Production of furan chemicals from contaminated biomass using hydrothermal-assisted activated persulfate strategy: Exploring the critical role of heavy metals on products

Abstract

Sustainable disposal of heavy metal contaminated biomass has always been a challenging task. Here, a strategy was proposed for directly producing valuable 5-hydroxymethylfurfural (HMF) and furfural (FF) from contaminated biomass through hydrothermal-assisted persulfate activation strategy. The optimal yields were obtained at 18.6 and 22.5 wt% for HMF and FF, respectively. The hydrothermal process promoted the release of Fe, Mn, Cu, Zn, and Cr from biomass into the liquid phase and then activated peroxymonosulfate (PMS) to destroy the lignocellulose structure and increase the accessible of cellulose and hemicellulose. Meanwhile, the metal and acidic environment provided by the reaction system act as natural catalysts to synergistically promote the production of HMF and FF. The controlled experiments revealed that Fe, Mn, Zn, and Cr played a major role in biomass conversion during this process. Moreover, possible reaction mechanisms and pathways were explored through quenching tests and density functional theory calculations. This study provides a simple pretreatment and promising valorization strategy for the sustainable utilization of heavy metal-contaminated biomass.