Ex-situ combined with in-situ catalytic pyrolysis: A strategic approach to enhancing furans production from biomass

Biomass, as a renewable resource, holds great significance in its conversion into valuable chemicals or fuels, representing a crucial avenue for its utilization. Nevertheless, catalytic pyrolysis currently faces constraints, demanding further enhancements in both the selectivity of target products and the recyclability of catalysts. Herein, we reported an innovative in-situ combined with ex-situ catalytic pyrolysis strategy by using red mud loaded with cobalt (Co/RM) and activated carbon (AC) as the catalyst for this combined catalytic pyrolysis system. By optimization of process conditions, the selectivity of furans was further improved significantly. The results showed that with a combined catalytic system constituted of Co/RM and Co/RM + AC, under conditions of a pyrolysis temperature of 400 °C, a catalytic temperature of 500 °C, and a mass ratio of catalyst to raw material of 20:1, the selectivity of furans can be increased to 80.1 %. Remarkably, this combined catalytic system exhibits excellent catalytic activity for furans production even after 20 cycles of operation. Moreover, the established combined catalytic system is capable of converting tobacco, bamboo, and wood into furans with more than 100 % increasement. These results suggest that this novel strategy harbors broad application prospects and has the potential to catalyze more efficient exploitation of biomass resources.