School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China.
Environ Pollut. 2022 Aug 1;306:119399. doi: 10.1016/j.envpol.2022.119399. Epub 2022 May 4.
Carbon dioxide (CO) is the main anthropogenic greenhouse gas contributing to global warming. In this study, a series of KOH-modified biochars derived from feedstock mixtures (i.e., S3W7 biomass consisting of 70% pine sawdust and 30% sewage sludge; S5W5 biomass consisting of 50% pine sawdust and 50% sewage sludge) at different temperature (i.e., 600-800 °C) were prepared for evaluating CO adsorption performance. The KOH-activated biochars prepared with S3W7 biomass displayed larger surface areas and micropore volumes compared to those of S5W5 biochars. In particular, the highest CO adsorption capacity (177.1 mg/g) was observed on S3W7 biomass at 700 °C (S3W7-700K), due to the largest surface area (2623 m/g) and the highest micropore volume (0.68 cm/g). Furthermore, surface functional groups, hydrophobicity, and aromaticity of biochar and presence of hetero atoms (N) also were actively involved in CO adsorption of biochar. In addition, in situ DRIFTS analysis advanced current understanding for the chemical sorption mechanisms by identifying the transformation composites of CO on biochars, and characterizing the weakly adsorbed and newly formed mineral species (e.g., carbonates) during the CO sorption process. This study may provide an insight into the research of CO capture by identifying physical and chemical adsorption, and expand the effective utilization of natural biomass-based biochar for mitigation greenhouse gas emission.
二氧化碳（CO）是主要的人为温室气体，导致全球变暖。在这项研究中，使用不同温度（即 600-800°C）下的原料混合物（即由 70%松木锯末和 30%污水污泥组成的 S3W7 生物质；由 50%松木锯末和 50%污水污泥组成的 S5W5 生物质）制备了一系列 KOH 改性生物炭，用于评估 CO 吸附性能。与 S5W5 生物炭相比，用 S3W7 生物质制备的 KOH 活化生物炭具有更大的比表面积和微孔体积。特别是，在 700°C 下（S3W7-700K），S3W7 生物质的 CO 吸附量最高（177.1 mg/g），这归因于最大的比表面积（2623 m/g）和最高的微孔体积（0.68 cm/g）。此外，生物炭的表面官能团、疏水性和芳香性以及杂原子（N）的存在也积极参与了 CO 的吸附。此外，原位 DRIFTS 分析通过识别 CO 在生物炭上的转化复合材料，以及表征 CO 吸附过程中弱吸附和新形成的矿物质（例如碳酸盐），为化学吸附机制提供了深入的了解。本研究通过识别物理和化学吸附，为 CO 捕集研究提供了新的见解，并扩展了天然生物质基生物炭在缓解温室气体排放方面的有效利用。
