The BMA process or Degussa process is a chemical process developed by the German chemical company
Degussa
Evonik Industries AG is a stock-listed German specialty chemicals company headquartered in Essen, North Rhine-Westphalia, Germany. It is the second largest chemicals company in Germany, and one of the largest specialty chemicals companies in the ...
for the production of
hydrogen cyanide from
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...
and
ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
in presence of a
platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver".
Pla ...
catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
. Hydrogen cyanide is used in the chemical industry for the production of intermediate chemicals like
acrylonitrile
Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid although commercial samples can be yellow due to impurities. It has a pungent odor of garlic or onions. In terms of its molecula ...
,
methyl methacrylate, and
adiponitrile
Adiponitrile is an organic compound with the chemical formula (CH2)4(CN)2. This viscous, colourless dinitrile is an important precursor to the polymer nylon 66. In 2005, about one million tonnes of adiponitrile were produced.M. T. Musser, "Adip ...
.
The name is abbreviated from Blausäure (hydrogen cyanide) from Methan (methane) and Ammoniak (ammonia) in German.
The reaction equation is analog to the
steam methane reforming (SMR) reaction of methane and water:
:CH
4 + NH
3 → HCN + 3 H
2, ΔH
R = 251 kJ / mol
The reaction is extremely
endothermic
In thermochemistry, an endothermic process () is any thermodynamic process with an increase in the enthalpy (or internal energy ) of the system.Oxtoby, D. W; Gillis, H.P., Butler, L. J. (2015).''Principle of Modern Chemistry'', Brooks Cole. ...
. The reactants react in a Platinum-covered pipe at approximately 1400 °C. The reaction mixture contains around 23 Vol.-% HCN and 72 Vol.-% H
2 as well as minor quantities of ammonia, nitrogen, and unreacted methane.
The gaseous mixture is introduced in a
scrubber and treated with an ammonia solution (producing
ammonium cyanide
Ammonium cyanide is an unstable inorganic compound with the formula NH4CN.
Uses
Ammonium cyanide is generally used in organic synthesis. Being unstable, it is not shipped or sold commercially.
Preparation
Ammonium cyanide is prepared in solutio ...
) allowing the other gaseous components: H
2, CH
4, and N
2 to pass through. In a second step the HCN is released by acidification of the solution, followed by a final distillation of the hydrogen cyanide. Because of the highly endothermic reaction, the BMA process is of lower importance for the production of HCN compared to the
Andrussow process
The Andrussow process is an industrial process for the production of hydrogen cyanide from methane and ammonia in the presence of oxygen and a platinum catalyst.
:2 CH4 + 2 NH3 + 3 O2 → 2 HCN + 6 H2O
The process is based on a reaction ...
.
References
External links
Process description
Chemical processes
Catalysis
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