An introduction to the applications of isopropyl alcohol dehydration and purification—save this now!

Isopropyl alcohol (IPA), also known as 2-propanol, is an organic compound with the molecular formula C3H8O. It is the isomer of n-propanol, a colorless, transparent liquid that is soluble in water and also miscible with alcohols, ethers, benzene, and many other organic solvents.

Isopropyl alcohol is an important chemical product and raw material, widely used in industries such as pharmaceuticals, cosmetics, plastics, fragrances, and coatings. What are the applications of dehydrated and refined isopropyl alcohol? Let’s take a look.

1. As a chemical raw material, it can be used to produce hydrogen peroxide, methyl isobutyl ketone, diisobutyl ketone, isopropylamine, isopropyl ether, various isopropyl esters of fatty acids, and isopropyl esters of chlorinated fatty acids, among others. In the development of the fine analytical chemistry industry, it can be directly employed in the production of isopropyl nitrate, isopropyl xanthate, tri‑isopropyl phosphite, aluminum isopropoxide, as well as pharmaceuticals and agrochemicals. Furthermore, dehydrative purification of isopropanol is utilized in industrial-scale production of isopropyl acetate and thymol, and also serves as an additive to enhance gasoline performance.

2. As a solvent, it is fully miscible with water, exhibits superior solubility for lipophilic substances compared to ethanol, and can be used as a solvent for rubber, coatings, shellac, and other materials. In the production of paints, inks, extractants, aerosols, and similar products, it also serves as an antifreeze, detergent, gasoline blending additive, dispersant in pigment manufacturing, color‑fixing agent in the textile dyeing and printing industries, anti‑fogging agent for glass and transparent plastics, and a dehydrating refining diluent for adhesives. Additionally, it finds applications as an antifreeze and a dehydrating agent.

3. As a chromatographic analytical technique, it is used to determine standard reference materials of barium, calcium, copper, magnesium, nickel, potassium, sodium, strontium, nitrite, cobalt, and others.

4. In the electronics industry, isopropyl alcohol can be used as a cleaning agent and degreaser after dehydration and purification.

5. In the petroleum industry, cottonseed oil extract can also be used to degrease animal tissue membranes.

What is the dehydration pervaporation step for isopropanol? Let’s take a look.

What is the dehydration pervaporation step for isopropanol? Let’s take a look.

1. The aqueous isopropanol feed, after being buffered in a storage tank, is pumped at a mass flow rate of 1,000 kg/h into the heat-exchange unit, where it undergoes preliminary heating. The heat source for this preheating is the vapor generated from the isopropanol product stream of the membrane separation module. Following preheating, the feed temperature is raised to 70–90°C, ideally maintained at 80 ± 2°C.

2. The preheated feedstock (pumped through piping) enters the evaporation unit, where the isopropyl alcohol containing 10% water is vaporized. The vaporized stream is at a pressure of 0.2–0.4 MPa and a temperature of 100–130°C, after which it proceeds to the membrane separation module for dehydration, completing half of the process.

3. The permeate side of the membrane separation module is maintained under vacuum by a fourth fluid‑handling device (a vacuum pump), with a vacuum pressure ranging from 0 to 30 kPa. The permeated water vapor is condensed in a third heat exchanger to produce liquid permeate, which is then buffered in a third storage tank and pumped to a storage tank by a third fluid‑handling system. The entire process of purifying isopropanol using a molecular sieve membrane is conducted in continuous mode.