Synthesis and Application of Isopropyl Alcohol_Industrial Additives

Isopropyl alcohol (IPA) is an organic compound and the simplest secondary alcohol. It is a colorless and transparent liquid, flammable, and smells like a mixture of ethanol and acetone. Soluble in water and most organic solvents such as alcohol, ether, benzene, and chloroform. Isopropyl alcohol is an important chemical product and raw material, mainly used in pharmaceuticals, cosmetics, plastics, spices, coatings, etc.

Synthesis method of isopropyl alcohol

1. Water connection is legal

Isopropyl alcohol can be produced by fermentation, and 16 tons of grain are consumed to produce 1t of 2-propanol. The propylene hydration method is used in industry, and the sulfuric acid hydration method (also known as the indirect hydration method) was used earlier. Propylene reacts with sulfuric acid to first obtain isopropyl hydrogen sulfate, which is hydrolyzed to form isopropyl alcohol.

Features: This method does not have high requirements on the purity of propylene, and the propylene conversion rate can reach 50%-60%, which can reduce refining costs. However, it consumes a large amount of sulfuric acid, and there are problems such as equipment corrosion and 40% of waste concentrated sulfuric acid.

2. Direct hydration method

In 1951, the British Burnemann Chemical Industry Company began to produce 2-propanol using the direct hydration method of propylene. Propylene and water are heated and pressurized in the presence of a catalyst to perform a hydration reaction.

3. Hydrogenation of acetone to produce isopropanol

This method emerged after 2005. It uses copper or zinc oxide as a carrier catalyst or nickel-based catalyst at 70-200°C and normal pressure. Acetone is hydrogenated to form isopropyl alcohol. The selectivity of this method is 97%, and the acetone conversion rate is 85%-90%. Features: low energy consumption and light equipment corrosion, but the cost of acetone raw materials is high. Mainly due to the price inversion between acetone and isopropyl alcohol (traditionally, one of the consumption uses of isopropyl alcohol is dehydrogenation to acetone).

With the development of science and technology, people want to obtain higher purity isopropyl alcohol. How to achieve this?

4. High-efficiency and energy-saving process for ultra-clean and high-purity isopropyl alcohol

It is characterized by: first entering industrial-grade isopropyl alcohol with a mass percentage concentration of 98% from the bottom of the molecular sieve adsorption tower, dehydrating the molecular sieve adsorption tower and then flowing out from the top of the tower to obtain high purity with a water content of less than 100 ppm. For isopropyl alcohol, the high-purity isopropyl alcohol taken out of the molecular sieve adsorption tower is sent to the filter to remove particles with a particle size of more than 1 μm, and then the filtered high-purity isopropyl alcohol is sent to the distillation tower, and after rectification Entering the condenser, the condensation is completed to obtain the ultra-clean and high-purity isopropyl alcohol.

Applications of isopropyl alcohol

1. Dissolution

Isopropyl alcohol is widely used as a solvent due to its miscibility with water, fatty compounds and many organic compounds. As a solvent, it is a relatively cheap solvent in industry and has wide uses. It can be freely mixed with water and has stronger solubility for lipophilic substances than ethanol. It can be used as a solvent for nitrocellulose, rubber, paint, shellac, alkaloids, etc. It can be used to produce coatings, inks, extraction agents, aerosol agents, etc.

2.Bactericidal effect

Isopropyl alcohol has excellent bactericidal effect, and its 70% aqueous solution is a massage agent widely used in homes and hospitals; aerosols such as insecticides, medicinal sprays, and glass cleaners for indoor and garden use.

3. Chemical intermediates

Because isopropyl alcohol can easily obtain ketones, esters and ethers through oxidation and catalytic reactions, and can also undergo many typical low molecular weight lower alcohol reactions, it is an important chemical intermediate and is used in fine chemicals. widely.

1 Isopropylamine produced by the ammoniation of isopropyl alcohol is an important intermediate for the synthesis of pesticides, pharmaceuticals and chemical products, and has developed rapidly in recent years. In terms of pesticides, isopropylamine is used to produce herbicides such as atrazine, prometryn, and glyphosate. In medicine, it is used to produce cardiovascular drugs such as propranolol, rifampicin, Ganle, and chloramphenicol. Isopropylamine is also used in the production of It can be used as hard water treatment agent and detergent, rubber vulcanizing agent, surfactant, textile auxiliary, detergent, depilatory agent, etc.

2 Methyl isobutyl ketone (MIBK) derived from isopropyl alcohol is a medium-boiling solvent with excellent performance and can be derived from many important chemical products. MIBK can be used as nitrocellulose, ethyl cellulose, etc. Solvents for cellulose-based coatings and resin-based coatings can also be used as solvents in the production of high-grade automotive paints, inks, audio tapes, and video tapes.

3Methyl isobutyl carbinol (MIBC), diisobutyl ketone (DIBK) and isopropyl acetate generated from isopropyl alcohol are mainly used in inks, coatings and paints.

4Isopropyl ether products produced by dehydration of isopropyl alcohol with sulfuric acid are mainly used in lubricating additives, cosmetics and personal protective equipment.

4.Other functions

For example, it can be used as antifreeze; as a petroleum fuel additive; it can also be used as a dehydrating agent in airports and railways; in daily chemicals, isopropyl alcohol can be used as cleaners, disinfectants, cosmetics and personal protective equipment, etc. ; Used as a coolant in beer production; as a dispersant in pigment production; as a fixative in the printing and dyeing industry; as a defoaming agent for PVC in the production of plastic floors; in addition, it can be used as a cleaner and desiccant in the production of electronic tubes, etc. .