The process employs a two-stage liquefaction and single- or multi-stage purification process. The two-stage liquefaction utilizes the operational characteristics of the refrigeration unit to operate under two distinct operating conditions, thereby fully leveraging the compressor’s efficiency and reducing the refrigeration unit’s power consumption. Compared to traditional liquefaction processes, refrigeration power consumption can be reduced by 25%, while simultaneously improving the CO₂ liquefaction rate—that is, increasing product yield and output—with a product yield of over 92%.

This system is a skid-mounted unit designed to utilize self-circulating distillation based on relative pressure differentials. It requires no external power, features low system resistance, and saves energy, while achieving a product purity of over 99.995%. Even when the catalytic dehydrocarbonization process is deactivated, this distillation system can still remove N₂, O₂, CH₄, H₂, and CO to meet food-grade CO₂ specifications.