A process in which gases are recovered in a series of regenerative filters, which contain internal heat exchangers, is presented. Gases that are collected on the sorbent material are then recovered during regeneration at high temperature. Finally, the filters are cooled and placed back into service. The focus of this paper is the use of a vapor-compression refrigeration system to recover heat from the filter being cooled and transferring it to the filter undergoing regeneration. Most importantly, a flash-gas phase is incorporated, by which a major portion of the total heat exchange is accomplished. At the beginning of a cycle change, the filters to be heated and cooled are isolated from the system and their pressures are equalized. Liquid refrigerant is then admitted to the high temperature filter wherein it flashes, cooling that filter and increasing local pressure. The flash gas then migrates to the low-temperature filter, where it condenses at the lower saturation pressure, thereby transferring heat to that device. The flashing continues until both components reach equilibrium temperature and pressure. This flash heat transfer is essentially instantaneous, and, compared to using only vapor compression, it greatly reduces cycle time and conserves energy.