1286b.    ---------------.  [GUMZ, W.] Gasification of Solid Fuels at Elevated Pressures.  Ind. Eng. Chem., vol. 44, 1952, pp. 1071-1074.

          Effect of pressure on the gasification of solid fuels is investigated by calculation and by evaluation of experimental data.  A method of calculation is presented based on the C, H₂, O₂, N₂ and S balances, and on the equilibrium constants of the gasification reactions.  Previously published methods have been extended to apply to the behavior of S during gasification.  An increase in pressure shifts the Boudonard reaction, the heterogeneous water-gas reaction, and CH₄ formation toward increased CO₂, H₂O, CH₄ content and higher equilibrium temperature.  S appears mainly as H₂S in the product gas. Other forms of S such as organic S and S vapor can occur only at extremely high pressures and in the absence of moisture.  This fact permits a simplified method of calculation, assuming that S occurs only as H₂S.  The increase in equilibrium temperature keeps gas quality nearly constant up to 10 atm. and allows higher steam and lower O₂ content in the blast at higher pressures.  Effect of absolute pressure on pressure drop through the fuel bed is calculated and the calculations are supported by experimental results.  Pressure drop is a simple function of pressure and is inversely proportional to the absolute mean pressure in the reactor.  Elevated pressure has no effect on the terminal velocity of fuel particles in suspension in the range of validity of Stokes’ law, but the terminal velocity decreases proportionately to 1/√‾P in the Newton range (constant resistance factor).  Formulas are given for the terminal velocity within the transition range of Reynolds numbers; they can be used to estimate carryover losses and the effect on reaction rates of pulverized-coal gasification.  Pressurizing is applicable to various coal-gasification processes; it has been applied to the manufacture of high-B.t.u. gas, and it has good prospects for playing a major role in synthesis-gas production and power gas for steam boilers and gas turbines.