This study characterizes mass transfer processes in a multi-stage fluidized bed (MSFB) using shallow fluidized beds. Multi-stage fluidized beds (MSFBs) are of interest for sour gas removal using adsorption, examples are ${\text{H}}_2$S/CO₂ removal from natural gas and CO₂ capture by amine sorbents. A phenomenological model based on the classical two-phase fluidization model is used to study the mass transfer process. Independent measurements and literature data are used to describe mixing, hold-ups, intraparticle mass transfer and adsorption kinetics. The bubble hold-up was experimentally measured. Mixing was investigated with a temperature response measurement. The mixing in the emulsion gas phase varies between plug flow and ideal mixing with increasing superficial gas velocity, while the solid phase is always ideally mixed. The presented fluidized bed model is able to describe the effects of superficial gas velocity, solid flux, bed height and inlet concentration. Mass transfer was further studied using a sensitivity analysis, which showed that the used shallow fluidized bed is already fairly optimized with respect to mass transfer. Shallow fluidized beds benefit from fast gas interchange because bubbles do not have the chance to grow. Optimal mass transfer and gas interchange conditions can be achieved in shallow fluidized beds for application in MSFBs.

这项研究表征了使用浅流化床的多级流化床（MSFB）中的传质过程。多级流化床（MSFB）是利用吸附去除酸性气体的重要原料，例如${\text{H}}_2$S / CO ₂从天然气和除去CO ₂被胺吸附剂捕获。基于经典两相流化模型的现象学模型用于研究传质过程。独立的测量和文献数据用于描述混合，滞留，颗粒内传质和吸附动力学。通过实验测量气泡保持率。通过温度响应测量研究混合。乳液气相中的混合在活塞流和理想混合之间随表观气体速度的增加而变化，而固相总是理想地混合。提出的流化床模型能够描述表观气体速度，固体通量，床层高度和入口浓度的影响。使用敏感性分析进一步研究了传质，这表明所用的浅层流化床在传质方面已经相当优化。浅流化床得益于快速的气体交换，因为气泡没有机会生长。可以在用于MSFB的浅流化床中实现最佳的传质和气体交换条件。