| 摘要 |
PURPOSE:To obtain acrylic acid as an aqueous solution and to circulate an exhaust gas at a second-stage outlet to a first-stage inlet in obtaining acrylic acid by catalytically oxidizing propylene by two stages in a gas phase, by using a complex oxide catalyst of Mo-Bi type at the first stage and a complex oxide catalyst of Mo-V type as the second stage. CONSTITUTION:In a method wherein propylene, molecular oxygen and an inert gas are subjected to a first-stage catalytic oxidation reaction and propylene is mainly converted into acrolein, the prepared formed gas of the first-stage reaction is optionally mixed with molecular oxygen and steam, subjected to a second-stage catalytic oxidation reaction and acrolein is meinly converted into acrylic acid, a complex oxide catalyst of Mo-Bi system is used in the first stage and a complex oxide catalyst of Mo-V type in the second stage. Acrylic acid is collected as an aqueous solution from a formed gas of the second-stage reaction, an exhaust gas from a collector is oxidized and burnt. Part of the burnt exhaust gas is used as an inert diluting gas for the first stage and the reaction is carried out by making the molar ratio of oxygen/propylene in the first-stage reaction gas of 1.17-2.50, 5-14% propylene concentration and the burnt exhaust gas concentration of 5-95%.
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