Rising global population and urbanization are major causes of waste generation, energy demand and carbon emissions. The atmospheric CO₂ concentration has increased of 44% from 284 ppm in 1850 to 409 ppm in 2018. In 2017, the world energy consumption was 582 quadrillion British thermal units (qBtu), including 495 qBtu of fossil fuels and 87 qBtu of renewable and nuclear energy sources. Therefore, there is a need for new energies and methods of carbon sequestration, for instance by recycling biomass into biochar. Here, we review the thermochemical valorization of waste biomass by pyrolysis, gasification, torrefaction and carbonization to produce biochar with promising and environmental applications. We detail parameters that control biochar yields, quality and composition. Physical and chemical routes of biochar activation are also described. We focus on the utilization of biochar as soil amendment and for the adsorption of pollutants from wastewater. We conclude by a discussion on the techno-economic and lifecycle assessment of biochar production technologies.

全球人口的增长和城市化是产生废物，能源需求和碳排放的主要原因。大气中的CO ₂浓度从1850年的284 ppm增加到2018年的409 ppm，增加了44％。2017年，世界能源消耗为582万亿英国热量单位（qBtu），其中包括495 qBtu的化石燃料和87 qBtu的可再生能源和核能。因此，需要例如通过将生物质再循环到生物炭中的碳固存的新能源和方法。在这里，我们通过热解，气化，焙干和碳化以产生具有前景和环境应用的生物炭来审查废物生物质的热化学增值。我们详细介绍了控制生物炭产量，质量和组成的参数。还描述了生物炭活化的物理和化学途径。我们专注于利用生物炭作为土壤改良剂以及吸附废水中的污染物。