The BMA process or Degussa process is a chemical process developed by the German chemical company
Degussa for the production of
hydrogen cyanide
Hydrogen cyanide (formerly known as prussic acid) is a chemical compound with the chemical formula, formula HCN and structural formula . It is a highly toxic and flammable liquid that boiling, boils slightly above room temperature, at . HCN is ...
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 abundance of methane on Earth makes ...
and
ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
in presence of a
platinum
Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...
catalyst
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
. 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. It has a pungent odor of garlic or onions. Its molecular structure consists of a vinyl group () linked to a nitrile (). It is an im ...
,
methyl methacrylate
Methyl methacrylate (MMA) is an organic compound with the formula . This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).
History
MMA ...
, 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, "Adipi ...
.
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
An endothermic process is a chemical or physical process that absorbs heat from its surroundings. In terms of thermodynamics, it is a thermodynamic process with an increase in the enthalpy (or internal energy ) of the system.Oxtoby, D. W; Gillis, ...
. 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
Scrubber systems (e.g. chemical scrubbers, gas scrubbers) are a diverse group of air pollution control devices that can be used to remove some particulates and/or gases from industrial exhaust streams. An early application of a carbon dioxide scr ...
and treated with an ammonia solution (producing
ammonium cyanide) 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.
References
External links
Process description
Chemical processes
Catalysis
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