PROCESS FOR REDUCING THE AMOUNT OF NORMAL PENTANE FROM A FEEDSTOCK

摘要

A process for separation and treatment of a naphtha feedstock to increase overall octane in a gasoline blending pool by reducing or removing the normal pentane in the feedstock. The feedstock is passed into a divided wall column having an undivided top portion, an undivided bottom portion and a wall dividing a middle portion into two sections. The intermediate faction can include either all normal pentane, which can be utilized on other processes, or it can include a mixture of normal pentane and C6 hydrocarbons, which can be isomerized in an isomerization zone to increase the octane and then passed to a gasoline blending pool.

主权项

1. A process for the separation and treatment of a naphtha feedstock comprising compounds containing from five to six carbon atoms, said process comprising:
passing the feedstock into a separation zone comprising a column divided into at least a first fractionization zone and a second fractionization zone by a dividing wall, the first fractionization zone being parallel to the second fractionization zone, each fractionization zone having an upper end and a lower end, the upper ends of the fractionization zones being in open communication at an undivided upper section of the column, and the lower ends of the fractionization zones being in open communication at an undivided lower section of the column, and the feedstock entering into the column in the first fractionization zone; separating the feedstock into: an overhead stream comprising isopentane; an intermediate fraction comprising n-pentane; and, a bottoms stream comprising compounds containing six or more carbon atoms; recovering the overhead stream from the upper section of the column; passing the overhead stream to a gasoline blending pool; recovering the intermediate fraction from the second fractionization zone; recovering the bottoms stream from the lower section of the column; passing the bottoms stream to an isomerization zone to increase the octane number of the bottoms stream and form an isomerate; and, passing the isomerate to the gasoline blending pool.