838.    ENGELS, W. H.  [Production of Hydrogen by the Interaction of Carbon Monoxide and Calcium Hydroxide and Acceleration of the Water-Gas Reaction by Means of Iron.]  Jour. Gasbeleucht., vol. 62, 1919, pp. 477-483, 493-500; Chem. Abs., vol. 14, 1920, p. 599.

                 Engels has investigated the conditions under which the reaction between CO and Ca(OH)₂ will best serve for the technical production of H₂.  An investigation with the purpose of determining whether the course of the reaction for the production of H₂ is represented by the equation CO+H₂O→H₂+CO₂ or by the equation Ca(OH)₂+CO₂=CaCO₃+H₂ is detailed.  The results indicate that the course of the reaction is determined principally by the latter equation, a little of the H₂, however, resulting from the reaction represented by the first equation.  The reaction is best carried out at about 500°.  The use of more steam in the water-gas mixture than that corresponding to the vapor pressure of Ca(OH)₂ at the temperature employed is to be avoided.  The reaction between Co and CaO is accelerated at least elevenfold by the catalytic action of Fe in consequence of the acceleration of the water-gas reaction by this catalyst.  The effect of temperature upon the equilibrium of the water-gas reaction is well represented by the thermo-dynamic relation previously deduced by Haber.