Fungible bitumen from paraffinic centrifugation

Abstract

A process for cleaning bitumen froth produced from an oil sands extraction process involves mixing a sufficient amount of paraffinic solvent with the bitumen froth; subjecting the resulting mixture to centrifugal separation in a centrifuge to yield a diluted bitumen product, a water byproduct stream, and a solids byproduct stream; and processing the diluted bitumen product to yield dry fungible bitumen product having a total water/solids content less than about 0.5 wt %, and a recyclable paraffinic diluent stream.

1 . A process for cleaning bitumen froth produced from an oil sands extraction process, comprising:
 a) mixing a sufficient amount of paraffinic solvent with the bitumen froth;   b) subjecting the resulting mixture to centrifugal separation in a centrifuge to yield a diluted bitumen product, a water byproduct stream, and a solids byproduct stream; and   c) processing the diluted bitumen product to yield dry fungible bitumen product having a total water/solids content less than about 0.5 wt %, and a recyclable paraffinic diluent stream.   
     
     
         2 . The process of  claim 1 , wherein the centrifuge is a decanter centrifuge. 
     
     
         3 . The process of  claim 1 , further comprising processing the water byproduct stream to recover residual bitumen and paraffinic solvent. 
     
     
         4 . The process of  claim 3 , further comprising processing the solids byproduct stream to prepare a dry granulated powder comprising asphaltenes and fine solids. 
     
     
         5 . The process of  claim 4 , comprising optionally, mixing a sufficient amount of the asphaltenes with the bitumen froth following addition of the paraffinic solvent in step (a). 
     
     
         6 . The process of  claim 5 , comprising optionally, subjecting the resulting mixture to mixing in a contactor prior to centrifugal separation in step (b). 
     
     
         7 . The process of  claim 1 , wherein centrifugal separation is conducted using a three-phrase decanter centrifuge. 
     
     
         8 . The process of  claim 7 , wherein the diluted bitumen product comprises bitumen, paraffinic solvent, and a water plus solids content that is less than about 0.5 wt %. 
     
     
         9 . The process of  claim 8 , wherein the diluted bitumen product is transferred from the decanter centrifuge to a diluent recovery unit for recovery of dry bitumen, light gas oil, and paraffinic solvent. 
     
     
         10 . The process of  claim 9 , wherein the dry bitumen has a total water/solids content less than about 0.5 wt % amenable to processing in a fluid coker or ebullating-bed hydrocracker, or to shipping as fungible bitumen. 
     
     
         11 . The process of  claim 9 , wherein the light gas oil is transferred to a hydroprocessing unit. 
     
     
         12 . The process of  claim 9 , wherein the paraffinic solvent is recycled in step (a). 
     
     
         13 . The process of  claim 9 , wherein the water byproduct stream comprises water, and residual hydrocarbon, paraffinic solvent, and fine solids. 
     
     
         14 . The process of  claim 13 , wherein the water byproduct stream is cleaned in a solvent recovery unit to yield a paraffinic solvent stream for recycling in step (a), and a separate water and fine solids stream for disposal in a tailings pond. 
     
     
         15 . The process of  claim 14 , wherein optionally, the water byproduct stream is passed through a disc stack centrifuge to recover residual hydrocarbon and paraffinic solvent before cleanup in the solvent recovery unit. 
     
     
         16 . The process of  claim 15 , wherein the residual hydrocarbon is mixed with the diluted bitumen product and transferred to the diluent recovery unit. 
     
     
         17 . The process of  claim 16 , wherein the residual paraffinic solvent is recovered in the solvent recovery unit. 
     
     
         18 . The process of  claim 17 , wherein the solids byproduct stream comprises asphaltenes, coarse and fine solids, residual paraffinic solvent, and hydrocarbon. 
     
     
         19 . The process of  claim 18 , wherein the solids byproduct stream is mixed with water and transferred to a flotation cell for separation of an overflow hydrocarbon-rich with fine solids stream and an underflow stream of clean coarse solids. 
     
     
         20 . The process of  claim 19 , wherein the hydrocarbon-rich with fine solids stream is mixed with paraffinic solvent and spray dried to yield dry granulated powder comprising asphaltenes and fine solids. 
     
     
         21 . The process of  claim 20 , wherein the powder is mixed with bitumen, heated, and thermally upgraded in a fluid bed or delayed coker. 
     
     
         22 . The process of  claim 20 , wherein the powder is converted into a syngas in a fluidized bed gasifier or fluid bed boiler. 
     
     
         23 . The process of  claim 20 , wherein the powder is used as a fuel for a utility boiler or stockpiled as an energy supply. 
     
     
         24 . The process of  claim 20 , wherein flashed overhead vapour comprising paraffinic solvent and water is condensed in an OVH condenser and decanter to separate the paraffinic solvent from the water. 
     
     
         25 . The process of  claim 24 , wherein the paraffinic solvent is recycled in step (a). 
     
     
         26 . The process of  claim 24 , wherein optionally, the water passes through the solvent recovery unit for recovery of residual paraffinic solvent before disposal in the tailings pond. 
     
     
         27 . The process of  claim 1 , wherein the ratio of paraffinic solvent to raw froth by weight percentage ranges from about 0.5 to about 4.5. 
     
     
         28 . The process of  claim 2 , wherein the decanter centrifuge is operated to generate a g-force ranging from about 1000 to about 5000.