Stripping process and apparatus

Abstract

A process and apparatus for stripping a hydrocarbon feedstock comprising: heating the feedstock forming a vapor stream and a liquid stream, separating the vapor stream from the liquid stream and then stripping the liquid stream with a counter-current flow of a gas.

That which is claimed:  
     
         1 . A process comprising the steps of: 
 (a) heating a hydrocarbon feedstock wherein at least a portion of said hydrocarbon feedstock is vaporized so as to form a first vapor stream and a first liquid stream;    (b) separating said first vapor stream and said first liquid stream;    (c) stripping said first liquid stream with a counter-current flow of a gas so as to form a second vapor stream and a second liquid stream; and    (d) recovering said second vapor stream and said second liquid stream.    
     
     
         2 . A process in accordance with  claim 1  wherein said stripping occurs in a stripper column comprising in the range of from 2 to 4 theoretical trays.  
     
     
         3 . A process in accordance with  claim 1  wherein said second liquid stream comprises compounds having at least 5 carbon atoms per molecule.  
     
     
         4 . A process in accordance with  claim 1  wherein said second liquid stream comprises compounds having at least 12 carbon atoms per molecule.  
     
     
         5 . A process in accordance with  claim 1  wherein said hydrocarbon feedstock is heated in step (a) to a temperature in the range of from about 100° F. to about 800° F.  
     
     
         6 . A process in accordance with  claim 1  wherein said hydrocarbon feedstock is mixed with a diluent gas prior to said heating in step (a).  
     
     
         7 . A process in accordance with  claim 6  wherein the ratio of said diluent gas to said hydrocarbon feedstock is in the range of from about 0.1:1 to about 8:1.  
     
     
         8 . A process in accordance with  claim 6  wherein said diluent gas is selected from the group consisting of hydrogen, nitrogen, carbon dioxide, methane, ethane, fuel gas, and combinations of any two or more thereof.  
     
     
         9 . A process in accordance with  claim 1  further comprising the step of: 
 (e) reboiling at least a portion of said second liquid stream to form a boil-up vapor stream and a bottoms residue stream for return of said boil-up vapor stream to said stripper column.  
 
     
     
         10 . A process in accordance with  claim 1  wherein said hydrocarbon feedstock is heated in step (a) such that from about 75% to about 99% of said hydrocarbon feedstock is vaporized.  
     
     
         11 . A process in accordance with  claim 1  wherein said hydrocarbon feedstock is heated in step (a) such that from 85% to 90% of said hydrocarbon feedstock is vaporized.  
     
     
         12 . A process in accordance with  claim 1  wherein said gas in step (c) is selected from the group consisting of hydrogen, nitrogen, carbon dioxide, methane, ethane, fuel gas, and combinations of any two or more thereof.  
     
     
         13 . A process in accordance with  claim 12  wherein the ratio of said gas in step (c) to said first liquid stream is in the range of from about 0.05:1 to about 6:1.  
     
     
         14 . A process in accordance with  claim 12  wherein the ratio of said gas in step (c) to said first liquid stream is in the range of from 0.1:1 to 2.4:1.  
     
     
         15 . A process in accordance with  claim 1  wherein said hydrocarbon feedstock comprises gasoline.  
     
     
         16 . A process in accordance with  claim 15  wherein said second liquid stream comprises compounds having in the range of from 12 to 35 carbon atoms per molecule.  
     
     
         17 . A process in accordance with  claim 15  wherein said second liquid stream comprises compounds having in the range of from 12 to 25 carbon atoms per molecule.  
     
     
         18 . A process in accordance with  claim 15  wherein said gasoline is heated in step (a) to a temperature in the range of from about 400° F to about 600° F.  
     
     
         19 . A process in accordance with  claim 15  wherein said gasoline is heated in step (a) to a temperature in the range of from about 440° F. to about 550° F.  
     
     
         20 . A process in accordance with  claim 15  wherein said gasoline is heated in step (a) to a temperature in the range of from 460° F. to  510 ° F.  
     
     
         21 . A process in accordance with  claim 15  wherein said gasoline is mixed with a diluent gas prior to said heating in step (a).  
     
     
         22 . A process in accordance with  claim 21  wherein the ratio of said diluent gas to said gasoline is in the range of from 0.1:1 to 2:1.  
     
     
         23 . An apparatus comprising: 
 (a) a vessel defining a vaporization zone;    (b) a vessel defining a liquid-vapor separation zone and a stripping zone, said vessel being in fluid flow communication with said vaporization zone.    
     
     
         24 . An apparatus in accordance with  claim 23  further comprising a reboiler in fluid flow communication with said vessel.  
     
     
         25 . An apparatus in accordance with  claim 23  wherein said vessel comprises from 2 to 4 theoretical trays.  
     
     
         26 . An apparatus comprising: 
 (a) a vaporization vessel defining a vaporization zone;    (b) a liquid-vapor separation vessel defining a liquid-vapor separation zone in fluid flow communication with said vaporization zone; and    (c) a stripping vessel defining a stripping zone in fluid flow communication with said liquid-vapor separation vessel.    
     
     
         27 . An apparatus in accordance with  claim 26  further comprising a reboiler in fluid flow communication with said stripping vessel.  
     
     
         28 . An apparatus in accordance with  claim 26  wherein said stripping vessel comprises from 2 to 4 theoretical trays.  
     
     
         29 . An apparatus comprising: 
 (a) A first vessel defining a vaporization zone and a liquid-vapor separation zone;    (b) a second vessel defining a stripping zone wherein said second vessel is in fluid flow communication with said first vessel.    
     
     
         30 . An apparatus in accordance with  claim 29  further comprising a reboiler in fluid flow communication with said second vessel.  
     
     
         31 . An apparatus in accordance with  claim 29  wherein said second vessel comprises from 2 to 4 theoretical trays.