Effect of Chlorella vulgaris methyl ester enriched with hydrogen on performance and emission characteristics of CI engine

Abstract

Microalgae have been mentioned as a favorable feedstock for biodiesel production. In this experimental study, the feasibility of using microalgae Chlorella vulgaris (MCV) biodiesel as an alternative fuel and the effects of various flow rates of hydrogen addition on engine performance and exhaust emissions were investigated. After biodiesel production via transesterification reaction, physical properties of MCV methyl ester were evaluated with regular diesel and ASTM standard. The blends of biodiesel-diesel fuel and hydrogen in the intake air (between 0 and 10 LPM) were injected in a diesel engine under full load operating condition and various speeds. The results revealed that using MCV biodiesel had led to lower emissions of CO, HC, and CO2 and has reduced the engine power and torque, whereas there was a minor increase in NOx emissions. By hydrogen enrichment, CO, CO2, and HC emissions decreased more, compared with the emissions of pure diesel, while NOx emissions kept an increasing trend. When the B20 blend of MCV methyl ester was enriched by 10 LPM hydrogen gas, power and torque of the engine, as well as brake specific fuel consumption (BSFC), were improved by 7.6%, 10.6%, and 6.6%, respectively. The experimental results showed considerable capabilities of applied MVC methyl ester under hydrogen enrichment in diesel engines in diminishing the pollution with comparable performance.