The Fischer-Tropsch process dates back to the 1920’s. The original invention of the process was discovered by two German researchers, Franz Fischer and Hans Tropsch hence the name Fischer-Tropsch. Since this discovery and invention, there have been many refinements and adjustments made to the process. The term Fischer-Tropsch is used synonymously to a wide variety of similar processes. The original process was invented in Germany where the land is deprived in petroleum but rich in coal and the need for liquid fuels was in demand. The process allowed for the development of synthetic fuel in excess of 124,000 barrels per day from 25 production plants. In 1944, 6.5 billion tons of the synthetic fuel was produced and used by Germany and Japan in their war efforts. The Fischer-Tropsch process is an established technology and is applied on a large scale throughout the world. For instance, the Shell ...view middle of the document...
This process can be thought of as a catalytic polymerization of carbon monoxide produced by a reaction with hydrogen to make methylene units of paraffin. The composition of the product varies depending on the hydrogen to carbon monoxide ratio and the process conditions. This produces a raw product which must be further processed in order to make it useful as a fuel. Basically, the purpose of the Fischer-Tropsch process is to produce a synthetic petroleum substitute for use as synthetic fuel and synthetic lubricating oils. The synthetic fuels and lubricating oils are derived from the processing of coal, natural gas, shale, or biomass.
One of the key advantages of Fischer-Tropsch fuels is that existing fuel distribution infrastructures can be utilized. This would allow for faster distribution throughout the United States. Another advantage to this alternative fuel, particularly in the jet fuel industry, is that the Fischer-Tropsch process provides a cleaner burning fuel. The final product is virtually free from trace sulfur and nitrogen-compounds which are found in conventional jet fuels. This fuel is also free from aromatic compounds. The absence of the aromatic compounds has its advantages and disadvantages. The biggest advantage of aroma free compound is that it burns cleaner and emits fewer particulates than conventional jet fuels. Since it has no sulfur there are no sulfur dioxide or sulfuric acid aerosol emissions.
On the contrary, there can be two disadvantages of not having aromatics in the fuel. First, the Fischer-Tropsch kerosene which meets all other specifications ends up being below the required minimum density for jet fuel usage. Second, there is concern over shrinkage of certain types of elastomers. While these elastomers usually swell under use with conventional jet fuels, it is a concern that the aromatic free Fischer-Tropsch fuels may cause them to shrink. If there is actual shrinkage then the result could lead to fuel leaks. The effect of aromatics on elastomers is actively being researched in the fuel industry. One possible solution is the use of additives that would ensure the swelling of the elastomers.