The MX Sorbex process recovers meta-xylene (m-xylene) from mixed xylenes. UOP’s innovative Sorbex technology uses adsorptive separation for highly efficient and selective recovery, at high purity, of molecular species that cannot be separated by conventional fractionation.
The process simulates a moving bed of adsorbent with continuous counter-current flow of liquid feed over a solid bed of adsorbent. Feed and products enter and leave the adsorbent bed continuously, at nearly constant compositions. A rotary valve is used to periodically switch the positions of the feed-entry and product-withdrawal points as the composition profile moves down the adsorbent bed. The fresh feed is pumped to the adsorbent chamber (2) via the rotary valve (1). M-xylene is separated from the feed in the adsorbent chamber and leaves via the rotary valve to the extract column (3). The dilute extract is then fractionated to produce 99.5 wt% m-xylene as a bottoms product. The desorbent is taken from the overhead and recirculated back to the adsorbent chamber. All the other components present
in the feed are rejected in the adsorbent chamber and removed via the rotary valve to the raffinate column (4). The dilute raffinate is then fractionated to recover desorbent as the overhead product and recirculated back to the adsorbent chamber.
Licensor: UOP LLC, A Honeywell Company