Radial flow oil shale retort

Abstract

A radial flow oil shale retort can include a central heating fluid conduit having a permeable outer wall and an outer heating fluid annulus positioned about the central heating fluid conduit, the outer heating fluid annulus having a permeable inner wall. An annular body of comminuted oil shale can be between the permeable outer wall of the central heating fluid conduit and the permeable inner wall of the outer heating fluid annulus. A heating fluid supply can be connected to either the central heating fluid conduit or the outer heating fluid annulus to flow a heating fluid in a radial direction through the annular body of the comminuted oil shale.

What is claimed is: 
     
         1 . A radial flow oil shale retort, comprising:
 a central heating fluid conduit having a permeable outer wall;   an outer heating fluid annulus positioned about the central heating fluid conduit, the outer heating fluid annulus having a permeable inner wall;   an annular body of comminuted oil shale between the permeable outer wall of the central heating fluid conduit and the permeable inner wall of the outer heating fluid annulus; and   a heating fluid supply connected to either the central heating fluid conduit or the outer heating fluid annulus to flow a heating fluid in a radial direction through the annular body of comminuted oil shale.   
     
     
         2 . The radial flow oil shale retort of  claim 1 , wherein the heating fluid supply is connected to the central heating fluid conduit to flow the heating fluid in a direction from the central heating fluid conduit to the outer heating fluid annulus. 
     
     
         3 . The radial flow oil shale retort of  claim 1 , wherein the heating fluid supply is connected to the outer heating fluid annulus to flow the heating fluid in a direction from the outer heating fluid annulus to the central heating fluid conduit. 
     
     
         4 . The radial flow oil shale retort of  claim 1 , further comprising a catalytic heater in the central heating fluid conduit or in the outer heating fluid annulus, wherein the catalytic heater produces heat by a chemical reaction of hydrocarbons in the heating fluid. 
     
     
         5 . The radial flow oil shale retort of  claim 1 , further comprising a rotary shale distributor positioned above the annular body of comminuted oil shale to distribute oil shale between the permeable outer wall of the central heating fluid conduit and the permeable inner wall of the outer heating fluid annulus. 
     
     
         6 . The radial flow oil shale retort of  claim 1 , wherein the heating fluid comprises steam. 
     
     
         7 . The radial flow oil shale retort of  claim 1 , wherein the heating fluid comprises hydrocarbons. 
     
     
         8 . The radial flow oil shale retort of  claim 1 , wherein the heating fluid comprises oxygen. 
     
     
         9 . The radial flow oil shale retort of  claim 1 , further comprising a combustor unit and a shale withdrawal conduit to convey spent shale to the combustor, wherein the combustor generates heat by combusting the spent shale. 
     
     
         10 . The radial flow oil shale retort of  claim 9 , wherein the combustor is a fluid bed combustor or a down flow bed combustor. 
     
     
         11 . The radial flow oil shale retort of  claim 1 , further comprising a vapor/gas product outlet connected to either the central heating fluid conduit or the outer heating fluid annulus, whichever is not connected to the heating fluid supply. 
     
     
         12 . The radial flow oil shale retort of  claim 1 , further comprising a liquid product outlet in fluid communication with the annular body of comminuted oil shale to collect liquid hydrocarbon products produced from the comminuted oil shale. 
     
     
         13 . The radial flow oil shale retort of  claim 1 , further comprising a heating unit connected to the heating fluid supply to heat the heating fluid before the heating fluid flows through the annular body of comminuted oil shale. 
     
     
         14 . The radial flow oil shale retort of  claim 1 , wherein the dimensions of the retort include the diameter at the outer walls of the retort from 10 feet to 100 feet or about 40 feet; the diameter at the permeable inner wall of the outer heating fluid annulus from 9 feet to 90 feet or about 38 feet; the diameter at the permeable outer walls of the central heating fluid conduit from 1 foot to 10 feet or about 6 feet; a bed depth measured from the permeable outer wall of the central heating fluid conduit to the permeable inner wall of the outer heating fluid annulus from 1 foot to 80 feet or about 16 feet; a bed height measured in the axial direction of the retort from 10 feet to 300 feet. 
     
     
         15 . A method of extracting hydrocarbons from oil shale, comprising:
 loading comminuted oil shale into a radial flow oil shale retort, wherein the radial flow oil shale retort comprises:
 a central heating fluid conduit having a permeable outer wall, and 
 an outer heating fluid annulus positioned about the central heating fluid conduit, the outer heating fluid annulus having a permeable inner wall, 
   
       wherein the comminuted oil shale is loaded into a space between the permeable outer wall of the central heating fluid conduit and the permeable inner wall of the outer heating fluid annulus;
 flowing a heating fluid in a radial direction between the central heating fluid conduit and the outer heating fluid annulus to heat the comminuted oil shale and extract hydrocarbons therefrom; and 
 collecting the extracted hydrocarbons. 
 
     
     
         16 . The method of  claim 15 , wherein the comminuted oil shale is substantially stationary during the extraction of the hydrocarbons, and further comprising loading and unloading the comminuted oil shale from the retort, such that the process is a batch process. 
     
     
         17 . The method of  claim 15 , wherein the comminuted oil shale continuously flows through the retort such that the process is continuous. 
     
     
         18 . The method of  claim 17 , further comprising continuously loading comminuted oil shale into the retort and continuously withdrawing spent oil shale from the retort. 
     
     
         19 . The method of  claim 17 , wherein the comminuted oil shale flows downward at a speed of 1 inch per hour to 100 feet per hour.