A demand-driven pressure swing adsorption biogas upgrading application is modelled using monolayer and multilayered (bilayer) beds, to gain insight on the impact of the adsorbent pellet size on the overall performance of such processes. Pellet radii in the range of 0.1–2.4 mm were studied, for fixed cycle settings and column dimensions. Varying the pellet size influences the sorption kinetics and flow resistance, resulting in the existence of an optimum pellet size for monolayered beds. For fixed cycle settings, small pellets may yield higher purities at low total productivities, yet show a more rapid decrease in product purity with increasing productivities due to the higher pressure drop. Furthermore, 18 configurations with beds containing a layer of larger pellets and a second layer of smaller pellets (bilayer) were investigated. Bilayered beds with 0.3 mm, 0.6 and 2.4 mm radius pellets were combined, with the first layer taking up 25, 50 or 75% of the bed. With respect to upward flow in the adsorption step, beds with the smallest pellet size in the top layer (LS beds) can offer higher product purity than beds with the smallest pellet in the bottom layer (SL beds).

使用单层和多层（双层）床对需求驱动的变压吸附沼气提质应用进行建模，以深入了解吸附剂颗粒尺寸对此类过程整体性能的影响。对于固定循环设置和色谱柱尺寸，研究了 0.1-2.4 mm 范围内的颗粒半径。改变颗粒尺寸会影响吸附动力学和流动阻力，从而导致单层床存在最佳颗粒尺寸。对于固定循环设置，小颗粒可能会在较低的总生产率下产生较高的纯度，但由于较高的压降，随着生产率的提高，产品纯度会下降得更快。此外，研究了 18 种床层配置，其中包含一层较大的颗粒和第二层较小的颗粒（双层）。将具有 0.3 毫米、0.6 和 2.4 毫米半径颗粒的双层床组合在一起，第一层占据床的 25、50 或 75%。关于吸附步骤中的向上流动，顶层颗粒尺寸最小的床（LS 床）可以提供比底层颗粒最小的床（SL 床）更高的产品纯度。