Critical Review on Biochar‐Supported Catalysts for Pollutant Degradation and Sustainable Biorefinery

• Published in: Advanced sustainable systems (Online) Vol. 4; no. 10
• Main Authors: Kumar, Manish, Xiong, Xinni, Sun, Yuqing, Yu, Iris K. M., Tsang, Daniel C. W., Hou, Deyi, Gupta, Juhi, Bhaskar, Thallada, Pandey, Ashok
• Format: Journal Article
• Language: English
• Published: 01.10.2020
• Subjects: advanced oxidation processes; catalytic degradation; engineered biochar; physical/chemical activation; sustainable biorefinery
• ISSN: 2366-7486; 2366-7486
• DOI: 10.1002/adsu.201900149

Biochar (BC) is a material synthesized from biomass by thermochemical conversion. Physicochemical and functional properties of BCs can be enhanced by several methods of activation or functionalization. The activated and functionalized BCs with a large surface area and abundant surface functional groups can serve as effective catalysts or catalyst supports for various chemical transformations as well as for adsorption/sorption/enrichment of low‐concentration pollutant streams. Among them, remediation of environmental contaminants and production of a range of bioproducts in biorefineries have attracted much attention in the context of achieving green and sustainable development. Although the applications of BC as adsorbents in removal of pollutants have been discussed extensively, there is a lot of untapped potential with new applications of BCs as catalysts or catalyst supports for advanced oxidation processes (AOPs) and sustainable biorefineries. In this review, the production and activation/functionalization of BCs are scrutinized. The mechanisms of activated and functionalized BC and BC‐supported catalysts in degradation of organic contaminants via AOPs assisted with hydrogen peroxide (H2O2), peroxydisulfate (PDS), and peroxymonosulfate (PMS) are reviewed. Emerging applications of BC as catalyst for production of biodiesel and high‐value chemicals, tar removal, bio‐syngas reforming, and energy storage and conversion devices are discussed in detail. Biochar from thermochemical conversion of biomass has wide‐spread environmental applications through tailored activation and functionalization. This state‐of‐the‐art review discusses the emerging applications of functionalized biochar and biochar‐supported catalysts in i) contaminant removal via advanced oxidation processes (AOPs) assisted with hydrogen peroxide (H2O2), peroxydisulfate (PDS), and peroxymonosulfate (PMS); ii) sustainable biorefinery such as production of biofuels and high‐value chemicals.