順丁烯二酸酐(MaleicAnhydride,MA)簡稱順酐,是一種常用的重要有機化工原料。那么你知道順酐的工藝如何嗎?下面
順酐廠家來解答:
Maleic Anhydride (MA), referred to as maleic anhydride, is a common and important organic chemical raw material. Do you know the production process of maleic anhydride? The manufacturer of maleic anhydride will answer the following questions:
順酐的工藝主要分為以下三步:
The production process of maleic anhydride is mainly divided into the following three steps:
1)以苯、碳四餾分或正丁烷為原料催化氧化制順酐;
1) Using benzene, C4 fraction or n-butane as raw materials for catalytic oxidation to maleic anhydride;
2)從氧化生成的混合氣中回收順酐得到粗酐;
2) Recovering maleic anhydride from the mixture gas generated by oxidation to obtain crude anhydride;
3)精制粗酐從而獲得順酐產(chǎn)品。
3) Refine crude anhydride to obtain maleic anhydride product.
順酐的技術(shù)路線主要分為苯氧化法、碳四烯烴法、苯酐副產(chǎn)法、正丁烷氧化法4種。
The technical routes of maleic anhydride production are mainly divided into four kinds: benzene oxidation method, C4 olefin method, phthalic anhydride by-product method and n-butane oxidation method.
1.丁烷法固定床工藝:丁烷法固定床工藝主要由亨斯邁公司、BP、SD、康斯爾(Conser)公司擁有,與苯氧化法基本相似,但正丁烷氧化轉(zhuǎn)化率和選擇性均比苯低,其順酐的摩爾收率按正丁烷計僅為50%~55%,而原料氣體中苯和正丁烷的摩爾濃度基本相同。因此對于同樣規(guī)模的裝置,正丁烷法需要較大的反應器和壓縮機。反應溫度400~450℃,壓力為125~130MPa。為了降低正丁烷的單耗,比利時的Pantochim公司采用尾氣循環(huán)工藝,吸收塔頂出來的尾氣約50%經(jīng)處理后與新鮮空氣一并進入反應器。該工藝可使正丁烷的單耗下降約10%。
1. Butane fixed bed process: The butane fixed bed process is mainly owned by Huntsman, BP, SD and CONSER, which is basically similar to the benzene oxidation process, but the conversion and selectivity of n-butane oxidation are lower than that of benzene. The molar yield of maleic anhydride is only 50%~55% based on n-butane, while the molar concentration of benzene and n-butane in the feed gas is basically the same. Therefore, for production units of the same scale, the n-butane process requires larger reactors and compressors. The reaction temperature is 400~450 ℃ and the pressure is 125~130MPa. In order to reduce the unit consumption of n-butane, Pantochim Company of Belgium adopts the tail gas circulation process. About 50% of the tail gas from the top of the absorption tower enters the reactor together with fresh air after treatment. This process can reduce the unit consumption of n-butane by about 10%.
2.丁烷法流化床工藝:流化床反應器中,正丁烷和空氣分別進入反應器后混合,避免了其混合時發(fā)生爆炸的可能因此原料氣中正丁烷的摩爾分數(shù)可以提高到4%,反應所需空氣約為固定床的一半,減少了空氣壓縮機的投資和操作費用。流化床工藝的能耗低于固定床,但丁烷的單耗要比固定床高約8%,另外流化床催化劑的磨損也較大。
2. Butane method fluidized bed process: in the fluidized bed reactor, n-butane and air respectively enter the reactor and mix, avoiding the possibility of explosion when mixing. Therefore, the mole fraction of n-butane in the feed gas can be increased to 4%, and the air required for the reaction is about half of the fixed bed, reducing the investment and operating costs of the air compressor. The energy consumption of the fluidized bed process is lower than that of the fixed bed, but the unit consumption of butane is about 8% higher than that of the fixed bed, and the wear of the fluidized bed catalyst is also large.
3.有機溶劑吸收法工藝:在采用丁烷法順酐的初期,主要是一些苯法裝置通過更換催化劑實現(xiàn),就是新建的裝置工藝也與苯法基本一致,均為水吸收法回收。由于丁烷氧化反應生成少量的乙酸和丙烯酸,而苯氧化反應幾乎不生成乙酸和丙烯酸,另外丁烷氧化生成的水也比苯氧化多1倍,所以丁烷法水吸收工藝遇到的腐蝕和堵塞問題要比苯法多。
3. Organic solvent absorption process: In the early stage of the production of maleic anhydride by the butane process, some benzene process units were mainly realized by replacing catalysts. Even the newly built unit process was basically the same as that of the benzene process, which was recovered by water absorption method. Since butane oxidation reaction generates a small amount of acetic acid and acrylic acid, while benzene oxidation reaction hardly generates acetic acid and acrylic acid, and the water generated by butane oxidation is also twice as much as that of benzene oxidation, so the butane water absorption process encounters more corrosion and blockage problems than benzene method.
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