关键词: 二氧化碳捕集, 吸附剂, 碳酸钠, 喷雾浸渍, 流化床

Abstract:

The traditional Na-based sorbent solid adsorbents have the bottleneck problem of large grain size, high gas diffusion resistance, and limited load, which leads to low CO₂ adsorption capability. A new adsorbent preparation method based on fluidized bed spray impregnation technology has been created. γ-Al₂O₃ was used as the support, and high-purity Na₂CO₃ was selected as the active component. The solution impregnation method and fluidized bed spray impregnation method were used to prepare several groups of adsorbents with different carrier structure and active component loading. Based on a fixed bed experimental setup combined with BET, XRD, SEM, XRF and other methods, the CO₂ adsorption capability of the adsorbents, as well as key parameters such as pore structure, crystal form, surface morphology, and loading capacity, were characterized. The results showed that the saturated adsorption capability and adsorption activity of the adsorbent prepared by the spray impregnation method were better than those of the traditional impregnation method under the same loading capacity of active components, because this method can control the loading depth of active components on the support. Meanwhile, the active components were mostly crystallized in needle or rod-shaped forms that were conducive to the reaction. The crystal size was generally 10%—20% smaller than that of traditional solution impregnation methods. Nevertheless, the pore structure of the carrier, such as specific surface area and pore size distribution, will still limit the reaction of the adsorbent prepared by the fluidized bed spray impregnation technology.

Key words: CO₂ capture, adsorbents, sodium carbonate, dry impregnation, fluidized-bed