Liquid carbon dioxide (chemical formula: CO2) is a colorless, transparent liquid formed under conditions of high pressure and low temperature, with a density of 1.101 g/cm³. It serves as an industrial raw material with diverse applications. In the food industry, it is utilized for preservation and refrigeration; in the chemical sector, it is employed in the production of soda ash and urea; and in oilfields, it is used for enhanced oil recovery. Additionally, it finds application in fields such as welding and fire suppression. Within the context of Carbon Capture, Utilization, and Storage (CCUS) technologies, liquid carbon dioxide is injected underground to displace oil, thereby achieving both the geological sequestration of CO2 and an increase in crude oil recovery rates.
This substance is classified as a hazardous chemical; given its characteristics of low temperature and high pressure, handling requires specialized protective measures. It must be stored in a cool, well-ventilated area, kept away from ignition sources, and its transportation and storage must strictly adhere to relevant safety regulations. Historical accident records indicate that the primary risks associated with this substance include the low-temperature embrittlement and failure of pipeline connections, system isolation failures resulting in gas intrusion into confined spaces, and valve-handling errors during loading and unloading operations-factors that have previously led to multiple fatal asphyxiation incidents. Road transportation requires the use of specialized vehicles designated for hazardous chemicals; transport personnel must possess the requisite professional qualifications, and the status of system valves must be verified prior to commencing any loading or unloading operations. For shipboard loading and unloading operations, reference should be made to the *Guidelines for Shipboard Loading and Unloading of Liquid Carbon Dioxide*. Relevant national standards include GB/T 6052-2025, *Industrial Liquid Carbon Dioxide*; for applications within the food industry, compliance with the national standard *Food Additives: Liquid Carbon Dioxide* is mandatory.
