Synthesis process of malonic acid

The invention relates to a synthesis process of malonic acid. The process comprises the following steps: firstly, pretreating resin, and then adding fuming sulfuric acid into the resin to carry out a first sulfonation reaction; sulfuric acid and water are sequentially added for a second sulfonation reaction, a product obtained after the second sulfonation reaction is added into L acid for a coordination complexation reaction, and solid superacid is obtained after cleaning; solid superacid is used as a catalyst to catalyze and hydrolyze a dimethyl malonate raw material, and a malonic acid product is obtained through separation and purification. The superstrong solid acid with a strong proton acceptor is used as the catalyst, and the catalyst has the advantages of high strength, long service life, low cost, no pollution, no waste salt and the like. 本发明涉及一种丙二酸的合成工艺。所述工艺包括以下步骤：先对树脂进行预处理，然后在树脂中加入发烟硫酸进行第一次磺化反应；依次加入硫酸和水进行第二次磺化反应，将经第二次磺化反应后的产物加入L酸中进行配位络合反应，清洗后得到固体超强酸；使用固体超强酸作为催化剂催化水解丙二酸二甲酯原料，经分离、提纯，得到丙二酸产品。本发明采用具有强质子