No it's not a centrifuge, CO2 is a product every air liquifaction plant. Air Liquifaction plants mostly produce oxygen and nitrogen by compressing air, cooling it, letting it expand, compressing it... CO2 liquifies at a higher tempature than oxygen and nitrogen so CO2 is a product of all plants and it is very cheap due to a lot of supply. Price is under $1 a pound $0.30 if you're buying railcars.