[semi-extrinsic]

That's for supercritical CO2 as it would be transported in pipelines, at a density about 0.6 times that of water.

IIRC we need to store many tens of Gigatonnes of CO2 per year. If you make it into plastic, you can divide by 5 (roughly). Total world plastic production is around 0.3 Gigatonnes

[worldsayshi]

Yeah, barely 10 Gigaton per year if you sum it all up [1]. But it's probably a fraction of that that is eligible for capture.

1 - https://www.co2.earth/global-co2-emissions