Coal chemical industry helps clean and efficient utilization of coal resources

Coal chemical concepts:

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. Chemical processing of coal. 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.

Development fields of coal chemical industry:

After years of development, the layout of China's coal chemical industry chain has gradually improved, and has gradually extended from the original traditional coal chemical industry field to the new coal chemical industry field, accompanied by the development of China's coal chemical industry, but also the expansion of business. Starting from the early coal coking business, it has gradually extended to coal gasification and other fields with methanol as the production node. At this stage, it has formed a dual-line business pattern including traditional coal chemical industry and new coal chemical industry. Starting from coal raw materials, it has established a comprehensive business platform of "one head and two lines of prolific production".

Coal chemical industry chain:

Coal chemical industry is mainly composed of traditional coal chemical industry based on coking industry chain and modern coal chemical industry which can realize comprehensive and efficient utilization of coal resources. Traditional coal chemical products mainly include coal to coke, calcium carbide, synthetic ammonia, etc. China's production scale in the above fields ranks first in the world. Modern coal chemical industry is the main goal of producing clean energy and chemical products, including coal to olefins/aromatics, coal to natural gas, coal to ethylene glycol and coal to oil, etc., which is the main route to realize petrochemical substitution in China. Modern coal chemical industry can realize clean and efficient utilization of coal, which is an important way to promote the structural adjustment of coal industry.

Coal chemical process flow:

The production process of coal chemical industry has the ability of saving carbon, and the development of coal chemical industry meets the requirement of "double carbon". Coal as a raw material to participate in the chemical reaction, part of the carbon into the product, converted into clean energy or chemicals, part of the carbon into carbon dioxide, a small amount of carbon with the ash loss, because part of the carbon into the product, and fully burned coal after all carbon into carbon dioxide, so the coal chemical production process has the ability to save carbon. Traditional coal chemical industry, coal coking related products include coal to synthetic ammonia (fertilizer, building materials), coal to coke (iron and non-ferrous metals), coal to calcium carbide (PVC plastic products). The modern coal chemical industry is coal as the main raw material to produce a variety of clean fuels and basic chemical raw materials of coal processing and transformation industry, the main development of coal to oil, coal to natural gas, coal to olefin, coal to ethylene glycol and other four categories of industries, mainly the production of oil and gas and related products (olefin, alcohol, oil, acid, ether, etc.), is the main route to achieve petrochemical substitution in China.

The production wastewater of coal chemical industry has the characteristics of high pollution and high water consumption, which is an important factor restricting coal production. In order to realize the sustainable development of coal chemical production, it is necessary to maximize the resource utilization of wastewater. According to the "Modern Coal chemical wastewater near zero discharge technology integration and optimization Recommendations", at present, the wastewater treatment process of modern coal chemical projects in operation mainly includes wastewater pretreatment, biochemical treatment, reuse of reclaimed water, salt wastewater membrane treatment, evaporation crystallization and so on. Biochemical treatment processes are mainly activated sludge methods such as A/O and SBR, while advanced treatment is carried out by patented technologies such as biological aeration filter (BAF) and biological membrane method (MBR). Some wastewater also requires advanced oxidation techniques. Under the near-zero discharge system of modern coal chemical wastewater, most of the water and saline wastewater produced by biochemical treatment units enter the membrane system for desalting treatment. The membrane system can take step membrane concentration according to the water quality, and the concentrated water generated will enter the evaporation crystallization system for treatment, and the crystalline salt will be landfill or resource utilization.

Coal chemical industry related policies:

The coal chemical industry has relatively high energy consumption and carbon emissions, and it is difficult to expand production capacity significantly under the implementation of the domestic dual-carbon policy. At present, the problems of high energy consumption and high carbon emission in coal chemical industry have not been solved by relatively mature industrial methods, which has brought certain environmental pollution. Therefore, for the healthy and orderly development of the coal chemical industry, the state has issued a series of environmental protection policies for the coal chemical industry.

The state conditionally supports the transformation and development of the modern coal chemical industry into a strategic emerging industry.  In November 2021, a special re-loan of 200 billion yuan was set up to support the clean and efficient use of coal, and in December, the Central Economic Work Conference further proposed that "new renewable energy and raw material energy use are not included in the total energy consumption control", and the pressure of coal chemical industry can be reduced sharply. Promoting the low-carbon transformation and development of coal chemical industry has become an inevitable requirement for the coal industry to achieve the goal of "double carbon".