Lignocellulosic biomass carbonization for biochar production and characterization of biochar reactivity

Lignocellulosic biomass (LB) pyrolysis and gasification technologies for bio-oil, syngas and process heat have been widely described, and biochar, as a significant byproduct of LB pyrolysis, has also received increasing attention because of it global sustainability. Biochar is attractive to researchers, mainly due to the value of its activity and reactivity, bringing the possibility of achieving carbon utilization and carbon neutralization. However, few studies have systematically described the changes in chemical composition and structure of LB during its carbonization process, as well as the origin of produced biochar's reactivity. A better understanding of what chemical substances have facilitated biochar reactivity and how they function is needed, which is of great value for environmental remediation analysis and green application strategy formulation. Herein, the new insights into the possible decomposition/transformation mechanisms of LB to functionalized biochar were discussed. Subsequently, the basic structure of lignocellulosic biomass derived biochar (LBC) was studied, and its reactivity-related compositions were also summarized. More importantly, discussion was expanded on the origin of LBC's reactivity and the reactivity expression ways. And the outlook section will highlight insights into future directions and prospects, aiming to overcome current limitations by developing more methods and exploring other green applications.

Automated summary

Lignocellulosic biomass pyrolysis and gasification technologies have been widely explored for the production of bio-oil, syngas, and process heat. The byproduct of this process, biochar, has attracted attention for its potential value in carbon utilization and carbon neutralization. However, there is a lack of systematic studies on the chemical composition and structure changes during the carbonization process of lignocellulosic biomass, as well as the origin of biochar reactivity. This article provides insights into the decomposition/transformation mechanisms of lignocellulosic biomass and the reactivity-related compositions of biochar. The discussion also expands on the origin of biochar's reactivity and potential ways to express its reactivity. The outlook section highlights future directions and prospects for further research and green applications.