UOP Sorbex processes

UOP raffinate process UOP Sarex process UOP Sorbex process UOP Sorbex processes UOP Sorbex separation... 

Such a concept was originally used in a process developed and Hcensed by UOP under the name UOP Sorbex (59,60). Other versions of the SMB system are also used commercially (61). Toray Industries built the Aromax process for the production of -xylene (20,62,63). Illinois Water Treatment and Mitsubishi have commercialized SMB processes for the separation of fmctose from dextrose (64—66). The foUowing discussion is based on the UOP Sorbex process. 

Fig. 9. Schematic diagram of a UOP Sorbex process. D, E, F, R, and. f represent flow rates for desorbent, extract, feed, raffinate, and net sobds.

UOP has developed a UOP Sorbex process for the recovery and purification of citric acid from fermentation broths. The process provides technical-grade citric acid, C HgOy, which can be further recrystaUized to obtain food-grade citric acid (qv). 

Separation of Fatty Acids. Tall oil is a by-product of the pulp and paper manufacturiag process and contains a spectmm of fatty acids, such as palmitic, stearic, oleic, and linoleic acids, and rosia acids, such as abietic acid. The conventional refining process to recover these fatty acids iavolves iatensive distillation under vacuum. This process does not yield high purity fatty acids, and moreover, a significant degradation of fatty acids occurs because of the high process temperatures. These fatty and rosia acids can be separated usiag a UOP Sorbex process (93—99) (Tables 8 and 9). 

Displacement-purge forms the basis for most simulated continuous countercurrent systems (see hereafter) such as the UOP Sorbex processes. UOP has licensed close to one hundred Sorbex units for its family of processes Parex to separate p-xylene from C3 aromatics, Molex tor /i-paraffin from branched and cyclic hydrocarbons, Olex for olefins from paraffin, Sarex for fruc tose from dextrose plus polysaccharides, Cymex forp- or m-cymene from cymene isomers, and Cresex for p- or m-cresol from cresol isomers. Toray Industries Aromax process is another for the production of p-xylene [Otani, Chem. Eng., 80(9), 106-107, (1973)]. Illinois Water Treatment [Making Wave.s in Liquid Processing, Illinois Water Treatment Company, IWT Adsep System, Rockford, IL, 6(1), (1984)] and Mitsubishi [Ishikawa, Tanabe, and Usui, U.S. Patent 4,182,633 (1980)] have also commercialized displacement-purge processes for the separation of fructose from dextrose. 

FIG. 16-59 UOP Sorbex process. Reprinted with permission of John Wiley Liquid Separation, in Kirk-Otbmer Encyclopedia of Gbemical Tecbnology, 4th ed., John Wiley [Pg.1557]

MX Sorbex A version of the UOP Sorbex process for removing m-xylene from its isomers. First licensed in 1995. 

Table 30 UOP sorbex processes for liquid phase separations ...

The most important applications are the UOP Sorbex processes (Ruthven, 1997). These are automated continuous processes that separate hydrocarbon mixtures mainly in the liquid phase. ... 

A chromatographic process for separation of Cg aromatic isomers has been recently developed by Asahi. The process operates in the liquid phase and is put forward as an alternative to the UOP Sorbex process (see Section 12.5). The adsorbent is an A or T zeolite but details of the ionic form have not been released. A schematic of the process, which uses three separation columns, is shown in Figure 10.6. The main column separates the mixed-feed stream into four cuts containing (a) ortho + meta + ethylbenzene (trace), (b) ortho + meta -f ethylbenzene + paraxylene (trace), (c) paraxylene + ethylenebenzene, and (d) pure paraxylene. Cut (d) is passed directly to product while cut (b) is returned to the isomerization unit. Cuts (a) and (c) are passed to further columns in order to produce essentially pure ethylbenzene and paraxylene as products. 

FIGURE 12,12, Schematic diagram of the UOP. Sorbex process showing simulated moving-bed system. (From ref. 2, reprinted by permission of UOP.)... 

Simulated moving bed (SMB) or the UOP Sorbex processes are used only for liquid-phase separations. No gas phase separation has been performed commercially by SMB due to the axial dispersion problem in the fixed beds. 

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