This paper reports on the experimental results of the combustion and emission characteristics of a conventional diesel engine mixed ammonia (NH3) gas into the intake air, and discusses its usability. In the experiments, NH3 gas was injected into the intake pipe of the diesel engine by a gas injector. The diesel engine has a natural aspiration single cylinder with 7.7 kW rated power at 1500 rpm and a diesel injection system to inject diesel fuel into the cylinder.
As experimental results on the combustion characteristics, it was confirmed that the compression and maximum pressures in the cylinder decreased and the ignition timing delayed with increasing the NH3 gas injection quantity. On the emission characteristics in the exhaust gas, NH3, water (H2O) and nitrous oxide (N2O) increased and carbon dioxide (CO2) decreased proportionally to the NH3 gas injection quantity. In contract, the nitrogen oxide (NO) was nearly the same. Moreover, it was confirmed that NH3 can be reduced by reacting with NO in a selective catalytic reduction (SCR) system.