REVIEW PAPER A COMPREHENSIVE REVIEW OF BIODIESEL APPLICATION IN IDI ENGINES WITH PROPERTY IMPROVING ADDITIVES INTRODUCTION Direct Injection (DI) diesel engines are in vogue so far in myriad energy applications. The diesel run DI engines have certain endemic problems majorly like tailpipe and carbon particle emission. DI engines also emit more noise and known for its high frequency vibration, which tells on the reliability of the engine parts in the long run and raise human health problems. Endeavors were made to reduce emissions and increase the combustion efficiency to improve reliability. Basic design changes like combustion chamber design, injection stratification, and additive technology were tried on these problems, but only resulted in unsatisfactory achievement. Now the engine technology is shifted to Indirect Diesel Injection (IDI) engine usage in regular small power generation with lower air pollution by tailpipe, noise and vibration emission reduction of the engine without entailing much change in the basic design of the engine. Alternate fuels were chosen to save foreign exchange in purchasing conventional diesel fuel. Biodiesel application in IDI engines is a successful attempt to alleviate the crank case oil dilution with the usage of 100% biodiesel. DI engine is not By having this privilege. The concept of using vegetable oils as fuel was exhibited by Rudolf Diesel who developed the first engine to run on peanut oil. Despite its success when diesel engines were operated with the vegetable oils for short term usage, the high viscosity and density of plant oils led to problems in the injection system and fuel atomization problems in the combustion chamber of the diesel engines with a long- term usage. The high viscosity problem of plant oils has been solved in several ways, such as preheating the oils or blending it with petroleum based diesel fuels [1]. The range of kinematic viscosities attained after trans-esterification of raw plant oils will be ranging in between 2 cSt to 7 cSt. This attainment also depends on the type a raw oil and the plant from which it has been derived and the processes implemented. Relatively higher viscosity biodiesel can be used in IDI engine because of its dual combustion chambers connected in series with pre combustion taking place in swirl chamber. Pre and main combustion chambers lead to almost total combustion of the fuel and this duo also form such a resonant chamber combination to reduce the high frequency noise emanation from the * Research Scholar, Department of Marine Engineering, Andhra University College of Engineering, Visakhapatnam, India. ** Professor, Department of Marine Engineering, Andhra University College of Engineering, Visakhapatnam, India. ABSTRACT Rapidly increasing consumption of fossil fuel and petroleum products has been a matter of concern for the many countries which import crude oil. This is at the expense of huge foreign exchange on one hand and increasing tailpipe emissions on the other hand. Therefore, it is necessary to investigate about renewable energy sources. Among the biomass resources, biodiesel offers a very promising alternative to diesel oil. It is renewable, and has similar or better properties. Biodiesel commands crucial advantages such as technical feasibility of blending in any ratio with petroleum diesel fuels. Extensive research and demonstration projects have shown that, it can be used pure or in blends with conventional diesel fuel in unmodified diesel engines. This paper presents the results of wider experimental campaign carried out on IDI engine by various authors and aimed at evaluating the overall performance, emissions and the combustion trends. Experimental results with different fuels like neat biodiesel, blends of biodiesel –diesel & biodiesel - additive combinations have been discussed in detail. Key words: Biodiesel, Vegetable Oil, IDI Engine, Performance and Emissions. ADITYA KOLAKOTI * B. V. A. RAO ** l i-manager’s Journal o Mechanical Vol. No. 4 2015 l n Engineering, 5 August - October 35