different types of fuels used in ic engines

Crackers can be simple in mechanical terms, consisting of a heated chamber furnished internally with a catalyst. The reformer can be set up to “crack” enough of the ammonia into hydrogen and nitrogen to support viable combustion. A promising variant of this approach is to place an on-board reformer between the fuel tank and the engine. The second option is to use hydrogen as the combustion promoter. However, as the patent subsequently notes, this approach “generally requires dual fuel storage systems, dual delivery systems, and dual injection systems, thus adding additional weight, complexity, and cost to the engine system.” In other words, one option is to use a liquid combustion promoter.

Most existing combustion engines that use ammonia as engine fuel typically require a combustion promoter (i.e., a second fuel such as gasoline, hydrogen, diesel, etc.) for ignition, operation at low engine loads and/or high engine speed.” This low combustion rate of ammonia causes combustion to be inconsistent under low engine load and/or high engine speed operating conditions. The Caterpillar Corporation put it succinctly in their 2008 patent application that covers a “power system having an ammonia-fueled engine”: “When ammonia is combusted, the combustion produces a flame with a relatively low propagation speed. This lack of clarity notwithstanding, consensus prevails about the technical challenges that an ammonia engine must overcome. Ammonia energy proponents look forward to the day when their fuel is used in internal combustion engines – but the state of this art is unsettled and it is not clear which combustion technologies will win in the end.

Different types of fuels used in ic engines