順酐廠家通知你順酐的消費(fèi)工藝及用處。什么是順酐?
Maleic anhydride manufacturers inform you of maleic anhydride consumption process and use. What is maleic anhydride?
順酐又稱順丁烯二酸酐，馬來酸酐，2,5-呋喃二酮等。斜方晶系無色針狀或片狀晶體。有激烈刺激氣息，溶于乙醇、乙醚和丙酮，難溶于石油醚和四氯化碳。與熱水作用而成馬來酸。主要用于消費(fèi)不飽和聚酯樹脂、醇酸樹脂、馬拉硫磷、高能低毒農(nóng)藥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
苯氧化為順酐是在催化劑存在下停止的。常用催化劑的活性組分均為釩的氧化物(見金屬氧化物催化劑)，為抑止苯被完整氧化，常參加鉬、磷、鈦、鎢、銀及堿金屬等元素的氧化物為添加劑，并采用低比外表的惰性物質(zhì)為催化劑載體，如α-氧化鋁、剛玉等。反響在常壓下停止，溫度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 ℃.
吸收劑用水或惰性有 機(jī)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(zhì)量)，需用共沸溶劑(例如二甲苯、苯甲醚)停止 脫水，把酸重新轉(zhuǎn)化成酸酐。脫水也可在膜式蒸發(fā)器中停止。粗酐經(jīng)減壓精餾可得廢品。以苯計(jì)算，整個(gè)過程的順酐收率為92%～96%(質(zhì)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烴氧化法
2. C4 hydrocarbon oxidation process
正丁烷與丁烯均含有與順酐相同的碳原子數(shù)，是消費(fèi)順酐的理想原料。由于正丁烷價(jià)錢較其他原料低廉，用正丁烷更為有利。其流程與苯氧化法根本相同，催化劑為釩-磷-氧體系，添加劑有鐵、鉛、鋅、銅、銻等元素的氧化物。可用固定床反響器或用流化床反響器，反響溫度約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-空氣混合物中正丁烷濃度為1.0%～1.6%(摩爾)。整個(gè)過程的順酐收率按正丁烷計(jì)約為50%。由于C4烴氧化的選擇性較低,因而設(shè)備投資較以苯為原料時(shí)為高，且后加工不能采用局部冷凝，而必 需將反響氣體中的順酐全部用吸收法回收，從而使能耗加大。但由于正丁烷價(jià)錢比苯廉價(jià)，而且苯毒性大。因而，以正丁烷為原料是有吸收力的，對本法所用催化劑的改良工作，各國都在鼎力停止中。
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.
順酐的用處
The use of maleic anhydride
順酐主要用于消費(fèi)不飽和聚酯樹脂、醇酸樹脂、馬拉硫磷、高能低毒、碘胺的原料。也是涂料、馬來松香、聚馬來酐、順酐-苯乙烯共聚物的共聚單體，也是消費(fèi)油墨助劑、造紙助劑、增塑劑、酒石酸、富馬酸、四氫呋喃等的有 機(jī)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.
關(guān)于順酐的用途及工藝就介紹到這里了，希望對大家有所幫助。想了解更多相識，可以關(guān)注順酐廠家http://www.topcax.com
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.topcax.com
