馬來酸酐又稱順丁烯二酸酐（MAH），簡稱順酐，是順丁烯二酸的酸酐，室溫下為有酸味的無色或白色固體，分子式為C4H2O3。順丁烯二酸酐以前用苯的催化氧化制備，但由于的緣故順酐的用途：
Maleic anhydride, also known as maleic anhydride (MAH), is an anhydride of maleic acid. It is a colorless or white solid with a sour taste at room temperature, and its molecular formula is C4H2O3. Maleic anhydride was previously prepared by catalytic oxidation of benzene, but due to price reasons, the purpose of maleic anhydride is:
1、用作1,4-丁二醇、四氫呋喃、琥珀酸、不飽和聚酯樹脂、醇酸樹脂等的原料，也用于醫藥和農藥。
1. Used as raw materials for the production of 1,4-butanediol, tetrahydrofuran, succinic acid, unsaturated polyester resin, alkyd resin, etc., as well as in pharmaceuticals and pesticides.
2、金屬選礦中充當捕收劑。
2. Act as a collector in metal beneficiation.
3、用于合成，也用作合成纖維中間體。
3. Used for synthesis and also as an intermediate for synthetic fibers.
4、順酐是一種重要的不飽和有酸酐的酐基本原料，在農藥上用于合成磷殺蟲藥的中間體順丁烯二酸二乙酯、噠嗪硫磷的中間體1-苯基-3，6-二羥基噠嗪，以及擬除蟲菊酯殺蟲藥胺菊酯、克菌丹的中間體。此外，還用于不飽和聚酯樹脂、油墨助劑、造紙助劑、涂料以及醫藥工業、食品工業等。
4. Maleic anhydride is an important unsaturated anhydride basic raw material used in the synthesis of phosphorus insecticides in pesticide production, including diethyl maleate, 1-phenyl-3,6-dihydroxypyridazine, as an intermediate of pyridazinon, and intermediate of pyrethroid insecticides such as fenpropathrin and chloramphenicol. In addition, it is also used in the production of unsaturated polyester resin, ink additives, paper additives, coatings, as well as the pharmaceutical and food industries.
5、主要用于不飽和聚酯樹脂、醇酸樹脂、長效碘胺的原料。也是涂料、馬來松香、聚馬來酐、順酐-苯乙烯共聚物。也是油墨助劑、造紙助劑、增塑劑和酒石酸、富馬酸、四氫呋喃等的化工原料。
5. Mainly used as raw materials for the production of unsaturated polyester resin, alkyd resin, and long-acting iodine amine. It is also a coating, maleic rosin, polymaleic anhydride, and maleic anhydride styrene copolymer. It is also a chemical raw material for producing ink additives, papermaking additives, plasticizers, and tartaric acid, fumaric acid, tetrahydrofuran, etc.
6、順酐是一種常用的重要基本化工原料。其下游產品有著相當廣泛的開發和應用前景。主要用于合成不飽和聚酯樹酯，它是制造汽車部件、船舶、耐腐蝕性化工設備和日用品的原料。順酐也是潤滑油的添加劑、涂料、農藥、富馬酸、共聚物、食品添加劑等重要中間體。
6. Maleic anhydride is a commonly used and important basic chemical raw material. Its downstream products have a wide range of development and application prospects. Mainly used for synthesizing unsaturated polyester resin, it is a raw material for manufacturing automotive components, ships, corrosion-resistant chemical equipment, and daily necessities. Maleic anhydride is also an important intermediate in the production of lubricants, coatings, pesticides, fumaric acid, copolymers, food additives, and other additives.
順酐的合成方法：
Synthesis method of maleic anhydride:
1、苯氧化法。
1. Benzene oxidation method.
苯蒸氣和空氣在以V2O5-MnO3等為活性組分，α-Al2O3為載體的催化劑上發生氣相氧化反應生成順酐。苯氧化法是順酐的傳統方法，工藝技術成熟可靠。
Benzene vapor and air are active components such as V2O5-MnO3, α- Gas phase oxidation reaction occurs on the catalyst supported by Al2O3 to generate maleic anhydride. The benzene oxidation method is a traditional production method for maleic anhydride, with mature and reliable process technology.
2、C4烯烴法。
2. C4 olefin method.
該法是以混合C4餾分中的有效成分正丁烯、丁二烯等為原料，和空氣(或氧氣)，在V2O5-P2O5系催化劑作用下經氣相氧化反應生成順酐，其中正丁烯在反應過程中先脫氫生成丁二烯，再氧化生成順酐。在反應過程中，除生成主產物外，還副產生成一氧化碳、二氧化碳和水以及少量的乙醛、乙酸和呋喃等，原料單耗高，收率低，該法已經逐漸被淘汰。
This method uses the active components such as n-butene and butadiene in the mixed C4 fraction as raw materials, and air (or oxygen), to undergo gas-phase oxidation reaction under the action of V2O5-P2O5 catalyst to generate maleic anhydride. n-butene is first dehydrogenated to produce butadiene during the reaction process, and then oxidized to produce maleic anhydride. In the reaction process, in addition to generating the main product, there are also by-products such as carbon monoxide, carbon dioxide, and water, as well as a small amount of acetaldehyde, acetic acid, and furan. The raw material consumption is high, and the yield is low. This method has gradually been phased out.
3、苯酐副產法。
3. Phthalic anhydride by-product method.
在苯酐時，可以副產得到一定數量的順酐產品，其產量約為苯酐產量的5%。在苯酐中，反應尾氣經洗滌塔除去物后排放到大氣中，洗滌液為順酐和少量的苯甲酸、苯二甲酸等雜質，經濃縮精制和加熱脫水后得到順酐產品。
When producing phthalic anhydride, a certain amount of maleic anhydride products can be obtained as a byproduct, with a yield of approximately 5% of the phthalic anhydride production. In the production of phthalic anhydride, the reaction tail gas is discharged into the atmosphere after being removed by a washing tower. The washing solution consists of maleic anhydride and a small amount of impurities such as benzoic acid and phthalic acid. After concentration, refinement, and heating dehydration, the product of maleic anhydride is obtained.
4、正丁烷氧化法。
4. N-butane oxidation method.
正丁烷氧化工藝是以正丁烷為原料，在V2O5-P2O5系催化劑作用下發生氣相氧化反應生成順酐。該工藝自實現工
The n-butane oxidation process takes n-butane as the raw material and undergoes a gas-phase oxidation reaction to produce maleic anhydride under the action of V2O5-P2O5 catalyst. This process is self actualized
