METHOD OF SYNTHESIS OF FORMALDEHYDE Russian patent published in 1998 - IPC

FIELD: chemical technology. SUBSTANCE: the parent reaction mixture containing methanol, oxygen and inert gas is passed successively through 3-5 layers of oxide catalyst. After each layer partially reacted mixture is cooled to 200-280 C. Ratio of volume parts of methanol and oxygen in the parent mixture is maintained at the range 1:(0.7-1.7). After each catalyst layer a mixture is passed through a layer of inert permeable material (hydraulic radius of pore channel is 2-4.5 mm). Optimal distribution of catalyst volumes by layers at order of successive passing a mixture through their for 3-layered reactor is 1:(1.1-1.6):(1.2-2.5), for 4-layered one is 1:(1.1-1.4): (0.8-1.7): (1.6-2.5), and for 5-layered one is 1:(1.0-1.4):(1.1-1.6):(0.7-1.8): (1.3-2.3). Catalyst layers are formed for two successive stages: firstly, preliminary layer is formed loading catalyst randomly, then basic layer is formed taking catalyst from the first layer by its all transverse section simultaneously at vertical rate of basic layer increase 8-100 mm/s. Invention can be used in chemical, petrochemical and wood working industry. EFFECT: improved method of synthesis. 4 cl