Methane carbonylation is thermodynamically unfavorable process.
For the process to occur it is necessary to produce high pressure at low
temperature or to apply light energy, or to couple the carbonylation with
thermodynamically favorable steps or processes. A principal possibility
of acetaldehyde formation with the Ziegler-Natta catalyst at 20 oC and
a pressure of 1-3 Kbar was shown. In the presence of ethylene, under the
same conditions, methyl ethyl ketone was formed. The formation of methyl
ethyl ketone are thermodynamically favorable process at the expense of
a double bond cleavage. Oxidative and reductive carbonylation of methane
are also thermodynamically favorable processes. By now the oxidative carbonylation
of methane is the most developed process. Two catalytic systems for
this process was found. The systems consist of rhodium compounds and any
kind of cocatalyst. The cocatalysts are of importance for transformation
of dioxygen into two-electron oxidants. The resulting products of the reaction
are methanol, formic acid, and acetic acid. At 95OC and 10 MPa the total
rate of the products formation at the initial gap is 60-120 mol/mol Rh
x h.