Desulfurization of hydrocarbons by solvent extraction

Abstract

A high sulfur content hydrocarbon feedstream is treated by mixing one or more selected solvents with a sulfur-containing feedstream for a predetermined period of time, allowing the mixture to separate and form a sulfur-rich solvent-containing liquid phase and a crude oil phase of substantially lowered sulfur content, and withdrawing the sulfur-rich stream and regenerating the solvent.

1 - 13 . (canceled) 
     
     
         14 . A process for the desulfurization of a hydrocarbon feedstream that includes one or more aromatic sulfur-containing hydrocarbon compounds, the process comprising:
 a. mixing the feedstream with a solvent feedstream including a solvent containing a furan ring that is selective for the one or more aromatic sulfur-containing hydrocarbon compounds;   b. separating as a first phase mixture having a reduced content of aromatic sulfur-containing hydrocarbon compounds and as a second phase the solvent and dissolved aromatic sulfur-containing hydrocarbon compounds from the feedstream;   c. recovering the first phase for further processing;   d. distilling the second phase to recover a solvent for use in step (a), above, that is more volatile than the remainder of the second phase including aromatic sulfur-containing hydrocarbon compounds; and   e. recovering aromatic sulfur-containing hydrocarbon compounds.   
     
     
         15 . The process as in  claim 14  further comprising subjecting the recovered aromatic sulfur-containing hydrocarbon compounds to hydroprocessing, and recovering a second liquid hydrocarbon stream having a reduced content of aromatic sulfur-containing hydrocarbon compounds from the hydroprocessor. 
     
     
         16 . The process as in  claim 14 , wherein step (d) occurs in an atmospheric distillation unit. 
     
     
         17 . The process of  claim 14  in which the solvent containing a furan ring is selected from the group consisting of furfural, furfuryl alcohol, 2-furyl methyl ketone and 5-methylfurfural 
     
     
         18 . The process of  claim 14  in which the hydrocarbon is selected from the group consisting of heavy, medium and light crude oils, and mixtures thereof. 
     
     
         19 . The process of  claim 14  in which the solvent is introduced into the feedstream prior to its introduction into a mixing vessel. 
     
     
         20 . The process of  claim 14  in which the ratio of solvent to hydrocarbon during mixing is in the range of from 0.5:1 to 3:1. 
     
     
         21 . The process of  claim 14  which includes adding an emulsion breaking composition to the mixture of solvent and whole crude oil to promote the formation of two liquid phases. 
     
     
         22 . The process of  claim 14  which includes the step of pretreating the whole crude oil by one or more processes selected from the group consisting of oil-water separation, gas-oil separation, desalting and stabilization. 
     
     
         23 . The process of  claim 18  in which the feedstream is subjected to a topping process prior to mixing with the one or more extractive solvents to produce a first hydrocarbon stream of low sulfur content and a second whole crude oil stream of increased sulfur content. 
     
     
         24 . The process of  claim 14  which is conducted as a batch process. 
     
     
         25 . The process of  claim 14  which is conducted as a continuous process in a column. 
     
     
         26 . The process of  claim 14  which includes the further steps of treating the first phase of reduced sulfur content recovered in step (c) to strip any retained solvent and recovering the stripped solvent for use in step (a).