Catalytic biomass pyrolysis in an auger reactor

Abstract

The present invention relates generally to the thermal conversion of biomass. Processes are disclosed for converting biomass to condensable vapor intermediates such as pyrolysis oil by means of catalytic pyrolysis in a reactor comprising at least one auger, where the catalyst also comprises a heat carrier. The intermediates produced may be further processed for production of renewable hydrocarbon fuels.

1 . A process comprising:
 (a) providing a thermal reactor comprising at least one auger, and a first mixture comprising at least one catalyst, wherein the at least one catalyst functions as both a heat carrier and catalyst;   (b) introducing a feedstock comprising biomass to the thermal reactor and contacting therein with the first mixture to produce a second mixture   c) pyrolyzing the feedstock in the second mixture thereby producing solids, condensable vapor intermediates, and non-condensable gases,   wherein the at least one catalyst transfers heat to the feedstock and also increases the rate at which the feedstock is converted,   wherein rotation of the auger increases direct contact between the feedstock and the catalyst and increases the rate of heat transfer from the catalyst to the feedstock,   (c) conveying the second mixture through the reactor for a defined residence time prior to removal from the reactor.   
     
     
         2 . The process of  claim 1 , wherein said thermal reactor is maintained at a pressure in a range from about 50 psig to about 500 psig and a temperature in a range from about 250° C. to about 1000° C. 
     
     
         3 . The process of  claim 1 , wherein said thermal reactor is maintained at a pressure in a range from about 15 psig to about 50 psig and a temperature in a range from about 350° C. to about 700° C. 
     
     
         4 . The process of  claim 1 , wherein upon introducing the feedstock to the reactor, the feedstock is heated by the catalyst at a rate from about 100° C. per second to about 10,000° C. per second. 
     
     
         5 . The process of  claim 1 , wherein the first mixture is introduced a first location that is proximal to a reactor first end and is conveyed by the at least one auger to a second location that is located downstream, wherein the feedstock is introduced at the second point and combines with the first mixture to form a second mixture. 
     
     
         6 . The process of  claim 1 , wherein the feedstock is introduced at a first location that is proximal to a reactor first end and is conveyed by the at least one auger to a second location located downstream, wherein the first mixture is introduced to the reactor at the second point and combines with the feedstock to form a second mixture. 
     
     
         7 . The process of  claim 1 , wherein the defined residence time is decreased as a result of step (b) 
     
     
         8 . The process of  claim 1 , wherein the at least one catalyst increases the rate of pyrolysis, such that the temperature required for pyrolysis is decreased, the required residence time of the feedstock is decreased, or combinations thereof. 
     
     
         9 . The process of  claim 1 , wherein the feedstock is converted in an atmosphere comprising an inert gas and less than 0.5 mol % oxygen gas. 
     
     
         10 . The process of  claim 1 , wherein the feedstock is converted to condensable vapor intermediates in the presence of a reactive gas selected from a group consisting of hydrogen, synthesis gas (i.e., CO+H2), steam/water, ammonia, methane, ethane, propane, butane, pentane, and natural gas, etc., and any combinations thereof. 
     
     
         11 . The process of  claim 1 , wherein rotation of the at least one auger increases contact between the at least one catalyst and the feedstock, thereby increasing the heating rate of the feedstock. 
     
     
         12 . The process of  claim 1 , wherein rotation of the at least one auger increases contact between the at least one catalyst and the feedstock to increase the catalytic pyrolysis of the feedstock. 
     
     
         13 . The process of  claim 1 , wherein the catalyst comprises at least one of Co, Ni, Mo, W, Zn, Ga, a zeolite, a metal-impregnated zeolite, and combinations thereof. 
     
     
         14 . The process of  claim 1 , wherein the catalyst comprises a solid material capable of both absorbing heat and transferring said heat to the feedstock, wherein the solid material is a member of the group consisting of silica, alumina, magnesium oxide, a zeolite and combinations thereof. 
     
     
         15 . The process of  claim 13 , wherein the solid material is physically linked to, impregnated with or exists as a solid amorphous mixture with at least one member of the group consisting of Co, Ni, Mo, W, Zn, Ga, and combinations thereof. 
     
     
         16 . A process comprising:
 (a) providing a thermal reactor comprising at least one auger, and a first mixture comprising at least one catalyst, wherein the at least one catalyst functions as both a heat carrier and catalyst;   (b) introducing a feedstock comprising biomass to the thermal reactor and contacting therein with the first mixture to produce a second mixture   c) pyrolyzing the feedstock in the second mixture thereby producing solids, condensable vapor intermediates, and non-condensable gases,   wherein the at least one catalyst transfers heat to the feedstock and also increases the rate at which the feedstock is converted,   wherein the at least one catalyst comprises a solid material capable of both absorbing heat and transferring said heat to the feedstock, wherein the solid material is a member of the group consisting of silica, alumina, magnesium oxide, a zeolite and combinations thereof,   wherein the solid material is physically linked to, impregnated with or exists as a solid amorphous mixture with at least one member of the group consisting of Co, Ni, Mo, W, Zn, Ga, and combinations thereof.   wherein rotation of the auger increases direct contact between the feedstock and the catalyst and increases the rate of heat transfer from the catalyst to the feedstock,   (c) conveying the second mixture through the reactor for a defined residence time prior to removal from the reactor.