Maleic anhydride manufacturers inform you of maleic anhydride consumption process and use. What is maleic anhydride?

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。有激烈刺激气息，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。主要用于消费不饱和聚酯树脂、醇酸树脂、马拉硫磷、高能低毒农药4049、碘胺的原料。

Maleic anhydride is also known as maleic anhydride, maleic anhydride, 2,5-furandione, etc. Orthorhombic crystals are colorless acicular or flaky crystals. It has strong irritating smell, soluble in ethanol, ether and acetone, and insoluble in petroleum ether and carbon tetrachloride. It reacts with hot water to form maleic acid. It is mainly used as raw materials for consumption of unsaturated polyester resin, alkyd resin, malathion, high energy and low toxicity pesticide 4049 and iodamine.

1、苯氧化法

1. Benzene oxidation process

苯氧化为顺酐是在催化剂存在下停止的。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)，为抑止苯被完整氧化，常参加钼、磷、钛、钨、银及碱金属等元素的氧化物为添加剂，并采用低比外表的惰性物质为催化剂载体，如α-氧化铝、刚玉等。反响在常压下停止，温度350～400℃。

The oxidation of benzene to maleic anhydride was stopped in the presence of catalyst. The active components of commonly used catalysts are vanadium oxides (see metal oxide catalysts). In order to prevent benzene from being completely oxidized, the oxides of molybdenum, phosphorus, titanium, tungsten, silver and alkali metals are often used as additives, and the inert materials with low specific surface area are used as catalyst carriers, such as α- Alumina, corundum, etc. The reaction stopped at normal pressure and the temperature was 350-400 ℃.

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)停止 脱水，把酸重新转化成酸酐。脱水也可在膜式蒸发器中停止。粗酐经减压精馏可得废品。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 to stop dehydration and convert the acid into anhydride again. Dehydration can also be stopped in the membrane evaporator. Waste product can be obtained from crude anhydride by vacuum distillation. Calculated by benzene, the yield of maleic anhydride in the whole process is 92% ～ 96% (mass).

2、C4烃氧化法

2. C4 hydrocarbon oxidation process

正丁烷与丁烯均含有与顺酐相同的碳原子数，是消费顺酐的理想原料。由于正丁烷价钱较其他原料低廉，用正丁烷更为有利。其流程与苯氧化法根本相同，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。可用固定床反响器或用流化床反响器，反响温度约400℃。

Both n-butane and butene contain the same number of carbon atoms as maleic anhydride, so they are ideal raw materials for maleic anhydride consumption. Because the price of n-butane is lower than other raw materials, it is more advantageous to use n-butane. The catalyst is V-P-O system, and the additives are oxides of iron, lead, zinc, copper and antimony. Fixed bed reactor or fluidized bed reactor can be used, and the reaction temperature is about 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%。由于C4烃氧化的选择性较低,因而设备投资较以苯为原料时为高，且后加工不能采用局部冷凝，而必 需将反响气体中的顺酐全部用吸收法回收，从而使能耗加大。但由于正丁烷价钱比苯廉价，而且苯毒性大。因而，以正丁烷为原料是有吸收力的，对本法所用催化剂的改良工作，各国都在鼎力停止中。

The concentration of n-butane in the mixture of n-butane and air is 1.0% ~ 1.6% (mole). The yield of maleic anhydride is about 50% based on n-butane. Due to the low selectivity of C4 hydrocarbon oxidation, the investment of equipment is higher than that of benzene, and local condensation can not be used in post-processing. It is necessary to recover all maleic anhydride in the reaction gas by absorption method, thus increasing energy consumption. But because n-butane is cheaper than benzene, and benzene is more toxic. Therefore, n-butane as raw material has absorptive capacity, and the improvement of catalyst used in this method is being vigorously carried out in various countries.

顺酐的用处

The use of maleic anhydride

顺酐主要用于消费不饱和聚酯树脂、醇酸树脂、马拉硫磷、高能低毒、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，也是消费油墨助剂、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。

Maleic anhydride is mainly used as raw material for consumption of unsaturated polyester resin, alkyd resin, malathion, high energy and low toxicity, and iodamine. It is also a comonomer of coatings, maleic rosin, polymaleic anhydride and maleic anhydride styrene copolymer, and an organic chemical raw material for consumption of ink additives, papermaking additives, plasticizers, tartaric acid, fumaric acid, tetrahydrofuran, etc.

关于顺酐的用途及生产工艺就介绍到这里了，希望对大家有所帮助。想了解更多相识，可以关注顺酐生产厂家http://www.jnjhhg.cn

The purpose and production process of maleic anhydride are introduced here, hoping to help you. If you want to know more, you can pay attention to maleic anhydride manufacturers http://www.jnjhhg.cn