Nanostructured biochar: production pathways and applications

Abstract

Hydrochar/biochar represents the solid yield of the hydrothermal carbonization and the pyrolysis processes of biomass. It is a nanostructured carbon-rich material with a high specific energy and density, high hydrophobicity and high friability. This coal-like material might appear like a very low-tech product. However, its physicochemical properties make it potentially useful in variety of fields such as energy storage, in environmental field as a sustainable way to mitigate anthropogenic CO2 by CO2 sorption and sequestration, in waste-water pollution remediation, as soil amendment, as a precursor for activated carbon, in the advanced material field as a primary material for nano-structured material generation (nanocomposites), in building insulation and bioenergy production. Biochar has H/O and O/C ratios similar to those of coal and a comparable caloric value with low ash and oxygen content. The production of hydrochar/biochar using either hydrothermal carbonization or pyrolysis techniques will be fully described. The potential applications of biochar and hydrochar will be presented and discussed.