Metal ferrite catalyst for conversion of CO2 and methane to synthesis gas via reforming
The invention provides a use of metal ferrite oxygen carrier for converting carbon dioxide to carbon monoxide or synthesis gas via three processes: catalytic dry reforming of methane, chemical looping dry reforming of fuel and promoting coal gasification with CO 2 . The metal ferrite oxygen carrier comprises M z Fe x O y , where M z Fe x O y is a chemical composition with 0<x≤4, z>0 and 0<y≤6 and M is one of Ca, Ba, and/or combinations thereof. For example, M z Fe x O y may be one of CaFe 2 O 4 , BaFe 2 O 4 , MgFe 2 O 4 , SrFe 2 O 4 and/or combinations thereof. In catalytic dry reforming, methane and carbon dioxide react in the presence of metal ferrites generating a product stream comprising at least 50 vol. % CO and H 2 . In another embodiment, chemical looping dry reforming process where metal ferrite is reduced with a fuel and then oxidized with carbon dioxide is used for production of CO from carbon dioxide. In another embodiment, the metal ferrite is used as a promoter to produce CO continuously from coal gasification with CO 2 .
1. A method of producing synthesis gas from methane comprising:
providing a catalytic reactor containing a metal ferrite catalyst bed comprising MzFexOy, where 0<x≤4, z>0 and 0<y≤5, and where M is at least one Group II alkali earth metal, and where the MzFexOy comprises at least 30 wt. % of a metal ferrite oxygen carrier;
delivering one continuous gas stream containing methane comprising at least >1 vol. % of the one continuous gas stream into the catalytic reactor;
delivering another continuous gas stream containing carbon dioxide comprising at least >1 vol. % of the other continuous gas stream into the catalytic reactor;
maintaining the catalytic reactor at a reaction temperature, where the reaction temperature is sufficient for the reaction of methane and carbon dioxide, and generating a continuous stream of gaseous products containing H 2 and CO gas; and
withdrawing a product stream from a fuel reactor, where the gaseous products comprise the product stream, and where at least >50 vol. % of the product stream consists of CO and H 2 .
2. The method of claim 1 wherein the Group II alkali earth metals comprise at least one of Mg, Ca, Ba, Sr and/or combinations thereof.
3. The method is claim 1 wherein the reaction temperature ranges from about 500° C. to about 1100° C.
4. The method of claim 1 where the metal ferrite catalyst further comprises an inert support, where the inert support comprises from about 5 wt. % to about 70 wt. % of the metal ferrite oxygen carrier.
5. The method of claim 4 wherein the inert support contains at least one of alumina, silica, zirconia, clay, alumina silicates, titania, monolith and/or combinations thereof.
6. The method of claim 1 where the catalytic reactor containing a metal ferrite catalyst bed may be diluted with an inert material comprising at least one of alumina, silica, zirconia, clay, titania and/or alumina silicates.
7. The method of claim 1 where heat for the method and at least one of the CO 2 gas streams may be provided by combustion of a fuel or chemical looping combustion of a fuel with an oxygen carrier.
8. The method of claim 1 where the Group II metal ferrite may be in an oxidized form or a reduced form.