Method for producing pure and highly concentrated carbon dioxide from a renewable lignocellulosic biomass feedstock

A low energy production method for producing carbon dioxide from a renewable lignocellulosic biomass feedstock comprising the following steps:

• i) extracting lignins and hemicelluloses by putting at least one solid lignocellulosic raw material in a presence of a mixture, composed of at least water and formic acid, at atmospheric pressure under controlled conditions of temperature between 80° C. and 110° C., with a dilution ratio of said at least one solid lignocellulosic raw material/liquid mixture comprised between 1 and 15, and for a period of time, depending on a nature of the at least one lignocellulosic raw material;
• ii) fractionating, at atmospheric pressure, a primary solid fraction and a primary liquid fraction obtained at an end of the preceding extracting step i);
• iii) separating the lignins from an intermediate liquid fraction, and obtaining a residual liquid fraction;
• iv) producing a synthetic gas by feeding a gasification equipment with at least one of at least part of said primary solid fraction or at least part of said residual liquid fraction;
• v) producing carbon dioxide and water by introducing dioxygen, or dioxygen enriched air, or air in said gasification equipment.