Bosch reaction

Carl Bosch (1874–1940)

The Bosch reaction is a chemical reaction between carbon dioxide and hydrogen , which produces elemental carbon ( graphite ), water and energy in the form of heat . It is named after the German chemist Carl Bosch (1874–1940).

Reaction mechanism

The reaction proceeds according to the following principle:

${\displaystyle \mathrm {CO_{2}+2\,H_{2}\longrightarrow C+2\,H_{2}O} ,\qquad \Delta H^{0}=-178{,}3\ \mathrm {kJ/mol} }$

Carbon dioxide reacts with hydrogen to form carbon and water, releasing energy

The above reaction is the result of a redox reaction , which actually consists of two individual reaction steps.

The first reaction, the water gas shift reaction , is fast

${\displaystyle \mathrm {CO_{2}+H_{2}\longrightarrow CO+H_{2}O} ,\qquad \Delta H^{0}=-2{,}925\ \mathrm {kJ/mol} }$

Carbon dioxide reacts with hydrogen to form carbon monoxide and water

The second reaction controls the rate of the reaction

${\displaystyle \mathrm {CO+H_{2}\longrightarrow C+H_{2}O} ,\qquad \Delta H^{0}=-175{,}375\ \mathrm {kJ/mol} }$

Carbon monoxide reacts with hydrogen to form carbon and water

At a reaction temperature of 650  ° C. , 2.3 · 10 ³ joules per gram of carbon are released.

The reaction can be accelerated by the presence of iron , cobalt , nickel or ruthenium as a catalyst . The elemental carbon that occurs during the reaction tends to settle on the surface of the catalyst. This adversely affects the efficiency of the reaction.

Applications

Research is currently being carried out into using the Bosch reaction and the Sabatier process in space travel. Since CO _{2 is} always available on space stations and spaceships (the oxygen contained in the breath is converted into CO ₂ by the body ), both processes could serve the following purposes:

• Purification of breathing air ( removing CO ₂ )
• Recovery of oxygen from CO ₂
• Production of water
• Extraction of fuel

Web links

• NASA: Evaluation of Bosch-Based Systems Using Non-Traditional Catalysts at Reduced Temperatures (PDF)

Individual evidence

1. ↑ METHODS OF WATER PRODUCTION ( Memento of the original from May 29, 2005 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.