Numerical analysis of a compression ignition engine powered in the dual-fuel mode with syngas and biodiesel

Biomass gasification for the release of a syngas and its use in combined heat and power (CHP) generation systems are attracting realities in the European market, due to the perspective to provide energy to remote districts by using local renewable sources, as residuals of forest practices or agro-food industries. The syngas produced from biomass gasification is a feasible alternative to traditional fuels in internal combustion engines at the micro and small power scales, although the quality of the produced gas is poorer in terms of calorific value and laminar flame speed. Therefore, as a direct consequence, proper modifications and optimizations of engines are needed to enhance energy efficiency and reduce the environmental impact. In the present work, a numerical model for the simulation of a compression ignition engine fueled in the dual-fuel mode with syngas and biodiesel is presented. The aim is to highlight the main influences on the combustion process related to the use of syngas and the effects of different biomass moisture contents on power output and main pollutants emission. The used extended coherent flamelet model for turbulent combustion is preliminary validated on the basis of experimental data of engine pressure cycles collected under only biodiesel fueling.