Adsorbent monoliths are gaining increasing interest in gas phase separation processes, but have rarely been studied for liquid phase separations. In this work, we investigate an activated carbon monolith for the recovery of biobutanol from model liquid mixtures as well as compare the obtained column dynamics with the adsorption of biobutanol from gas mixtures. Single solute adsorption isotherms of acetone, n-butanol and ethanol revealed the carbon’s larger affinity for n-butanol (0.11 g/g adsorbed at 2 wt%), while dynamic separations on a fixed-bed of crushed monolith granules proved its capability to effectively separate an aqueous mixture of these three fermentation products. In contrast, liquid phase breakthrough experiments of n-butanol on the monolith column were marked by almost instantaneous detection of adsorbate at the outlet (< 5 min.) and broad tailing of the concentration curve. Measures to improve inlet flow distribution or increasing temperature to enhance mass transfer were unsuccessful. In contrast, using the same inlet flow distributors, a sharp breakthrough profile could be obtained in vapor phase, while the gas contact time (17 s) was much lower than in liquid phase (1300 s). A comparison of characteristic mass transfer times of the adsorption process highlighted the important role of the external film resistance in liquid compared to vapor phase adsorption.

吸附剂整料在气相分离过程中越来越受到关注，但很少有人研究用于液相分离。在这项工作中，我们研究了一种用于从模型液体混合物中回收生物丁醇的活性炭整体，并将获得的柱动力学与从气体混合物中吸附生物丁醇进行比较。丙酮、正丁醇和乙醇的单一溶质吸附等温线揭示了碳对正丁醇的更大亲和力（0.11 g/g 吸附量为 2 wt%），而在粉碎的整体颗粒固定床上的动态分离证明其能够有效地分离这三种发酵产物的含水混合物。相反， n的液相突破实验整体柱上的-丁醇通过在出口处几乎瞬时检测到吸附物（< 5 分钟）和浓度曲线的宽拖尾来标记。改善入口流量分布或提高温度以增强传质的措施均未成功。相比之下，使用相同的入口流量分配器，可以在气相中获得明显的突破剖面，而气体接触时间（17 秒）远低于液相（1300 秒）。吸附过程的特征传质时间的比较突出了液体外膜电阻与气相吸附相比的重要作用。