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).

苯氧化為強放熱反應，工業(yè)上常采用列管式固定床反應器，有很大的傳熱面，管外為冷 卻系統(tǒng)，反應熱可用于產生高壓蒸汽。離開反應器的氣體中含順酐約1%（摩爾），用冷 卻的辦法可將其中所含一半左右的順酐冷凝為液體，其余部分則用吸收法回收。

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.

吸收劑用水或惰性有 機溶劑，大多數(shù)工廠采用的是水。所得到的吸收液是順丁烯二酸的水溶液，濃度35%～40%(質量)，需用共沸溶劑（例如二甲苯、苯甲醚）進行脫水，把酸重新轉化成酸酐。脫水也可在膜式蒸發(fā)器中進行。粗酐經(jīng)減壓精餾可得成品。以苯計算，整個過程的順酐收率為92%～96%（質量）。

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).

金昊化工是一家集、研發(fā)、貿易為一體的綜合性化工公司。主要涵蓋無機化工產品、有 機化工產品、實驗儀器等幾大系列。主營產品為氫氧化鉀、過硫酸銨、過硫酸鈉、順酐、二氯甲烷、水泥防水劑、色譜儀器毛細管等六十多個品種。

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.