Influence of Fuel Injection Timing and Hydrogen Enrichment on Waste Plastic Oil: Performance, Combustion, and Emissions Analysis

Abstract

The escalating global demand for fossil fuels, coupled with geopolitical uncertainties, underscores the imperative for alternative fuels in internal combustion engines. Simultaneously, the pressing issue of plastic waste disposal necessitates sustainable solutions. This research delves into the impact of hydrogen enrichment on a CRDI-diesel engine using diesel and waste plastic oil, varying fuel injection timing (23, 25, and 27) °CA bTDC at 400 bar fuel injection pressure. The addition of hydrogen at 4 lpm improves Brake Thermal Efficiency (BTE) and lowers Brake Specific Fuel Consumption (BSFC), resulting in reduced hydrocarbons (HC) and carbon monoxide (CO) emissions, though Exhaust Gas Temperature (EGT) and NOx emissions increase. The WPO10+4H2 blend at 25 °CA bTDC demonstrates an 8.7% BTE increase, a 10.5% BSFC reduction at full load, and substantial decreases in HC and CO emissions compared to diesel. Despite these advantages, NOx emissions increase by 8% compared to pure diesel. Hydrogen integration in CRDI engines enhances performance and addresses sustainability, while waste plastic oil in diesel engines repurposes plastic waste, reduces fossil fuel dependency, and supports a circular economy with energy recovery.