Industrial & Engineering Chemistry Research, Vol.54, No.30, 7502-7515, 2015
A Novel Radial Adsorber with Parallel Layered Beds for Prepurification of Large-Scale Air Separation Units
The scale of cryogenic air separation units (ASV's) has increased continuously in recent years. To better meet the requirements of large scale ASUS, in terms of achieving both good prepurification performance and energy-saving effects, a novel radial adsorber with parallel layered adsorbent be is proposed in this Article. The main purpose of the novel adsorber is to reduce the pressure drop and increase the adsorption performance with a relatively compact structure, which may gain long-tern energy-saving: effects for large-scale ASUs as well as other similar applications. The novel adsorber is modeled in the cylindrical coordinate system using the mass, conservation equation, energy conservation equation, adsorbing isotherm equation) and LDF mass transfer equation. The geometric dimensions of the two passage and three passage adsorbers are both calculated using a proposed scheme, indicating the volume reductions of 27.8% and 31.7% and the pressure loss reductions of 10.8% and 56.4%; respectively. Furthermore, the adsorption, and desorption simulations of adsorbers with both parallel and single layered beds are performed, and the results show that better,adsorbent utilization is achieved by the parallel one than the single one due to, reduced feed velocities, increasing the breakthrough time by about 23.1%.