Patent EA-004690-B1 (EA)
Title: Method of selective extraction refining of petroleum products
Inventor: ASCERSON MICHAEL D
IPC: C10G21/02
Filed: 2002-01-17
Abstract: 1. A method of refining a petroleum product comprising: providing an unrefined petroleum product containing a first petroleum fraction and a second fraction to be separated, the first petroleum fraction having a melt point temperature, and wherein the unrefined petroleum product contains an amount of extractant, the extractant having a freezing point temperature that is greater than the melt point temperature of the first petroleum fraction, the unrefined petroleum product being at or above the pour point temperature of the unrefined petroleum product so that the extractant is in a substantially liquefied state with the first petroleum fraction being substantially dissolved within the extractant; admixing with the unrefined petroleum product a solvent in which the second fraction is soluble so that the second fraction is dissolved within the solvent, and wherein the extractant is substantially insoluble within the solvent; bringing the mixture of unrefined petroleum product and solvent to a temperature below the freezing point temperature of the extractant so that the extractant containing the dissolved first petroleum fraction is crystallized and the solvent containing the dissolved second fraction is in a liquid phase; and separating the crystallized extractant containing the dissolved first petroleum fraction from the liquid phase. 2. The method of claim 1, wherein: the first petroleum fraction is a hydrocarbon saturate. 3. The method of claim 1, wherein: the second fraction includes aromatic hydrocarbons. 4. The method of claim 1, wherein: the second fraction includes polar compounds. 5. The method of claim 1, wherein: the extractant has a freezing point temperature of about -0 degree F (-17.8 degree C) or greater. 6. The method of claim1, wherein: the mixture of unrefined petroleum product and solvent are brought to a temperature of from about-20 degree F (-28.9 degree C) to about 75 degree F (23.9 degree C) upon admixing of the solvent. 7. The method of claim 1, wherein the extractant constitutes a fraction of the unrefined petroleum product. 8. The method of claim 1, wherein the first petroleum fraction and the extractant include those hydrocarbon saturates having an average molecular weight ranging from about 250 g/mol to about 1500 g/mol. 9. The method of claim 1, wherein the extractant is a hydrocarbon saturate. 10. A method of refining a petroleum product comprising: providing an unrefined petroleum product containing a first petroleum fraction and a second fraction to be separated, the first petroleum fraction having a melt point temperature, and wherein the unrefined petroleum product contains an amount of extractant, the extractant having a freezing point temperature that is greater than the melt point temperature of the first petroleum fraction, the unrefined petroleum product being at a temperature at or above the pour point temperature of the unrefined petroleum product so that the extractant is in a substantially liquefied state, with the first petroleum fraction being substantially dissolved within the liquefied extractant; admixing with the unrefined petroleum product a first solvent in which the second fraction is soluble so that the second fraction is dissolved within the first solvent, and wherein the extractant is substantially insoluble within the first solvent; bringing the mixture of unrefined petroleum product and first solvent to a temperature below the freezing point temperature of the extractant so that the extractant containing the dissolved first petroleum fraction is crystallized and the first solvent containing the dissolved second fraction is in a liquid phase; separating the crystallized extractant containing the dissolved first petroleum fraction from the liquid phase. 11. The method of claim 10, further comprising: separating the first petroleum fraction from the second solvent. 12. The method of claim10, wherein: the first petroleum fraction is a hydrocarbon saturate. 13. The method of claim 10, wherein: the second fraction includes aromatic hydrocarbons. 14. The method of claim 10, wherein: the second fraction includes polar compounds. 15. The method of claim 10, wherein: the extractant has a freezing point temperature of about 0 degree F (-17.8 degree C) or greater. 16. The method of claim 10, wherein: the mixture of unrefined petroleum product and first solvent are brought to a temperature of fromabout-20 degree F (-28.9 degree C) to about 75 degree F (23.9 degree C) upon admixing of the first solvent. 17. The method of claim 10, wherein: the extractant constitutes a fraction of the unrefined petroleum product. 18. The method of claim 10, wherein the method of refining the petroleum product is a continuous flow process, and wherein at least a portion of the extractant is recycled after separating the first petroleum fraction by combining said portion with the unrefined petroleum product. 19. The method of claim 10, wherein the first petroleum fraction and the extractant include those hydrocarbon saturates having an average molecular weight ranging from about 250 g/mol to about 1500 g/mol. 20. The method of claim 11, wherein the separated first petroleum fraction is lubricating oil, and wherein the lubricating oil has a viscosity index of from about 90 or greater. 21. The method of claim11, wherein the separated first petroleum fraction is lubricating oil, and wherein the lubricating oil has a viscosity index of from about 95 or greater. 22. The method of claim 10, wherein: the extractant is a hydrocarbon saturate. 23. The first petroleum fraction separated by the method of claim 10. 24. The extractant separated from the first petroleum fraction by the method of claim 10. 25. A method of preparing lubricating oil from a petroleum product comprising: providing a petroleum product containing a lubricating oil fraction and a second fraction to be separated from the lubricating oil fraction, the lubricating oil fraction having a melt point temperature, and wherein the petroleum product contains an amount of extractant, the extractant having a freezing point temperature that is greater than the melt point of the lubricating oil fraction, the petroleum product being at a temperature at or above the pour point temperature of the petroleum product so that the extractant is in a substantially liquefied state, with the lubricating oil fraction being substantially dissolved within the liquefied extractant; admixing with the petroleum product a first solvent in which the second fraction is soluble so that the second fraction is dissolved within the first solvent, and wherein the extractant is substantially insoluble within the first solvent; bringing the mixture of petroleum product and first solvent to a temperature at or below the freezing point temperature of the extractant so that the extractant containing the dissolved lubricating oil fraction is crystallized and the first solvent containing the dissolved second fraction is in a liquid phase; separating the crystallized extractant containing the dissolved lubricating oil fraction from the liquid phase; admixing a second solvent to the crystallized extractant and lubricating oil fraction, with the lubricating oil fraction being soluble within the second solvent so that the lubricating oil fraction is dissolved within the second solvent; separating the lubricating oil fraction and second solvent from the crystallized extractant; and separating the lubricating oil fraction from the second solvent. 26. The method of claim 25, wherein: the separated lubricating oil has a viscosity index of from about 90 or greater. 27. The method of claim 25, wherein: the separated lubricating oil has a viscosity index of from about 100 or greater. 28. The lubricating oil prepared by the method of claim 25.