Bosch reaction

The Bosch reaction is a chemical reaction between carbon dioxide and hydrogen that produces elemental carbon (graphite), water and a 10% return of invested heat. This reaction requires the introduction of iron as a catalyst and requires a temperature level of 530-730 degrees C. [Messerschmid, Ernst and Reinhold Bertrand. Space Stations. Springer. 1999. ]

The overall reaction is as follows:

CO₂(g) + 2 H₂(g) → C(s) + 2 H₂O(l)

The above reaction is actually the result of two reactions. The first reaction, the water gas shift reaction, is a fast one.

CO₂ + H₂ → CO + H₂O

The second reaction controls the reaction rate.

CO + H₂ → C + H₂O

The overall reaction produces 2.3×10³ joules for every gram of carbon produced at 650 °C. Reaction temperatures are in the range of 450 to 600 °C.

The reaction can be accelerated in the presence of an iron, cobalt or nickel catalyst. Ruthenium also serves to speed up the reaction. The production of elemental carbon tends to foul the catalyst's surface, which is detrimental to the reaction's efficiency.

Together with the Sabatier reaction the Bosch reaction is studied as a way to remove carbon dioxide and to generate clean water aboard a space station [http://oregonstate.edu/~atwaterj/h2o_gen.htm]

The reaction is also used to produce graphite for radiocarbon dating with Accelerator Mass Spectrometry.

It is named after the German chemist Carl Bosch Fact|date=March 2008.

The Bosch reaction is also being investigated for use in maintaining space station life support. Though the Bosch reaction would present a completely closed hydrogen and oxygen cycle which only produces atomic carbon as waste, difficulties maintaining its higher required temperature and properly handling carbon deposits mean significantly more research will be required before a Bosch reactor could become a reality. One problem is that the production of elemental carbon tends to foul the catalyst's surface, which is detrimental to the reaction's efficiency.

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