Compressor Applications in the Carbon Dioxide Gas Industry

  • Carbon dioxide, a carbon oxide compound with the chemical formula CO2 and a chemical formula of 44.0095, is a colorless, odorless or colorless gas with a slightly sour aqueous solution at room temperature and pressure. It is also a common greenhouse gas and a component of the air (accounting for 0.03% -0.04% of the total volume of the atmosphere). In terms of physical properties, carbon dioxide has a melting point of -56.6 ℃ and a boiling point of -78.5 ℃, with a higher density than air (under standard conditions) and is soluble in water. In terms of chemical properties, carbon dioxide has inactive chemical properties and high thermal stability (only 1.8% decomposition at 2000 ℃). It cannot be burned and usually does not support combustion. It belongs to the category of acidic oxides and has the properties of acidic oxides. It reacts with water to produce carbonic acid, which is the anhydride of carbonic acid.
  • Carbon dioxide can generally be obtained by calcining limestone at high temperatures or reacting limestone with dilute hydrochloric acid. It is mainly used for refrigerated perishable foods (solid), as a refrigerant (liquid), manufacturing carbonated soft drinks (gaseous), and as a solvent for homogeneous reactions (supercritical state). Regarding its toxicity, research has shown that low concentrations of carbon dioxide are not toxic, while high concentrations of carbon dioxide can cause animal poisoning.
  • Main applications:

    High purity carbon dioxide is mainly used in the electronics industry, medical research and clinical diagnosis, as a calibration gas for carbon dioxide lasers and detection instruments, and in the preparation of other special mixed gases. It is used as a regulator in polyethylene polymerization reactions.

    Solid carbon dioxide is widely used in refrigerated dairy products, meat, frozen foods, and other perishable foods during transportation. It is used as a refrigerant in many industrial processes, such as crushing thermosensitive materials, rubber polishing, metal cold treatment, contraction assembly of mechanical parts, vacuum cold traps, etc.

    Gaseous carbon dioxide is used for carbonation of soft drinks, pH control in water treatment processes, chemical processing, food preservation, inert protection in chemical and food processing processes, welding gases, plant growth stimulants, hardening molds and cores in casting, and for pneumatic devices, It is also used as a diluent for bactericidal gas (i.e. using a mixture of ethylene oxide and carbon dioxide as a disinfectant, insecticide, and fumigant, widely used for sterilization of medical equipment, packaging materials, clothing, fur, bedding, bone powder disinfection, and fumigation of warehouses, factories, cultural relics, and books).

    Liquid carbon dioxide can be used as a refrigerant for low-temperature testing of aircraft, missiles, and electronic components, improving oil well recovery, rubber polishing, and controlling chemical reactions. It can also be used as a fire extinguishing agent.

    Supercritical carbon dioxide can be used as a solvent for dissolving non polar, non ionic, and low molecular weight compounds, making it widely used in homogeneous reactions.

  • Carbon dioxide compressor refers to a compressor used to pressurize and transport carbon dioxide gas. Mainly used in urea synthesis plants. When designing and using, it should be noted that the critical temperature of carbon dioxide is high and can be liquefied at 31.3 ℃ and 7.14 MPa. During winter use, the interstage cooling temperature should not be too low; When carbon dioxide is below 60MPa, it is beneficial for gas compression; Due to the high relative density of carbon dioxide gas, it is not advisable to use an excessively high average piston speed, otherwise the resistance of the gas valve will be high; Carbon dioxide gas contains a small amount of water and has strong corrosiveness, so gas valves, coolers, and buffer tanks need to be made of stainless steel.
  • 二氧化碳压缩机是指用于使二氧化碳气体增压并实现输送的压缩机。主要用于尿素合成装置。设计和使用时应注意:二氧化碳临界温度高,在31.3℃、7.14MPa下即可液化,冬季使用时,级间冷却温度不能过低;二氧化碳在60MPa以下时,有利于气体的压缩;由于二氧化碳气体相对密度较大,不宜采用过大的活塞平均速度,否则气阀阻力大;二氧化碳气体中含有少量水分,具有较强的腐蚀性,故气阀、冷却器及缓冲罐等都需用不锈钢制造。