Process for generating electricity and concentrated carbon dioxide

1. A process for the generation of electricity and the production of a concentrated carbon dioxide stream using a molten carbonate fuel cell, the fuel cell comprising an electrolyte sandwiched between an anode and a cathode, an anode chamber and a cathode chamber, wherein the process comprises:

feeding a fuel gas to the anode chamber and a cathode inlet gas comprising carbon dioxide and a molecular oxygen to the cathode chamber;

producing electricity, an anode off-gas and a cathode off-gas via anode and cathode reactions;

feeding at least part of the anode off-gas to a catalytic afterburner wherein it is oxidized with an oxidant to obtain an oxidized anode off-gas;

recycling the remainder of the anode off-gas to the anode chamber; wherein the oxidant consists of part of the cathode off-gas and/or part of a molecular oxygen containing external oxidant stream, which external oxidant stream comprises at most 20% (v/v) nitrogen;

the oxidized anode off-gas is brought into heat-exchange contact with the remainder of the cathode off-gas and the remainder of the external oxidant stream to obtain a cooled anode off-gas and a heated mixture of cathode off-gas and external oxidant;

the cathode off-gas is cooled before it is brought in heat-exchange contact with the oxidized anode off-gas;

the cooled anode off-gas and the heated mixture of cathode off-gas and external oxidant are fed to the cathode chamber as cathode inlet gas;

as soon as a set point in the carbon dioxide concentration at the cathode chamber outlet of in the range of from 5 to 40% (v/v) is reached, part of the cooled anode off-gas is withdrawn from the process, where it is processed to obtain a concentrated carbon dioxide stream.

2. The process of claim 1 , wherein the withdrawn anode off-gas is further cooled to separate water from it and to obtain the concentrated carbon dioxide stream.

3. The process of claim 1 , wherein the fuel gas is a hydrocarbonaceous gas, and wherein the fuel gas is converted into a carbon monoxide and hydrogen containing gas in the anode chamber.

4. The process of claim 3 , wherein only part of the anode off-gas is fed to the catalytic afterburner and the remainder is recycled to the anode chamber.

5. The process of claim 3 , wherein the fuel gas is selected from the group consisting of natural gas, methane, biogas, and land-fill gas.

6. The process of claim 1 , wherein the fuel gas is a reformer effluent comprising hydrogen and carbon monoxide.

7. The process of claim 1 , wherein the fuel gas contain at most 25% (v/v) nitrogen.

8. The process of claim 1 , wherein 35% to 90% (v/v) of the anode off-gas is recycled to the anode chamber.

9. The process of claim 1 , wherein 50% to 80% (v/v) of the anode off-gas is recycled to the anode chamber.

10. The process of claim 1 , wherein the fuel gas contains at most 15% (v/v) nitrogen.

11. The process of claim 1 , wherein the fuel gas contains at most 10% (v/v) nitrogen.

12. The process of claim 1 , wherein the fuel gas contains substantially no nitrogen.

13. The process of claim 1 , wherein the set point in carbon dioxide concentration at the cathode chamber outlet is in the range of from 10% to 30% (v/v).

14. The process of claim 1 , wherein the external oxidant stream is substantially pure oxygen.