Carbon dioxide is a commonly used compound in the air. Its chemical formula is CO2. It is a colorless gas at room temperature. It is soluble in water and reacts with water to form carbonic acid. It won't ignite. The melting point of carbon dioxide is -56.60°C (0.52mpa) and the boiling point is -78.6°C

According to different forms, carbon dioxide can be divided into gas, solid and liquid; according to the purity can be divided into general carbon dioxide and high-purity carbon dioxide. Generally, carbon dioxide includes water vapor, air, a small amount of particulate impurities, etc., and its purity is between 90.0% and 99.9%; for high-purity carbon dioxide, the average purity is generally >99.999%. The downstream of the carbon dioxide industry chain is mainly its raw material supply industry. Among them, the carbon dioxide raw material supply industry is divided into tail gas recovery industry and gas field development industry according to the source of carbon dioxide.

The downstream of the carbon dioxide industry chain is mainly the application field of carbon dioxide. Because carbon dioxide has high civil and industrial value. Carbon dioxide is not only widely used in chemical industry, petroleum mining, metallurgy, welding, agriculture, low temperature refrigerant, machinery manufacturing, artificial rainfall, fire protection, papermaking, food, medical and health and many other fields, but also widely used in critical solvents, bioengineering, laser technology and the nuclear industry. With the development of carbon dioxide permeation technology, carbon dioxide has been gradually used in new fields such as plant gas fertilizer, vegetable (meat) preservation, degradable plastic production, and food processing.

Tail gas recovery industry: The main sources of carbon dioxide in my country are the exhaust gas from the decarbonation process of the synthetic ammonia plant, the by-product gas of the hydrogen production unit, the kiln gas of calcined limestone and the by-product of petrochemical products. As countries around the world increase the development and utilization of new energy sources, hydrogen energy has developed rapidly in my country as a renewable resource, and the development of the hydrogen production industry has provided exhaust gas recyclers with sufficient raw material gas. In recent years, my country's regulation of greenhouse gas emissions has become more and more stringent, resulting in increased willingness of companies with high-content carbon dioxide waste gas sources to recover carbon dioxide. These provide sufficient raw materials for the production of carbon dioxide.

The production of the gas field exploitation industry has obtained abundant raw materials: China has many high carbon dioxide gas fields, including Jiangsu Taixing carbon dioxide gas field, Huangqiao gas field in northern Jiangsu, Tianchang gas field in Anhui, Shandong Shengli Oilfield Binnan gas field, Guangdong Nanhai deep gas field, Guangdong Gas field in northern Sanshui Basin, etc. Among them, the large-scale carbon dioxide gas field in the Huangqiao area of ​​northern Jiangsu has reserves of 100 billion cubic meters, with a purity of over 99%. The wellhead pressure of the manufacturing well is as low as 8.6mpa. Carbon dioxide is liquid at the time of manufacture, which is extremely convenient to develop and use. China has strict restrictions on gas field research and development. However, because the production cost of carbon dioxide caused by gas field mining is significantly higher than the production cost of tail gas recovery, some companies have illegal mining activities, which seriously affects the development order of the carbon dioxide industry.

Chemical industry: After years of development, China's chemical industry is relatively complete. The development of the traditional chemical industry is relatively mature and the industry scale is relatively large. At present, my country's chemical industry has fierce market competition and high market concentration, which urgently needs industrial transformation and upgrading. In the chemical industry, carbon dioxide is mainly used for the manufacture of urea, ammonium bicarbonate, soda ash and inorganic salts, of which the application in the field of urea accounts for the largest proportion. As far as the urea industry is concerned, China is the largest urea producer and consumer in the world, and its output and consumption account for about one third of the world's total output. Domestic urea is mainly used domestically and imported less. In addition, domestic urea is also exported to foreign markets. In 2017, China's urea production was 26.294 million tons and consumption was 19.352 million tons.