In-Situ Upgrading of Biomass Pyrolysis Vapor

Abstract

Processes for thermal conversion of biomass are provided. The processes involve upgrading the pyrolysis vapor from a pyrolysis reactor. The steps include thermally converting a biomass feedstock in a pyrolysis reactor, recovering a pyrolysis vapor from the reactor, passing the pyrolysis vapor in contact with a cracking catalyst, a water-gas shift reaction catalyst, a hydrotreating catalyst, and an acid catalyst, and converting the resulting upgraded pyrolysis vapor into a liquid product. The resulting biooil liquid product is more refined, and the overall processes offer economic and energy efficiency.

What is claimed is: 
     
         1 . A process for the thermal conversion of biomass comprising the steps of:
 a) thermal conversion of a biomass feedstock in a pyrolysis reactor;   b) recovering a pyrolysis vapor from the reactor;   c) passing the pyrolysis vapor in contact with a cracking catalyst, a water-gas shift reaction catalyst, a hydrotreating catalyst, and an acid catalyst to produce an upgraded pyrolysis vapor; and   d) converting the upgraded pyrolysis vapor from step c) into a liquid product.   
     
     
         2 . The process of  claim 1 , further comprising combining the liquid product directly with crude oil to make a gasoline product. 
     
     
         3 . The process of  claim 1 , wherein the catalysts in step c) are layered in a single reactor. 
     
     
         4 . The process of  claim 3 , wherein the catalysts are layered so that the pyrolysis vapor contacts the cracking catalyst first, the water-gas shift reaction catalyst second, the hydrotreating catalyst third, and the acid catalyst last. 
     
     
         5 . The process of  claim 3 , wherein the catalysts are layered so that the pyrolysis vapor contacts the water-gas shift reaction catalyst first, the hydrotreating catalyst second, the acid catalyst third, and the cracking catalyst last. 
     
     
         6 . The process of  claim 3 , wherein hydrogen produced in the water-gas shift reaction is used in the hydrotreating catalyst. 
     
     
         7 . The process of  claim 3 , wherein a reaction temperature is controlled for each catalyst layer in order to promote the corresponding reaction. 
     
     
         8 . The process of  claim 7 , wherein the temperature is changed for each catalyst layer. 
     
     
         9 . The process of  claim 1 , wherein the catalysts in step c) are contacted with the pyrolysis vapor in separate reactors connected in series. 
     
     
         10 . The process of  claim 9 , wherein the pyrolysis vapor contacts a guard bed before at least one of the reactors. 
     
     
         11 . The process of  claim 9 , wherein hydrogen produced in the water-gas shift reactor is used in the reactor with the hydrotreating catalyst. 
     
     
         12 . The process of  claim 9 , wherein the pyrolysis vapor contacts the cracking catalyst first, the water-gas shift reaction catalyst second, the hydrotreating catalyst third, and the acid catalyst last. 
     
     
         13 . The process of  claim 9 , wherein the pyrolysis vapor contacts the water-gas shift reaction catalyst first, the hydrotreating catalyst second, the acid catalyst third, and the cracking catalyst last. 
     
     
         14 . The process of  claim 9 , wherein a temperature and pressure is controlled for each of the reactors. 
     
     
         15 . The process of  claim 14 , wherein the temperature is different for each reactor. 
     
     
         16 . The process of  claim 1 , The process of  claim 1 , wherein the cracking catalyst comprises a zeolite, the water-gas shift reaction catalyst comprises a transaction metal or transaction metal oxide, the hydrotreating catalyst comprises a noble metal catalyst, nickel molybdenum catalyst, or cobalt molybdenum catalyst, and the acid catalyst comprises a sulfated zirconium catalyst. 
     
     
         17 . The process of  claim 1 , wherein the liquid product has a pH in a range of from about 2 to about 5. 
     
     
         18 . The process of  claim 1 , wherein the liquid product has a water content in the range of about 15 to about 25 weight percent. 
     
     
         19 . The process of  claim 1 , wherein the liquid product has an oxygen content in the range of from about 30 to about 40 weight percent.