Solvent extraction process to stabilize, desulphurize and dry wide range diesels, stabilized wide range diesels obtained and their uses

Abstract

A process allowing the removal of contaminants from an unstable oil such as those produced by thermal or catalytic cracking, wherein, in at least one step of the process, mixing of the unstable oil with a pure or impure solvent having a dipole moment greater than 2 is performed. The stabilized diesels thereby obtained exhibit interesting properties among which significant stability features and are useful in numerous applications, some of these stabilized wide range diesels are new as well as their uses.

What is claimed is: 
     
         1 . A process to stabilize and to remove contaminants from unstable oil and to produce a stabilized diesel showing, according to ASTM method D46468 for at least one day, said process comprising the following steps of:
 a) intimately contacting a stream of the unstable oil with an initial solvent having a dipole moment greater than 2, to obtain two mixtures, a first mixture being of an oil-solvent type, which comprises treated oil, solvent, and impurities, and a second mixture being of a solvent-oil type, which comprises treated oil, solvent, residues, and impurities;   b) separating the treated oil, present in the first mixture obtained in step a), from the solvent leaving most of the impurities in the solvent phase;   c) separating the solvent and the treated oil, present in the second mixture obtained in step a) from the residues; and   d) recycling, in the process, one or more solvents with impurities, recovered in step b) or c) and partially regenerated before being recycled to said process;   wherein in step b) at least 70% wt of the impurities remain in the solvent phase;   wherein in step d), at least one of each solvent is regenerated, for at least 50% wt, but for less or equal to 98% wt to obtain a regenerated solvent stream, before recycling,   optionally, wherein the treated oil recovered from the first mixture is mixed with the treated oil recovered from the second mixture.   
     
     
         2 . The process of  claim 1 , wherein the stabilized diesel is stable for at least a day. 
     
     
         3 . The process of  claim 1 , wherein the stabilized diesel is stable for at least a week, and most preferably for about 6 months. 
     
     
         4 . The process of  claim 1 , wherein the stabilized diesel has a sulphur content that is, according to Iso 8754, less than 0.2% wt. 
     
     
         5 . The process of  claim 1 , wherein the stabilized diesel has a sulphur content that is, less than 0.1% weight and more preferably is about 0.08% weight. 
     
     
         6 . The process of  claim 1 , wherein the stabilized diesel has a boiling temperature, according to ASTM D-86, that ranges from 150° C. to 500° C. and preferably ranges from 175° C. to 450° C. 
     
     
         7 . The process of  claim 1 , wherein the stabilized diesel has an abnormal peak in the ASTM D-86 curb in the area of the peak of the recycled solvent that has passed at least once through the process. 
     
     
         8 . The process of  claim 1 , wherein the stabilized diesel has an abnormal peak in the ASTM D-86 curb in the area of 0 to 10% of distilled volume, preferably in the area of 5% of distilled volume. 
     
     
         9 . The process of  claim 1 , wherein the stabilized diesel shows:
 according to ASTM method D6468, a stability for at least a day;   according to ASTM method D1500, a colour index that is lower than 3; and   an abnormal peak, in the ASTM D-86 curb, in the area of 0 to 10% of distilled volume.   
     
     
         10 . The process of  claim 9 , wherein the stabilized diesel has a boiling temperatures range according to ASTM D-86, comprised between 150° C. and 450° C. 
     
     
         11 . A process to stabilize and to remove contaminants from unstable oil and to produce a stabilized diesel having an abnormal peak in the ASTM-D-86 curb in the area of the peak of the recycled solvent that has passed at least once through the process, said process comprising the following steps of:
 a) intimately contacting a stream of the unstable oil with an initial solvent having a dipole moment greater than 2, to obtain two mixtures, a first mixture being of an oil-solvent type, which comprises treated oil, solvent, and impurities, and a second mixture being of a solvent-oil type, which comprises treated oil, solvent, residues, and impurities;   b) separating the treated oil, present in the first mixture obtained in step a), from the solvent leaving most of the impurities in the solvent phase;   c) separating the solvent and the treated oil, present in the second mixture obtained in step a) from the residues; and   d) recycling, in the process, one or more solvents with impurities, recovered in step b) or c) and partially regenerated before being recycled to said process;   wherein in step b) at least 70% wt of the impurities remain in the solvent phase;   wherein in step d), at least one of each solvent is regenerated, for at least 50% wt, but for less or equal to 98% wt to obtain a regenerated solvent stream, before recycling,   optionally, wherein the treated oil recovered from the first mixture is mixed with the treated oil recovered from the second mixture.   
     
     
         12 . The process of  claim 11 , wherein the stabilized diesel is stable for at least a day. 
     
     
         13 . The process of  claim 11 , wherein the stabilized diesel is stable for at least a week, and most preferably for about 6 months. 
     
     
         14 . The process of  claim 11 , wherein the stabilized diesel has a sulphur content that is, according to Iso 8754, less than 0.2% wt. 
     
     
         15 . The process of  claim 11 , wherein the stabilized diesel has a sulphur content that is, less than 0.1% weight and more preferably is about 0.08% weight. 
     
     
         16 . The process of  claim 11 , wherein the stabilized diesel has a boiling temperature, according to ASTM D-86, that ranges from 150° C. to 500° C. and preferably ranges from 175° C. to 450° C. 
     
     
         17 . The process of  claim 11 , wherein the stabilized diesel has a boiling temperature, according to ASTM D-86, that ranges from 175° C. to 450° C. 
     
     
         18 . The process of  claim 11 , wherein the stabilized diesel has an abnormal peak in the ASTM D-86 curb in the area of 0 to 10% of distilled volume, preferably in the area of 5% of distilled volume. 
     
     
         19 . The process of  claim 11 , wherein the stabilized diesel shows:
 according to ASTM method D6468, a stability for at least a day;   according to ASTM method D1500, a colour index that is lower than 3; and   an abnormal peak, in the ASTM D-86 curb, in the area of 0 to 10% of distilled volume.   
     
     
         20 . The process of  claim 19 , wherein the stabilized diesel has a boiling temperatures range according to ASTM D-86, comprised between 150° C. and 450° C.