Abstract:

In low-temperature Fischer-Tropsch synthesis slurry bed reactors, three types of multiphase separation challenges are involved, including the separation of liquid products from catalyst particles, the separation of liquid (solid) entrained in the gas at the top of the reactor, and the removal of catalyst fines in slurry. Efficient solution of these three separation challenges is paramount for the continuous and stable operation of slurry bed reactors. The paper reviewed the application and research advancements of various separation techniques in addressing three types of multiphase separation challenges. For the separation of liquid products and catalyst particles, in-vessel filtration was a commonly employed technique in industrial plants, but there existed issues such as gas leakage. External filtration can avoid the issues existing in in-vessel filtration, yet the research thereon was relatively lacking. The innovation of gravity sedimentation equipment and its combination with other techniques can effectively shorten the separation cycle. Magnetic separation and supercritical fluid extraction had potential advantages due to their relatively high separation accuracy, but the current research was still in the laboratory stage. For the separation of liquid (solid) entrained in gases, cyclone and baffle-plate separator were primarily employed. According to industrial recommendations, the combined use of the two equipment can effectively enhance the separation performance. For the removal of catalyst fines in slurry, the filter units with different pore sizes were impractical due to the inability to accurately control the size of the removed particles, while the hydrocyclone "dialysis" continuous classification technology can efficiently remove catalyst fines and recover coarse catalyst simultaneously. Finally, the subsequent research was prospected. Guided by industrial application, broader and deeper research is the key direction in the future.

Key words: low temperature Fischer-Tropsch synthesis, slurry bed reactor, liquid solid separation, gas liquid (solid) separation, particle classification

摘要：

在低温费-托合成浆态床反应器中涉及液态产品与催化剂颗粒的分离、反应器顶部气体中夹带液体（固体）的分离与浆液中催化剂细粉的去除三类多相分离问题，三类问题的有效解决对浆态床反应器的连续、稳定运行至关重要。本文综述了不同分离技术用于解决三类多相分离问题的应用与研究进展。对于液态产品与催化剂颗粒分离，器内过滤是工业装置普遍采用的技术，但存在气体泄漏等问题。器外过滤可避免器内过滤存在的问题，但研究相对欠缺。重力沉降设备的创新及与其他技术的结合可有效缩短分离周期。磁分离与超临界流体萃取因分离精度较高具有潜在优势，但目前研究尚处于实验室阶段。对于气体中夹带液体（固体）分离，主要采用旋风分离器和折流板分离器，根据工业建议，两种设备的组合使用可提升分离效果。对于浆液中催化剂细粉去除，不同孔径的过滤单元因无法精确控制去除颗粒大小而无法实施，而基于水力旋流器的“透析式”细粉连续分级技术可在高效去除细粉的同时回收有效催化剂。最后，对后续的研究进行了展望，以工业应用为导向，开展更广、更深的研究是未来的重点方向。

关键词: 低温费-托合成, 浆态床反应器, 液固分离, 气液（固）分离, 颗粒分级