2535.     ORSONI, B.  [Utilization of Synthetic Ammonia Plant for Production of Methanol.]  Chimica e industria (Milan), vol. 29, 1947, pp. 137-139; British Abs., 1949, B, I, p. 199.

        Details of the preparation of the reaction-gas mixture and of the necessary adaptation of the NH₃ plant equipment to the synthesis of MeOH.  The method of preparation of the gas mixture depends on the process in operation for making NH₃.  If the H₂ is obtained from water gas, this need be only partly converted to eliminate S as H₂S.  The required CO:H₂ ratio can be attained by regulating the steam.  A small amount of residual CO₂ helps to promote the synthesis of MeOH, thus economizing in water for washing the gas mixture.  The water may contain 0.6-0.7 cc. CO₂ per m.³  This offers an advantage over the requirements of NH₃ synthesis.  When the CO, CO₂, and H₂ content of the gases reaches about 70-75% in the catalytic cycle, the residual gas must be freed from N₂ and CH₄, preferably by fractionation in the NH₃ plant.  This involves the consumption of about 0.25 kw.-hr. per kg. of MeOH, but it can be avoided if O₂, which is always available in an NH₃ plant, is used for the production of water gas (about 0.5 m.³ O₂ is required per kg. of MeOH).  For pressures of 2.5-25 atm., steel pipes must be plated (against corrosion by CO) with Zn and other surface with Sn; 6% Cr-V-Mo or Cr-Ni steel should be used when higher pressures are applied.