1. Oxidation of benzene to maleic anhydride

加热到管状催化反应器后，苯通过热交换器与空气(苯为1%-1.4%)混合。氧化反应在0.1-0.2MPa压力和350-400℃温度的反应条件下进行。产生的产品通过两个热交换器和一个冷却器，冷却到露点附近(55-65℃)。

After heating to the tubular catalytic reactor, benzene is mixed with air (benzene is 1% - 1.4%) through the heat exchanger. The oxidation reaction was carried out under the reaction conditions of 0.1-0.2mpa pressure and 350-400 ℃. The resulting product is cooled near the dew point (55-65 ℃) through two heat exchangers and a cooler.

冷却反应物进入分离器，分离器底部得到粗马来酸酐并进入粗顺酐槽。分离器的顶部流出物被送入洗涤塔并用水洗涤。空气顶部和未反应的苯可以通过吸附回收。洗涤塔底部的水溶液被送入脱水器，水被分离，产生的顺酐被送入粗马来酸酐罐。粗马来酸酐进一步进入蒸馏塔进行蒸馏和精炼，以获得顺酐。由此产生的山东顺酐可以异构化得到富马酸和苹果酸。

The cooled reactant enters the separator, the crude maleic anhydride is obtained at the bottom of the separator and enters the crude maleic anhydride tank. The top effluent of the separator is sent to the scrubber and washed with water. Air top and unreacted benzene can be recovered by adsorption. The aqueous solution at the bottom of the scrubber is sent to the dehydrator, the water is separated, and the generated maleic anhydride is sent to the crude maleic anhydride tank. Crude maleic anhydride further enters the distillation tower for distillation and refining to obtain maleic anhydride. The resulting Shandong maleic anhydride can be isomerized to fumaric acid and malic acid.

2.C4部分氧化成顺酐

2. Partial oxidation of C4 to maleic anhydride

顺酐的工业生产，使用不分离的C4部分或异丁烯和丁二烯分离后的C4部分作为原料。C4馏分与空气混合，然后送入人流化床氧化反应器，并在300-500℃的温度下与反应器中的催化剂接触，产生马来酸酐。氧化反应器顶部的反应产物进入吸收塔，水作为吸收剂，顶部气体通过废水。

For the industrial production of maleic anhydride, the non separated C4 part or the C4 part after the separation of isobutene and butadiene is used as raw material. C4 fraction is mixed with air, then sent to the fluidized bed oxidation reactor, and contacted with the catalyst in the reactor at the temperature of 300-500 ℃ to produce maleic anhydride. The reaction products at the top of the oxidation reactor enter the absorption tower, water is used as absorbent, and the top gas passes through the wastewater.