Good news everyone!
I`ve found a new way to storing gases. Although it described as max pressure in gas valve as 100 g/s gas pump and gas pipes can contain much more!
Gas pump even in description marked as 500 g/s. Gas pipe can contain 10 000 g/s! See attached srcennshot.
So you can make a snake-like gas pipe and store 10 kg gas per cell instead of 2 at normal conditions!
Build a closed room. Build a gas vent in it. Pump all CO2 (or any other gas) that you have in it by gas pipes. After a gas pressure in room in all cell become 2066 g gas starting to accumulate in pipes with max amount of 10 kg in one pipe segment.