Char-based Fe-Ni-Ca material for capturing AAEM from biomass pyrolysis volatiles and recyclability in catalytic reforming of volatiles

Hydrogen production derived from biomass catalytic pyrolysis has received increasing attention, to solve the excessive consumption of renewable energy. However, considerable amounts of the issues (e.g., slag formation, corrosion, and scaling on the heat exchange surface) related to alkali and alkali earth metals (AAEM) have hindered its application. To address these challenges and improve the yield of H2, char-based Fe-Ni-Ca material is proposed to capture AAEM from biomass pyrolysis volatiles while increasing the H2. Char-based materials exhibit excellent AAEM capture ability, with K, Na, and Mg contents detected in spent materials being 3.4 times, 1.4 times, and 1.5 times higher than those in fresh, respectively. Besides, the spent Fe-Ni-Ca exhibits excellent stability after regeneration, with H2 production comparable to that of fresh material, and CO production exceeding that of fresh Fe-Ni-Ca. It was disclosed that the char support can adsorb AAEM in volatiles, and then chemical reactions will occur between metal elements (Fe, Ni, and Ca) in the material and AAEM in the volatiles, trapping AAEM in the material and catalytic reforming volatiles. This work provides a novel strategy to deal with AAEM in volatiles.