苯蒸气与空气可形成爆破混合物对顺酐的分离起主导作用,因此进入反应器的混合气体中苯的浓度应在爆破极限之外,一般为1%~1.4%。
Benzene Vapor and air can form a blast mixture that dominates the separation of maleic anhydride, so the concentration of benzene in the mixture entering the reactor should be outside the blast limit, typically 1% to 1.4% .
苯的氧化是强烈的放热反应。 顺酐厂家常选择管式固定床反应器,其传热面大,管外设有冷却系统。 反应热可用于产生高压蒸汽。
The oxidation of benzene is a strong exothermic reaction. MALEIC anhydride producers often choose tubular fixed bed reactors with large heat transfer surfaces and external cooling systems. The heat of reaction can be used to produce high-pressure steam.
离开反应器的气体含有约1%的顺酐,其中约一半的可通过冷却冷凝成液体,其余可通过吸收回收。吸水或惰性有机溶剂,大多数工厂选择水。
The gas leaving the reactor contains about 1% maleic anhydride, of which about half of the MALEIC anhydride can be cooled to a liquid and the rest can be recovered by absorption. Absorbent or inert organic solvent, most plants choose water.
得到的吸收液为浓度为35%~40%的马来酸水溶液。 它需要用共沸溶剂脱水。
顺酐厂家将酸从头转化为酸酐。 脱水也可以在薄膜蒸发器中进行。减压蒸馏可得粗酸酐。
The absorption solution is maleic acid aqueous solution with concentration of 35% ~ 40% . It needs to be dehydrated in AZEOTROPIC solvents. Manufacturers of MALEIC anhydride convert acid from scratch to anhydride. Dehydration can also be done in a thin film evaporator. Crude anhydride can be obtained by vacuum distillation.