Porous carbons are considered to be promising sorbents for carbon capture and sequestration. As precursors, the use of biomass materials has acquiring special interest due to its low cost and high availability. Among all the possibilities to convert low-value biomass into these interesting sorbents, hydrothermal carbonization has demonstrated several advantages such as lower energy consumption over pyrolysis. In this work, activated hydrochars using two-phase olive mill waste as precursor have been prepared through physical and chemical activation using CO₂ and KOH, respectively. Additionally, with the aim to study the influence of the nitrogen on their adsorption capacity, N-doped adsorbents have been prepared through a one-step hydrothermal carbonization. The behaviour of these adsorbents has been studied in terms of CO₂ uptake capacity at an absolute pressure of 15 kPa and temperatures of 0, 25 and 75 °C, apparent selectivity towards CO₂ over N₂, and isosteric heat of adsorption. Among all these samples, the physically activated hydrochar appears to be the best due to its higher CO₂ uptakes, adsorption rates and values of selectivity at 25 °C. Therefore, considering these results, doping these materials with nitrogen does not appear to enhance their adsorption properties, contrary to what some authors have previously reported.

多孔碳被认为是用于碳捕获和隔离的有前途的吸附剂。作为前体，生物质材料的使用由于其低成本和高可用性而引起了特别的兴趣。在将低价值生物质转化为这些有趣的吸附剂的所有可能性中，水热碳化已显示出一些优势，例如，与热解相比，能耗更低。在这项工作中，通过使用CO ₂进行物理和化学活化，制备了以两相橄榄磨机废料为前体的活性炭。和KOH分别。另外，为了研究氮对其吸附容量的影响，已经通过一步水热碳化制备了氮掺杂的吸附剂。已经研究了这些吸附剂的行为，涉及的条件是在15 kPa的绝对压力和0、25和75°C的温度下的CO ₂吸收能力，在N _2上对CO _2的表观选择性以及吸附的等排热。在所有这些样品中，由于其较高的CO ₂含量，物理活化的水焦炭似乎是最好的吸收，吸附速率和25°C下的选择性值。因此，考虑到这些结果，与一些作者先前报道的相反，用氮掺杂这些材料似乎不会增强其吸附性能。