Recovery of CFCs from refrigeration equipment. Current processes

摘要

Processes for removal of freon from refrigerators and freezers are used for the removal of CFC 12, the refrigerant in the cooling system and removal of CFC 11, which is found in the cells of the polyurethane insulating material. CFC 12 is removed using well-established techniques from the refrigeration industry, suited to the purpose of quickly emptying discarded refrigerators and freezers of both their refrigerant and oil. It is possible to recover at least 95% of both refrigerant and oil. CFC 11 must first be removed from the polyurethane foam and then be isolated in liquid form. In the late 1980s a number of methods were developed in Germany which were based on mechanical destruction of the cells and recovery of the CFC 11 gas thus liberated. It is difficult to establish how good results have been since it is not known with certainty how much CFC 11 remains in discarded refrigerators and freezers. A system for recovery of CFCs from 60000 refrigerators and freezers a year requires an investment (not including the cost of the premises themselves) of 6 million SEK for a manual process and 18 million SEK for a mechanical one. The operating cost is approximately 175 SEK per unit including the revenue from metal recovery. A mechanical process is to be preferred from an environmental point of view. All existing processes need further development. Feasible and reliable yields of at least 80% R 11 should be possible within a year or two. Mechanical shredding is considered to have the best potential. It is recommended that recovery and removal of freon be started in Sweden on the basis of German techniques using mechanical shredding and with open disclosure of yield. 12 refs., 15 figs.