Waste-Derived Biochar for Sustainable Rural Revitalization

Biochar is a porous carbonaceous material produced during the thermochemical decomposition of biomass feedstock in the presence of little or no oxygen by pyrolysis, hydrothermal carbonization, gasification, torrefaction, and microwave heating, varying in thermochemical temperature and duration. Biomass feedstock can be any organic waste materials which include crop and forest residues, wood chip, algae, sewage sludge, manure, and organic municipal solid wastes. Interest in biochar is largely based on its two distinct benefits: First, biochar production can offset greenhouse gas emissions because it stores carbon in a stable form, preventing the release of greenhouse gases into the atmosphere from biomass degradation. Second, biochar is an effective, low-cost, and environment-friendly adsorbent/carrier, which is related to its relatively large surface area and abundant surface functional groups.

With the improvement of agricultural production and living standard in rural areas, the daily output of waste biomass resources (e.g., crop residues, pruning of fruit trees, animal waste, food waste, and domestic sludge) has increased tremendously. The large amount, random dumping, and open burning of these wastes have seriously threatened the ecological environment in rural areas. Therefore, the high-value utilization of waste biomass resources will help to build a zero-waste city, develop a circular economy, and promote the worldwide battle to prevent and control pollution. At the same time, it also helps to achieve the goal of peaking carbon emissions and achieving carbon neutrality.