Preparation method for biochar supported catalyst for simultaneous removal of SO2, NOx and Hg

The invention relates to a preparation method for a biochar supported catalyst for simultaneous removal of SO2, NOx and Hg , and belongs to the technical field of catalysts. The method comprises thesteps: washing biomass raw materials, crushing the washed biomass raw materials, then placing the crushed raw materials to an inert-gas atmosphere, and under the temperature condition of 400-1200 DEGC, performing high-temperature roasting for 2-6h, performing grinding, performing screening through a sieve, and performing washing with water until no suspended turbid substances exist in a supernatant, and performing drying to obtain a biochar; mixing the biochar and a chemical activator uniformly, and performing roasting for 2-6h under the temperature condition of 300-900 DEG C to obtain a biochar supporter, placing the biochar supporter into an impregnating solution, performing immersion treatment for 0.5-2h, then performing drying under the temperature condition of 50-100 DEG C, then placing the dried material to a