Treatment of oil-contaminated solids

Abstract

The disclosure pertains to systems and methods for removing hydrocarbon contaminants from a contaminated solid using an environmentally benign extractant and an oleophilic absorber, where the environmentally benign extractant and the oleophilic absorber are separate components.

What is claimed: 
     
         1 . A system for removing a hydrocarbon contaminant from a contaminated solid, comprising an environmentally benign extractant and an oleophilic absorber, wherein the environmentally benign extractant and the oleophilic absorber are separate components of the system. 
     
     
         2 . The system of  claim 1 , wherein the contaminated solid comprises drilling cuttings. 
     
     
         3 . The system of  claim 1 , wherein the environmentally benign extractant is a biodegradable material. 
     
     
         4 . The system of  claim 1 , wherein the environmentally benign extractant is a naturally-derived material. 
     
     
         5 . The system of  claim 1 , wherein the oleophilic absorber comprises a substrate bearing an oleophilic coating. 
     
     
         6 . The system of  claim 1 , wherein the oleophilic absorber comprises an uncoated oleophilic substance. 
     
     
         7 . The system of  claim 1 , wherein the oleophilic absorber comprises an oil-swellable oleophilic substance. 
     
     
         8 . The system of  claim 1 , wherein the oleophilic absorber comprises an oleophilic material selected from the group consisting of crumb rubber, modified crumb rubber, thermoplastic elastomers, and polymers and copolymers of styrene, butadiene, isoprene, ethylene, and vinyl acetate. 
     
     
         9 . The system of  claim 1 , wherein the oleophilic absorber is less dense than water. 
     
     
         10 . The system of  claim 1 , wherein the oleophilic absorber comprises a polymeric bead. 
     
     
         11 . A method for separating a hydrocarbon contaminant from a contaminated solid, the contaminated solid comprising a solid substrate and the hydrocarbon contaminant, the method comprising:
 providing an environmentally benign extractant,   mixing the environmentally benign extractant with the contaminated solid to produce a treated solid wherein the hydrocarbon contaminant is separable from the solid substrate,   providing an oleophilic absorber capable of extracting the hydrocarbon contaminant from the solid substrate,   mixing the oleophilic absorber with the treated solid to extract the hydrocarbon contaminant from the solid substrate onto the oleophilic absorber, thereby forming a spent oleophilic absorber, wherein the spent oleophilic absorber comprises the hydrocarbon contaminant, and   separating the spent oleophilic absorber from the treated solid, thereby separating the hydrocarbon contaminant from the solid substrate.   
     
     
         12 . The method of  claim 11 , wherein the contaminated solid comprises drilling cuttings. 
     
     
         13 . The method of  claim 11 , wherein the oleophilic absorber comprises an oleophilic material on a substrate surface. 
     
     
         14 . The method of  claim 11 , wherein the oleophilic absorber comprises coated beads, and wherein the coated beads are coated with an oleophilic material. 
     
     
         15 . The method of  claim 11 , further comprising separating the hydrocarbon contaminant from the spent oleophilic absorber. 
     
     
         16 . The method of  claim 11 , further comprising recovering the environmentally benign extractant from the spent oleophilic absorber. 
     
     
         17 . The method of  claim 11 , further comprising disposing of the spent oleophilic absorber. 
     
     
         18 . A method of treating drilling cuttings contaminated with a hydrocarbon contaminant, comprising: (a) washing the drilling cuttings with an environmentally benign extractant and (b) adding an oleophilic absorber to the drilling cuttings after Step (a), wherein the oleophilic absorber absorbs the hydrocarbon contaminant from the drilling cuttings. 
     
     
         19 . The method of  claim 18 , further comprising:
 (c) the step of segregating the oleophilic absorber from the drilling cuttings after Step (b).   
     
     
         20 . The method of  claim 19 , further comprising:
 (d) the step of separating the hydrocarbon contaminant from the oleophilic absorber after Step (c).   
     
     
         21 . The method of  claim 19 , further comprising disposing of the oleophilic absorber after Step (c).