The test engine—one of the company’s 4.9-liter, 6-cylinder units—was designed to use HEC’s proprietary Oxx Boxx engine controller and a dual-fuel injection system. Although the engine is capable of running exclusively on hydrogen, the test was conducted using 95% ammonia and 5% hydrogen used as a combustion catalyst.
The increased density of hydrogen associated with the ammonia fuel provides the engine with significantly more power than hydrogen alone. The small amount of hydrogen needed can be generated onboard the engine, thus eliminating the need for a second fuel. Because ammonia contains no carbon, emissions byproducts include only slightly increased amounts of water vapor and trace amounts of NOx.
We have been awaiting the day when we could add ammonia to the world’s list of potential fuels and today is the day. The performance of the engine is very impressive. This demonstration clearly shows that anhydrous ammonia can be used as a fuel.—Ted Hollinger, HEC President
HEC has filed 5 patents on its ammonia engines. The company will continue endurance testing, then will install an ammonia/hydrogen-fueled engine in the Oxx Power hydrogen-fueled genset that is currently powering the company’ dyno room.
Ammonia (NH3) is the second-most prevalent chemical in the world, and is widely used as the primary input for the majority of worldwide nitrogen fertilizer production.
Worldwide ammonia production is largely based on modifications of the Haber-Bosch process in which NH3 is synthesized from a 3:1 volume mixture of hydrogen and nitrogen at elevated temperature and pressure in the presence of an iron catalyst.
Nitrogen used is obtained from the air, while the hydrogen is obtained from the steam reforming of natural gas or other light hydrocarbons, or by the partial oxidation of heavy fuel oil or coal. According to a June 2004 review of greenhouse gas emissions in fertilizer production prepared for the IEA Bioenergy Task Force, about 85% of world ammonia capacity is based on natural gas.
The synthesis of ammonia is a very energy demanding process, with the current fertilizer manufacturers typically consuming around 25-35 GJ/tonne ammonia through the steam reforming process. Thus, due to consumption of natural gas or other hydrocarbons both for the hydrocarbon feedstock and to meet energy requirements of the process, CO2 emissions are the major component of GHG budgets for ammonia manufacture.
The IEA report cites a number of studies that identify the greenhouse gas emissions associated with ammonia production as ranging from 1,150 grams to 2,163 grams of CO2-equivalent emissions per kilogram of ammonia produced.
For the US, the Department of Energy has estimated average specific energy in ammonia manufacture of 14.8MJ/lb, or 32.6 GJ/tonne, and CO2-equivalent emissions of about 2,440 pounds/ton of ammonia (or 1,220 grams/kg).
DOE Industrial Technologies Program (ITP) Chapter 5 - The Agricultural Chemicals Chain