Conversion of Waste Polypropylene into Hydrocarbon Fuel – Analysis of Combustion Ability of Yield Hydrocarbon in Direct Injection Internal Combustion Engine.

Abstract

Recycling of plastic waste has gained increasing attention as land filling and incineration become more expensive and less accepted due to environmental impacts. More attention is thus being given to new recycling methods which are more environmentally attractive. Pyrolysis is one such promising method for the treatment of mixed and contaminated plastic wastes. In pyrolysis, plastics are thermally degraded to produce liquid hydrocarbons. Pyrolysis of waste plastics was investigated in a reactor system which consists of a semi batch reactor, a condenser and a liquid-gas separator. Liquid fuel obtained by the process was found to consists of light and middle distillate in the range of C5 to C12 hydrocarbons with higher concentrations of C7, C8 and C9 fractions. Non-condensable gas obtained was chemically equivalent to the LP (liquid petroleum) gas. The calorific value of liquid and gaseous fuel was found to be 43.5 MJ/kg and 42.5 MJ/kg respectively. In order to investigate the combustion ability of yield hydrocarbon fuel from waste Polypropylene (PP), experiments were conducted in a direct injection, compression ignition, internal combustion engine. Fuel derived from waste PP blended with diesel by the percentages of 10%, 20%, 30%, 40%, 50%, 60%, 70% and 80% were used in the experiments. The engine was able to run without any deviation in performances and vibration paterns up to50% blend and small deviation were observed at 60% blend. A major deviations in performances, vibration paterns and sustaining engine speed was obseved with 70% blend and the engine was unable to run with 80% blend. Combustion ability of waste PP derived fuel in direct injection, internal combustion engine is at better level and the performance charasteristics of the engine when runing with fuel blends up to 50% is similar or better than that of diesel. Therefore, it can be concluded that the blends of waste polypropylene derived fuel can be used as a fuel for the diesel engines. However, purity of waste PP derived fuel fuel has to be increased to avoid negetive impact on the engine.