Processes Penex

Fig. 13. UOP Penex-Molex process. AC = adsorbent chamber, EC = extract column, RC = raffinate column.

The hydroisomerization of linear alkanes nowadays is among the most demanded technologies for transformation of naphtha into high octane gasoline. However, while the processes for hydroisomerization of C4 and C5 - C6 cuts are well established (PENEX, ISOTEX, TIP, HYSOMER, ISOFIN, SKIP, PAR-ISOM), there is no suitable technology for the conversion of longer alkanes (C7 - C8 cuts). 

Penex [Pentane and hexane isomerization] A process for converting n-pentane and n-hexane and their mixtures into branched-chain pentanes and hexanes of higher octane number by catalytic isomerization. The catalyst is similar to the Butamer catalyst. The product is used in high-octane gasoline. First commercialized by UOP in 1958. More than 75 units were operating as of 1996. 

Penex-Plus A petroleum refining process that combines the Penex process with a process for hydrogenating benzene to cyclohexane. Developed by UOP for reducing the benzene content of gasoline first offered for license in 1991. 

The gasoline Molex process is the first of three processes since it separates the lowest molecular weight feed of the three Molex normal paraffin separahon processes. Gasoline Molex was developed to optimize a Refiner s octane pool by extracting low octane value normal paraffins (specifically C5, 5) from naphtha. In a typical refinery flow scheme, a gasoline Molex unit is integrated with a catalyhc isomeriza-hon unit (Penex unit) which converts the Molex unit s extracted normal paraffins into desired iso-paraffins. These iso-paraffins are desirable because they possess higher octane value than their linear counterpart. 

Penex process a continuous, nonregenerative process for isomerization of C5 and/or Q fractions in the presence of hydrogen (from reforming) and a platinum catalyst. 

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