A gas turbine system, comprising: an oxidant system; a fuel system; a control system; a plurality of combustors adapted to receive and combust an oxidant from the oxidant system and a fuel from the fuel system to produce a plurality of exhaust gases; a plurality of oxidant-flow adjustment devices, wherein each of the plurality of oxidant-flow adjustment devices is operatively associated with one of the plurality of combustors, wherein each of the oxidant-flow adjustment devices are configured to independently regulate an oxidant flow rate into an associated combustor; and a plurality of exhaust sensors (406, 502, 602) in communication with the control system, wherein the exhaust sensors (406, 502, 602) are provided - on an exhaust line out of each combustor, respectively; and/or - on a turbine expander adapted to receive the exhaust gases and to generate power; and/or - in an expander exhaust section of the gas turbine, wherein the exhaust sensors (406, 502, 602) are adapted to measure an oxygen concentration and a carbon monoxide concentration in each of the plurality of the exhaust gases, and wherein the control system is configured to independently adjust the plurality of oxidant-flow adjustment devices based, at least in part, on the oxygen concentrations and carbon monoxide concentrations measured by the plurality of exhaust sensors to maintain a combined oxygen and carbon monoxide concentration of the plurality of exhaust gases within a predetermined range of less than 2 mol% to achieve an equivalence ratio within a predetermined range of from 0.85 to 1.15. an oxidant system; a fuel system; a control system; a plurality of combustors adapted to receive and combust an oxidant from the oxidant system and a fuel from the fuel system to produce a plurality of exhaust gases; a plurality of oxidant-flow adjustment devices, wherein each of the plurality of oxidant-flow adjustment devices is operatively associated with one of the plurality of combustors, wherein each of the oxidant-flow adjustment devices are configured to independently regulate an oxidant flow rate into an associated combustor; and a plurality of exhaust sensors (406, 502, 602) in communication with the control system, wherein the exhaust sensors (406, 502, 602) are provided - on an exhaust line out of each combustor, respectively; and/or - on a turbine expander adapted to receive the exhaust gases and to generate power; and/or - in an expander exhaust section of the gas turbine, - on an exhaust line out of each combustor, respectively; and/or - on a turbine expander adapted to receive the exhaust gases and to generate power; and/or - in an expander exhaust section of the gas turbine, wherein the exhaust sensors (406, 502, 602) are adapted to measure an oxygen concentration and a carbon monoxide concentration in each of the plurality of the exhaust gases, and wherein the control system is configured to independently adjust the plurality of oxidant-flow adjustment devices based, at least in part, on the oxygen concentrations and carbon monoxide concentrations measured by the plurality of exhaust sensors to maintain a combined oxygen and carbon monoxide concentration of the plurality of exhaust gases within a predetermined range of less than 2 mol% to achieve an equivalence ratio within a predetermined range of from 0.85 to 1.15.