Steam reaction with coke

Example 15. Water gas, a combustible mixture of CH4 and CO, is made by the reaction of water with coke at elevated temperature. This reaction can be written as 3Cg,. + 2H20(g) CH4(gl + 2CO(g) and has an equilibrium constant of 118 at 1000°C (see Problem 13). What is the ratio of the partial pressure of CO to that of H20 in the gas mixture formed at 1000°C and 10 atm pressure by passing steam over coke ... 

The reason why the minimum steam ratio goes down with temperature is not known with certainty. One possibility is that the competing reactions of carbon production and consumption have such kinetics that the rate of coke consumption increases faster with temperature than the rate of coke generation, which suggests that the carbon-steam reaction has a higher activation energy than the methane cracking and carbon monoxide disproportionation reaction. 

With cydopentanc, the amounts of carbon deposited on Re/Al20j are extremely low (0.1-0.2%). This is certainly due to the very poor dehydrogenating activity of Re. To estimate the effect of steam of the coking rate, the reaction was carried out with a mixture of cyclopentane (82%), cyclopentene (8.7%) and cyclopenladiene (8.4%), the composition being close to the thermodynamic equilibrium at 4(XTC,... 

The carbonate is regenerated in two steps (1) the sulfite and sulfate are reduced to sulfide by reaction with a form of carbon, such as petroleum coke and (2) the sulfide is converted to carbonate by reaction of the melt with steam and carbon dioxide, liberating hydrogen sulfide. The hydrogen sulfide is then converted to elemental sulfur in a Claus plant. 

Derivation (1) Made almost pure by placing a mixture of oxygen and carbon dioxide in contact with incandescent graphite, coke, or anthracite. (2) Action of steam on hot coke or coal (water gas) or on natural gas (synthesis gas). In the latter case, carbon dioxide is removed by absorption in amine solution, and the hydrogen and carbon monoxide separated in a low-temperature unit. (3) By-product in chemical reactions. (4) Combustion of organic compound with limited amount of oxygen, as in automobile cylinders. (5) Dehydration of formic acid. 

Water-gas was first obtained via the reaction of steam with coke. Catalysts are used to promote the following equilibrium in the direction of hydrogen [18,132] ... 

Reaction of Steam with Coke on Solid Substrates... 

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