In-situ and ex-situ selective catalysis of biochar-based catalysts for the production of high-quality bio-oil and H2-rich gas from tobacco stem

Optimizing the catalytic pyrolysis process is a promising approach to enhance the quality of the resulting products. Thus, four metals (Ni, Fe, Co, Cu) were loaded on biochar support to prepare biochar-based catalysts, and the mechanism of its effect on quality improvement of bio-oil and pyrolysis gas during in-situ and ex-situ pyrolysis of tobacco stem was investigated. The results showed that the biochar-based catalyst has high selectivity for H-2-rich and phenols production during in-situ pyrolysis, while the phenols content reached 57.99 % and H-2 content reached 49.91 % in Fe@BC group. It is highly selective to H-2-rich and N-containing compounds during ex-situ pyrolysis, and the content of N-containing compounds reached 47.23 % and the content of H reached 47.59 % in the Ni@BC group. This contributes to the efficient use of high-quality bio-oils and the production of clean gases. Biochar-based catalysts hold significant potential for the pyrolysis industry, paving the way for large-scale production and application of high-quality pyrolysis products.