Carbon dioxide (CO₂) capture is critical for emission reduction. Biochar is a promising adsorbent for CO₂ capture. In this work, the effect of relative humidity and biochar activation with steam or KOH treatment on CO₂ capture was investigated. The results demonstrate that the biochar sample activated by KOH has a high CO₂ capture capacity (50.73 mg g⁻¹). In addition, the biochar after 1.0 h of steam treatment showed a carbon capture capacity of 38.84 mg g⁻¹. The results also show that the capture ability of biochar decreased as CO₂ concentration decreased from 100% to 15%. The relative humidity had a negative impact on CO₂ capture over biochar. The CO₂ capture capability of biochar materials treated by steam decreased by a range of 31.38%–62.89% as the relative humidity rose from 8.8% to 87.9%. Furthermore, the lifetime of biochar samples at various relative humidity shows that increased relative humidity had a negative impact on CO₂ adsorption due to water molecules occupying active sites.

二氧化碳 (CO ₂ ) 捕获对于减排至关重要。_{生物炭是一种很有前途的 CO 2}捕获吸附剂。在这项工作中，研究了相对湿度和使用蒸汽或 KOH 处理的生物炭活化对 CO ₂捕获的影响。结果表明，KOH活化的生物炭样品具有较高的CO ₂捕获能力（50.73 mg g ^-1）。此外，蒸汽处理 1.0 h 后的生物炭显示出 38.84 mg g ^-1的碳捕获能力。结果还表明，随着CO ₂浓度从100%下降到15%，生物炭的捕获能力下降。相对湿度对CO _{2有负面影响}捕获 biochar。随着相对湿度从8.8%上升到87.9%，蒸汽处理的生物炭材料的CO ₂捕集能力下降了31.38%~62.89%。此外，生物炭样品在各种相对湿度下的寿命表明，由于水分子占据活性位点，增加的相对湿度对 CO _{2吸附具有负面影响。}