Production and utilization of diesel-equivalent renewable fuels from waste cooking oil and low-density polyethylene: Experimental investigation on performance, combustion, and emission characteristics

Diesel-equivalent fuel from waste cooking oil (WCO) and low-density polyethylene (LDPE), were produced and used in this study to replace 10 %, 20 %, and 30 % of commercial diesel fuel (B10, B20, and B30 respectively). A maximum in-cylinder pressure of 69.85 and 68.55 bars was observed for the B30 blends compared to 68.92 bar for diesel. Similarly, maximum heat release of 39.64 and 38.78 J degrees CA- 1 was observed for the B30 blends and 37.09 J degrees CA- 1 for diesel. Similarly, the rate of pressure rise, combustion duration, cumulative heat release rate, and mass fraction burned were also comparable with that of conventional diesel fuel at all fuel blends. The performance of the fuel blends in the compression ignition engine was also comparable with diesel. However, an 8.5 % reduction in brake thermal efficiency was observed for the B30 blends. Similarly 16 % more fuel consumption was observed for the B30 blends owing to higher fractions of long-chain hydrocarbons in the fuel. The emissions in terms of carbon monoxide, nitrogen oxides, and carbon dioxide were alike for diesel and other fuel blends. Hence, the pyrolyzed oils can replace up to 30 % of commercial diesel and upon further purification, higher fractions of diesel can be replaced.