Influence of hydrogen enriched producer gas (HPG) on the combustion characteristics of a CRDI diesel engine operated on dual-fuel mode using renewable and sustainable fuels

•Dual-fuel engine with CRDIS provide the enhanced performance with reduced emissions and slightly amplified NOx emissions compared to CMFIS facility.•Dual-fuel operation with CRDIS and RCC provide 4-8% decreased power derating.•HPG induction and biodiesel as pilot fuel provided smooth engine operation. In the present experimental investigation, an effort has been made to enhance the performance of a producer gas fueled diesel engine. In this present work, producer gas was being mixed with hydrogen with a flow rate of 8 lpm. To harness maximum performance, CRDI diesel engine was operated at four injection timings in the range from 0 (TDC) to 15 deg., before top dead center (bTDC) and varied in steps of 5. Similarly, injection pressures were varied in the range of 600 to 1000 bar in steps of 200. In the first phase of the work, influence of common rail direct injection system (CRDIS) on the performance and emission characteristics of a single cylinder four stroke water cooled compression ignition (CI) engine operated on dual-fuel mode using neem oil methyl ester (NeOME) and hydrogen enriched producer gas (HPG) have been investigated. Results obtained were compared to the engine operation with conventional mechanical fuel injection system (CMFIS). Subsequently in the next phase of the work; influence of combustion chamber for optimum performance was investigated. In order to match proper combustion chamber for optimum fuel injection timing (FIT) and fuel injection pressure (FIP), two types of combustion chambers such as hemispherical (HCC) and re-entrant configurations (RCC) were used. Results of investigation on NeOME-HPG operation with RCC and optimized conditions showed 3.02% increased brake thermal efficiency with 22.4% reduced smoke, 12.2% reduced HC, 10.8% reduced CO, and 18.6% increased NOx levels compared to the same fuel combination with HCC. Further, increased cylinder pressure and HRR were observed with RCC. Investigation with NeOME-enriched PGwith hydrogen based dualfuel operation showed satisfactory engine operation.