Effect of Energy Balance Approximations on Simulation of Fixed-Bed Adsorption
Effect of Energy Balance Approximations on Simulation of Fixed-Bed Adsorption
复制标题
能量平衡近似对固定床吸附模拟的影响
DOI：
10.1021/ie050065g
复制
发表时间：
2005
影响因子：
4.2
通讯作者：
M. LeVan
中科院分区：
文献类型：
--
作者：
Krista S. Walton;M. LeVan
对于绝热吸附过程，考察了固定床模拟对常见能量平衡近似的敏感性。用局部平衡理论确定了水蒸气在4A沸石分子筛固定床上吸附的温升和穿透行为。考虑的情况是，吸附相热容量在气相值和液相值之间变化，并且允许等量热随温度和负荷变化，或者被赋予一个恒定值。不同近似的平台温度、分压和载荷的差异很小，但对突破行为的影响可能很大。当吸附相的热容近似为液体的热容，且等容热为常量时，与基本情况的差别最大；这些近似导致很大程度上高估了突破时间。
The sensitivity of fixed-bed simulations to common energy balance approximations is examined for an adiabatic adsorption process. Local equilibrium theory is used to determine temperature rise and breakthrough behavior for water vapor adsorbed in a fixed bed of 4A zeolite molecular sieve. Cases are considered in which the adsorbed-phase heat capacity is varied between gas- and liquid-phase values, and the isosteric heat is allowed to vary with temperature and loading or is assigned a constant value. The differences in plateau temperature, partial pressure, and loading for the different approximations are small, but the impact on breakthrough behavior can be large. The most dramatic differences from the base case occur when the adsorbed-phase heat capacity is approximated by that of a liquid and the isosteric heat is a constant; these approximations lead to a largely overestimated breakthrough time.