Use of cooling media in biomass conversion process

Abstract

Biomass is converted into a bio-oil containing stream in a riser reactor containing a cooling media. The cooling media quenches the rapid heat transfer to the biomass during cracking of the biomass in the mixing zone of the riser. By lowering the temperature to which the mixing zone effluent is exposed, production of carbon monoxide and light gases is decreased during thermolysis of the biomass.

What is claimed is: 
     
         1 . A process of subjecting solid biomass to thermolysis in a riser reactor having a mixing zone and a zone upstream from the mixing zone, the process comprising:
 (i) introducing a first solid particulate heated to a temperature of T 1  into the mixing zone of the riser reactor;   (ii) introducing solid biomass into the mixing zone downstream from the first solid particulate;   (iii) mixing the solid biomass and the first solid particulate in the mixing zone and reacting the solid biomass in the mixing zone to render a mixing zone effluent;   (iv) introducing the mixing zone effluent into the zone upstream from the mixing zone, wherein the temperature in the upstream zone is cooled by the addition of a cooling media into the upstream zone, the cooling media comprising a second solid particulate and/or a vaporizable liquid and the cooling media having a temperature, T 2 , wherein T 2  is less than T 1 ; and   (v) subjecting the solid biomass to fluidized catalytic thermolysis in the upstream zone.   
     
     
         2 . The process of  claim 1 , wherein the first solid particulate is sand. 
     
     
         3 . The process of  claim 1 , wherein at least one of the following conditions prevail:
 (a) the temperature in the mixing zone during mixing is between from about 900° F. to about 1350° F.;   (b) T 1  is from about 1100° F. to about 1400° F. and T 2  is from about 500° F. to about 1100° F.;   (c) the first solid particulate and the second solid particulate are catalysts;   (d) the first solid particulate and the second solid particulate are of different sizes and/or density;   (e) the difference between T 2  and T 1  is about 50° F. to about 500° F.;   (f) the temperature in the mixing zone at the time of introduction of biomass into the mixing zone is between from about 900° F. to about 1400° F.;   (g) the weight ratio of the first solid particulate to second solid particulate in the cooling media introduced into the riser reactor is between from about 85:15 to about 15:85; and   (h) the temperature in the mixing zone is controlled by adjusting the ratio of first solid particulate to biomass introduced into the mixing zone;   
     
     
         4 . The process of  claim 3 , wherein T 1  is from about 1100° F. to about 1400° F. and T 2  is from about 500° F. to about 1100° F. 
     
     
         5 . The process of  claim 4 , wherein the difference between T 2  and T 1  is about 50° F. to about 500° F. 
     
     
         6 . The process of  claim 3 , wherein the weight ratio of the first solid particulate to second solid particulate in the cooling media introduced into the riser reactor is between from about 85:15 to about 15:85. 
     
     
         7 . The process of  claim 1 , wherein the cooling media comprises a vaporizable liquid. 
     
     
         8 . The process of  claim 7 , wherein the vaporizable liquid is a distillate from a treated bio-oil stream hydrogenated in a hydrotreater. 
     
     
         9 . The process of  claim 7 , wherein the vaporizable liquid is ethanol, methanol, butanol, a glycol or a combination thereof. 
     
     
         10 . The process of  claim 7 , wherein the vaporizable material is a liquid stream from a fractionator. 
     
     
         11 . The process of  claim 1 , wherein the first solid particulate and the second solid particulate are catalysts and wherein (i) the first solid particulate and the second solid particulate are the same; or (ii) the first solid particulate and the second solid particulate are different catalysts and the first solid particulate and the second solid particulate are separable from each other. 
     
     
         12 . The process of  claim 1 , further comprising removing the first solid particulate and the second solid particulate from the riser reactor and regenerating at least a portion of the first solid particulate and/or second solid particulate. 
     
     
         13 . The process of  claim 12 , wherein the first solid particulate and the second solid particulate removed from the riser reactor are separated and regenerated in different regenerators. 
     
     
         14 . The process of  claim 12 , wherein at least a portion of the first solid particulate and/or second solid particulate material are regenerated upstream from the cooling media. 
     
     
         15 . The process of  claim 12 , further comprising regenerating the first solid particulate and/or second solid particulate and introducing the regenerated first solid particulate and/or regenerated second solid particulate into the upstream zone as the cooling media. 
     
     
         16 . A process of subjecting solid biomass to thermolysis in a riser reactor having a mixing zone and an upper zone, the process comprising:
 (a) introducing a first solid particulate heated to a temperature T 1  into the mixing zone of the riser reactor,   (b) introducing solid biomass into the mixing zone downstream from the first solid particulate;   (c) mixing the solid biomass and the first solid particulate in the mixing zone and treating the mixture to pyrolysis wherein at least a portion of the solid biomass is pyrolyzed;   (d) introducing into the upper zone a second solid particulate heated to a temperature T 2 , wherein T 2  is less than T 1 , and further wherein the second solid particulate is a catalyst;   (e) subjecting the treated mixture to fluidized catalytic thermolysis in the upper zone;   (f) removing at least a portion of the first solid particulate and the second solid particulate from the riser reactor;   (g) separating the removed first solid particulate and the second solid particulate;   (h) regenerating at least a portion of the separated first solid particulate and the separated second solid particulate;   (i) feeding at least a portion of the regenerated first solid particulate into the riser reactor upstream from the mixing zone;   (j) cooling at least a portion of the regenerated second solid particulate to the temperature T 2 ; and   (k) feeding at least a portion of the cooled regenerated second solid particulate into the upper zone.   
     
     
         17 . The process of  claim 16 , wherein the first solid particulate is an inorganic particulate. 
     
     
         18 . The process of  claim 17 , wherein the inorganic particulate is sand. 
     
     
         19 . The process of  claim 16 , wherein at least one of the following conditions prevail:
 (a) the temperature in the mixing zone during mixing is between from about 900° F. to about 1350° F.;   (b) T 1  is from about 1100° F. to about 1400° F. and T 2  is from about 500° F. to about 1100° F.; or   (c) the difference between T 2  and T 1  is about 50° F. to about 500° F.;   (d) the temperature in the mixing zone at the time of introduction of biomass into the mixing zone is between from about 950° F. to about 1400° F.   
     
     
         20 . The process of  claim 16 , wherein the weight ratio of first solid particulate to the second solid particulate introduced into the riser reactor is between from about 85:15.