New method for producing active carbon by using biomass wastes

The invention discloses a new method for producing efficient active carbon by using biomass wastes (walnut shells, rape stems, wheat straws, Chinese medicinal dregs and the like) as raw materials, using pyrolusite as a hole forming agent and using zinc chloride as an active agent. The method comprises the following processes of: (1) drying the biomass waste raw materials till the water content is less than 15 percent, mechanically crushing the raw materials, and sieving the crushed raw materials with a sieve of 100 meshes; (2) adding 5 to 10 percent of pyrolusite into the raw materials, and mixing the pyrolusite and the raw materials uniformly; (3) soaking the pre-treated raw materials into 3 to 7mol/L zinc chloride solution for 24 hours, wherein the soaking ratio (the mass of the raw materials to the mass of the zinc chloride solution) is 1:1-1:2; (4) putting the soaked raw materials into a tubular furnace, introducing inert gas (such as nitrogen or carbon dioxide gas), heating to the temperature of between 400 and 600 DEG C, and performing one-step carbonization (synchronous carbonization and activation) for 0.5 to 1.5 hours; and (5) cooling, washing and drying the activated carbide to obtain the active carbon. The method improves the performance of the active carbon, reduces the preparation cost of the active carbon, and realizes recycling utilization.