IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 01, 2015 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 1321 A Review on Waste Heat Recovery and Utilization from Exhaust Gas of I.C Engine Pradip G. Karale 1 Dr. J.A Hole 2 1 Student 2 Professor 1,2 Department of Mechanical Engineering 1,2 Rajarshi Shahu College of Engineering, Pune, Maharashtra Abstract— In many applications I.C engine is used as primary power source. Out of the total heat supplied to the I.C engine in the form of fuel 30-40% heat is converted into useful work and remaining 60-70 % as a part of waste heat as friction, exhausts gas and engine cooling system. Through the exhaust of engine 30-40 % of heat is lost to the environment. Rapid economy development results in increasing energy demand, consequently fuel consumption and fuel prices which results in environmental pollution. This attracts the researchers to find more energy efficient techniques and concentrates on hard work on investigation of suitable waste heat recovery system. Waste heat utilization reduces the fuel (fossil fuel) consumption and reduces the amount of waste heat and greenhouse gases. A significant waste heat recovery systems or methods have been developed to recover the heat from exhaust gas of I.C engine. This article shows the Benefits of waste heat recovery, the available waste heat from I.C engine, Amount of heat carried away by exhaust gas and possible techniques to recover the heat from exhaust gas of I.C. engine. Waste heat recovery system is the best solution to recover waste heat to reduce waste heat, fuel consumption and pollution. Key words: I.C Engine, Green House I. INTRODUCTION The I.C engine is a device which converts the chemical energy of fuel into heat and again heat energy in to mechanical work. It is the fact that the total heat supplied to the engine in the form of fuel approximately only 30-40% get converted in to useful mechanical work and remaining almost 70% of the energy released from fuel due to combustion is lost mainly in the form of Heat. Approximately 25-30% of the total energy generated by the engine is dissipated in the form of Exhaust loss energy [1]. Increase in economy the energy demand also increases which results in more usages of fossil fuels which causes the emission of harmful greenhouse gases. Large amount of heat is released in the atmosphere from the engines without utilizing for any purpose. if some amount of this waste heat could be recovered it possible to reduce the primary fuel required. Waste heat utilization is the major source of cost saving. If exhaust gases of engines are directly released into atmosphere it will not only waste heat but also causes the environmental problems, so it is required to utilize the waste heat for useful work to increase the efficiency of engine.[2] The- recovery and utilization of waste heat from engine results in reduction in fuel consumption, reduction in waste heat loss and engine emission, increases the engine efficiency. It is necessary that continuous and serious efforts should be taken for conserving this waste heat by using proper waste heat recovery techniques. This paper shows the review of waste heat from I.C engine, Heat available from engine exhaust and existing and possible waste heat recovery systems for I.C engine. Fig. 1: Fuel Energy Balance in I.C Engine II. BENEFITS OF WASTE HEAT RECOVERY FROM I.C. ENGINE Benefits of waste heat recovery from engines can be broadly classified in two categories A. Direct Benefits: Recovery of waste heat has a direct effect on the combustion process efficiency. This is reflected by reduction in the utility consumption and process cost. B. Indirect Benefits: 1) Reduction in pollution: A number of toxic combustible wastes such as carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM) etc, releasing to atmosphere. Recovering of heat reduces the environmental pollution levels. 2) Reduction in equipment sizes: Waste heat recovery reduces the fuel consumption, which leads to reduction in the flue gas produced. This results in reduction in equipment sizes. 3) Reduction in auxiliary energy consumption: Reduction in equipment sizes gives additional benefits in the form of reduction in auxiliary energy consumption. [3] III. WASTE HEAT AVAILABLE FROM I.C ENGINE Waste heat is heat, which is generated in a process by way of fuel combustion or chemical reaction, and then “dumped” into the environment even though it could still be reused for some useful and economic purpose. This heat depends in part on the temperature of the waste heat gases and mass flow rate of exhaust gas. Waste heat losses arise both from equipment inefficiencies and from thermodynamic limitations on equipment and processes.