1834.  KEMMER, H. [Municipal Gas.] German Patent 617,565, Aug. 21, 1935 (Cl. 26a-3.02). Chem. Abs., vol. 30, 1936, p. 843.

Gas, free from CO, is obtained by subjecting coal gas containing CO to successive oxidation by steam and reduction by H₂. The calorific value of the original gas containing CO is raised by oxidizing in the first stage until only 4-5% of CO remains; the H₂ freed in this process is used for the reducing stage. Oxidizing agents such as active C may be employed in the oxidizing stage, and contact agents such Ni, ThO₂, and active C may be used in the reducing stage.