Waste heat is extracted from the exhaust (20) of a biomass dryer (14) in a grain alcohol plant (10). A boiler circuit (74) provides high pressure steam to a balance of the plant (64). A recovered energy circuit (76) extracts heat from the exhaust via a dryer exhaust condensing economizer (24) and provides a steam mixture (60) to satisfy an intermediate pressure steam demand of the balance of the plant, thereby bypassing a portion of the boiler circuit. Working fluids in the boiler and recovered energy circuits are intermixed in a boiler feed vessel (72). Dryer exhaust condensate (30) may be used in an exhaust gas scrubber (22) upstream of the dryer exhaust condensing economizer to remove pollutants and to saturate (26) the exhaust gas for improved heat transfer. Heat transfer may be further improved by operating the dryer exhaust condensing economizer at an elevated pressure.
