Reflux ratio reforming

A small amount of EB is present in crude oil and also is formed in cat reforming. You might recall from Chapter 3 that there is only a 4°F difference between the boiling points of EB and para-xylene Consequently, a superdistillation column is needed for the separation-. In process engineers terms, it would have about 300 theoretical trays, be about 200 feet tall, and even then have a high reflux ratio to accomplish the separation. All this is necessary because the EB stream must be quite pure to be used for styrene manufacture. 

Reforming and Isomerization Feedstocks. Some saturated fractions contain substantial amounts of low octane-number normal pentane or normal hexane. These chemical species can be isomerized for antiknock performance enhancement. It is, however, useful to remove branched compounds from the feedstock by sharp distillation. A de-isohexanizer, for example, may need 60 or more actual valve plates and a high reflux ratio. The modeling of equipment for this purpose follows standard distillation design procedures, but because of the narrow relative volatilities, special care is needed with the basic data. 

Reformate Splitter (Debutanizer) 1. Reflux ratio 2. Overhead (or bottom) draw rate 3. Control stage temperature 1. Reflux ratio 2. Mole purity of C5 in the overhead 3. Control stage temperature... 

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