What is the development status of China's oxygen industry?

I. Introduction of Pressure Swing Adsorption Oxygen Production The pressure swing adsorption oxygen production has the characteristics of fast start-up, low energy consumption, simple operation, wide load operation adjustment range and simple maintenance. Widely used in nonferrous metal smelting (copper smelting, zinc smelting, lead smelting, gold smelting, nickel smelting, titanium dioxide smelting, etc. ), ferrous metal smelting (blast furnace oxygen-enriched coal injection ironmaking, electric furnace steelmaking, etc. ), oxygen-enriched combustion (industrial boilers, glass furnaces, electrolytic aluminum), chemical gasification (synthetic ammonia, methanol, ethylene, ethylene glycol production, etc. ), medical field and sewage treatment (oxygen-enriched explosion). Pressure swing adsorption oxygen production has been widely promoted and applied. Especially in today's macro-control climate where the country is determined to control the industrial economy, enterprises must save energy and reduce costs if they want to survive and develop. Pressure swing adsorption oxygen production has its unique advantages in saving overall investment, reducing floor space, saving energy consumption and reducing costs. Since 1980s, with the maturity of pressure swing adsorption technology, pressure swing adsorption has become the main method to obtain low-cost oxygen in the world without high-purity oxygen. Although the development of pressure swing adsorption oxygen production in China started late, it developed rapidly. In a short time, the device has developed from miniaturization to large-scale, and the technology is mature, stable and advanced. With the successful development of new molecular sieve adsorbent for pressure swing adsorption oxygen production and the introduction of new adsorbent from abroad, the energy consumption index of domestic pressure swing adsorption oxygen production plant has reached ≤0.35kwh/ m? 0? 6. Close to and reach the level of foreign advanced equipment. Hundreds of pressure swing adsorption VPSA oxygen generators have been put into operation or under construction in China, with a design and manufacturing capacity of 35000m? 0? 6/h pure oxygen, purity ≥90%. The largest device that has been successfully operated is 12000NM? 0? 6/hO2, energy consumption of 0.35KWh/ M? 0? 6O2, stable and reliable operation, variable working conditions adjustment operation, such as output (large and medium-sized devices) can do multi-working conditions adjustment operation, the purity can be adjusted between 65% and 93%, and the energy consumption is basically not increased during output adjustment operation. Oxygen production by pressure swing adsorption can be divided into three processes: high pressure adsorption atmospheric desorption (PSA), atmospheric adsorption vacuum desorption (VSA) and low pressure adsorption vacuum desorption (VPSA). In fact, the three processes are only slightly different in operating pressure and the essence is the same. VPSA process with low pressure adsorption and vacuum desorption has the lowest energy consumption standard, stable and reliable device and advanced economy, which represents the development trend of pressure swing adsorption. Therefore, the currently used and commonly mentioned PSA oxygen plant is usually VPSA plant. This VPSA equipment is also recommended and adopted by our company. Relying on the long-term mastery of oxygen generator technology by state-owned leading enterprises, the company absorbed the experience and lessons of other oxygen generator enterprises through further development and research by technicians, and formed its own set of advanced and reliable new technologies and processes. The research and development of VPSA oxygen production process has become the main direction and focus of the company's development. The company focuses on the research and development of new efficient radial flow adsorption tower and argon removal process, in order to achieve a higher level of VPSA process, further reduce energy consumption, improve the cost performance of the device and improve market competitiveness. 2. Oxygen production by pressure swing adsorption 1. Application of pressure swing adsorption oxygen production in black smelting 1. 1 There are many successful experiences and examples in the application of pressure swing adsorption oxygen production in electric furnace steelmaking. About 60%∽70% EAF steelmaking enterprises in Taiwan Province Province and Japan use pressure swing adsorption to make oxygen and steel. In China, the pressure swing adsorption oxygen production method for electric furnace steelmaking has been very popular (such as Acheng Steel Plant of Xilin Iron and Steel Company, Guiyang Special Steel Plant and Huaiyin Steel Plant of Jiangsu Province, etc.). Let's analyze the characteristics of electric furnace steelmaking: electric furnace steelmaking itself takes scrap steel as the main raw material, and electric furnace steelmaking mainly relies on electric arc to melt scrap steel. Oxygen only produces chemical heat in the process of oxygen decarbonization during electric furnace smelting and power failure, so as to improve the smelting temperature. Because it is mainly arc melting and oxygen is only auxiliary, oxygen purity is required. Converter steelmaking is different. The main raw material is blast furnace molten iron. After the blast furnace molten iron enters the converter, it must be blown with high-purity oxygen, so that the impurities such as Si, S, P and Mn in the molten iron can be fully burned and removed before it can be reduced to molten steel. It can be seen that oxygen plays a very important role in converter steelmaking, so the requirement for oxygen purity is also relatively high. According to some data, converter steelmaking needs oxygen with 99.2% purity (qualified product) (generally, the oxygen purity of low-temperature oxygen generator is 99.6%). However, there is no data showing that electric furnace steelmaking must have 99.2% pure oxygen. Our company is engaged in the manufacture, supply, installation and debugging of oxygen generator all the year round, and has close working contact with many steel design institutes across the country. For this question, our company consulted relevant experts and got the answer that PSA can be used in electric furnace steelmaking. Like the relevant theoretical data, it is not said that 99.2% pure oxygen must be used in electric furnace steelmaking. In fact, the purity of oxygen used in many factories that make oxygen and steel by pressure swing adsorption is between 9 1%-93%. Some investors put forward: "Pressure swing adsorption oxygen production has low purity, can it be used to smelt special steel?" The process before smelting special steel in electric furnace is the same as that before ordinary steel. The processes of melting scrap steel by electric arc, blowing oxygen to help melting, decarbonizing by blowing oxygen when power is off and blowing oxygen are all completed in electric furnace. There is no need to blow oxygen during refining. Other components are added to the electric furnace to change the composition of steel and obtain the required steel grade. Therefore, the oxygen requirement for smelting special steel by electric furnace is essentially the same as that for smelting ordinary steel. Some investors say that our steelmaking varieties include marine steel, and the nitrogen content in smelting with low pure oxygen may exceed the standard, resulting in steel brittleness. Pressure swing adsorption can produce more than 93% oxygen, 4% argon and 1 ~ 3% nitrogen. Argon is harmless to steelmaking, and the nitrogen content of 1 ~ 3% may cause the nitrogen content of some brands of special steels to exceed the standard. The state clearly stipulates that the nitrogen content of low-temperature impact-resistant steel such as marine steel and oil well pipe should be ≤70ppm, while alloy steel such as spring steel, bearing steel and seamless steel pipe used at room temperature is not clearly stipulated (even less common steel). However, most of our EAF steelmaking plants do not smelt low-temperature impact-resistant steel, so the range of smelting special steel by pressure swing adsorption should be very wide. Even if the enterprise smelts a part of low-temperature impact-resistant steel according to the market demand and is worried that the nitrogen content will exceed the standard, it can also switch some oxygen from the original low-temperature oxygen generator or low-temperature liquid tank for "fire cutting" to complete the temporary smelting task. In fact, the control of nitrogen content exceeding the standard is largely in the control of production process, not in the purity of oxygen. For example, the cleanliness of charge cleaning, the amount of pig iron (or hot charging of molten iron) and so on. I have been to a large electric furnace steelmaking plant in China, and I have been smelting special steel with pressure swing adsorption oxygen making equipment as the main body, and the purity of oxygen used is ≥92%. Nitrogen content of special steel (such as 17Cr2Ni2H, GCr 15, 40MMoV, etc.). ) The smelting in this factory has been controlled at about 80ppm, which is ideal, and the products have always occupied a considerable market share in China. The production technology department of this factory told us that they mainly did a good job in the control of the production process and did not take special measures to improve the purity of oxygen. In fact, most EAF steelmaking plants smelt more special steel than ordinary steel. Special steel smelting pays more attention to quality while paying attention to quantity, mainly paying attention to the added value of products. Most manufacturers also produce in batches according to orders, so its characteristics determine intermittent production. In this case, the economy of pressure swing adsorption oxygen production equipment is particularly prominent.