Biomass based oil and hydrogen co-combustion in the compression ignition engine

Paper presents results from investigation focused on combustion progress of biomass based oil assisted with hydrogen in the internal combustion compression ignition (CI) engine. Hydrogen was added at amounts in the range from 0 to 40% by energy. The main target of this analysis was to determine impact of hydrogen on the following: combustion phases, smoke opacity and toxic emissions in the compression ignition engine. Literature review shows hydrogen can cause significant changes in combustion process even if it is added in small amounts. In this manuscript, investigation was carried out on a test bench consisted of a single cylinder compression ignition engine with common rail injection system. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at full engine load. Results from experiments show that increasing amounts of hydrogen into the engine contribute to shorten ignition delay time that also affect main combustion phase. Additionally, it implicates heat release rate and toxic emissions (THC, CO, NO_x). Moreover, decrease in smoke (mainly soot) in the exhaust gases was observed with increase of hydrogen amounts to the engine. (paper)