A comparative assessment of single cylinder diesel engine characteristics with plasto-oils derived from municipal mixed plastic waste

Abstract

Recycling of municipal mixed plastic waste (MPW) is an emerging technology for conversion of waste to wealth. In the current study, MPW was processed to produce plasto-oils (PO1 and PO2) by thermochemical depolymerization in a batch production of 0.5 ton/batch. These oils were used in a 3.7 kW rated power single cylinder direct injection compression ignition (CI) engine to assess performance, combustion and emission behavior of the engine. The experimental results with plasto-oils were compared with base diesel fuel operation at different brake mean effective pressures (BMEPs) of 1.8, 3.8, 5.8, 7.8 and 10.8 bar. It is explored that brake thermal efficiency of the test engine with plasto-oils was almost comparable with the diesel fuel at all engine loads. Carbon based emissions such as unburnt hydrocarbon (HC), carbon monoxide (CO), and smoke emissions from the engine at 3.8–10.8 bar BMEPs were slightly higher with plasto-oils than diesel fuel. Nitrogen oxides emission decreased faintly with the use of plasto-oils at medium and high BMEPs (5.8–10.8 bar). However, at lower BMEPs (1.8–3.8 bar), emission behavior of the engine (HC, CO, smoke and NOx emissions) was same with all kinds of fuels (diesel, PO1 and PO2). Overall, it is ascertained from the study that the plasto-oils exhibited a comparable performance with the conventional diesel fuel, which further promises its viability to use as a fuel candidate for CI engines.