advanced new fuel technology
Nope, it's not new at all.
Even though at the moment there is no transport fleet operating with ammonia as fuel, the use of ammonia as an alternative to fossil fuels for transportation vehicles was considered during the twentieth century. The first well-known example is the case of the bus fleet operated in Belgium during World War II due to the limited availability of diesel fuel (Koch, 1949). The first dual-fuel engine was invented: coal gas, composed of 50% H2, was directly injected into the combustion chamber filled with ammonia. In the mid-60s, several studies (Cornelius et al., 1965; Garabedian and Johnson, 1965; Gray et al., 1966; Starkman et al., 1966, 1967; Pearsall and Garabedian, 1967; Sawyer et al., 1968) focused on the possibility of using ammonia as fuel in thermal engines, first providing recommendations about the compatibility of ammonia with engineering materials and lubricants, due to its corrosiveness to copper, copper alloys, nickel, and even some plastics.
However, its combustion characteristics (high minimum ignition energy and auto-ignition temperature, low combustion speed in comparison to usual hydrocarbon fuels) are drawbacks that have so far limited its use.
consensus prevails about the technical challenges that an ammonia engine must overcome. 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 low combustion rate of ammonia causes combustion to be inconsistent under low engine load and/or high engine speed operating conditions. 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.”
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