A direct-fired biomass-fueled pressurized gas turbine system comprising: a pressurized feed system comprising: a plurality of chambers wherein a first chamber receives biomass particles at atmospheric pressure and supplies a second chamber with biomass particles under pressure, a first valve positioned at an inlet of the first chamber, a second valve positioned at an outlet of the first chamber to the second chamber, and an air compressor arranged to pressurize the first chamber; a cyclonic combustor for combustion (400, 800, 1000) of biomass particles under pressure to produce a combustion gas and particulate ash, the cyclonic combustor (400, 800, 1000) comprising: a combustion liner forming a combustion chamber having a generally cylindrical shape, wherein the combustion chamber has a pressure less than the pressure of the second chamber of the pressurized feed system, a biomass feed inlet (102, 414) at one end of the combustion chamber formed through the combustion liner for receiving the biomass particles from the pressurized feed system, wherein the biomass feed inlet (102, 414) is formed so that the biomass particles are introduced into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner, and a plurality of air tuyeres formed through the combustion liner for receiving compressed air, wherein the plurality of air tuyeres are arranged to introduce the compressed air into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner; and a gas turbine comprising: a turbine section comprising an inlet in communication with the combustion chamber for receiving the combustion gas from the combustion chamber, wherein the turbine section is driven by the combustion gas, characterized in that the plurality of tuyeres increase in size along the length of the longitudinal axis of the combustion liner. a pressurized feed system comprising: a plurality of chambers wherein a first chamber receives biomass particles at atmospheric pressure and supplies a second chamber with biomass particles under pressure, a first valve positioned at an inlet of the first chamber, a second valve positioned at an outlet of the first chamber to the second chamber, and an air compressor arranged to pressurize the first chamber; a plurality of chambers wherein a first chamber receives biomass particles at atmospheric pressure and supplies a second chamber with biomass particles under pressure, a first valve positioned at an inlet of the first chamber, a second valve positioned at an outlet of the first chamber to the second chamber, and an air compressor arranged to pressurize the first chamber; a cyclonic combustor for combustion (400, 800, 1000) of biomass particles under pressure to produce a combustion gas and particulate ash, the cyclonic combustor (400, 800, 1000) comprising: a combustion liner forming a combustion chamber having a generally cylindrical shape, wherein the combustion chamber has a pressure less than the pressure of the second chamber of the pressurized feed system, a biomass feed inlet (102, 414) at one end of the combustion chamber formed through the combustion liner for receiving the biomass particles from the pressurized feed system, wherein the biomass feed inlet (102, 414) is formed so that the biomass particles are introduced into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner, and a plurality of air tuyeres formed through the combustion liner for receiving compressed air, wherein the plurality of air tuyeres are arranged to introduce the compressed air into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner; and a combustion liner forming a combustion chamber having a generally cylindrical shape, wherein the combustion chamber has a pressure less than the pressure of the second chamber of the pressurized feed system, a biomass feed inlet (102, 414) at one end of the combustion chamber formed through the combustion liner for receiving the biomass particles from the pressurized feed system, wherein the biomass feed inlet (102, 414) is formed so that the biomass particles are introduced into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner, and a plurality of air tuyeres formed through the combustion liner for receiving compressed air, wherein the plurality of air tuyeres are arranged to introduce the compressed air into the combustion chamber with a tangential component relative to the longitudinal axis of the combustion liner; and a gas turbine comprising: a turbine section comprising an inlet in communication with the combustion chamber for receiving the combustion gas from the combustion chamber, wherein the turbine section is driven by the combustion gas, characterized in that the plurality of tuyeres increase in size along the length of the longitudinal axis of the combustion liner. a turbine section comprising an inlet in communication with the combustion chamber for receiving the combustion gas from the combustion chamber, wherein the turbine section is driven by the combustion gas, characterized in that the plurality of tuyeres increase in size along the length of the longitudinal axis of the combustion liner.