title: Novel simulated moving-bed adsorber for the fractionation of gas mixtures.
abstract: The separation of propylene-propane mixture is an energy intensive operation commercially practiced using cryogenic distillation. The separation by pressure swing adsorption has been studied as an alternative. A fixed-bed pressure swing adsorption yields the heavy component as a pure product. The product recovery and the productivity are not high. In a moving-bed process, because of the counter-current solid-gas contact, the separation achieved is similar to that of the fractionation by distillation. Although the moving-bed operation offers the upper limit for the performance of a cyclic adsorptive process, due to mechanical complexities in the handling of solids the 'simulated' moving-bed is preferred. By moving the inlet and outlet ports of streams located along the length of the bed, a moving-bed process can be realized in a fixed bed. We describe here a 'moving-port' system which permits injection or withdrawal of the fluid along the axial direction in a fixed bed. A fixed bed embedded with the moving-port systems emulates a simulated moving-bed adsorber. The proposed adsorber can fractionate a binary gas mixture into two product streams with high purities. It is similar to the Sorbex process of UOP but does not have the eluent as an additional separating agent. A parametric study indicates that high purity products and a higher productivity by an order of magnitude can be achieved with simulated moving-beds compared to the fixed beds.
authors.affiliation: Indian Institute of Technology Kanpur, Kanpur 208016, India. dprao@iitk.ac.in
authors.forename: D P
authors.initials: DP
authors.lastname: Rao
authors.forename: S V
authors.initials: SV
authors.lastname: Sivakumar
authors.forename: Susmita
authors.initials: S
authors.lastname: Mandal
authors.forename: Sridevi
authors.initials: S
authors.lastname: Kota
authors.forename: B S G
authors.initials: BS
authors.lastname: Ramaprasad
mesh_terms: D000327:Adsorption; D005740:Gases / Q000737:chemistry*
chemical_list: D005740:Gases