Separation and purification of maleic anhydride from Shandong Province. Benzene vapor and air can form explosive mixture, so the concentration of benzene in the mixture entering the reactor should be beyond the explosion limit, generally 1% - 1.4% (mole).

苯氧化为强放热反应，工业上常采用列管式固定床反应器，有很大的传热面，管外为冷 却系统，反应热可用于产生高压蒸汽。离开反应器的气体中含顺酐约1%（摩尔），用冷 却的办法可将其中所含一半左右的顺酐冷凝为液体，其余部分则用吸收法回收。

Benzene oxidation is a strong exothermic reaction. Tubular fixed bed reactor is often used in industry. It has a large heat transfer surface and a cooling system outside the tube. The reaction heat can be used to produce high-pressure steam. The gas leaving the reactor contains about 1% (mole) maleic anhydride, about half of which can be condensed into liquid by cooling, and the rest can be recovered by absorption.

吸收剂用水或惰性有 机溶剂，大多数工厂采用的是水。所得到的吸收液是顺丁烯二酸的水溶液，浓度35%～40%(质量)，需用共沸溶剂（例如二甲苯、苯甲醚）进行脱水，把酸重新转化成酸酐。脱水也可在膜式蒸发器中进行。粗酐经减压精馏可得成品。以苯计算，整个过程的顺酐收率为92%～96%（质量）。

Absorbent water or inert organic solvents, most plants use water. The absorption solution obtained is an aqueous solution of maleic acid with a concentration of 35% - 40% (mass). Azeotropic solvents (such as xylene and anisole) are used for dehydration to convert the acid into anhydride again. Dehydration can also be carried out in a membrane evaporator. The crude anhydride can be obtained by vacuum distillation. Calculated by benzene, the yield of maleic anhydride in the whole process is 92% ～ 96% (mass).

npv加速器官网是一家集生产、研发、贸易为一体的综合性化工公司。主要涵盖无机化工产品、有 机化工产品、实验仪器等几大系列。主营产品为海外梯子npv推荐、过硫酸铵、过硫酸钠、顺酐、二氯甲烷、水泥防水剂、色谱仪器毛细管等六十多个品种。

Jinhao chemical is a comprehensive chemical company integrating production, R & D and trade. Mainly covers inorganic chemical products, organic chemical products, experimental instruments and other major series. The main products are potassium hydroxide, ammonium persulfate, sodium persulfate, maleic anhydride, dichloromethane, cement waterproof agent, capillary of chromatographic instrument, etc.