NOVELTY - Preparing modified porous bamboo charcoal material comprises pre-treating by soaking porous bamboo charcoal raw material in nitric acid solution, filtering, washing using deionized water to neutral pH, and drying to obtain a first porous bamboo charcoal material, activating the first porous bamboo charcoal material under carbon dioxide atmosphere to obtain a second porous bamboo charcoal material, soaking in metal nitrate or metal chloride aqueous solution, filtering, and drying to obtain the product, where the metal ions are loaded on the surface of the second porous bamboo charcoal material.    USE - The bamboo charcoal is useful for separating carbon dioxide from methane.    DETAILED DESCRIPTION - Preparing modified porous bamboo charcoal material comprises: (i) pre-treating by soaking porous bamboo charcoal raw material in nitric acid solution (0.1-2 M) at 70-90 degrees C for 0.5-2 hours, filtering, washing the raw material using deionized water to neutral pH, and drying the raw material at 100-110 degrees C to obtain a first porous bamboo charcoal material; (ii) activating the first porous bamboo charcoal material at an activating temperature of 800-950 degrees C for 0.5-5 hours under carbon dioxide atmosphere to obtain a second porous bamboo charcoal material, where the specific surface area of the second porous bamboo charcoal material is more than specific surface area of the first porous bamboo charcoal material; and (iii) soaking the second porous bamboo charcoal material in a metal nitrate or metal chloride aqueous solution (0.05-0.2 M) for 20-24 hours under a constant temperature of 30-70 degrees C, filtering, and drying at 100-120 degrees C to obtain the modified porous bamboo charcoal material, where the metal ions are loaded on the surface of the second porous bamboo charcoal material. An INDEPENDENT CLAIM is also included for a modified porous bamboo charcoal, prepared by the above mentioned method, where the modified porous bamboo charcoal material is loaded with metal ions on the surface of the second porous bamboo charcoal material.