Systems and methods of CO2 desublimation are presented in which refrigeration content is retained within the system. Most preferably, refrigeration content is recycled by providing the refrigeration content of a CO2-lean feed gas to the CO2-containing feed gas and to pre-cooling of a desublimator, and/or by providing refrigeration of effluent of a desublimator in regeneration to a refrigerant in a closed refrigeration cycle for deep-cooling of another desublimator.