Heat integrated separation system with active vapor control

Abstract

A separation system includes a column including a stripping section proximal to a lower end of the column, a rectifying section proximal to an upper end of the column, and an intermediate section disposed between the stripping section and the rectifying section. The intermediate section includes first and second vertical sides separated by a vertical wall. The column includes a feed port to receive a material stream to be separated. The separation system further includes a reboiler in fluid communication with the column. The reboiler provides vapor to the stripping section. The separation system also includes a condenser in fluid communication with the column. The condenser provides liquid to the rectifying section, the condenser to provide a distillate effluent stream. The separation system further includes an active vapor control to control the relative vapor flow rate to the first and second sections.

What is claimed is: 
     
         1 . A separation system comprising:
 a first column including a stripping section proximal to a lower end of the column, a rectifying section proximal to an upper end of the column, and an intermediate section disposed between the stripping section and the rectifying section;   a reboiler in fluid communication with the column, the reboiler to receive liquid from the stripping section and to provide vapor to the stripping section, the reboiler to provide a bottoms effluent stream;   a condenser in fluid communication with the column, the condenser to receive vapor from the rectifying section and to provide liquid to the rectifying section, the condenser to provide a distillate effluent stream;   a second column fluidically coupled to the first column to receive vapor from the first column from between the stripping section and the intermediate section, to receive liquid from the first column from between the intermediate section and the rectifying section, to provide vapor to the first column between the intermediate section and the rectifying section, and to provide liquid to the first column between the intermediate section and the stripping section; and   an active vapor control to control the relative vapor flow rate to the intermediate section of the first column and to the second sides.   
     
     
         2 . The separation system of  claim 1 , further comprising a feed port on the second column to receive a feed stream. 
     
     
         3 . The separation system of  claim 2 , further comprising an effluent port to access the intermediate section of the first column. 
     
     
         4 . The separation system of  claim 1 , further comprising a feed port on the first column to receive a feed stream. 
     
     
         5 . The separation system of  claim 1 , further comprising an effluent port to access the second column. 
     
     
         6 . The separation system of  claim 1 , wherein the active vapor control comprises:
 a control valve disposed in a vapor line extending from the first column between the stripping section and the intermediate section to the lower end of the second column.   
     
     
         7 . The separation system of  claim 1 , further comprising an analyzer to determine composition, the control valve to control vapor flow rate through the vapor bypass line based on input from the analyzer. 
     
     
         8 . The separation system of  claim 1 , further comprising a temperature analyzer, the control valve to control vapor flow rate through the vapor bypass line based on input from the temperature analyzer. 
     
     
         9 . The separation system of  claim 1 , further comprising a flow meter in line with the vapor line, the control valve to control vapor flow rate through the vapor line based on input from the flow meter. 
     
     
         10 . The separation system of  claim 1 , further comprising a liquid distributor to receive liquid from a lower end of the rectifying section and to distribute liquid to the intermediate section of the first column and to the second column. 
     
     
         11 . The separation system of  claim 1 , wherein the intermediate section of the first column comprises vapor-liquid contactors that are different from vapor-liquid contactors of the second column. 
     
     
         12 . The separation system of  claim 11 , wherein the intermediate section of the first column includes packing vapor-liquid contactors and the second column includes tray vapor-liquid contactors. 
     
     
         13 . The separation system of  claim 11 , wherein the intermediate section of the first column includes tray vapor-liquid contactors and the second column includes packing vapor-liquid contactors. 
     
     
         14 . The separation system of  claim 1 , further comprising a pressure drop element disposed in the intermediate section of the first column. 
     
     
         15 . The separation system of  claim 14 , wherein the pressure drop element comprises a chimney type tray.