 moles of alcohol stoichiometrically. However, transesterification is an equilibrium reaction in which excess alcohol is required to drive the reaction close to completion. The vegetable oil was chemically reacted with an alcohol in presence of a catalyst to produce vegetable oil esters. Glycerol was produced as a by-product of transesterification reaction. The chemical reaction of the transesterification process

Economic analysis

The cost of making biodiesel from linseed oil is shown in Table 1. However cost of different vegetable oils keeps fluctuating since the markets are small. The costs of different fuels assumed in this study are given in Table 2. For diesel, cost was taken as the 2007 fuel price in India.

The cost of vegetable oils is slightly higher than diesel because of the fragmented nature of vegetable oil market. There are several middle-men involved which increase the cost of vegetable oils. The cost of

Experimental setup

The present study was carried out to investigate the performance and emission characteristics of linseed oil, mahua oil, rice bran oil and LOME in a stationary single cylinder four-stroke diesel engine and compare it with baseline data of diesel fuel. Specific gravity of different fuels was measured using a precision hydrometer. Kinematic viscosity was measured using kinematic viscometer (Setavis, UK). Calorific value and flash point were measured using bomb calorimeter and pensky marten's

Results and discussion

Different blends of linseed oil (10, 20, 30, and 50%, v/v), mahua oil (10, 20, and 30%, v/v), rice bran oil (10, 20, and 30%, v/v) and LOME (10, 20, 30, 50, and 100%, v/v) with mineral diesel were prepared. Engine experiments were conducted at a constant speed of 1500 rpm at different loads.

Conclusions

The prospects for large-scale vegetable oil-based fuel production are very attractive for developing countries like India. In the present investigation, a host of blends of different vegetable oils, ester with mineral diesel oil were prepared and tested on a single-cylinder constant speed diesel engine for its performance and emission. The performance and emission parameter for different fuel blends were found to be very close to diesel. Smoke density and BSFC were slightly higher for vegetable

Acknowledgments

The authors acknowledge help, assistance, and suggestions of Mritunjay Shukla of Engine Research Laboratory, IIT Kanpur. Grant from Department of Science and Technology, Government of India, for conducting these experiments is highly acknowledged.

References (18)

S. Saka et al.
Biodiesel fuel from rapeseed oil as prepared in supercritical methanol
Fuel
(2001)
M. Diasakou et al.
Kinetics of the non-catalytic transesterification of soybean oil
Fuel
(1998)
M.J. Haas et al.
A process model to estimate biodiesel production costs
Bio-resour Technol
(2006)
M.P. Dorado et al.
An approach to the economics of two vegetable oil based biofuels in Spain
Renew Energy
(2006)
C.S. Wassell et al.
Are subsidies for biodiesel economically efficient?
Energy Policy
(2006)
A.K. Agarwal
Vegetable oils versus diesel fuel: development and use of biodiesel in a compression ignition engine
TERI Inf Digest on Energy
(1998)
T. Murayama et al.
Evaluating waste vegetable oils as a diesel fuel
Proc Inst Mech Eng D
(2000)
Akasaka Y, Ssuzaki T, Saurai Y. Exhaust emissions of a DI diesel engine fuelled with blends of biodiesel and low sulfur...
Marshall W, Schumacher LG, Howell S. Engine exhaust emissions evaluation of a Cummins L10E when fuelled with biodiesel...

There are more references available in the full text version of this article.

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Performance evaluation of a vegetable oil fuelled compression ignition engine

Abstract

Introduction

Section snippets

Blending

Transesterification

Economic analysis

Experimental setup

Results and discussion

Conclusions

Acknowledgments

Fuel

Fuel

Bio-resour Technol

Renew Energy

Energy Policy

Vegetable oils versus diesel fuel: development and use of biodiesel in a compression ignition engine

TERI Inf Digest on Energy

Evaluating waste vegetable oils as a diesel fuel

Proc Inst Mech Eng D