Systems and methods for partial or complete oxidation of fuels

Abstract

A system used for converting multiple fuel feedstocks may include three reactors. The reactor system combination can be so chosen that one of the reactors completely or partially converts the fuel while the other generates the gaseous product required by utilizing the gaseous product from the second reactor. The metal-oxide composition and the reactor flow-patterns can be manipulated to provide the desired product. A method for optimizing the system efficiency where a pressurized gaseous fuel or a pressurized utility is used for applications downstream can be used to any system processing fuels and metal-oxide.

What is claimed is: 
     
         1 . A system for the production of syngas, comprising:
 a first reactor comprising a plurality of oxygen carrying particles comprising a first metal oxide, wherein the first reactor is configured to provide a counter-current contact mode between the first metal oxide and a first fuel to reduce the first metal oxide to a second metal oxide;   a second reactor in communication with the first reactor, the second reactor configured to oxidize the second metal oxide to a third metal oxide, and further configured to reduce the third metal oxide to a fourth metal oxide with a second fuel to provide a partially or fully oxidized gaseous fuel comprising one or more of CO, CO 2 , H 2 , and H 2 O, wherein the second metal oxide is oxidized to the third metal oxide using an enhancing gas of CO 2  and H 2 O, the partially or fully oxidized gaseous fuel, or a combination thereof, to generate syngas; and   a third reactor in communication with the second reactor, the third reactor configured to regenerate the first metal oxide by oxidizing the fourth metal oxide with an oxygen source.   
     
     
         2 . The system of  claim 1 , wherein the counter-current contact mode between the first metal oxide and the first fuel is such that the first metal oxide moves downward and the first fuel moves upward. 
     
     
         3 . The system of  claim 1 , wherein the first metal oxide is introduced to the top of the first reactor, and the first fuel is introduced to the bottom of the first reactor. 
     
     
         4 . The system of  claim 1 , wherein the second reactor is configured to provide a counter-current contact mode between the second metal oxide and the enhancing gas, and a counter-current contact mode between the third metal oxide and the second fuel. 
     
     
         5 . The system of  claim 4 , wherein the second metal oxide is introduced to the top of the second reactor, the enhancing gas is introduced to the middle of the second reactor, and the second fuel is introduced to the bottom of the second reactor. 
     
     
         6 . The system of  claim 1 , wherein the second reactor is configured to provide a co-current contact mode between the second metal oxide and the enhancing gas, and a co-current contact mode between the third metal oxide and the second fuel. 
     
     
         7 . The system of  claim 6 , wherein the second metal oxide is introduced to the top of the second reactor, the enhancing gas is introduced to the middle of the second reactor, and the second fuel is introduced to the top of the second reactor. 
     
     
         8 . The system of  claim 6 , wherein the second metal oxide is introduced to the top of the second reactor, the enhancing gas is introduced to the top of the second reactor, and the second fuel is introduced to the top or the middle of the second reactor. 
     
     
         9 . The system of  claim 1 , wherein at least a portion of the enhancing gas is derived from the first reactor resulting from the reduction of the first metal oxide with the first fuel. 
     
     
         10 . The system of  claim 1 , wherein at least a portion of the enhancing gas is derived from oxidation of a carbon-containing or hydrogen-containing source in the third reactor, a fourth reactor, or a combination thereof. 
     
     
         11 . The system of  claim 1 , wherein the third reactor is communication with the first reactor, wherein at least a portion of the second metal oxide is circulated directly to the third reactor, and oxidation of a carbon-containing or hydrogen-containing source with an oxygen source in the third reactor generates a stream of enhancing gas, wherein at least a portion of the enhancing gas generated in the third reactor is used in the second reactor as an enhancing gas. 
     
     
         12 . The system of  claim 1 , comprising a fourth reactor in communication with the first reactor, configured to generate a stream of enhancing gas comprising CO 2  and H 2 O. 
     
     
         13 . The system of  claim 12 , wherein at least a portion of the enhancing gas generated in the fourth reactor is used in the second reactor as an enhancing gas. 
     
     
         14 . The system of  claim 1 , wherein the first fuel is a solid fuel selected from biomass, coal, pet-coke, solid hydrocarbon-based waste products, or a combination thereof. 
     
     
         15 . The system of  claim 1 , wherein the first fuel is a gaseous fuel selected from natural gas, gasified coal, a light hydrocarbon off-gas stream, or a combination thereof. 
     
     
         16 . The system of  claim 1 , wherein the second fuel is a solid fuel selected from biomass, coal, pet-coke, solid hydrocarbon-based waste products, or a combination thereof. 
     
     
         17 . The system of  claim 1 , wherein the second fuel is a gaseous fuel selected from natural gas, gasified coal, a light hydrocarbon off-gas stream, or a combination thereof. 
     
     
         18 . The system of  claim 1 , wherein the second reactor is in communication with a Fischer-Tropsch or methanol synthesis system that produces a light hydrocarbon tail-gas, wherein the second reactor provides syngas to the Fischer-Tropsch or methanol synthesis system and the light hydrocarbon tail-gas is optionally recycled to first reactor, the second reactor, or a combination thereof. 
     
     
         19 . The system of  claim 1 , wherein
 the first metal oxide has formula FeO a Ti x  or FeO a Al x ,   the second metal oxide has formula FeO b Tix or FeO b Al x ,   the third metal oxide has formula Fe c Ti x  or FeO c Ti x , and   the fourth metal oxide has formula FeO d Ti x  or FeO d Alx,   wherein 1.5>a>b, b<c>d, 1.5>c, and x is 0.01 to 5.   
     
     
         20 . The system of  claim 1 , wherein
 the first metal oxide has formula FeO a TiO 2  or FeO a Al 2 O 3 ,   the second metal oxide has formula FeO b TiO 2  or FeO b Al 2 O 3 ,   the third metal oxide has formula FeO c TiO 2  or FeO c Al 2 O 3 , and   the fourth metal oxide has formula FeO d TiO 2  or FeO d Al 2 O 3 ,   wherein 1.5>a>b, b<c>d, and 1.5>c.