Several biochars and activated carbons are prepared from cellulose fraction of some agricultural wastes (linen, cotton and wheat). The obtained carbons are characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM), ¹³C nuclear magnetic resonance (¹³C NMR), CO₂ adsorption-desorption at 0 °C, Raman spectroscopy and X-ray photoelectron spectroscopy. The biochars are synthesized at different pyrolysis temperatures while activated carbons are obtained from a biochar (pyrolysis at 500 °C) using KOH as activation agent in different amounts. The adsorption values in the biochars increase proportionally to the temperature levels (about 2.5 mmol CO₂ g⁻¹ at 25 °C and 760 mm of Hg). The highest the temperature of pyrolytic treatment, the highest the adsorption values. These values remain stable for several cycles in the case of samples synthesized at the highest temperature. The chemical activation of the biochar with KOH improves its microporosity as well as its CO₂ adsorption capacity (3.6 mmol CO₂ g⁻¹ at 25 °C and 760 mm of Hg). Moreover, these biochars and activated carbons are evaluated for the adsorption of N₂ or H₂. The N₂ and H₂ adsorption capacity is much lower than that of CO₂. Consequently, these biochars and activated carbons are highly selective for the CO₂ capture. They have also shown a high H₂ adsorption at −196 °C which makes them having a high potential in H₂ storage at low temperature levels.

一些生物炭和活性炭是从一些农业废物（亚麻、棉花和小麦）的纤维素部分制备的。获得的碳通过X射线衍射（XRD）、透射电子显微镜（TEM）、¹³ C核磁共振（¹³ C NMR）、0°C下CO ₂吸附-解吸、拉曼光谱和X射线光电子能谱表征. 生物炭是在不同的热解温度下合成的，而活性炭是从生物炭（在 500°C 下热解）使用不同量的 KOH 作为活化剂获得的。生物炭中的吸附值与温度水平成比例增加（约 2.5 mmol CO ₂ g ^-1在 25 °C 和 760 毫米汞柱下）。热解处理温度最高，吸附值最高。在最高温度下合成的样品的情况下，这些值在几个循环中保持稳定。用 KOH 对生物炭进行化学活化提高了其微孔率和 CO ₂吸附能力（3.6 mmol CO ₂ g ^-1在 25 °C 和 760 mm Hg 下）。此外，还评估了这些生物炭和活性炭对 N ₂或 H ₂的吸附。N ₂和H _{2 的}吸附能力远低于CO _{2 的}吸附能力。因此，这些生物炭和活性炭对 CO 具有高度选择性₂捕获。它们还在-196 °C 下表现出高 H ₂吸附，这使得它们在低温水平下具有很高的 H ₂储存潜力。