Flow configurations using a normal paraffin separation unit with isomerization in the reforming unit

Abstract

A process is presented for recovering the hydrocarbon components from a naphtha feed to pass to a gasoline blending pool or to change the operations to increase the production of light olefins. The process includes the separation of the naphtha feedstock into a light naphtha stream and a heavy naphtha stream. The process further includes separating the light naphtha stream to recovery high quality non-normal hydrocarbons, and to separate normal hydrocarbons to the feed to the cracking unit.

1 . A process for increasing light olefin yields from naphtha, comprising:
 passing a naphtha feedstream to a naphtha splitter to generate a light naphtha stream and a heavy naphtha stream, wherein the naphtha splitter is operated to split the naphtha stream around the normal boiling point of methylcyclopentane;   passing the heavy naphtha stream to a reforming unit to generate a reformer effluent comprising aromatics;   passing the light naphtha stream to a separation unit to generate an extract stream comprising normal hydrocarbons and a raffinate stream comprising non-normal hydrocarbons; and   passing the extract stream to a cracking unit.   
     
     
         2 . The process of  claim 1  wherein the naphtha splitter is operated increasing the temperature to split the naphtha stream around the normal boiling point of cyclohexane. 
     
     
         3 . The process of  claim 1  wherein the naphtha splitter is operated increasing the temperature to split the naphtha stream around the normal boiling point of dimethylpentane. 
     
     
         4 . The process of  claim 1  further comprising:
 passing the reformer effluent to an aromatics recovery unit to generate an aromatics stream and a recovery unit aromatics raffinate stream. 
 
     
     
         5 . The process of  claim 4  further comprising passing the recovery unit raffinate stream to the separation unit. 
     
     
         6 . The process of  claim 1  wherein the separation unit is an adsorption separation unit. 
     
     
         7 . The process of  claim 6  wherein the adsorption separation unit uses a light desorbent. 
     
     
         8 . The process of  claim 7  wherein the light desorbent is n-butane or n-pentane. 
     
     
         9 . The process of  claim 1  further comprising passing the raffinate stream to a gasoline blending pool. 
     
     
         10 . The process of  claim 4  further comprising passing the aromatics raffinate stream to the cracking unit. 
     
     
         11 . The process of  claim 4  further comprising passing the aromatics raffinate stream to the separation unit. 
     
     
         12 . The process of  claim 4  further comprising passing the aromatics stream to an aromatics complex. 
     
     
         13 . A process for increasing gasoline blending stock from naphtha, comprising:
 passing a naphtha feedstream to a naphtha splitter to generate a light naphtha stream and a heavy naphtha stream, wherein the naphtha splitter is operated to split the naphtha stream around the normal boiling point of methylcyclopentane;   passing the heavy naphtha stream to a reforming unit to generate a reformer effluent comprising aromatics;   passing the light naphtha stream to a separation unit to generate an extract stream comprising normal hydrocarbons and a raffinate stream comprising non-normal hydrocarbons;   passing the raffinate to a raffinate splitter to generate a raffinate splitter bottoms stream and a raffinate splitter overhead stream; and   passing the extract stream to a cracking unit.   
     
     
         14 . The process of  claim 13  wherein the raffinate splitter includes a side draw stream. 
     
     
         15 . The process of  claim 13  wherein the raffinate splitter is operated to send iC5 and iC4 into the overhead stream, further comprising passing the raffinate splitter overhead stream to the reformer to isomerize the iC5 and iC4 components to nC5 and nC4. 
     
     
         16 . The process of  claim 15  further comprising passing the reformer effluent stream to an aromatics recovery unit to generate an aromatics stream and an aromatics raffinate stream. 
     
     
         17 . The process of  claim 16  further comprising passing the aromatics raffinate stream to the separation unit to recover normal paraffins. 
     
     
         18 . The process of  claim 13  wherein the adsorption separation unit uses a light desorbent. 
     
     
         19 . The process of  claim 14  wherein the raffinate splitter is operated to send iC5, cyclopentane, iC6 and methylcyclopentane into the side draw stream. 
     
     
         20 . The process of  claim 14  further comprising passing the side draw stream to a gasoline blending stock. 
     
     
         21 . The process of  claim 14  further comprising passing the raffinate splitter bottom stream to the reforming unit to convert methylcyclopentane and heavier components to aromatics.