Experimental study on water recovery from high‐humidity flue gas using condensation combined with acoustic agglomeration

Abstract High‐humidity flue gas downstream of wet flue‐gas desulfurization (WFGD) contains recoverable water, whereas indirect condensation alone may provide limited recovery under laboratory conditions. Although condensation–acoustic agglomeration arrangements have been reported for flue‐gas treatment, the water‐collection response of the present laboratory system and its dependence on cooling and acoustic variables required clarification. Here, a simulated high‐humidity flue gas was treated using a Flue Gas Condenser combined with an acoustic agglomeration chamber. The effects of cooling‐water flow rate, cooling‐water inlet temperature, water‐vapor volume fraction, acoustic frequency, sound pressure level (SPL), and nominal residence time were evaluated. Under the reported optimum cooling condition at 55°C and α = 17%, condensation alone achieved a water‐recovery efficiency of 38.51%. With the acoustic field operated at 1000 Hz, 130 dB, and a nominal residence time of 5 s, the reported recovery reached 46.93%, an increase of 8.42 percentage points (21.9% relative to condensation alone). The observed non‐monotonic responses to frequency, SPL, and residence time identify an operating window for the tested apparatus. These findings provide an experimental reference for optimizing operating conditions in condensation–acoustic agglomeration systems and support further evaluation for water recovery from representative high‐humidity WFGD gas.