Production of fuel-blends from waste tyre and plastic by catalytic and integrated pyrolysis for use in compression ignition (CI) engines

Abstract

The increase in energy demand and depletion of oil reserves has prompted researchers to seek alternative fuels for compression ignition engines. In this study, the characteristics of the fuels obtained from waste tyres/plastics were determined and compared with those of diesel fuel. The waste plastic oil was obtained from polyethylene terephthalate, polypropylene, high-density polyethylene, polystyrene, low-density polyethylene, and poly (vinyl chloride), thereafter, they were each blended with distilled waste tyre oil from used Dunlop tyres, in different ratios, for use as substitute fuels in a CI engine. The engine (Kirloskar, TAF 1 model) performance was studied based on its combustion, brake thermal efficiency (BTE) and emission characteristics when run on the fuels obtained from the waste-tyres/plastics. The test results showed the engine gave a higher performance in terms of BTE for E (33.9%) and F (36.9%) whereas, others gave lower performance (A- (31.9%), B (30%), C (29.7%), D (32.4%) with respect to diesel fuel. The pyrolyzed Polystyrene/tyre blends gave the highest BTE of 36.9%, with low emission. Although lower emissions were recorded for the blended fuels relative to the diesel fuel, the resulting peak emissions for the blends are in the following increasing order: unburnt HC (B (30.1) < D (30.1) < F (30.2) < A(30.4) < E (30.7) < C(31 ppm), NOx (F (1001) < B (1100) < D (1107) < C (1107) < E (1108) < 1150 ppm) and CO (F (0.003) < E (0.004) < B (0.005) < A(0.006) < C(0.007) < D (0.008) ppm.