How is methanol made?

1. the production of methanol mainly depends on synthesis, and the chemical reaction formula of synthesis is: 2H2+CO→CH3OH[3]?

2. Pre-rectifying the synthesized crude methanol to remove methyl ether. High-pressure method is the earliest method to realize industrial synthesis, but it is replaced by ICI low-pressure and medium-pressure method and Lurgi low-pressure and medium-pressure method because of its high energy consumption, complex process, harsh requirements on materials and many by-products in products. Almost all methanol in industry is synthesized by catalytic hydrogenation of carbon monoxide under pressure, and the process includes gasification, synthesis and purification, methanol synthesis and crude methanol rectification. )

3. Purification of crude methanol, including rectification and chemical treatment. Chemical treatment mainly uses alkali to destroy impurities that are difficult to separate during distillation and adjust pH value. Distillation is mainly to remove volatile components such as dimethyl ether, as well as ethanol, higher alcohols and water which are difficult to volatilize. The purity after crude extraction can generally reach above 98%.

4. Reduce the water content of industrial methanol to below 0.0 1% by rectification. Acetone can be removed by treatment with sodium iodate. Purified methanol is obtained by rectification.

5. The preparation of BV-Ⅲ grade methanol mainly adopts rectification process. Using industrial methanol as raw material, high-purity methanol products were obtained through rectification, ultra-clean filtration and ultra-clean sub-packaging. Generally, industrial methanol is used as raw material, water is distilled at atmospheric pressure, the top of the tower is controlled at 64 ~ 65℃, and insoluble substances are removed by filtration.

Second, dry distillation method

Methanol was first made by dry distillation of wood, so methanol is also called wood alcohol. There is little methanol in natural free state, so this method not only wastes wood, but also contains impurities such as acetone, which is difficult to remove. Because this method can't meet the needs, people began to stop using this method gradually after 1924.

Extended data:

Methanol (CH3OH) is a saturated monohydric alcohol with the simplest structure, with CAS number of 67-56- 1 or 170082- 17-4, molecular weight of 32.04 and boiling point of 64.7℃.

It is also called "lignin alcohol" or "lignin essence" because it was first discovered in dry distillation wood. It is a colorless, alcoholic and volatile liquid. The lowest dose of human oral poisoning is about 100mg/kg body weight, and 0.3 ~ 1 g/kg can cause death.

It is used to make formaldehyde, pesticides and so on. And used as extractant of organic matter and denaturant of alcohol. The finished product is usually made by the reaction of carbon monoxide and hydrogen.

References:

Baidu encyclopedia-methanol