Recycling of waste engine oil through pyrolysis process for the production of diesel like fuel and its uses in diesel engine

A comparative assessment of electrical and microwave-assisted pyrolysis (MAP) of waste engine oil was carried out at 350 degrees C for the production of diesel-like fuel. The higher energy savings of MAP compared to electrical pyrolysis was found to be 56% at 1.1 kW power supplied with maximum energy recovery being 26,807 kJ/kg. Hence, the diesel-like fuel obtained from MAP process was selected for further engine study. Physicochemical characteristics of microwave pyrolysis oil (MPO) such as calorific value, elemental analysis, GC-MS and FTIR were found to be on par with diesel. Also, the viscosity of MPO was more than that of diesel, which leads to poor combustion under standard operating condition. Therefore, engine studies were conducted using MPO under different fuel injection pressure of 200, 230, 260, 280, 300 and 340 bar for better combustion. The performance and emission analysis showed that the fuel injection pressure at 280 bar was the optimum condition when using MPO in a CI engine. There was a 4% improvement in brake thermal efficiency under the optimum condition compared to diesel. At the same time, carbon monoxide, unburnt hydrocarbons, nitric oxide and smoke emissions decreased by 0.6%, 37.74%, 17.4% and 43.69% respectively. (C) 2020 Elsevier Ltd. All rights reserved.