Ammonia and Gasoline Fuel Blends for Internal Combustion Engines

Abstract

Ammonia, when blended with hydro carbon fuels, can be used as a composite fuel to power existing IC engines. Such blends, similar to ethanol and gasoline fuel blends, can be used to commercialize ammonia as an alternative fuel. Feasibility of developing ammonia gasoline liquid fuel blends and the use of ethanol as an emulsifier to enhance the solubility of ammonia in gasoline were studied using a small thermostated vapor liquid equilibrium (VLE) high pressure cell in this research. A larger VLE cell was used to develop identified fuel blends in sufficient quantities for engine dynamo-meter tests. A engine dynamometer equipped with a 2.4L gasoline engine was used to benchmark performance of ammonia fuel blends against standard fuels. Solubility test results proved that ethanol free gasoline is capable of dissolving 4.5% of ammonia on volume basis (23 g/l on mass basis) at 50 psi [344.7 kPa] pressure and 286.65 K temperature in liquid phase. Solubility levels are increased with the use of ethanol. Gasoline with 30% ethanol can retain 18% of ammonia in the liquid phase by volume basis (105 g/l by mass basis) at the same pressure and temperature. Dynamometer results show the ability of new composite fuel blends to produce the same amount of torque and power in the lower rpm limits. At higher rpm levels ammonia rich fuels result in an increased torque and power. Thus it can be concluded that hydrogen energy can be stored as ammonia-gasoline fuel blends and recovered back successfully without any strenuous modification to the existing infrastructure and end user equipment or behavior.