Effects of the injection timing on the engine performance and the exhaust emissions of a diesel engine fuelled by tyre pyrolysis oil–diesel blends

Abstract

In this study, the production of tyre pyrolysis oil using pyrolysis between the temperatures of 673 K and 873 K is reported. The effects of the injection timing on the performance and the exhaust emissions of a four-cylinder in-line diesel engine using tyre pyrolysis oil blends (in 10% increments from 0% to 20%) are experimentally investigated. The engine speeds are set at 1440 r/min, 2160 r/min and 3600 r/min under a constant engine load (85 N m). Adjusting the shim thickness adjusts the injection timings at 10° crank angle before top dead centre, 14° crank angle before top dead centre and 18° crank angle before top dead centre. The experimental results indicate that tyre pyrolysis oil blends with identical injection timings generate higher levels of carbon monoxide and nitrogen oxide emissions and increased the brake specific fuel consumption, as well as reducing the oxygen emission, compared with the corresponding situation when diesel is used. An advanced injection timing in all the test situations resulted in lower carbon monoxide and oxygen concentrations than the default injection timing did. However, the nitrogen oxide concentration is higher than that for the default injection timing. In contrast, although a delayed injection timing can reduce the nitrogen oxide and oxygen emission concentrations, the carbon monoxide emission concentrations are increased. Regarding the brake specific fuel consumption, the advanced and the delayed injection timings result in negative effects for all the test situations and oil samples.