2172. MAYLAND, B. J. (Phillips Petroleum Co.). Carbon Monoxide and Hydrogen Synthesis Gas. United States Patent 2,618,543, Nov. 18, 1952. Chem. Abs., vol. 47, 1953, p. 2963.

Efficiency of a hydrocarbon partial-oxidation synthesis-gas-manufacturing process for production of CO and H₂ is greatly increased by recovering elemental C formed in the reaction as an aqueous slurry and recycling this slurry to quench the gases from above 1,200° F. (preferably 1,500°-1,800° F.) to about 800°-900° F., at which temperature no further C formation will take place. Steam is then condensed from the gas, and the elemental C is recovered as an aqueous slurry, which is again recycled for partial gasification in the quenching stage. Efficiency of the process for manufacture of H₂ and CO from natural gas is thus raised from about 80% of theoretical to 83.5%. In United States Patent 2,618,611 (abs. 2179), a synthesis gas of high H₂:CO ratio is made by first partly oxidizing a hydrocarbon gas, cooling the products to <1,500° F., and treating the gaseous mixture with a reduced Fe or Ni water-gas shift catalyst at 800°-1,500° F. in the presence of 0.01-0.25 mole of O₂ per mole of CO. Contrary to Rideal (Jour. Chem. Soc., vol. 115, 1919, pp. 993-1006), who stated that at 400° C. H₂ is burned more rapidly than CO, the ratio H₂:CO may actually be increased instead of decreased. In an example, a synthesis gas made from pure CH₄ by partial combustion with O₂ had the following compound: H₂ 60.99, CO 32.1, CO₂ 1.06, and H₂O 5.85 mole %. The H₂:CO ratio of this gas was 1.9. After 0.03 mole O₂ was added and mixture allowed to come to equilibrium over a reduced-Fe shift catalyst at 1,200 F., the gas had a composition of H₂ 59.99, CO 27.1, CO₂ 6.06, and H₂O 6.85 mole %, and the H₂:CO ratio was 2.21. If natural gas with small percentages of heavier hydrocarbons is used, the H₂:CO ratio is 1.6:1.7 for the 1^st step. This gas can also be improved by addition of O₂ and the shift reaction.