Due to the finite stock of fossil fuels and its negative impact on the environment, many countries across the world are now leaning toward renewable sources energies like solar energy, wind energy, biofuel, hydropower, geothermal and ocean energy to ensure energy for the countries development security. Biodiesel is one kind of biofuel that is renewable, biodegradable and has similar properties of fossil diesel fuel. The aim of this paper is to provide the substantial information on biodiesel to the researchers, engineers and policy makers. To achieve the goal, this paper summarizes the information on biofuel development, feedstocks around the world, oil extraction technic, biodiesel production processes. Furthermore, this paper will also discuss the advantages of biodiesel compared to fossil fuel. Finally, the combustion behavior of biodiesel in an internal combustion engine is discussed and it will help the researchers and policy maker and manufacturer. To determine the future and goal of automotive technology the study found that, feedstock selection for biodiesel production is very important as it associates 75% production cost. Moreover, the test of fuel properties is very important before using in the engine which depends on the type of feedstocks, origin country, and production process. Most of the researchers reported that the use of biodiesel in diesel engine reduces engine power slightly but reduces the harmful emission significantly. Finally, the study concludes that biodiesel has the potential to be used as a diesel fuel substitute in diesel engines to solve the energy and environment crisis.

Production, characterization and performance of biodiesel as an alternative fuel in diesel engines – A review

Biofuels have grabbed the attention of engine researchers ever since the oil-crisis and escalating costs of petro-chemicals cropped up in the ׳70s. Ethanol and methanol were the most widely researched alcohols in IC engines. However, the last decade has witnessed significant amount of research in higher alcohols due to the development of modern fermentation processes using engineered micro-organisms that improved yield. Higher alcohols are attractive second/third generation biofuels that can be produced from sugary, starchy and ligno-cellulosic biomass feedstocks using sustainable pathways. The present work reviews the current literature concerning the effects of using higher alcohols ranging from 3-carbon propanol to 20-carbon phytol on combustion, performance and emission characteristics of a wide range of diesel engines under various test conditions. The literature is abound with evidence that higher alcohols reduce carcinogenic particulate emissions that are prevalent in diesel engines. NOx emissions either increased or decreased based on the domination of either cetane number or heat of evaporation. Brake specific fuel consumption (BSFC) of the engine usually suffered due to low energy content of alcohols. A notable feature is that the combination of higher alcohols (like butanol or pentanol), high exhaust gas recirculation (EGR) rates and late injection timing enabled low temperature combustion (LTC) in diesel engines that can simultaneously reduce smoke and NOx emissions with improved engine efficiency. It can be concluded that higher alcohols reduce smoke emissions with their fuel-borne oxygen; enhance air/fuel mixing by offering long ignition delay and eventually replace fossil diesel (partially or wholly) to enable a clean and efficient combustion in compression-ignition engines. The chief thrust areas include developing mutant strains with higher yield, higher tolerance to toxic inhibition and low-cost substrates for fermentation. Further work is required in stipulating optimum blend-fuel characteristics and ensuring the long-term durability of the engines using these fuels.

Use of higher alcohol biofuels in diesel engines: A review

The increasing energy demand, surging oil prices, depleting oil reserves and environmental pollution problems associated with the use of fossil fuels have sparked renewed interest to find out clean alternative fuels. Alcohols such as methanol, ethanol and butanol are competitive alternative fuels due to their liquid nature, high oxygen contents, high octane number and their production from renewable biomass. In this review, the fuel properties of these alcohols are compared with conventional gasoline and diesel fuel. The comparison of fuel properties represents that butanol has the potential to overcome the problems associated with the use of methanol and ethanol. Progresses of their production from different sources are also introduced. Further, several techniques such as alcohol–diesel fuel blends and alcohol–diesel fuel emulsions are discussed, especially for lower alcohols, in order to use them in diesel engines. The effects of diesel–alcohol blends on the combustion, performance and emissions of diesel engines are also analyzed. It is examined that blending of alcohols, along with some CN improver, to diesel fuels can reduce diesel engine emissions without adverse impacts on the performance of diesel engines. These studies also reveal that butanol is a better alternative for diesel fuel due to its superior fuel properties and miscibility with diesel fuel than those of methanol and ethanol. Finally, some critical conclusions and future research directions are highlighted.

Advances in diesel–alcohol blends and their effects on the performance and emissions of diesel engines

The effect of nano-additives in diesel-biodiesel fuel blends: A comprehensive review on stability, engine performance and emission characteristics

Combined effect of influence of nano additives, combustion chamber geometry and injection timing in a DI diesel engine fuelled with ternary (diesel-biodiesel-ethanol) blends

Piston Bowl Optimization for Single Cylinder Diesel Engine Using CFD

Ethanol is a bio-based renewable and oxygenated fuel, thereby providing potential to reduce the PM emission in diesel engine and to provide reduction in life cycle of carbon di-oxide. So that reduces ozone layer depletion. There are several studies which reports improvement in the engine performance and emission by using ethanol blend fuels. Many researches going on in the area of ethanol as alternate fuel, the commercialization of this fuel is not achieved in the Indian automobile scenario. It is mainly because of installation of refilling stations and the problems encountered in the engine while ethanol is used as a fuel. The problem such as starting trouble, cold starting problem, Aldehyde emission coming out from the engine and the stringent norms followed by the government for the use of ethanol. The main objective of this project is to study the performance, and to control the emissions of the diesel engine using blended fuel by preheating the inlet air. The present work has been carried out using single cylinder, four stroke, water cooled diesel engine. In this phase, experiment investigations are conducted using five sets of blended fuels i.e 10%, 15%, 20%, 25%, 30% Ethanol — Diesel blend have been prepared and preheating the inlet air to 40oC, 50oC and 60oC. The performance and emission characteristics are studied and compared with the base fuel.

Experimental investigation on D.I. diesel engine fuelled by ethanol diesel blend with varying inlet air temperature

The methyl and ethyl esters of vegetable oils, known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engine. In the present work, methyl and ethyl esters of nerium oil were prepared by transesterification using both methanol and ethanol. However, viscosity of ethyl esters of nerium oil (EEON) was slightly higher than that of methyl esters of nerium oil (MEON). A single cylinder stationary kirloskar engine is used to compare the Performance and Emission and Combustion characteristics between pure diesel and nerium blends. The nerium oil blends are in percentage of 20%, 40%, 60%, 80%, and 100% of nerium oil to 80%, 60%, 40%, 20% and 0% of diesel. Results show that methyl esters of nerium oil (MEON) produced slightly higher efficiency than ethyl esters of nerium oil (EEON). Exhaust emissions and Combustion characteristics of methyl esters of nerium oil (MEON) were also higher than ethyl esters of nerium oil (EEON). Hence methyl and ethyl esters of nerium blend can be used in existing diesel engines without compromising the engine performance.

Optimization of Esters of Nerium Biodiesel in a Diesel Engine

This study presents utilizing hybrid vegetable oil from Pongamia pinnata and Madhuca indica as an alternative diesel fuel. Raw pongamia oil and mahua oil were mixed (50:50) for preparing hybrid vegetable oil (HVO). A 20% blend of methyl ester of pongamia oil (MEOP), 20% blend of methyl ester of mahua oil (MEOM) and 20% blend of methyl ester of hybrid vegetable oil (MEHVO) with 80% of neat diesel were used as a fuel in diesel engine. A 20% blend of MEHVO with 80% of diesel gave competitive performance nearing diesel. In MEHVO blend, HC, CO is reduced, however CO2 and NOx emission is slightly increased when compared to pure diesel.

http://nopr.niscair.res.in/bitstream/123456789/14631/1/JSIR%2071%289%29%20612-615.pdf

Experimental study of using hybrid vegetable oil blends in diesel engine

Biodiesel would be a futuristic alternative for compression ignition engines because of its environmental benefits and the source being renewable. Jatropha, Pongamia pinnata, Mahua, cotton seed are the oils being tested by the researchers. In this experimental investigation Adelfa biodiesel (Nerium Oil Methyl Ester – NOME) has been used as the test fuel. The most common method of production of biodiesel is by transesterification. In most of the researches, suggested biodiesel blend was 20% by volume with petroleum diesel. Though biodiesel fuel show an appreciable results on performance and few emission parameters, the penalty being the elevated oxides of nitrogen (NOx) emission. This problem persists in almost all the biodiesel blends. In this experimental research, Di ethyl ether (DEE) has been used as a fuel additive (20% Adelfa by volume with diesel + DEE) focusing on reducing emission and improving efficiency. Comparison between diesel, A20 and A20 + DEE with various proportions has been analyzed. Measured quantities were within the range of prescribed emission standards.

http://nopr.niscair.res.in/bitstream/123456789/29349/1/JSIR%2073%289%29%20627-632.pdf

K. Annamalai

Papers

Piston Bowl Optimization for Single Cylinder Diesel Engine Using CFD

Experimental investigation on D.I. diesel engine fuelled by ethanol diesel blend with varying inlet air temperature

Optimization of Esters of Nerium Biodiesel in a Diesel Engine

Experimental study of using hybrid vegetable oil blends in diesel engine

Adelfa (NOME Nerium Oil Methyl Ester) with DEE as the fuel additive for NOx reduction in DI Diesel engines - An experimental investigation