Systems and Methods of Converting Fuel

Abstract

Systems and methods for converting fuel are provided wherein the system comprises at least reactors configured to conduct oxidation-reduction reactions. The first reactor comprises a plurality of ceramic composite particles, wherein the ceramic composite particles comprises at least one metal oxide disposed on a support. The first reactor is configured to reduce the least one metal oxide with a fuel to produce a reduced metal or a reduced metal oxide. The second reactor is configured to oxidize the reduced metal or reduced metal oxide to produce a metal oxide intermediate. The system may also comprise a third reactor configured to oxidize the metal oxide intermediate to regenerate the metal oxide of the ceramic composite particles.

1 . A system for converting fuel comprising:
 a first reactor comprising a plurality of ceramic composite particles, the ceramic composite particles comprising at least one metal oxide dispersed on a support, wherein the first reactor is configured to reduce the at least one metal oxide with a fuel to produce a reduced metal or a reduced metal oxide, and is further configured to produce carbon dioxide, steam, or combinations thereof;   a second reactor configured to oxidize at least a portion of the reduced metal or reduced metal oxide from the first reactor to produce a metal oxide intermediate, and is further configured to produce hydrogen, carbon monoxide, syngas, heat or combinations thereof wherein the oxidant utilized in the oxidizing steps comprises steam, carbon dioxide, air, oxygen, or combinations thereof, wherein the oxidants being configured to produce the syngas in the second reactor; and   a third reactor in communication with the first reactor, the second reactor or both that is configured to regenerate the at least one metal oxide by oxidizing the metal oxide intermediate of the second reactor, and is further configured to produce heat in the third reactor.   
   
   
       2 . A system according to  claim 1  wherein the second reactor is also configured to produce H 2 , CO, heat, or combinations thereof. 
   
   
       3 . A system according to  claim 1  wherein the H 2 /CO ratio of the syngas is controlled by recycling part of the second reactor product, or controlling the amount of CO 2  and steam oxidants inputted into the second reactor. 
   
   
       4 . A system according to  claim 1  wherein the ceramic composite particles comprise a promoter. 
   
   
       5 . A system according to  claim 1  wherein the fuel comprises a solid fuel, a liquid fuel, a gaseous fuel, or combinations thereof. 
   
   
       6 . A system according to  claim 1  further comprising a separation unit configured to remove ash, char, or unwanted materials from a product stream of the second reactor, the third reactor, or both. 
   
   
       7 . A system according to  claim 8  wherein the ash separator comprises a cyclone, a sieve, a particle classifier, or combinations thereof. 
   
   
       8 . A system according to  claim 1  wherein the first and second reactors are configured to operate at a pressure of between about 1 atm to about 150 atm. 
   
   
       9 . A system according to  claim 1  wherein the first and second reactors are configured to operate at a temperature of between about 400 to about 1200 C. 
   
   
       10 . A system according to  claim 1  wherein the metal oxide comprises a metal selected from the group consisting of Fe, Cu, Ni, Sn, Co, Mn, and combinations thereof, and the support material comprises at least one component selected from the group consisting of SiC, oxides of Al, Zr, Ti, Y, Si, La, Sr, Ba, and combination thereof. 
   
   
       11 . A system according to  claim 1  further comprising a power generation section configured to produce electricity from a product of the second reactor. 
   
   
       12 . A system according to  claim 1  further comprising at least one heat exchanger configured to heat a feed comprising water, steam and combinations thereof. 
   
   
       13 . A system according to  claim 1  wherein the first reactor and the second reactor comprise at least one moving bed reactor, a series of fluidized bed reactors, a rotatory kiln, a fixed bed reactor, or combinations thereof. 
   
   
       14 . A system according to  claim 13  wherein the first reactor and the second reactor defines a countercurrent contacting pattern between gas and solids. 
   
   
       15 . A system according to  claim 1  wherein the first reactor is a moving bed reactor comprising a mixing device inserted in the moving bed to radially distribute the ceramic composite particles and mix unconverted fuel with the ceramic composite particles. 
   
   
       16 . A system according to  claim 1  wherein the first reactor is a moving bed reactor defines an annular region created around the moving bed, the annular region being location where a fuel is introduced. 
   
   
       17 . A system according to  claim 1  further comprising a conveyor or pneumatic feeding device configured to deliver the solid fuel to the first reactor. 
   
   
       18 . A system according to  claim 1  further comprising a solid fuel gasifier, a candle filter, a mercury removal unit, a gas cleanup component, a pressure swing absorption unit, a water gas shift reactor, or combinations thereof. 
   
   
       19 . A system according to  claim 1  wherein the first reactor comprises metal carbonates, metal oxides, or metal hydroxides configured to capture pollutants, heavy metals, or combinations thereof. 
   
   
       20 . A system according to  claim 1  wherein the first reactor is operable to receive a recycled H 2  stream at a bottom portion of the reactor. 
   
   
       21 . A system according to  claim 1  wherein the first reactor is operable to receive the fuel at a first reactor region below a feed region of the ceramic composite particles. 
   
   
       22 . A system according to  claim 1  wherein the first reactor is operable to receive feeds including oxygen, CO 2 , air, steam, and combinations thereof at a location adjacent the middle region in which the fuel is fed. 
   
   
       23 . A system according to  claim 1  wherein the system is coupled to a solid oxide fuel cell. 
   
   
       24 . A system according to  claim 1  wherein the system is in fluid communication with a Fischer-Tropsch reactor. 
   
   
       25 . A system according to  claim 24  further comprising a refining section. 
   
   
       26 . A system according to  claim 1  wherein the first and second reactors comprise packed beds in the form of portable cassettes, wherein the portable cassettes are configured to generate and store hydrogen in a vehicle. 
   
   
       27 . A system comprising:
 a Fischer-Tropsch reactor configured to produce hydrocarbon fuel from a feed mixture comprising fuel;   a first reactor comprising a plurality of ceramic composite particles, the ceramic composite particles comprising at least one metal oxide disposed on a support, wherein the first reactor is configured to reduce the at least one metal oxide with fuel to a reduced metal or a reduced metal oxide, the fuel being comprised at least partially of the hydrocarbon product of the Fischer-Tropsch reactor; and   a second reactor configured to oxidize the reduced metal or reduced metal oxide with steam to produce metal oxide intermediates,   wherein the second reactor is also configured to produce syngas.   
   
   
       28 . A system according to  claim 27  further comprising:
 a gaseous fuel feed source;   a refining system to treat the hydrocarbon products generated in the system.   
   
   
       29 . A system according to  claim 27 , wherein the oxidant is steam, CO, air, O 2 , or combinations thereof. 
   
   
       30 . A system according to  claim 27 , wherein the steam utilized in the second reactor comprises at least partially steam generated in a Fischer-Tropsch reactor or a gasifier. 
   
   
       31 . A system according to  claim 27  further comprising a third reactor in communication with the first reactor and configured to regenerate the at least one metal oxide by oxidizing the metal oxide intermediates. 
   
   
       32 . A system according to  claim 27  wherein the second reactor is also configured to produce hydrogen. 
   
   
       33 . A system according to  claim 27  wherein the fuel fed to the first reactor comprises at least partially syngas produced by gasification of a hydrocarbon fuel. 
   
   
       34 . A system according to  claim 27  wherein byproducts of the Fischer-Tropsch reactor are recycled to the first reactor. 
   
   
       35 . A system according to  claim 27  further comprising a steam turbine configured to produce electricity from steam generated in the system. 
   
   
       36 . A system according to  claim 27  further a gaseous fuel mixing location, wherein a gaseous fuel feed and a hydrogen containing product from the second reactor are operable to mix to produce a gaseous fuel having a molar ratio of hydrogen to carbon monoxide equal to about 2 to 1, the gaseous fuel being used in the feed mixture of the Fischer-Tropsch reactor. 
   
   
       37 . A method of preparing ceramic composite particles comprising the steps of reacting a metal oxide with a support material;
 heat treating the mixture of metal oxide and support material at temperatures of between about 200 to about 1500° C. to produce ceramic composite powders;   converting the ceramic composite powders into ceramic composite particles;   reducing and oxidizing the ceramic composite particles prior to use in a reactor.   
   
   
       38 . A method according to  claim 37  further comprising adding a promoter material to the mixture of metal oxide and support material. 
   
   
       39 . A method according to  claim 37  wherein heat treating occurs in the presence of inert gas, steam, oxygen, air, H 2 , and combinations thereof at a pressure of between vacuum pressure and about 10 atm. 
   
   
       40 . A method according to  claim 37  further comprising chemically treating the mixture of metal oxide and promoter to activate a ceramic composite powder. 
   
   
       41 . A method according to  claim 37  wherein the reacting step occurs via spray drying, direct mixing, co-impregnation, or combinations thereof. 
   
   
       42 . A method according to  claim 37  wherein the conversion of ceramic composite powders occurs via extrusion, granulation, pelletization, and combinations thereof. 
   
   
       43 . A particle produced by the method of  claim 37 . 
   
   
       44 . A particle according to  claim 43  wherein the metal oxide comprises a metal selected from the group consisting of Fe, Cu, Ni, Sn, Co, Mn, and combinations thereof. 
   
   
       45 . A particle according to  claim 43  wherein the ceramic composite comprises at least 40% by weight of the metal oxide. 
   
   
       46 . A particle according to  claim 43  wherein the support material comprises at least one component selected from the group consisting of SiC, oxides of Al, Zr, Ti, Y, Si, La, Sr, Ba, and combination thereof. 
   
   
       47 . A particle according to  claim 43  wherein the ceramic composite comprises at least 5% by weight of the support material. 
   
   
       48 . A particle according to  claim 43  wherein the particle comprises a promoter comprising a pure metal, a metal oxide, a metal sulfide, or combinations thereof, wherein the metal comprises one or more from the group consisting of Fe, Ni, Sn, Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, B, P, V, Cr, Mn, Co, Cu, Zn, Ga, Mo, Rh, Pt, Pd, Ag, and Ru. 
   
   
       49 . A particle according to  claim 48  wherein the ceramic composite comprises up to 40% by weight of the promoter material. 
   
   
       50 . A method according to  claim 37  wherein the ceramic composite particles are in the form of pellets, monoliths, blocks, or combinations thereof. 
   
   
       51 . A method according to  claim 37  wherein the particle is operable to maintain activity after 10 or more regeneration cycles.