Sulfur tolerant molten carbonate fuel cell anode and process

Claim 2

In a process for production of electricity in a molten alkali metal carbonates fuel cell using a fuel gas mixture obtained by gasification of naturally occurring carbonaceous material, the improvement comprising passing said fuel gas mixture comprising about 10 to about 35 volume percent CO and about 1 ppm to about 10 ppm H 2 S on a volume basis through a porous anode comprising about 0.5 to about 20 weight percent of a sulfur tolerant water-gas-shift catalyst selected from the group consisting of Cr 2 O 3 , FeO, Fe 2 O 3 , Fe 3 O 4 , Al 2 O 3 , LiAlO 2 , LiCrO 2 , MoO 2 , MoO 3 , WO 3 , and mixtures thereof and the remainder being substantially a metal selected from the group consisting of nickel, cobalt, and mixtures thereof whereby over about 25 volume percent of the water-gas-shift equilibrium conversion of CO to H 2 obtained with no H 2 S present is maintained in the presence of said H 2 S.

Claim 3

The process of claim 1 wherein said catalyst is present in about 5 to about 15 weight percent.

Claim 4

The process of claim 2 wherein said anode comprises about 85 to 95 weight percent of a metal selected from the group consisting of nickel, cobalt, and mixtures thereof.

Claim 5

The process of claim 2 wherein said anode comprises about 85 to 95 weight percent nickel.

Claim 6

The process of claim 1 wherein said anode comprises about 80 to 99.5 weight percent of a metal selected from the group consisting of nickel, cobalt, and mixtures thereof.

Claim 7

The process of claim 1 wherein said anode comprises about 80 to 99.5 weight percent nickel.

Claim 8

The process of claim 1 wherein said fuel cell is operated below about 700° C.

Claim 9

The process of claim 1 wherein said fuel cell is operated at about 500° to about 650° C.

Claim 10

The process of claim 1 wherein over about 50 volume percent of the water-gas-shift equilibrium conversion of CO to H 2 obtained with no H 2 S present is maintained in the presence of said H 2 S.

Claim 11

The process of claim 1 wherein said gas has a residence time in the zone of said anode for greater than about 2 seconds.

Claim 12

The process of claim 1 wherein said gas has a residence time in the zone of said anode of about 2 to about 4 seconds.

Claim 13

The process of claim 1 wherein said fuel gas comprises about 1 to about 5 ppm by volume H 2 S.

Claim 14

The process of claim 1 wherein said catalyst is present in about 5 to about 15 weight percent, said anode comprises about 85 to 95 weight percent nickel, said fuel cell is operated at about 500° to about 650° C., and said gas has a residence time in the zone of said anode for greater than about 2 seconds.

Claim 15

The process of claim 1 wherein said catalyst is present in about 5 to about 15 weight percent, said anode comprises about 85 to 95 weight percent nickel, said fuel cell is operated at about 500° to about 650° C., said gas has a residence time in the zone of said anode of about 2 to about 4 seconds, and said fuel gas comprises about 1 to about 5 ppm by volume H 2 S.

Claim 16

In a process for production of electricity in a molten alkali metal carbonates fuel cell having a porous sulfur tolerant catalytic anode having improved fuel cell electrical output under carbonate fuel cell operating conditions when using a fuel gas mixture comprising about 10 to about 35 volume percent CO and about 1 to about 10 ppm H 2 S on a volume basis, said process comprising passing said fuel gas mixture through said sulfur tolerant catalytic anode comprising about 0.5 to about 20 weight percent of a sulfur tolerant water-gas-shift catalyst selected from the group consisting of MoO 2 , MoO 3 , WO 3 , and mixtures thereof and the remainder being substantially a metal selected from the group consisting of nickel, cobalt and mixtures thereof, said anode being electrochemically active and said water-gas-shift catalyst being at catalytically effective temperatures of about 500° C. to about 700° C. whereby over about 25 volume percent of the water-gas-shift conversion of CO to H 2 obtained with no H 2 S present is maintained in the presence of said H 2 S.

Claim 17

In a process for production of electricity in a molten alkali metal carbonates fuel cell having a porous sulfur tolerant catalytic anode having improved fuel cell electrical output under carbonate fuel cell operating conditions when using a fuel gas mixture comprising about 10 to about 35 volume percent CO and about 1 to about 10 ppm H 2 S on a volume basis, said process comprising passing said fuel gas mixture through said sulfur tolerant catalytic anode comprising about 0.5 to about 20 weight percent of a sulfur tolerant water-gas-shift catalyst selected from the group consisting of MoO 2 , MoO 3 , WO 3 , and mixtures thereof and the remainder being substantially a metal selected from the group consisting of nickel, cobalt and mixtures thereof, said anode being electrochemically active and said water-gas-shift catalyst being at catalytically effective temperatures of about 500° C. to about 700° C. whereby over about 25 volume percent of the water-gas-shift conversion of CO to H 2 obtained with no H 2 S present is maintained in the presence of said H 2 S.

Claim 18

In a process of claim 15 wherein said catalyst is present in about 5 to about 15 weight percent.

Claim 19

In a process of claim 15 wherein said anode comprises about 80 to 99.5 weight percent cobalt.

Claim 20

In a process of claim 15 wherein said anode comprises about 85 to 95 weight percent nickel.

Claim 21

In a process of claim 15 wherein said catalyst is selected from the group consisting of MoO 2 and MoO 3 .

Claim 22

In a process of claim 15 wherein said catalyst is WO 3 .