Abstract: A liquid-hydrocarbon fuel is used to produce thermal energy by introducing the liquid-hydrocarbon fuel and air to a vaporizer. The liquid-hydrocarbon fuel is vaporized in the vaporizer to produce hydrocarbon-fuel vapor, and the hydrocarbon-fuel vapor and air are blended to form a hydrocarbon-fuel-vapor-and-air mixture. Then, hydrocarbon-fuel-vapor-and-air mixture is introduced to a catalytic combustor including a catalyst, wherein the catalyst promotes oxidation of the hydrocarbon-fuel vapor to form a carbon-dioxide- and water-vapor-containing exhaust and to generate thermal energy. The carbon-dioxide- and water-vapor-containing exhaust and air is then introduced to a recuperator, wherein the recuperator transfers thermal energy from the carbon-dioxide- and water-vapor-containing exhaust to the air to produce heated air.