Synthetic method

1. The production of methanol is mainly a synthetic method, and the chemical reaction formula for the synthesis is: 2H2 + CO → CH3OH

2. The crude methanol after synthesis is subjected to pre-rectification to remove methyl ether. (The high pressure method was the first to achieve industrial synthesis, but because of its large energy consumption, complex processing, demanding materials, and many by-products in the product, it was replaced by ICI low and medium pressure methods and Lurgi low and medium pressure methods. Almost all methanol uses the method of carbon monoxide pressurized catalytic hydrogenation. The process includes gas generation, synthesis purification, methanol synthesis, and crude methanol rectification.)

3. Purify the crude methanol. The purification process includes rectification and chemical treatment. Chemical treatment mainly uses alkali to destroy impurities that are difficult to separate during rectification, and adjusts the pH value; rectification is mainly to remove volatile components such as dimethyl ether, as well as refractory ethanol, high alcohols and water. The purity after crude distillation can generally reach more than 98%.

4. Distillation of industrial methanol will reduce the water content to below 0.01%. After treatment with sodium hypoiodate, acetone can be removed. Pure methanol was obtained by distillation.

5. BV-Ⅲ grade methanol is mainly prepared by distillation. Using industrial methanol as raw material, high-purity methanol products are obtained through rectification, ultra-clean filtration, and ultra-clean packaging. Generally, industrial methanol is used as the raw material, and the water is often removed by distillation under pressure. The top of the column is controlled at 64-65 ° C, and the insoluble matter can be removed by filtration.

Application area

One of the basic organic raw materials, used to make a variety of organic products such as methyl chloride, methylamine and dimethyl sulfate. It is also one of the raw materials for pesticides (insecticides, acaricides), medicines (sulfonamides, hemycin, etc.), and one of the raw materials for the synthesis of dimethyl terephthalate, methyl methacrylate and methyl acrylate.

The main application area of methanol is the production of formaldehyde. Formaldehyde can be used to produce adhesives. It is mainly used in the wood processing industry. Secondly, it is used as a treatment agent for molding materials, coatings, textiles and paper.

Another major use of methanol is in the production of acetic acid. The consumption of acetic acid accounts for about 7% of global methanol demand. It can produce vinyl acetate, cellulose acetate, and acetate, and its demand is closely related to the needs of coatings, adhesives and textiles.

Methanol can be used to make methyl formate. Methyl formate can be used to produce formic acid, formamide and other fine chemical products. It can also be used as pesticide, fungicide, fumigant, tobacco treatment agent and gasoline additive.

Methanol can also be used to produce methylamine. Methylamine is an important fatty amine. It uses liquid nitrogen and methanol as raw materials and can be separated into monomethylamine, dimethylamine, and trimethylamine through processing. It is one of the basic chemical raw materials.

It can be synthesized into dimethyl carbonate, which is an environmentally friendly product, used in medicine, agriculture and special industries.

It can be synthesized into ethylene glycol and is one of the petrochemical intermediate raw materials. It can be used to produce polyester and antifreeze.

Can be used to make growth promoters. It can increase the yield of crops in large quantities, keep the branches and leaves fresh and sturdy, and not wither in the summer. It can greatly reduce irrigation water and is beneficial to the growth of dryland crops.

It can synthesize methanol protein. Methanol protein produced by microbial fermentation using methanol as raw material is called second-generation single-cell protein. Compared with natural protein, it has higher nutritional value. Crude protein content is much higher than fish meal and soybean. Rich in amino acids, minerals and vitamins, can replace fish meal, soy, bone meal, meat and skimmed milk meal.

Methanol is used as a cleaning and degreasing agent. MOS grade is mainly used for discrete devices, medium and large-scale integrated circuits, and BV-Ⅲ grade is mainly used for ultra-large scale integrated circuit process technology.

Used as analytical reagents, such as solvents, methylation reagents, and chromatography reagents. Also used in organic synthesis.

Methanol is generally a better solvent than ethanol and can dissolve many inorganic salts. It can also be blended with gasoline as an alternative fuel. Since the 1980s, methanol has been used to produce gasoline octane additive methyl tert-butyl ether, methanol gasoline, methanol fuel, and methanol protein, which has promoted the development of methanol production and market demand.

Methanol is not only an important chemical raw material, but also an excellent energy source and vehicle fuel. The reaction of methanol with isobutylene yields MTBE (methyl tert-butyl ether), which is a high-octane lead-free gasoline additive and can also be used as a solvent. In addition, it can also produce olefins and propylene to solve the problem of resource shortage.

Methanol can be used to produce dimethyl ether. In addition to dimethyl ether, it has a wide range of uses in daily chemicals, pharmaceuticals, pesticides, dyes, and coatings. Easily pressurized for liquid, easy storage and other fuel properties. A new liquid fuel prepared from methanol and dimethyl ether at a certain ratio is called alcohol ether fuel. Its combustion efficiency and thermal efficiency are higher than liquefied gas.

Safety measures

Methanol is well known and is toxic. Industrial alcohol contains about 4% of methanol. If fake elements are used as edible alcohol to make fake wine, methanol poisoning will occur after drinking. The lethal dose of methanol is about 70 ml.

The toxicity of methanol has the greatest impact on the nervous system and blood system of the human body. It can cause toxic reactions when ingested through the digestive tract, respiratory tract, or skin. In a methanol production plant, relevant Chinese authorities have stipulated that the concentration of air methanol is limited to PC-stel = 50mg / m3 and PC-TWA = 25mg / m3. Gas masks must be worn when working on-site with methanol gas, and factory wastewater must be treated. Emission, allowable methanol content less than 200mg / L.

The poisoning mechanism of methanol is that methanol is metabolized by the human body to produce formaldehyde and formic acid (commonly known as formic acid), which then harms the human body. Common symptoms include drunkenness, headaches, nausea, vomiting, and blurred vision a few hours later. In severe cases, blindness can lead to death. Causes of blindness: Formic acid, a metabolite of methanol, accumulates in the eye area and destroys visual nerve cells. Cranial nerves are also damaged, causing permanent damage. After formic acid enters the blood, it will make the tissue more and more acidic, damage the kidneys and cause renal failure.