Ammonia as a Diesel Engine Fuel: Theory and Application

Theoretical and experimental investigations were carried out for the purpose of predicting and measuring the performance which results from operation of compression ignition engines when anhydrous ammonia is used rather than diesel fuel. Predictions were that ammonia would give slightly increased output but that fuel consumption would also increase 2-1/2 fold.

By equipping the engine with a spark ignition system, it was possible to operate successfully on ammonia at normal compression ratios and retain the same fuel injection system. Fuel injection and spark timing were found to be critical. Indicated power output was reduced by about 10%, which differed from prediction. The discrepancy was due to the poor combustion characteristics of ammonia. Predicted increases in fuel consumption were experienced. Because ammonia is not “smoke limited” as is diesel fuel, it was possible to increase the smoke free output from the engine by going to richer mixtures with ammonia.