Production And Processing Method Of Stearic Acid

wallpapers Robot Industry 2020-12-10
Stearic acid, or octadecanoic acid, has a molecular formula of C18H36O2, which is produced by the hydrolysis of fats and oils, and is mainly used to produce stearates. Each gram is dissolved in 21ml ethanol, 5ml benzene, 2ml chloroform or 6ml carbon tetrachloride.
 
Production and processing methods
 
It is mainly industrially produced by the oil hydrolysis method.
Grease hydrolysis is divided into three types according to pressure conditions:
1. Hydrolysis with catalyst under normal pressure, the hydrolysis cycle is long, it takes tens of hours, the conversion rate of fatty acid is low, and the separation effect in the later stage is poor.
2. Medium-pressure hydrolysis: No catalyst is needed, the hydrolysis cycle is about ten hours, and the conversion rate basically reaches 90%. It is an intermittent reaction and is gradually being eliminated in China.
3. High-pressure hydrolysis: no catalyst is needed, the hydrolysis cycle is about 5 hours, the conversion rate is basically 98-99%, and continuous production. The prepared stearic acid has good color, high content and few impurities.

 
At present, domestic projects are basically produced by this method. The technology has been researched and developed domestically, and some have introduced foreign technology and equipment.
The domestic source of stearic acid is basically made from imported palm oil as raw material after catalytic hydrogenation, followed by high-pressure hydrolysis, fatty acid dehydrogenation, and then vacuum distillation.
 
Stearic acid exists in animal fats, oils and some vegetable oils in the form of glycerides. These oils are hydrolyzed to obtain stearic acid.
Stearic acid is a kind of fatty acid that exists widely in nature. Almost all oils contain stearic acid with varying content. The content of stearic acid in animal fat is relatively high. For example, the content in tallow can reach 24%, and the content in vegetable oil is less. , Tea oil is 0.8%, palm oil is 6%, but the content of cocoa butter is as high as 34%.
 
The production methods of industrial stearic acid mainly include fractionation method and pressing method. The decomposing agent is added to the hardened oil, then hydrolyzed to obtain crude fatty acid, and then washed with water, distilled, and decolorized to obtain the finished product. At the same time by-product glycerin.

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