Booster air heater for high moisture fuels

A selective catalytic reduction system equipped combustion system fueled by high moisture fuel comprising:

• a mill for pulverizing high moisture fuel to obtain pulverized fuel;
• an interior chamber;
• an air heater operable to heat primary air to an increased temperature using a first flue gas stream and a second flue gas stream, the second flue gas stream being a portion of the flue gas exiting the interior chamber of the combustion system prior to passing through a heat exchanger and being a higher temperature than the first flue gas stream;
• a booster air heater operable to heat primary air of an increased temperature to a higher temperature using the second flue gas stream;
• and
• a fuel duct for passage of higher temperature primary air through the mill to dry the pulverized fuel and to carry the dry pulverized fuel from a mill outlet to a combustion furnace.