A process for preparing methanol from a carbon-containing feedstock by producing synthesis gas therefrom in a synthesis gas production unit, converting the synthesis gas to methanol in a methanol synthesis unit and working up the reaction mixture obtained stepwise to isolate the methanol, wherein the carbon monoxide, carbon dioxide, dimethyl ether and methane components of value from the streams separated off in the isolation of the methanol are combusted with an oxygenous gas, and the carbon dioxide in the resultant flue gas is separated off in a carbon dioxide recovery unit and recycled to the synthesis gas production unit and/or to the methanol synthesis unit.