A system, comprising: a turbine combustor comprising a first diffusion fuel nozzle, wherein the first diffusion fuel nozzle comprises first and second passages that separately inject respective first and second flows into a chamber of the turbine combustor to produce a diffusion flame, wherein the first flow comprises a first fuel and a first diluent, and the second flow comprises a first oxidant; wherein the first and second passages have respective first and second outlets that are disposed along a downstream end of the first diffusion fuel nozzle, and the first and second passages are isolated from one another along the first diffusion fuel nozzle; a turbine driven by combustion products from the diffusion flame in the turbine combustor; and an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path, wherein the first diluent comprises a portion of the exhaust gas, steam, nitrogen, another inert gas, or any combination thereof and wherein the turbine combustor further comprises a diluent injection system disposed downstream from the first diffusion fuel nozzle, the diluent injection system being configured to inject a portion of the exhaust gas, steam, nitrogen, or another inert gas, or a combination thereof, into the chamber of the turbine combustor downstream from the first diffusion nozzle; and the diluent injection system comprising a plurality of openings in a liner of the turbine combustor, and the plurality of openings is configured to inject the portion of the exhaust gas into the chamber of the turbine combustor; and a first wall disposed about the chamber, a second wall disposed about the first wall, and an exhaust passage disposed between the first and second walls, wherein the dilution injection system comprises a plurality of diluent injectors extending through the first and second walls (496, 498) of the turbine combustor and configured to inject the portion of the exhaust gas, steam, nitrogen, or another inert gas into the chamber of the turbine combustor. a turbine combustor comprising a first diffusion fuel nozzle, wherein the first diffusion fuel nozzle comprises first and second passages that separately inject respective first and second flows into a chamber of the turbine combustor to produce a diffusion flame, wherein the first flow comprises a first fuel and a first diluent, and the second flow comprises a first oxidant; wherein the first and second passages have respective first and second outlets that are disposed along a downstream end of the first diffusion fuel nozzle, and the first and second passages are isolated from one another along the first diffusion fuel nozzle; a turbine driven by combustion products from the diffusion flame in the turbine combustor; and an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path, wherein the first diluent comprises a portion of the exhaust gas, steam, nitrogen, another inert gas, or any combination thereof and wherein the turbine combustor further comprises a diluent injection system disposed downstream from the first diffusion fuel nozzle, the diluent injection system being configured to inject a portion of the exhaust gas, steam, nitrogen, or another inert gas, or a combination thereof, into the chamber of the turbine combustor downstream from the first diffusion nozzle; and the diluent injection system comprising a plurality of openings in a liner of the turbine combustor, and the plurality of openings is configured to inject the portion of the exhaust gas into the chamber of the turbine combustor; and a first wall disposed about the chamber, a second wall disposed about the first wall, and an exhaust passage disposed between the first and second walls, wherein the dilution injection system comprises a plurality of diluent injectors extending through the first and second walls (496, 498) of the turbine combustor and configured to inject the portion of the exhaust gas, steam, nitrogen, or another inert gas into the chamber of the turbine combustor.