The traditional production method of isopropyl alcohol in industry is mainly based on propylene hydration, and the process route can be divided into two types: indirect water law and direct water law.
1.1 Indirect water law of propylene
Propylene indirect hydration, also known as propylene sulphuric acid hydration, dissolves propylene in a sulphuric acid solution to produce the isopropyl hydrogen sulphate and diisopropyl sulphate, which is then hydrolyzed to produce crude isopropanol. High purity isopropyl alcohol product. The process is complicated, the selectivity is low, the equipment corrosion is serious, the waste water and waste gas treatment are difficult, and the raw material consumption and production cost are high, which limits its development.
1.2 Propylene Hydrolysis
Propylene direct hydration is currently the main method for the industrial production of isopropanol. It is the direct hydration reaction of propylene in the presence of a catalyst to isopropanol, and by-production of n-propanol. Propylene direct water can be divided into three types: gas-phase direct water law, liquid-phase direct water law and gas-liquid miscibility.
The gas-phase direct water law is represented by the Vibha method developed by Germany's Weiba Company; the liquid-phase direct water law is represented by the solution method of Japan's Deshan Cao Da Company; and the gas-liquid miscible method is by Deutche, USA. Texaco's ion exchange resin method is representative.
Propylene has good selectivity for direct hydration, low by-products, high total propylene conversion rate, high selectivity for isopropanol production, greatly improved equipment corrosion and pollution problems, short process flow, simple equipment, and is currently the mainstream production process. .