Coal and biomass fly ash was impregnated with tetraethylenepentamine (TEPA) to prepare solid CO₂ sorbent. Experimental CO₂ adsorption capacities of the sorbent in fixed-bed column were fitted to several kinetic equations. The modified Avrami fractional kinetic model could accurately predict the CO₂ adsorption kinetic behaviors of the sorbent under different conditions. CO₂ adsorption rate increases with the increase in temperature, initial CO₂ concentration and gas flow rate, as a result of the decreased CO₂ diffusion resistance. A mathematical model was proposed and demonstrated to well predict the CO₂ adsorption breakthrough curves in the fixed-bed column. Effects of temperature, initial CO₂ concentration and gas flow rate on the mass transfer kinetic behaviors of the desired sorbent were investigated. The positive effect of these factors on promoting the overall mass transfer coefficient and the internal mass transfer coefficient is not significant. The external mass transfer coefficient will be remarkably reinforced with the increase in these operating parameters, due to the change in viscosity and density of the gas phase and the reduced external mass transfer resistance. Internal mass transfer process is determined as the rate-limiting step for CO₂ adsorption. The results will lay the groundwork for future scale-up application of the sorbent in post-combustion CO₂ capture.

用四亚乙基五胺（TEPA）浸渍煤和生物质粉煤灰，以制备固体CO ₂吸附剂。将固定床塔中吸附剂的实验性CO ₂吸附容量拟合到多个动力学方程式。改进的Avrami分数动力学模型可以准确预测在不同条件下吸附剂的CO ₂吸附动力学行为。由于降低的CO ₂扩散阻力，CO ₂吸附速率随温度，初始CO ₂浓度和气体流速的增加而增加。提出并证明了一个数学模型可以很好地预测CO ₂固定床色谱柱的吸附穿透曲线。研究了温度，初始CO ₂浓度和气体流速对所需吸附剂传质动力学行为的影响。这些因素对提高整体传质系数和内部传质系数的积极作用并不显着。随着这些操作参数的增加，由于气相的粘度和密度的变化以及外部传质阻力的降低，外部传质系数将得到显着增强。内部传质过程被确定为CO ₂吸附的限速步骤。该结果将为吸附剂在燃烧后的CO _2中的未来扩大应用奠定基础。 捕获。