Fuente: WIPO "tomato" A method for supplying CO2 gas to a site comprising a facility (20) that requires CO2 or a mixture comprising CO2, such as an abattoir or a greenhouse for cultivating plants, comprises the following steps: a boiler (4) capable of supplying hot water to the site is arranged within the site, the boiler carrying out the process of oxycombustion between a fuel (14) and pure oxygen (1), the oxygen that supplies the boiler being obtained from a liquid oxygen source present on the site; and some or all of the CO2 contained in the flue gas produced by the boiler is recovered by transferring heat between the flue gas and the liquid oxygen in an exchanger (2).