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1. One of the basic organic raw materials. Mainly used for manufacturing organic products such as formaldehyde, acetic acid, methyl chloride, methylamine and dimethyl sulfate;
2. Used as solvent for paint, varnish, shellac, ink, adhesive, dye, alkaloid, cellulose acetate, cellulose nitrate, ethyl cellulose, polyvinyl butyral, etc.
3. It is the raw material for manufacturing pesticides, medicines, plastics, synthetic fibers and organic chemical products such as formaldehyde, methylamine, methyl chloride and dimethyl sulfate. Others are used as automobile antifreeze, metal surface cleaning agent and alcohol denaturant;
It is an important fuel and can be mixed with gasoline as an alternative fuel. Since 1980s, methanol has been used to produce gasoline octane number additives such as methyl tert-butyl ether, methanol gasoline, methanol fuel and methanol protein, which greatly promoted the development of methanol production and market demand. Methanol has been used as a fuel additive for F/KLOC-0 racing cars and widely used in methanol fuel cells.
5. Used as analytical reagents, such as solvents, methylation reagents and chromatographic analysis reagents. Also used in organic synthesis;
6. Methanol is used as cleaning degreaser, MOS grade is mainly used for discrete devices and medium and large scale integrated circuits, and BV-III grade is mainly used for VLSI process.
Use of methanol
Methanol is a widely used basic organic chemical raw material and high-quality fuel. Mainly used in fine chemicals, plastics and other fields, it is used to make various organic products such as formaldehyde, acetic acid, methyl chloride, methylamine and dimethyl sulfide, and it is also one of the important raw materials for pesticides and medicines. After deep processing, methanol can be used as a new clean fuel or mixed with gasoline. The reaction of methanol and ammonia can produce monomethylamine.
Source of methanol
Methanol can be made from coal, especially inferior high-sulfur coal and coke oven gas. It can also be extracted from biomass (such as forest trees and organic garbage). Methanol production is a mature industry in China's chemical industry, with simple production process and low investment and production cost. In 20 12, China's annual methanol production capacity was 50.74 million tons, and the annual output was about 26.4 million tons, which was a serious overcapacity. A new factory with an annual output of 600,000 tons will be built with an investment of about 2 billion yuan. Its production technology and equipment can be completely based in China, with independent intellectual property rights.
manufacturing method
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. The purification process of crude methanol includes 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, and difficult volatile components such as ethanol, higher alcohols and water. The purity after crude extraction can generally reach above 98%. )
The water content of industrial methanol was reduced to below 0.0 1% by rectification. Acetone can be removed by treatment with sodium iodate. Rectifying to obtain pure methanol;
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.
It can also be separated from wood vinegar obtained in the process of wood dry distillation;
Methanol is mainly prepared by distillation. Using industrial methanol as raw material, high-purity methanol products were obtained through rectification, ultra-clean filtration and ultra-clean sub-packaging.
Toxicity information
Methanol is very toxic to human body, because methanol will be oxidized into formaldehyde and formic acid (formic acid) which are more toxic than methanol in human metabolism, so drinking alcohol containing methanol will lead to blindness, liver disease and even death. If you drink more than 4 ml by mistake, you will have poisoning symptoms. If you drink more than 10 ml, you will be blind due to permanent damage to the optic nerve, and 30 ml can already lead to death.
The initial symptoms of poisoning include rapid heartbeat, abdominal pain, vomiting (vomiting), diarrhea, loss of appetite, headache, dizziness and general weakness. In severe cases, people will be unconscious and have shortness of breath to failure. Blindness is its most typical symptom. When methanol enters the blood, it will make the tissue acidic, cause acidosis and lead to renal failure. The worst thing is death.
However, there are still many unscrupulous businessmen who blend fake wine with industrial alcohol containing methanol and sell it regardless of life and death. But there is also a very small amount of methanol in the genuine wine, which is also one of the reasons for the hangover. Methanol poisoning can be detoxified with ethanol. Because methanol is oxidized to formaldehyde by alcohol dehydrogenase in the liver, and then formic acid. Ethanol can compete with methanol for ethanol dehydrogenase, giving the human body time to eliminate methanol.
Symptomatic measures
Physical hazard: it has anesthetic effect on the central nervous system; It has a special selective effect on optic nerve and retina, causing pathological changes; Can cause metabolic acidosis.
Acute poisoning: mild upper respiratory tract irritation after short-term inhalation (gastrointestinal irritation after oral administration); After a period of incubation, headache, dizziness, fatigue, dizziness, drunkenness, confusion, delirium and even coma appear. Optic nerve and retinopathy may include blurred vision, diplopia and even blindness. When metabolic acidosis occurs, the binding force of carbon dioxide decreases and breathing accelerates.
Chronic effects: neurasthenia syndrome, autonomic nerve dysfunction, mucosal irritation, decreased vision, etc. Skin diseases and dermatitis appear on the skin.
Skin contact: take off contaminated clothes and rinse skin thoroughly with soapy water and clean water.
Eye contact: Lift eyelids and rinse with running water or normal saline. See a doctor.
Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor.
Intake: Drink enough warm water to induce vomiting. Gastric lavage with clean water or 1% sodium thiosulfate solution. See a doctor.
Toxicity: It belongs to moderate toxicity.
Acute toxicity: LD505628mg/kg (taken orally by rats); 15800mg/kg (rabbit percutaneous); LC5082776mg/kg for 4 hours (inhaled by rats); People take 5 ~ 10 ml orally, and the incubation period is 8 ~ 36 hours, causing coma; Retinitis and blindness occurred within 48 hours after oral administration of 1.5 ml; 30 ~ 100 ml oral dose seriously damaged the central nervous system, leading to respiratory failure and death.
Subacute and chronic toxicity: Rats inhaled 50mg/m3, 12 hours/day for 3 months, and within 8 ~ 10 weeks, tracheal and bronchial mucosa damage and cerebral cortical cell malnutrition were observed.
Mutagenicity: microbial mutagenicity: Saccharomyces cerevisiae 12pph. DNA inhibition: 300mmol/L human lymphocytes.
Reproductive toxicity: The lowest oral toxic concentration (TDL0) of rats is 7500mg/kg (7 ~ 19 days of pregnancy), which affects the behavior of newborn rats. The lowest toxic concentration of inhalation in rats (TCL 0):20000 ppm(7 hours), (1 ~ 22 days of pregnancy), causing abnormal development of musculoskeletal, cardiovascular and urinary systems.
Emergency treatment
Quickly evacuate the personnel in the leaked and polluted area to a safe area, isolate them, and strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and anti-static work clothes. Don't touch the leak directly. Cut off the leakage source as much as possible. Prevent it from flowing into confined spaces such as sewers and flood discharge ditches. Small amount of leakage: adsorbed or absorbed by sand or other nonflammable substances. It can also be washed with plenty of water, diluted and put into the wastewater system. A large number of leaks: damming or digging holes to contain them. Cover with foam to reduce steam disaster. Use explosion-proof pump to transfer it to tank car or special collector, and recycle it or transport it to waste disposal site for treatment.
Matters needing attention
Operation: airtight operation, strengthen ventilation. Operators must be specially trained and strictly abide by the operating procedures. Operators are advised to wear filter gas masks (half masks), chemical safety glasses, anti-static work clothes and rubber gloves. Stay away from kindling and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation system and equipment. Prevent the steam in the workplace from leaking into the air. Avoid contact with oxidants, acids and alkali metals. When filling, the flow rate should be controlled, and grounding devices should be provided to prevent static electricity accumulation. Equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment. Empty containers may leave harmful substances behind.
Storage: Store in a cool and ventilated warehouse. Stay away from fire and heat sources. The reservoir temperature should not exceed 30℃. Keep the container sealed. Should be stored separately from oxidants, acids, alkali metals, etc. , and should not be mixed. Adopt explosion-proof lighting and ventilation facilities. It is forbidden to use mechanical equipment and tools that are easy to generate sparks. The storage area should be equipped with emergency response equipment for leakage and suitable accommodation materials.