A hydrogen gas supply apparatus includes a compressor configured to compress hydrogen gas and supply the hydrogen gas compressed to a pressure accumulator which accumulates the hydrogen gas, an adsorption column disposed between the discharge port of the compressor and the pressure accumulator, and configured to include an adsorbent for adsorbing impurities in the hydrogen gas discharged from the compressor, and a plurality of valves disposed at the gas inlet/outlet port side of the adsorption column, being at a discharge port side of the compressor, and configured to be able to seal the adsorption column, wherein the space in the adsorption column is sealed using the plurality of valves such that the inside of the adsorption column is maintained to have a high pressure by the hydrogen gas compressed in the case where the compressor is stopped.

This disclosure relates to systems and methods for removing CO2 from flue gas. The system includes a first heat exchanger for receiving and cooling the flue gas, a compressor for increasing the pressure of the cooled gas, a second heat exchanger to further cool the compressed gas, and a drying unit for removing water from the cooled compressed gas. The system further includes a pressure swing adsorption unit for adsorbing CO2 from the dried, cooled compressed gas using an adsorption media, the adsorption unit comprising a vacuum compressor for pulling the CO2 off the adsorption media. A compressor may be used for extracting the CO2 from the tank and boosting the pressure of the CO2 gas.