1. Carbon dioxide can be used to extinguish fire and is a commonly used extinguishing agent. In the chemical industry, carbon dioxide is an important raw material and is used in large quantities to produce soda ash (Na2CO3), baking soda (NaHCO3), urea [CO(NH2)2], ammonium bicarbonate (NH4HCO3), pigment lead white [Pb( OH)2 2PbCO3] etc.; 2. In light industry, carbon dioxide is required for the production of carbonated beverages, beer, soft drinks, etc. In modern warehouses, carbon dioxide is often charged to prevent food insects and vegetables from rotting, and prolong the shelf life;’ 3. It is an effective stimulus for human respiration. It stimulates the respiration by stimulating the chemical receptors outside the human body. If a person inhales pure oxygen for a long time, the carbon dioxide concentration in the body is too low, which can cause breathing to stop. Therefore, clinically, the mixed gas of 5% carbon dioxide and 95% oxygen is used in the treatment of carbon monoxide poisoning, drowning, shock, alkalosis and anesthesia. Liquid carbon dioxide cryosurgery is also widely used; 4. Storage of grain, fruits and vegetables. Due to the lack of oxygen and the inhibitory effect of carbon dioxide itself, the food stored with carbon dioxide can effectively prevent the growth of bacteria, molds and insects in the food, avoid deterioration and the production of peroxides that are harmful to health, and can preserve and maintain the original flavor of the food. nutrient content. Carbon dioxide does not cause drug residues and atmospheric pollution in grains. Using carbon dioxide into the rice warehouse for 24 hours can kill 99% of the insects; 5. As an extractant. Foreign countries generally use carbon dioxide for food and beverages. Processing and extraction of oils, spices, medicines, etc.; 6. Using carbon dioxide and hydrogen as raw materials, it can produce methanol, methane, methyl ether, polycarbonate and other chemical raw materials and new fuels; 7. As an oil field injection agent, it can effectively drive oil and improve oil recovery; 8. Protected arc welding can not only avoid oxidation of the metal surface, but also increase the welding speed by about 9 times.