Method and system for extracting hydrocarbon fuel products from contaminated soil

Abstract

A method and system for extracting hydrocarbon fuel products from contaminated soil provides extraction of usable fuel components from waste materials such as oil contaminated materials and soils. The materials (or hydrocarbon portion thereof) are liquified and introduced to a chamber where the liquid material is agitated and a negative relative pressure (vacuum) is applied. The liquid is maintained at a substantially constant temperature and the vacuum draws the off-gas hydrocarbon products out for condensation and further processing, while unconverted char is removed to an ash dump. An auger feed unit with agitator buckets is used to propel the char through a feed while agitating the liquid to enhance the rate of gas removal.

What is claimed is:  
     
         1 . A system for extracting usable hydrocarbon fuel pre-products from contaminated soil, comprising: 
 a process chamber for receiving said contaminated soil and heating said waste material until said fuel pre-products are in a liquid form;    a heater for heating said process chamber to a substantially constant temperature, whereby said fuel pre-products are converted to gaseous hydrocarbon fuel products; and    a vacuum whereby said gaseous hydrocarbon fuel products are extracted from said liquid fuel pre-products by reducing a vapor pressure of said fuel products, thereby promoting off-gassing from said liquid fuel pre-products.    
     
     
         2 . The system of  claim 1 , further comprising an agitator for agitating said liquid fuel pre-products, whereby said off-gassing is further promoted.  
     
     
         3 . The system of  claim 1 , further comprising a melting chamber for heating said fuel pre-products to produce said liquid fuel pre-products prior to introduction to said process chamber.  
     
     
         4 . The system of  claim 3 , wherein said melting chamber is heated to a temperature substantially equal to 585 degrees Fahrenheit.  
     
     
         5 . The system of  claim 1 , wherein said process chamber is heated to a temperature substantially equal to 850 degrees Fahrenheit.  
     
     
         6 . The system of  claim 1 , wherein said process chamber has a continuous feed, wherein said waste material is received at a first end, said gaseous hydrocarbon fuel components are removed through said vacuum system and a remainder of said waste material is ejected at a second end.  
     
     
         7 . The system of  claim 6 , wherein said process chamber comprises: 
 an auger for feeding said waste material through said process chamber; and    an auger housing for enclosing said auger, wherein a drive system is coupled to said auger for rotating said auger to feed said waste material through said process chamber.    
     
     
         8 . The system of  claim 7 , wherein said auger further comprises agitator buckets attached to a blade of said auger for agitating said liquid fuel pre-products, whereby said off-gassing is further promoted.  
     
     
         9 . The system of  claim 7 , wherein a portion of said auger is included in a melting chamber for heating said fuel pre-products to produce said liquid fuel pre-products prior to introduction to said process chamber, said melting chamber auger portion being heated to a lower temperature than a temperature of the process chamber auger portion.  
     
     
         10 . The system of  claim 1 , wherein said heater comprises a pressure chamber disposed around said process chamber, whereby hot air is circulated to heat said process chamber.  
     
     
         11 . The system of  claim 9 , wherein said pressure chamber comprises a: 
 first cylinder enclosing said process chamber, said first cylinder having perforations though a wall of said cylinder for diffusing heat from an inner wall to an outer wall of said first cylinder for providing a uniform temperature at said process chamber; and    a second cylinder enclosing said first cylinder, said second cylinder including a plurality of pipes disposed radially between an outer wall of said second cylinder and an inner wall of said first cylinder, whereby heated air may pass from said outer wall of said second cylinder to said process chamber.    
     
     
         12 . The system of  claim 1 , wherein said heater is a closed-system air heater, wherein said air is recirculated around said process chamber.  
     
     
         13 . The system of  claim 12 , comprising multiple process chambers coupled to said heater.  
     
     
         14 . The system of  claim 13 , wherein a remainder of said contaminated soil material from each of said multiple process chambers is fed through an additional process chamber coupled to said heater for removing any remaining hydrocarbon fuel products from said remainder.  
     
     
         15 . A system for extracting usable hydrocarbon fuel pre-products from contaminated soil, comprising: 
 means for liquifying said hydrocarbon fuel pre-products;    means for heating said hydrocarbon fuel pre-products to form gaseous hydrocarbon fuel products; and    means for continuously removing said gaseous hydrocarbon fuel products so that said hydrocarbon fuel pre-products will continue to off-gas.    
     
     
         16 . The system of  claim 17 , further comprising means for agitating said liquid hydrocarbon fuel products to promote said off-gassing.  
     
     
         17 . The system of  claim 17 , further comprising means for removing a remainder of said contaminated soil from said liquid hydrocarbon fuel products.  
     
     
         18 . The system of  claim 17 , wherein said means for removing said remainder further comprises means for agitating said liquid hydrocarbon fuel products to promote said off-gassing.  
     
     
         19 . A method for extracting usable hydrocarbon fuel pre-products from contaminated soil material, comprising: 
 liquifying said usable hydrocarbon fuel pre-products to form a liquid;    heating said liquid until said liquid off-gasses gaseous hydrocarbon fuel products; and    removing said gaseous hydrocarbon fuel products by a vacuum system.    
     
     
         20 . The method of  claim 21 , further comprising agitating said liquid to promote said off-gassing.  
     
     
         21 . The method of  claim 20 , further comprising the step of rotating an auger within said process chamber, and wherein said agitating is performed by said rotating, and wherein said auger further moves a remainder of said contaminated soil out of said liquid.  
     
     
         22 . The method of  claim 21 , wherein said contaminated soil is a mixture of oil waste with soil, and wherein said liquifying liquifies only said oil waste.  
     
     
         23 . The method of  claim 21 , wherein said contaminated soil contains plastic material and wherein said liquifying liquifies said plastic material.