| 摘要 |
PURPOSE: To obtain formalin in an economically advantageous way by making use of the methanol produced from methylamine production process to suppress the decomposition of the methanol into CO, CO2 and CH4 and to attain the improvement of effective component yield. CONSTITUTION: In producing the objective formalin using methanol and air as the main feedstocks, the methanol derived from methylamine production process is used as part or the whole of said methanol. For example, both ammonia and methanol as feedstocks are brought into contact with a solid acid catalyst such as silica-alumina at 300-400 deg.C to obtain reaction products comprising methylamine, an excess of ammonia, water as a byproduct, and unreacted methanol followed by separation, recovery or circulation of the reaction products, and 10-30wt.% of the finally obtained methanol is used as the aimed feedstock; and this feedstock gas is brought into contact with a silver catalyst, and the resultant formaldehyde is absorbed into water and condensed. |
