Processes and systems for producing heat for rapid thermal processing of carbonaceous material

Abstract

Embodiments of processes and systems for producing heat for rapid thermal processing of carbonaceous material are provided. The process comprises the steps of contacting bubbles of an oxygen containing gas advancing through a fluidized bubbling bed with a grating to form smaller bubbles. The fluidized bubbling bed is contained in a reheater and comprises inorganic heat carrier particles and char. The reheater is operating at combustion conditions effective to burn the char into ash and heat the inorganic heat carrier particles to form heated inorganic particles. The heated inorganic particles are advanced to a reactor.

1 . A process for producing heat for rapid thermal processing of carbonaceous material, the process comprising the steps of:
 contacting bubbles of an oxygen containing gas advancing through a fluidized bubbling bed with a grating to form smaller bubbles, the fluidized bubbling bed contained in a reheater and comprising inorganic heat carrier particles and char;   operating the reheater at combustion conditions effective to burn the char into ash and heat the inorganic heat carrier particles to form heated inorganic particles; and   advancing the heated inorganic particles to a reactor.   
     
     
         2 . The process according to  claim 1 , wherein the combustion conditions include a reheater temperature of from about 650 to about 750° C. 
     
     
         3 . The process according to  claim 1 , wherein the inorganic heat carrier particles comprise sand. 
     
     
         4 . The process according to  claim 1 , wherein the reheater comprises a gas distribution grid proximate a lower portion of the fluidized bubbling bed, and the process further comprising the step of advancing the oxygen containing gas through the gas distribution grid to the lower portion of the fluidized bubbling bed. 
     
     
         5 . The process according to  claim 4 , wherein the grating is a first grating that is disposed within the fluidized bubbling bed and is above the gas distribution grid at a distance of from about 1.2 to about 1.9 meters. 
     
     
         6 . The process according to  claim 5 , wherein the reheater comprises a second grating that is disposed within the fluidized bubbling bed above the first grating and the smaller bubbles above the first grating coalesce to form larger bubbles, and the process comprises the step of contacting the larger bubbles with the second grating to form a second plurality of smaller bubbles. 
     
     
         7 . The process according to  claim 6 , wherein the second grating is disposed above the first grating at a distance of from about 1.2 to about 1.9 meters. 
     
     
         8 . The process according to  claim 1 , further comprising the steps of:
 contacting the carbonaceous material with the heated inorganic particles in the reactor; and   operating the reactor at reaction conditions effective to pyrolyze the carbonaceous material.   
     
     
         9 . The process according to  claim 8 , wherein the reactor is an upflow transport reactor, and the process further comprises the steps of:
 introducing the carbonaceous material and the heated inorganic particles to a lower portion of the upflow transport reactor; and   advancing the carbonaceous material and the heated inorganic particles from the lower portion to an upper portion of the upflow transport reactor during pyrolysis of the carbonaceous material.   
     
     
         10 . The process according to  claim 9 , wherein the reaction conditions include a temperature of from about 650 to about 750° C. in the lower portion of the upflow transport reactor, and a temperature of from about 450 to about 550° C. in the upper portion of the upflow transport reactor. 
     
     
         11 . The process according to  claim 1 , wherein the carbonaceous material is biomass. 
     
     
         12 . The process according to  claim 1 , wherein the grating has a plurality of openings having dimensions of from about 1 to about 4 inches, and the step of contacting bubbles includes advancing the bubbles through the openings to form the smaller bubbles having diameters of from about 2.5 to about 10 cm. 
     
     
         13 . A system for producing heat for rapid thermal processing of carbonaceous material, the system comprising:
 a reheater containing a fluidized bubbling bed that comprises inorganic heat carrier particles and char with bubbles of an oxygen containing gas advancing through the fluidized bubbling bed, wherein the reheater comprises a grating disposed in the fluidized bubbling bed, and wherein the grating is configured for contacting the bubbles to form smaller bubbles and the reheater is configured to operate at combustion conditions effective to burn the char into ash and heat the inorganic heat carrier particles to form heated inorganic particles; and   a reactor in fluid communication with the reheater to receive the heated inorganic particles.   
     
     
         14 . The system according to  claim 13 , further comprising a gas distribution grid proximate a lower portion of the fluidized bubbling bed and configured to fluidly communicate the oxygen containing gas to the fluidized bubbling bed, and wherein the grating is a first grating that is disposed above the gas distribution grid. 
     
     
         15 . The system according to  claim 14 , wherein the first grating is disposed above the gas distribution grid at a distance of from about 1.2 to about 1.9 meters. 
     
     
         16 . The system according to  claim 14 , further comprising a second grating that is disposed within the fluidized bubbling bed above the first grating, the second grating configured for contacting the bubbles to form smaller bubbles. 
     
     
         17 . The system according to  claim 16 , wherein the second grating is disposed above the first grating at a distance of from about 1.2 to about 1.9 meters. 
     
     
         18 . The system according to  claim 13 , wherein the grating has a plurality of openings having dimensions of from about 2.5 to about 10 cm. 
     
     
         19 . The system according to  claim 13 , wherein the reactor is configured to contact the carbonaceous material with the heated inorganic particles and to operate at reaction conditions effective to pyrolyze the carbonaceous material. 
     
     
         20 . The system according to  claim 19 , wherein the reactor is an upflow transport reactor having an upper portion and a lower portion, the upflow transport reactor is configured to receive the carbonaceous material and the heated inorganic particles in the lower portion and to advance the carbonaceous material and the heated inorganic particles to the upper portion during pyrolysis of the carbonaceous.