We do not use high temperature or pressures – they are expensive (and dangerous). We use chemical engineering – a 1st year undergraduate could knock up and publish a working system in an afternoon.
We have a solar panel or little wind turbine linked to a vacuum pump. We exert 1m of vacuum onto brown water – river or sea water
It boils, losing all salts or contaminants. We extract water vapour, we sump to a holding reservoir. We can then pump the water to high storage, and let gravity distribute it.
This idea works supremely well for hot countries like Saudi Arabia. WE can irrigate the high desert – also Chilli by the Atacama.
So we grow loads of plants – that sunk the CO2 from the air. Though to be true, there is a massive excess of photosynthesis going on on the land and seas of the Earth.
This has resulted in average cO2 levels being at a pre-industrial 2 parts per million. CO2 levels are higher above the high Arctic – where the ice blocks off the CO2 from photosynthesis.
So burning the Fossil Fuels has re-established life on Earth. It has not affect the gas composition in the air.Such graphs are spurious science fiction – paid for by nuclear power.