713.    ---------------.  [DOLCH, P.]  [Water-Gas Generation From Coke and Coal.]  Gas- u. Wasserfach, vol. 75, 1932, p. 807-811; Chem. Abs., vol. 27, 1933, p. 399.

     Calculations from the experiments of Bunte and Dolch show that the reaction of water vapor on C and the formation of CO₂ is determined by the water-gas equilibrium rather than the water-gas reaction.  The degree of attainment of the water-gas equilibrium depends on the reactivity of the coke on which the reaction takes place.  No evidence is found for the direct action of water vapor on C according to the reaction C+2H₂O=CO₂+2H₂.  Experiments with mixtures of CO₂ and H₂ over wood charcoal at temperatures of 600°-1,000° indicated that CO₂ and H₂ first react to form CO and H₂O at about 600°, while CO₂ first begins to react with C at about 750°; with coke the corresponding temperatures are 800° and 980°.  The significance of coke reactivity for technical water-gas manufacture is outlined, showing that a very reactive coke is desirable for the run, but that it leads to an excessive CO content during the blow period.  Special adjustments of blow and run periods are required with the very reactive brown-coal coke.  High reactivity is desirable, however, for the newer continuous water-gas proce3sses using recuperators.  The use of cokes from young coals should permit the manufacture of gas high in H₂ and CO₂, from which the CO₂ can readily be washed out to give a gas with high H₂ content for synthesis purposes.