735.    DORSCHNER, O.  [Gas Pipeline Transmission of Methane Derived From Pressure Gasification and Synthesis.]  Erdöl u. Kohle, vol. 2, 1949, pp. 59-65; Chem. Abs., vol. 43, 1949, p. 4832.

     For obtaining a gas of high calorific value from the residual Fischer-Tropsch synthesis, a process has been developed that combines pressure gasification of coal with Fischer-Tropsch synthesis.  Pressure gasification may be carried out with lignite or coal (moisture and ash content up to 35%, particle size 2-40 mm.) and an O₂-steam mixture at 10-30 atm.  The exothermic CH₄ reaction reduces the O₂ consumption to ½ of that used in similar processes.  The percentage compositions of the raw gas, synthesis gas (after removal of CO₂), and CH₄ gas (residual gas from Fischer-Tropsch synthesis) follow, respectively:  CO₂, 28.6, 1.0, 3.9; C_nH_m, 0.9, 1.2, 1.8, CO, 18.7, 25.5, 2.7; H₂, 38.1, 53.3, 3.2; CH₄, 12.4, 17.2, 82.1; N₂, 1.3, 1.6, 6.3; heats of combustion in kcal. per m.³ were 3,150, 4,350, 8,450.  There is no reduction in yield of liquid products nor in catalyst activity.  The heat balance for ordinary synthesis gas:  3,066 kcal. = 100%; liquid hydrocarbons, paraffin 1,385 kcal. = 45%; residual gas 1,062 kcal. = 34.7%; steam 414 kcal. = 13.6%; loss 205 kcal. = 6.7%.  Heat balance for pressure gasification 4,135 kcal. = 100%; liquid products 1,240 kcal. = 30%; CH₄ gas 2,290 kcal. = 55.4%; steam 400 kcal. = 9.7%; loss 202 kcal. = 4.9%.  The gas also may be utilized as fuel for motor vehicles, locomotives (gas turbines), or raw material for C₂H₂ manufacture.  Diagram of process.