Ammonia for industrial combustion

Many companies are investigating switching from conventional fossil fuels to "green" fuels such as hydrogen to reduce CO2 emissions. This assumes hydrogen is made by an environmentally-friendly method such as electrolysis using renewable energy. However, there are concerns with hydrogen. For example, it leaks very easily, is extremely flammable, and is more difficult to transport than other fuels. A potential solution is to use ammonia as an alternative method of supplying hydrogen to a combustion process, assuming it is made in an environmentally-friendly manner. Like H2, ammonia also does not produce any carbon-containing pollutants such as carbon monoxide, carbon dioxide, or soot. It has transport properties like propane, so it is easier to contain and transport than hydrogen. However, there are some concerns with ammonia. It is a caustic and hazardous chemical with a pungent odor so it must be handled accordingly. It has the potential to generate very high levels of NOx which means a post-treatment system like an SCR may be required. Existing burners may need to be modified or replaced. While ammonia is a potentially important future green fuel, there are concerns that require attention and further research. This paper compares methane, hydrogen, and ammonia combustion and discusses the advantages and disadvantages of ammonia in particular.