Dry ice is a solid form of carbon dioxide that usually exists in white lumps or granules. Its production process mainly includes the following steps:
Extraction of carbon dioxide:The production of dry ice first requires the extraction of carbon dioxide gas. Carbon dioxide can be obtained through the combustion of fossil fuels, yeast fermentation, natural gas extraction, etc.
Compressed carbon dioxide:The extracted carbon dioxide gas is compressed to a liquid state. The critical temperature of carbon dioxide at standard atmospheric pressure is -785 degrees Celsius, the critical pressure is 511 atmospheres, so it needs to be compressed into a liquid at a very low temperature and pressure.
Relieve stress:The compressed liquid carbon dioxide is relaxed by a specific device to allow it to gradually expand into a gaseous state. This process is accompanied by a decrease in temperature, which partially solidifies the carbon dioxide gas into solid dry ice.
Formation of dry ice:In the process of relieving the pressure, the carbon dioxide gas part changes directly from a liquid state to a solid state, forming a block or granular structure of dry ice.
It is important to note that due to the excellent refrigeration performance of carbon dioxide, the process of preparing dry ice requires strict safety measures to prevent the leakage of high-pressure liquid carbon dioxide and the occurrence of safety accidents. In industrial production, specialized equipment and processes are often used to prepare dry ice.