Mechanical Engineering Program - DESTACAR Research Group, Faculty of Engineering, Universidad de La Guajira, km 3+354 via Maicao, 440001, Riohacha, Colombia.
Department of Processes and Energy - Applied Thermodynamics and Alternative Energies Research Group, Faculty of Mines, Universidad Nacional de Colombia Sede Medellín, Cra. 80 No 65 - 223, 050034, Medellín, Colombia.
Environ Sci Pollut Res Int. 2024 Mar;31(12):18765-18784. doi: 10.1007/s11356-024-32028-3. Epub 2024 Feb 13.
In this study, an experimental strategy to obtain biochar and activated carbon from torrefied palm kernel shell as an efficient material for CO removal was evaluated. Biochar was obtained by slow pyrolysis of palm kernel shell at different temperatures (350 °C, 550 °C, and 700 °C) and previously torrefied palm kernel shell at different temperatures (220 °C, 250 °C, and 280 °C). Subsequently, activated carbons were prepared by physical activation with CO from previously obtained biochar samples. The CO adsorption capacity was measured using TGA. The experimental results showed that there is a correlation between the change in the O/C and H/C ratios and the functional groups -OH and C=O observed via FTIR in the obtained char, indicating that both dehydration and deoxygenation reactions occur during torrefaction; this favors the deoxygenation reactions and makes them faster through CO liberation during the pyrolysis process. The microporous surface area shows a significant increase with higher pyrolysis temperatures, as a product of the continuous carbonization reactions, allowing more active sites for CO removal. Pyrolysis temperature is a key factor in CO adsorption capacity, leading to a CO adsorption capacity of up to 75 mg/g for biochar obtained at 700 °C from non-torrefied palm kernel shell (Char700). Activated carbon obtained from torrefied palm kernel shell at 280 °C (T280-CHAR700-AC) exhibited the highest CO adsorption capacity (101.9 mg/g). Oxygen-containing functional groups have a direct impact on CO adsorption performance due to electron interactions between CO and these functional groups. These findings could provide a new experimental approach for obtaining optimal adsorbent materials exclusively derived from thermochemical conversion processes.
在这项研究中，评估了一种从热解棕榈仁壳中获得生物炭和活性炭的实验策略，将其作为去除 CO 的有效材料。生物炭是通过在不同温度（350°C、550°C 和 700°C）下对棕榈仁壳进行慢速热解以及在不同温度（220°C、250°C 和 280°C）下对先前热解的棕榈仁壳获得的。随后，通过先前获得的生物炭样品中 CO 的物理活化制备活性炭。使用 TGA 测量 CO 吸附容量。实验结果表明，在获得的炭中，O/C 和 H/C 比的变化与通过 FTIR 观察到的 -OH 和 C=O 等官能团之间存在相关性，表明在热解过程中既发生了脱水反应，也发生了脱氧反应；这有利于脱氧反应，并通过在热解过程中释放 CO 使其更快进行。微孔表面积随着更高的热解温度显著增加，作为连续碳化反应的产物，为 CO 去除提供了更多的活性位。热解温度是 CO 吸附容量的关键因素，导致未经热解的棕榈仁壳在 700°C 下获得的生物炭的 CO 吸附容量高达 75mg/g（Char700）。在 280°C 下从热解棕榈仁壳获得的活性炭（T280-CHAR700-AC）表现出最高的 CO 吸附容量（101.9mg/g）。含氧官能团对 CO 吸附性能有直接影响，这是由于 CO 与这些官能团之间的电子相互作用。这些发现为获得完全源自热化学转化过程的最佳吸附材料提供了一种新的实验方法。
