A system and method recover process gas from a source volume at a source pressure to a destination volume at an equal or greater pressure. A regulation process receive the process gas from the source volume and steps down the pressure. Each regulation uses one or more stage each using a pressure control valve for pressure step down and a heat exchanger for reheating the process gas thereafter. A gas scrubber receives the process gas from the regulation stages and collecting liquid from the process gas. A compression process receives the process gas from the gas scrubber and steps up the intermediate pressure to a final pressure. The compression can use one or more compression stages, each having a compression cycle for pressure step up and a heat exchanger for cooling the process gas thereafter. A discharge vessel receives the process gas from the compression process and discharges the process gas at the final pressure to the destination volume. The final pressure is equal to or greater than the destination pressure.