| 摘要 |
1,135,476. Oxidation of methanol. BADISCHE ANILIN- & SODA-FABRIK A.G. 6 April, 1966 [7 April, 1965], No. 15240/66. Heading C2C. Production of formaldehyde by removing a fraction of lower boiling point than methanol from a crude liquid methanol, vaporizing the remainder, subjecting the resulting vapour to oxidative dehydrogenation with oxygen or a gas containing free oxygen in contact with a metallic silver catalyst, optionally in the presence of steam, at elevated temperature to form formaldehyde characterized by adding alkali to the crude methanol before, during and/or after removal of the said fraction of lower boiling point than methanol and before vaporization of the remainder. The liquid crude methanol used is obtained by conventional methods from carbon monoxide and hydrogen and may contain water and other specified impurities. The fraction of lower boiling point than methanol may be contaminated with iron carbonyl and boils in the range 55‹ to 64‹ C. The preferred alkalis are hydroxides, oxides or carbonates of the alkali metals or alkaline earth metals in solid form or dissolved in water and are added, at a temperature in the range 30‹ to 150‹ C., in amounts such that a pH of 11 to 13À5 is established in the crude liquid methanol. Conventional metallic silver catalysts are used in the oxidative dehydrogenation which is effected at from 400‹ to 750‹ C. |
