152.    BASHKIROV, A. N., KRYUKOV, Y. B., AND KAGAN, Y. B.  [Mechanism of the Synthesis of Hydrocarbons From Carbon Monoxide and Hydrogen.]  Compt. rend. acad, sci. U.R.S.S., vol. 67, 1949, pp. 1029-1031; Assoc. Tech. Services, Transl. RJ-21, March 1950; Chem. Abs., vol. 43, 1949, p. 9415.

                  The reaction observed on Fe catalysts, 2CO+H₂→: CH₂+CO₂ (I), in contrast to the reaction CO+2H₂→: CH₂+H₂O (II) occurring on Ni and Co, is interpreted as the sum of the primary reaction (II) and the subsequent secondary reaction CO+H₂O→CO₂+H₂ (III).  This point of view is corroborated by analyses of the gaseous products obtained, on precipitated Fe catalyst, with mixtures of CO:H₂=1:1 in the presence of added H₂O vapor, at 220°-250°, under atmospheric pressure, at space velocity~100 per hr.  The balance, by reaction I, is expressed by CO+mH₂→1/2xCH₂: +1/2xCO₂+(1-x)CO+(m-1/2x)H₂, where x=mole fraction CO reacted, m=moles H₂ per mole CO.  With reaction III occurring simultaneously with II, the balance is CO+mH₂+pH₂O→1/2xCH₂: +(1/2x+z)CO₂+(p-z) H₂O+(1-x-z)CO+(m-1/2x+z)H₂, where z=mole fraction CO reacted according to equation III, and p=moles H₂O per mole CO in the initial gas.  The contraction k, in the first case, is k=2a/(1+2a/(1+2a) (where a=CO₂ content in the product), in the second case, k’=[2a/(1+2a)]-[3z/(1+2a)(1+m)].  The difference ∆=k-k’ is termed the contraction depression.  Experimentally, ∆ attains high values, up to 60-70%.  H₂O added in amounts up to 20% of the reacting gas mixture is found to have reacted completely according to III, for example, with an initial mixture of CO:H₂:H₂O=44.5:44.5:11, on an Fe-Cu=Zn-K₂CO₃-kieselguhr catalyst, at 240°, a=36.6%, ∆ experimental=22.3%, calculated=21.4%.  A gas mixture CO:H₂:H₂O=33:34:33, on an Fe-Cu-Mn-K₂CO₃-kieselguhr catalyst, at 230° gave a negative contraction of –32.5%, a=29.7%, ∆=72.4%; the yield of hydrocarbons is depressed by H₂O but is restored when H₂O is eliminated.  The ratio of the rates of reactions III and I, on the 1^st catalyst, at 240°, is 3.4, on the 2d catalyst, at 230°, it is 13.6.  The primary reaction on Ni, Co, and Fe is reaction II, and CO₂ is a secondary product.