C4 Olex process

Mixed C4 olefins (primarily iC4) are isolated from a mixed C olefin and paraffin stream. Two different liquid adsorption high-purity C olefin processes exist the C4 Olex process for producing isobutylene (iCf ) and the Sorbutene process for producing butene-1. Isobutylene has been used in alcohol synthesis and the production of methyl tert-butyl ether (MTBE) and isooctane, both of which improve octane of gasoHne. Commercial 1-butene is used in the manufacture of both hnear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE)., polypropylene, polybutene, butylene oxide and the C4 solvents secondary butyl alcohol (SBA) and methyl ethyl ketone (MEK). While the C4 Olex process has been commercially demonstrated, the Sorbutene process has only been demonstrated on a pilot scale. 

The C4 Olex process is designed with the full allotment of Sorbex beds in addition to the four basic Sorbex zones. The C4 Olex process employs sufficient operating temperature to overcome diffusion limitations with a corresponding operating pressure to maintain liquid-phase operation. The C4 Olex process utilizes a mixed paraffin/olefin heavy desorbent. In this case it is an olefin/paraffin mix consisting of n-hexene isomers and -hexane. A rerun column is needed to remove heavy feed components such as Cs/C because they would contaminate or dilute the hexene/hexane desorbent. Table 8.5 contains the typical feed and product distributions. 

Table 8.5 C4 Olex process typical feed and extract composition.

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