Effect of hydrogen-diesel fuel co-combustion on exhaust emissions with verification using an in-cylinder gas sampling technique

The results showed a decrease in the particulates, CO and THC emissions and a slight increase in CO2 emissions with the addition of hydrogen, with fixed diesel fuel injection periods. NOx emissions increased steeply with hydrogen addition but only when the combined diesel and hydrogen co-combustion temperatures exceeded the threshold temperature for NOx formation. The in-cylinder gas sampling results showed higher NOx levels between adjacent spray cones, in comparison to sampling within an individual spray cone.