什么是顺酐？顺酐又称顺丁烯二酸酐，马来酸酐，2,5-呋喃二酮等。斜方晶系无色针状或片状晶体。有强烈刺激气味，溶于乙醇、乙醚和丙酮，难溶于石油醚和四氯化碳。与热水作用而成马来酸。主要用于生产不饱和聚酯树脂、醇酸树脂、农药马拉硫磷、低毒农药4049、长效碘胺的原料。

What is maleic anhydride? Maleic anhydride is also known as maleic anhydride, maleic anhydride, 2,5-furanedione, etc. Orthorhombic crystals are colorless needle-shaped or flaky crystals. It has a strong pungent smell and is soluble in ethanol, ether and acetone, but insoluble in petroleum ether and carbon tetrachloride. It reacts with hot water to form maleic acid. It is mainly used as raw material for the production of unsaturated polyester resin, alkyd resin, pesticide malathion, high-efficiency and low-toxicity pesticide 4049, and long-acting iodamine.

顺酐的生产工艺：

Production process of maleic anhydride:

1、苯氧化法

1. Benzene oxidation method

苯氧化为顺酐是在催化剂存在下进行的。常用催化剂的活性组分均为钒的氧化物（见金属氧化物催化剂），为抑制苯被完全氧化，常加入钼、磷、钛、钨、银及碱金属等元素的氧化物为添加剂，并采用低比表面的惰性物质为催化剂载体，如α－氧化铝、刚玉等。反应在常压下进行，温度350～400℃。

The oxidation of benzene to maleic anhydride is carried out in the presence of catalyst. The active components of common catalysts are vanadium oxides (see metal oxide catalysts). In order to inhibit the complete oxidation of benzene, oxides of molybdenum, phosphorus, titanium, tungsten, silver and alkali metals are often added as additives, and inert substances with low specific surface are used as catalyst carriers, such as α－ Alumina, corundum, etc. The reaction is carried out under normal pressure at 350~400 ℃.

工艺过程由苯的氧化，顺酐的分离和提纯两大部分组成。苯蒸气和空气能形成爆炸混合物，所以进入反应器的混合气中，苯的浓度应在爆炸限之外，一般为1%～1.4%(摩尔)。

The process consists of oxidation of benzene, separation and purification of maleic anhydride. Benzene vapor and air can form explosive mixture, so the concentration of benzene in the mixed gas entering the reactor should be outside the explosion limit, generally 1%~1.4% (mol).

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. In industry, tubular fixed-bed reactors are often used, with large heat transfer surface. The outside of the tube is a cooling system, and the reaction heat can be used to generate high-pressure steam. The gas leaving the reactor contains about 1% (mol) of maleic anhydride. About half of the maleic anhydride 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 solvent, most plants use water. The obtained absorption solution is an aqueous solution of maleic acid with a concentration of 35%~40% (mass). It needs to be dehydrated with azeotropic solvents (such as xylene and anisole) to convert the acid back into anhydride. Dehydration can also be carried out in membrane evaporator. Crude anhydride can be obtained by vacuum distillation. Based on benzene, the yield of maleic anhydride in the whole process is 92%~96% (mass).

2、C4烃氧化法

2. C4 hydrocarbon oxidation method

正丁烷与丁烯均含有与顺酐相同的碳原子数，是生产顺酐的理想原料。由于正丁烷较其他原料低廉，用正丁烷更为有利。其流程与苯氧化法基本相同，催化剂为钒-磷-氧体系，添加剂有铁、铅、锌、铜、锑等元素的氧化物。

Both n-butane and butene contain the same carbon atoms as maleic anhydride, and are ideal raw materials for the production of maleic anhydride. Because the price of n-butane is lower than other raw materials, it is more advantageous to use n-butane. The process is basically the same as that of benzene oxidation. The catalyst is vanadium - phosphorus - oxygen system, and the additives are oxides of iron, lead, zinc, copper, antimony and other elements.

可用固定床反应器或用流化床反应器，反应温度约400℃。正丁烷-空气混合物中正丁烷浓度为1.0%～1.6%(摩尔)。整个过程的顺酐收率按正丁烷计约为50%。

Fixed bed reactor or fluidized bed reactor can be used, and the reaction temperature is about 400 ℃. The concentration of n-butane in the n-butane-air mixture is 1.0%~1.6% (mol). The yield of maleic anhydride in the whole process is about 50% based on n-butane.

由于C4烃氧化的选择性较低,因此设备投资较以苯为原料时为高，且后加工不能采用部分冷凝，而必须将反应气体中的顺酐全部用吸收法回收，从而使能耗加大。

Due to the low selectivity of C4 hydrocarbon oxidation, the equipment investment is higher than that when benzene is used as raw material, and partial condensation cannot be used for post-processing. Instead, all maleic anhydride in the reaction gas must be recovered by absorption method, thus increasing energy consumption.

顺酐主要用于生产不饱和聚酯树脂、醇酸树脂、农药马拉硫磷、低毒农药4049、长效碘胺的原料。也是涂料、马来松香、聚马来酐、顺酐-苯乙烯共聚物的共聚单体，也是生产油墨助剂、造纸助剂、增塑剂、酒石酸、富马酸、四氢呋喃等的有机化工原料。您有需求可以四十来我们完网站http://www.jinhao360.com咨询！

Maleic anhydride is mainly used as raw material for the production of unsaturated polyester resin, alkyd resin, pesticide malathion, high-efficiency and low-toxicity pesticide 4049, and long-acting iodamine. It is also a comonomer of paint, maleic rosin, polymaleic anhydride, maleic anhydride-styrene copolymer, and an organic chemical raw material for the production of ink additives, paper additives, plasticizers, tartaric acid, fumaric acid, tetrahydrofuran, etc. If you need, you can come to our website at forty http://www.jinhao360.com consulting service