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of the Japanese Catalyst Company in the 1880s. The reaction temperature of the first | of the Japanese Catalyst Company in the 1880s. The reaction temperature of the first | ||
step is 320-330℃. If other additives such as W, Co, K, Si and O are added to the | step is 320-330℃. If other additives such as W, Co, K, Si and O are added to the | ||
− | catalyst MoBiFe, the yield of acrolein can reach more than 90% | + | catalyst MoBiFe, the yield of acrolein can reach more than 90%. The reaction |
temperature of the second step is 210-255 ℃. The compositions of the catalyst are | temperature of the second step is 210-255 ℃. The compositions of the catalyst are | ||
− | Mo, Bi, Fe, Co, K and O. The yield of acrylic acid can reach 97.5% | + | Mo, Bi, Fe, Co, K and O. The yield of acrylic acid can reach 97.5%. The yield |
of acrylic acid in the two-step oxidation process is much higher than that of the | of acrylic acid in the two-step oxidation process is much higher than that of the | ||
direct oxidation of propylene to produce acrylic acid. This is because the reaction | direct oxidation of propylene to produce acrylic acid. This is because the reaction | ||
temperature in the one-step process is 325-350 ° C, at which the conversion of propylene | temperature in the one-step process is 325-350 ° C, at which the conversion of propylene | ||
− | to acrolein is high. But acrolein and acrylic acid are further oxidized at that temperature | + | to acrolein is high. But acrolein and acrylic acid are further oxidized at that temperature. Therefore, to obtain higher yields of acrylic acid, control the reaction at |
− | + | ||
different stages by controlling the temperature and changing the catalyst composition | different stages by controlling the temperature and changing the catalyst composition | ||
in the two-step method is more reasonable and more valuable. As the most widely used | in the two-step method is more reasonable and more valuable. As the most widely used |
Revision as of 13:43, 1 November 2017