Fischer-Tropsch process
The Fischer-Tropsch process is a catalyzed chemical reaction in which carbon dioxide, carbon monoxide and methane are converted into liquid hydrocarbons of various forms. Iron or cobalt are generally used as the catalyst. The principal purpose of this process is to produce a synthetic petroleum substitute.
The original Fischer-Tropsch process is as follows:
- <math>CH_n + O_2 \rarr \frac{1}{2}n H_2 + CO<math>
- <math>2nH_2 + CO \rarr -(CH_2-)_n- + H_2O<math>
The resulting hydrocarbon products are then refined to produce the desired synthetic fuel. Catalysts are based on iron and cobalt.
Since the invention of the original process by the German researchers Franz Fischer and Hans Tropsch, working at the Kaiser Wilhelm Institute in the 1920s, many refinements and adjustments have been made, and the term "Fischer-Tropsch" now applies to a wide variety of similar processes (Fischer-Tropsch synthesis or Fischer-Tropsch chemistry)
The Fischer-Tropsch process was used by Germany and Japan during World War II to produce alternative fuels. After the war captured German scientists continued to work on synthetic fuels in the United States in Operation Paperclip.
The carbon dioxide and carbon monoxide is generated by partial oxidation of coal and wood-based fuels. The utility of the process is primarily in its role in producing fluid hydrocarbons or hydrogen from a solid feedstock, such as coal or solid carbon-containing wastes of various types. Non- oxidative pyrolysis of the solid material produces syngas which can be used directly as a fuel without being taken through Fischer-Tropsch transformations. If liquid petroleum-like fuel, lubricant, or wax is required, the Fischer-Tropsch process can be applied. Finally, if hydrogen production is to be maximized, the water gas shift reaction can be performed, generating only carbon dioxide and hydrogen and leaving no hydrocarbons in the product stream.
It is today used in South Africa to produce most of the country's diesel fuel from coal by the company Sasol. The process was used in South Africa to meet its energy needs, during its isolation under Apartheid. This process has received renewed attention in the quest to produce low sulfur diesel fuel in order to minimize the environmental impact from the use of diesel engines.
It is expected by geologists that supplies of natural gas will peak 5–15 years after oil does. There are large coal reserves which may increasingly be used as a fuel source during oil depletion. Since there are large coal reserves in the world, this technology could be used as an interim transportation fuel if conventional oil were to become more expensive. There are several companies developing the process to enable practical exploitation of so-called stranded gas reserves, those reserves which are impractical to exploit with conventional gas pipelines and LNG technology.
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Categories: Peak oil | Petroleum production | Organic reaction | Organometallic chemistry