Efficient byproduct harvesting from fuel cells

A fuel cell system, comprising:

• a reformer configured to reform a fuel containing methane (CH4) with steam to produce a reformed fuel having methane (CH4), carbon monoxide (CO), and hydrogen (H2);
• a fuel cell having an anode, a cathode, and an electrolyte separating the anode from the cathode, the anode being configured to receive the reformed fuel while the cathode being configured to receive air having oxygen (O2), wherein the fuel cell is configured to perform an electrochemical reaction between a first portion of the reformed fuel received at the anode and oxygen (O2) in the air received at the cathode to produce electricity and an exhaust from the anode, the exhaust having carbon dioxide (CO2), water (H2O), and a second portion of the reformed fuel;
• an oxygen enricher configured to generate an oxygen enriched gas having an oxygen concentration from about 95% to about 99%;
• a combustion chamber coupled to the fuel cell to receive the exhaust from the anode and to receive the oxygen enriched gas from the oxygen enricher, the combustion chamber being configured to combust the second portion of the reformed fuel with the oxygen enriched gas, thereby converting the second portion of the reformed fuel into additional carbon dioxide (CO2) and water (H2O) with at least a reduced amount of nitrogen (N2) introduced into the exhaust when compared to combusting the second portion of the reformed fuel with air;
• an analyzer configured to analyze a composition of the exhaust subsequent to combusting the second portion of the reformed fuel with the oxygen enriched gas;
• and
• a controller configured to regulate a control valve to reduce the oxygen enriched gas introduced into the combustion chamber when a concentration of oxygen is above a threshold.

A method of operating fuel cell systems, the method comprising:

• introducing a fuel having methane (CH4), carbon monoxide (CO), and hydrogen (H2) into an anode of a fuel cell while introducing air into a cathode of the fuel cell;
• performing an electrochemical reaction between a first portion of the reformed fuel introduced to the anode and oxygen (O2) in the air introduced to the cathode of the fuel cell to produce electricity and an exhaust from the anode, the exhaust having carbon dioxide (CO2), water (H2O), and a second portion of the reformed fuel;
• and
• combusting, in a combustion chamber, the second portion of the reformed fuel in the exhaust with an oxygen enriched gas, thereby converting the second portion of the reformed fuel into additional carbon dioxide (CO2) and water (H2O) with at least a reduced amount of nitrogen (N2) introduced to the exhaust when compared to combusting the second portion of the reformed fuel with air;
• analyzing a composition of the exhaust subsequent to combusting the second portion of the reformed fuel with the oxygen enriched gas;
• and
• regulating a control valve to increase the oxygen enriched gas introduced into the combustion chamber when a concentration of methane (CH4), carbon monoxide (CO), or hydrogen (H2) is above a threshold and to reduce the oxygen enriched gas introduced into the combustion chamber when a concentration of oxygen is above another threshold.