China is a big manufacturer of maleic anhydride, so let's understand the differences between maleic anhydride and maleic acid in what aspects?

　　1、称取大约相同的量，用水溶解后，再用碱滴定，消耗碱多的是酐，消耗碱少的是酸。

　　1. Weigh about the same amount, dissolve it with water, and then titrate it with alkali. The one that consumes more alkali is anhydride, and the one that consumes less alkali is acid.

　　2、或取少量相同量的样品溶解于水，用pH计检测，pH值低的是酐，pH稍高的是酸。

　　2. Or take a small amount of the same amount of sample to dissolve in water, and use pH meter to detect. The lower pH value is anhydride, and the higher pH value is acid.

　　3、用熔点检测也可以，酐与酸的熔点不同。顺酐约52~53℃，顺酸约130℃。

　　3. It can also be detected by melting point. The melting point of anhydride is different from that of acid. Maleic anhydride is about 52-53 ℃, and maleic acid is about 130 ℃.

　　4、简单的办法，找一小块不锈钢片，将两种样品各放一点于钢片两侧，用打火机在两个样品中间加热，先液化并挥发的是顺酐。

　　4. In a simple way, find a small piece of stainless steel sheet, place two samples on both sides of the sheet, heat them in the middle of the two samples with a lighter, and the first thing that liquefy and volatilize is maleic anhydride.

　　制作方式：

　　Production method:

　　1. 苯氧化制山东顺酐

　　1. Oxidation of benzene to Shandong maleic anhydride将苯与空气混合(苯为1%-1.4% )经换热器预热后，进人列管式催化反应器。在压力为0.1-0.2MPa、温度为350-400℃的反应条件下进行氧化反应，所得产物经两台换热器、一台冷却器后，冷却到接近露点(55―65℃)。冷却后的反应物进入分离器，分离器底部得粗顺酐，进入粗顺酐罐。分离器顶部流出物进人洗涤塔，用水洗涤，塔顶为多余空气和未反应的苯，苯可用吸附回收。洗涤塔塔底水溶液进人脱水器，分离出水，所得粗顺酐进人粗顺酐罐。粗顺酐进一步进人蒸馏塔进行蒸馏精制，得顺酐。所得山东顺酐可进行异构化得富马酸和苹果酸。

　　The mixture of benzene and air (benzene is 1% - 1.4%) is preheated by heat exchanger and then put into the tubular catalytic reactor. The oxidation reaction was carried out at the pressure of 0.1-0.2mpa and the temperature of 350-400 ℃. The product was cooled to the dew point (55-65 ℃) by two heat exchangers and one cooler. The cooled reactant enters the separator, and the crude maleic anhydride is obtained at the bottom of the separator and enters the crude maleic anhydride tank. The effluent from the top of the separator enters into the washing tower and is washed with water. The top of the tower is redundant air and unreacted benzene, which can be recovered by adsorption. The bottom water solution of the washing tower enters into the human dehydrator, the separated water, and the obtained crude maleic anhydride enters into the human crude maleic anhydride tank. Crude maleic anhydride is further distilled into a distillation tower to obtain maleic anhydride. The maleic anhydride can be isomerized to fumaric acid and malic acid.

　　2.C4馏分部分氧化制顺酐

　　2. Partial oxidation of C4 fraction to maleic anhydride工业上用不经分离的C4馏分或分离异丁烯和丁二烯后的C4馏分为原料顺酐。C4馏分与空气混合后进人流化床氧化反应器，在300―500℃温度下，与反应器中的催化剂接触顺酐。氧化反应器顶部流出的反应生成物进人吸收塔，用水作为吸收剂，塔顶气体经废水Maleic anhydride is produced from C4 fraction without separation or C4 fraction after separation of isobutylene and butadiene. C4 fraction is mixed with air and then enters the fluidized bed oxidation reactor. At 300-500 ℃, it contacts with the catalyst in the reactor to produce maleic anhydride. The reaction products from the top of the oxidation reactor enter the absorption tower, and water is used as the absorbent. The gas from the top of the tower flows through the waste water以上就是对顺酐和顺酸两者不同之处都体现在哪些方面的详细介绍，想要了解更多，请点击官网http://www.jnjhhg.cn
The above is a detailed introduction of the differences between maleic anhydride and maleic acid. To learn more, please click http://www.jnjhhg.cn