Chemical method for methionine production is an efficient industrial process for amino acid manufacturing. Methyl mercaptan synthesis is one of the key stages of the chemical method. Methanol and hydrogen sulfide are used as feedstocks for the production of methyl mercaptan.
Synthesis of methyl mercaptan is carried out in eight series reactors. At the first stage of the process, methyl mercaptan synthesis is performed over ICT-31-1 catalyst. The process is carried out in excess of hydrogen sulfide, which is preheated in the furnace.
CH3OH + H2S →CH3SH + H2O
In addition to the main reaction, a number of side reactions occur in the reactor, in which dimethyl sulfide is formed:
2CH3OH + H2S →(CH3)2S + 2H2O
At the second stage, dimethyl sulfide is converted to methyl mercaptan over ICT-32-1 catalyst:
(CH3)2S + H2S →2CH3SH
Methanol is supplied to each stage of the methyl mercaptan synthesis. The synthesis reaction is exothermic and maintained at 380 °C. After passing through the reactors, the process gas condenses and undergoes separation.