Coal chemical industry, what is coal chemical industry?

Coal chemical industry refers to the process of using coal as raw material and transforming coal into gas, liquid and solid fuel and chemicals through chemical processing. It mainly includes coal gasification, liquefaction, dry distillation, tar processing and calcium carbide acetylene chemical industry. Coal chemical process The industry of converting coal into gas, liquid and solid products or semi-products, and then further processing into chemical and energy products.

Including coking, calcium carbide chemistry, coal gasification and so on. With the decrease of petroleum resources in the world, coal chemical industry has a broad prospect.

The process of converting coal into gas, liquid and solid fuels and chemicals by chemical processing.

It mainly includes coal gasification, liquefaction, dry distillation, tar processing and calcium carbide acetylene chemical industry.

Among the production technologies available in the coal chemical industry, coking was the earliest process and is still an important part of the chemical industry today.

Coal gasification plays an important role in coal chemical industry, is used to produce various gas fuels, is a clean energy, is conducive to improving people's living standards and environmental protection; Syngas produced from coal gasification is the raw material for a variety of products such as synthetic liquid fuels.

Direct coal liquefaction, or high pressure hydroliquefaction of coal, can produce artificial petroleum and chemical products. In times of oil shortage, coal liquefaction products will replace the current natural oil.

Development and application

Coal chemical industry began in the second half of the 18th century, and a complete coal chemical system was formed in the 19th century. In the 20th century, many organic chemicals that use agricultural and forestry products as raw materials are mostly produced by coal, and coal chemical industry has become an important part of the chemical industry. After the Second World War, the petrochemical industry developed rapidly, and the production of many chemicals was transferred from coal to oil and natural gas as raw materials, thus weakening the position of coal chemical industry in the chemical industry. The chemical structure of organic matter in coal is based on the aromatic thick ring as the unit core, connected by bridge bonds, and the macromolecular structure with various functional groups. Through thermal processing and catalytic processing, coal can be converted into various fuels and chemical products. Coking is the earliest and still the most important method, its main purpose is to produce metallurgical coke, while by-product gas and benzene, toluene, xylene, naphthalene and other aromatics. Coal gasification also plays an important role in coal chemical industry, which is used to produce city gas and various fuel gases, and also used to produce syngas. Liquid fuel is mainly produced in the process of coal low temperature distillation, direct coal liquefaction and indirect coal liquefaction.

Processing process

The chemical structure of organic matter in coal is the aromatic thick ring as the unit core and consists of bridge bond

Processing process

Macromolecular structures connected with each other and with various functional groups (see coal chemistry) can be converted into various fuels and chemical products through thermal and catalytic processing (see figure). In the various chemical processes of coal, coking is the earliest and still the most important method, its main purpose is to produce metallurgical coke, while by-product gas and benzene, toluene, xylene, naphthalene and other aromatics; Coal gasification also plays a very important role in coal chemical industry, which is used to produce city gas and various fuel gases (widely used in machinery, building materials and other industries), and is also used to produce syngas (as a raw material for synthesis of ammonia and methanol). Coal low temperature distillation, direct coal liquefaction and indirect coal liquefaction are mainly the production of liquid fuel, which has been developed in the first half of the 20th century. After the Second World War, due to the economic inability of its products to compete with natural oil, it tends to stop. At present, only in South Africa still has indirect coal liquefaction plants. Other direct chemical processing of coal, the production of lignite wax, sulfonated coal, humic acid and activated carbon, etc., still have small-scale applications.

Coal chemical equipment

There are many kinds of coal chemical equipment, mainly divided into dynamic and static two categories. Among them, pressure vessels such as hydrogenation reactors, gasifiers, reduction furnaces, heat exchangers, carrying vessels, pipelines, valves and so on belong to static equipment, and pumps, fans, compressors, air separation equipment and so on belong to dynamic equipment. Gasifier is the most critical equipment of coal chemical industry, and most coal chemical projects need to go through the process of converting coal into syngas through gasifier. Air separation equipment is also one of the key equipment of coal chemical industry, coal gasification and coal liquefaction need to use a lot of high-purity oxygen, and have high technical barriers.

World coal chemical industry

The coal produced in the world is used mainly as fuel for power stations and industrial boilers; A certain proportion is used in coal chemical industry, which is mainly coking and gasification of coal. In the 1980s, the annual production of coke in the world was about 340Mt, and the annual production of coal tar was about 16Mt (from which the naphthalene extracted was about 1Mt). Coal tar processing products are widely used in the production of plastics, dyes, spices, pesticides, medicines, solvents, preservatives, adhesives, rubber, carbon products and so on. In 1981, the world's total synthetic ammonia production was 95.3Mt, mainly from oil and natural gas. Only about 10% of ammonia is produced from coal; The proportion of methanol synthesis from coal is also very small, accounting for only about 1% of the total methanol production.

In 1984, the United States used 717.7Mt of coal, of which 5.5% was used for coking, up to 39.5Mt. The by-product of coking benzene accounts for 9% of the total production of benzene, and the ethylene acetate produced from calcium carbide acetylene accounts for 8% of the total production. In 1984, the United States built a plant to produce high calorific value city gas from lignite gasification and re-methanation, processing lignite 22kt per day and producing gas 3.89Mm. In recent years, many new technology tests have been carried out in coal gasification and liquefaction.

In 1984, the Federal German coal industry used 84.8Mt of coal (excluding lignite), coking coal accounted for 32.6%, 27.6Mt, and the annual output of coal tar was about 1.4Mt. Coal tar produced by coke ovens of steel and other enterprises in the country is concentrated in five tar processing plants for processing, and more than 500 kinds of chemicals are produced. There have been great developments in the chemical industry of calcium carbide acetylene, and there are still technical improvements at present. There are also some new advances in the research of pressurized gasification and direct liquefaction of coal.

Japan coal chemical industry in 1984, Japan shared 106.9Mt coal, due to its steel industry is very developed, iron and other metallurgical coke demand is very large, so coking coal accounted for 66%, 70.5Mt. Coal tar production reaches 2.4Mt per year, providing an industrial source of all naphthalene. The ethylene acetate produced from calcium carbide acetylene accounted for 23% of the total production.

South Africa is currently the world still has coal indirect liquefaction plants in the region, SASOL-I, SASOL-II, SASOL-III three synthetic liquid fuel plants, processing coal a total of about 33Mt, the production of gasoline, diesel, jet fuel and other oil products millions of tons, by-products of gaseous hydrocarbons, ethanol, ammonia, sulfur and other chemicals hundreds of thousands of tons.

China coal chemical Industry

From the total point of view, there are 30 coal chemical projects under construction in 2006, with a total investment of more than 80 billion yuan, and the new production capacity of 8.5 million tons of methanol, 900 million tons of dimethyl ether, 1 million tons of olefin, and 1.24 million tons of coal to oil. Only the registered methanol project has a capacity of 34 million tons, 3 million tons of olefin, and 3 million tons of coal-to-oil. In 2006, the National Development and Reform Commission issued policies and widely solicited opinions through various channels in order to regulate and support the development of the coal chemical industry. In 2006, China's independent intellectual property rights of coal chemical technology has also made great progress, and began to move from the laboratory to production.

In 2007, China's coal chemical industry steadily promoted the year, in the international oil prices once hit the 100 yuan mark, the global demand for alternative chemical raw materials and alternative energy increasingly urgent background, China's coal chemical industry with its leading industrialization progress has become an important part of China's energy structure. The investment opportunities of the coal chemical industry are still highly concerned by international and domestic investors, the industrial scale-up of coal chemical technology continues to make breakthroughs, the construction of large coal-to-oil and coal-to-olefin plants is progressing smoothly, and the related product standards such as dimethyl ether have been introduced.

The new coal chemical industry is mainly based on the production of clean energy and alternative petrochemical products, such as diesel, gasoline, aviation kerosene, liquefied petroleum gas, ethylene raw materials, polypropylene raw materials, alternative fuels (methanol, dimethyl ether), etc., which can be combined with energy and chemical technology to form a new industry of coal-energy chemical integration. The coal energy chemical industry will play an important role in the sustainable use of energy in China, and is an important development direction in the next 20 years, which is of great significance for China to reduce environmental pollution caused by coal burning and reduce China's dependence on imported oil. It can be said that the coal chemical industry is facing new market demand and development opportunities in China.