The potentialities in the use of biochars prepared by steam-assisted slow pyrolysis as adsorbents of gases of strategic interest (N2, CO2, and CH4) and their mixtures were explored. The biochars prepared from Populus nigra wood and cellulose fibers exhibited a narrow microporosity, with average pore sizes ranging between 0.55 and 0.6 nm. The micropore volume increased with the pyrolysis temperature, allowing CO2 and CH4 uptakes at room temperature between 1.5 and 2.5 mmol/g and between 0.1 and 0.5 mmol/g, respectively. These values are in line with those from the literature on biomass-derived carbon-based materials, exhibiting much higher porous features than those reported herein. As for the separation of CO2/N2 and CO2/CH4 gas mixtures, data showed that the prepared biochars exhibited good selectivities for CO2 over both N2 and CH4: between ca. 34 and 119 for a CO2/N2 mixture in typical post-combustion conditions (15:85, v/v) and between 14 and 34 for a CO2/CH4 mixture typical of natural gas upgrading (30:70, v/v).

中文翻译：

---

评估通过蒸汽辅助慢速热解法制备的生物炭对CO2吸附和分离的潜力。

探索了利用蒸汽辅助缓慢热解法制备的生物炭作为具有战略意义的气体（N2，CO2和CH4）及其混合物的吸附剂的潜力。由黑杨和纤维素纤维制得的生物炭表现出较窄的微孔性，平均孔径在0.55至0.6 nm之间。微孔体积随热解温度的增加而增加，从而使得室温下的CO2和CH4吸收量分别为1.5至2.5 mmol / g和0.1至0.5 mmol / g。这些值与来自生物质衍生的碳基材料的文献中的值相符，与本文报道的那些相比，表现出高得多的多孔性。至于CO2 / N2和CO2 / CH4气体混合物的分离，数据表明，所制备的生物炭在N2和CH4上均表现出对CO2的良好选择性。