Open the door of petrochemical industry and coal chemical industry

Overview of petrochemical industry and Coal chemical industry 1. Process overview: differences in structural components and variable process paths

Petrochemical industry refers to the processing industry that uses oil and natural gas as raw materials to produce both petroleum products and petrochemical products. Specifically, the petroleum processing industry can be divided into two major industries from the perspective of processing and use, one is that petroleum through refining can produce a variety of fuel oil (such as gasoline, kerosene, diesel, etc.) and lubricating oil as well as liquefied petroleum gas, coke, paraffin, asphalt and other petroleum products, that is, the refining process or petroleum refining industrial system; The second is to separate petroleum into raw material fractions, crack raw material oil and gas to generate basic chemical raw materials represented by ethylene, propylene, butadiene, benzene, toluene, xylene, and then use these basic chemical raw materials to produce a variety of organic chemical raw materials (about 200 kinds) and synthetic materials (plastics, synthetic fibers, synthetic rubber), that is, the petrochemical system. Oil refining and chemical industry depend on each other, mutual penetration, huge and complex, jointly promote the development of petrochemical technology, but also improve the economic benefits of petroleum, petroleum industry has become one of the pillar industry sectors in China.

Coal chemical industry is a process in which coal is converted into gas, liquid and solid products or semi-products and chemicals through chemical processing. From the processing process of coal, coal chemical industry mainly includes coal dry distillation (including coking and low temperature dry distillation), gasification, liquefaction and synthetic chemicals. Among them, coking is the earliest process in the coal chemical utilization technology, and is still an important part of the coal chemical industry. The products include the production of coke for iron making, coke oven gas, benzene, naphthalene, anthracene, asphalt and carbon materials. Coal gasification is used to produce various fuel gases, and the resulting syngas is the raw material for the synthesis of liquid fuel, methanol and other products. Direct coal liquefaction can produce artificial petroleum and chemical products, indirect liquefaction refers to the first production of syngas, and then catalytic synthesis of liquid products. Coal low temperature distillation can produce semi-coke, low temperature tar and gas.

2. A brief history of development: petrochemical industry came behind

Coal chemical industry started in the industrial revolution, with the development of war. China is one of the earliest countries to use coal, as early as BC with coal smelting copper ore, burning ceramics, the Ming Dynasty has used coke to smelt iron. However, it was after the modern industrial Revolution that coal was used as a raw material for the chemical industry and gradually formed an industrial system. In the second half of the 18th century, due to the progress of the industrial revolution, the demand for iron coking coke increased significantly, coke oven came into being, opened the initial period of coal chemical industry, and in 1763 the development of coal for coking honeycomb coke oven. During World War I, the rapid development of the steel industry, and the urgent need for ammonia, benzene and toluene as raw materials for explosives, led to the further development of the coking industry and the formation of the recycling and utilization of coking by-product chemicals.

On the eve of World War II and during the war, coal chemical industry has achieved comprehensive development and entered a brilliant period. A series of production technologies such as Fischer-Tropsch synthesis, direct coal hydroliquefaction and low temperature dry distillation came into being. In 1938, the output of carbon monoxide hydrogenation synthetic liquid fuel had reached 590,000 tons; in 1939, the method of high pressure hydrogenation liquefaction of coal to produce liquid fuel could reach 1.1 million tons of annual production capacity; by the end of 1944, the annual production capacity of warm distillation tar had reached 945,000 tons. In addition, the small industry of direct chemical processing of coal to produce sulfonated coal, humic acid and lignite wax, and the chemical industry of using coal as raw material to produce calcium carbide and then acetylene as raw material has also been developed.

After World War II, due to the exploitation of a large number of cheap oil and natural gas, large-scale industrial production of liquid fuels from coal was temporarily suspended, and the rise of petroleum and natural gas as raw materials. Coal's share of the world's energy mix has fallen from 65-70% to 25-27%, and many industrialized countries have replaced domestic gas with natural gas. It is worth mentioning that due to the continuous development of the iron and steel industry, the coking industry of coal chemical industry is also growing.

Petrochemical industry emerged in the 1920s, originated in the United States, and was initially dependent on the petroleum refining industry. It developed rapidly before and after the Second World War, followed in Europe in the 1950s, and further expanded to Japan and other countries in the 1960s. At this time, the production of many chemicals has shifted from coal to oil and natural gas as raw materials, and the production structure and raw material system of the world chemical industry have undergone major changes. In the early 1970s, the United States petrochemical production of a variety of petrochemical products, as many as thousands of new processes and new products in the petrochemical industry continue to emerge.