Fischer Tropsch: solid fuel to liquid fuel

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The Fischer Tropsch synthesizing a liquid fuel

Keywords: fisher, Tropsh, process, liquefaction, fuel, solid, liquid, coal, carbon, biomass, syncrude, syngas, synthetic fuel, biofuel, biofuels.

The Fischer Tropsch process is a quite complex liquefaction process of a solid or gaseous fuel. In other words, it provides a liquid fuel from a gas or solid fuel.

The interest of the liquefaction process is obvious, here 2 its main arguments:

- A liquid fuel has generally a most interesting volume calorific, Ie that the same chemical potential energy will take a much smaller volume when the fuel is in a solid liquid and more for gas. This enables easier storage and transport.
Example: for the same stored energy, wood pellets are about 3,5 times more volume than oil.

- a liquid fuel is usually much easier to ignite and allows much easier power regulation. What may be a fundamental criterion in certain energy fields such as transport, for example.

The Fischer-Tropsch process (according to Wikipedia)

The Fischer-Tropsch process is a chemical reaction of carbon monoxide and hydrogen catalysis to convert the hydrocarbon. The most common catalysts are iron or cobalt.

The value of the conversion is to produce synthetic liquid fuel, Syncrude, from coal, wood or gas. The Fischer-Tropsch conversion process is very efficient in terms of yield, but requires considerable investment, which makes it economically vulnerable to downward fluctuations in oil barrel. Moreover, the step of producing synthesis gas (a mixture of CO and H2) presents a rather mediocre performance, penalizing the overall process efficiency.

Equation Fischer-Tropsch

The Fischer-Tropsch synthesis as discovered by its two inventors is as follows:

CH4 1 + / 2O2 -> 2H2 + CO

(2n 1 +) + H2 nCO -> CnH (2n 2 +) + nH2O

The carbon monoxide and hydrogen mixture is called synthesis gas or syngas. The resulting production (synthetic crude or syncrude) is refined to obtain the desired synthetic fuel.

Wikipedia has this process (according to Wikipedia)

The invention of the Fischer Tropsch process 1925 date and is attributed to two German scientists, Franz Fischer and Hans Tropsch, working for Kaiser Wilhelm Institute the (Germany). This process is based on the catalytic reduction of carbon oxides with hydrogen to convert the hydrocarbon. His interest is to produce from coal or gas, synthetic oil (syncrude) which is then refined to provide synthetic liquid fuel (SynFuel).

The German origin: 124 000 synthetic barrels per day in 1944 ...

This process was developed and operated by Germany, poor in oil and oil colonies, but rich in coal to produce liquid fuel, which was heavily used by the Germans and the Japanese during World War II. Thus was installed the first pilot plant by Ruhrchemie AGS 1934 and 1936 in industrialized.

Early in 1944, the Reich produced some 124 000 barrels / day of fuel from coal, which accounted for over 90% of its aviation fuel needs and more than 50% of the total need of fuels countries.

The resulting fuel was still lower quality (and especially consistency) that the fuel of petroleum origin, the engineer has therefore been using water injection to compensate for relatively low octane numbers. More: water injection in the Messerschmitt.

This production came from 18 direct liquefaction plants but also small factories 9 FT, which produced some 14 000 barrels / day.

... But also in Japan

Japan also tried to produce fuels from coal, production was effected mainly by low temperature carbonization, somewhat effective but simple process.

However, the company Mitsui bought a license from the Fischer Tropsch process Ruhrchemie to build three factories in Miike, Amagasaki and Takikawa, who never reached their rated capacity which is due to design problems.

In the years 1944 114 000 Japan produced tons of fuel from coal, but only 18.000 of them were made according to the FT process. 1944 and 1945 between German and Japanese factories were badly damaged by Allied bombing, and the majority was dismantled after the war.

Abandonment of technology after the war except in South Africa

German scientists who developed the FT process were captured by the Americans and seven of them sent to the United States as part of Operation Paperclip. However after structuring of the oil market and the sharp drop in prices, the United States abandoned the search and the Fischer-Tropsch fell into disuse.

In 1950 years, however, he found interest in South Africa: countries with abundant coal resources, has built highly mechanized mines (Sasol) that supply CTL units, whose production is based on two separate Fischer-Tropsch synthesis:
- Arge method (developed by Lurgi Ruhrchemie-) for the production of hydrocarbons high boiling point, such as diesel and waxes.
- Synthol process for the production of hydrocarbons to lower boiling points, such as gasoline, acetone and alcohols.

Production enough to supply its road fuels.

Still currently used

In 2006, these units cover about a third of South African needs, and Sasol has become one of the world experts in the field.

After the first oil shock 1973, which caused the increase in crude oil prices, several companies and researchers have tried to improve the basic process of Fischer-Tropsch, which has spawned a variety of similar processes grouped under the component synthesis or Fischer-Tropsch chemistry Fischer-Tropsch.

A B-52 stealing coal in the US

Since 2000 years, the process thus find an economic interest. Thus the department of US defense advocated in September 2005 the development of oil industry based on US energy resources exploitation of coal to produce fuel via the Fischer-Tropsch process and so not be dependent on external natural resources for its own needs.

Since 2006, a B52 US Air Force conducts tests with the Fischer-Tropsch fuel, mixed with 50% or pure. For now, it is a success that will allow the US military to regain independence for strategic military fuel.

éconologiques and sustainable applications

The fact liquefy coal or gas does not change anything, or very little, to the greenhouse effect and depletion of fossil resources, in fact; carbon will be released sooner or later into the atmosphere and used the natural resource is not renewable.

It is quite another using the Fischer-Tropsch process from biomass, biogas or even industrial organic waste.

So the general principle of the Fischer-Tropsch reaction has diversified greatly since the beginning, and gave birth to more generic processes and appellations such as CtL (Coal to Liquids), GTL (Gas to Liquids) but especially BtL (Biomass to Liquids). This last sector of particular interest econologic.

Many organizations, including CEA, are working to improve conversion processes, in fact, the overall energy efficiency of this technology also remains a weak point.

Example, liquefaction of industrial waste by a German company (released in November Autoplus 2005)

fischer Tropsch in autoplus


- Liquefaction of biomass by CEA
- Another coal liquefaction: the process Makhonnine
- The energy mix, energy solution of the future?


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