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U.S. Department of Energy
Office of Scientific and Technical Information

Method for sulfur dioxide and nitrogen reduction in boiler stacks

Patent ·
OSTI ID:5151284
This patent describes a method for sulfur dioxide and nitrogen oxide reduction in combustion stack gas effluent. It includes feeding combustion gases from a boiler through a combustion stack fitted with stack extension of a diameter to reduce exit gas velocity below 20{prime} per second, the stack extension being fitted with a demister and a low pressure drop distillation tray located a minimum of two feet below the demister; flushing the demister at intervals with water; feeding through a circulating pump an iron chelate in an ammonia sulfite-sulfate solution through a liquid gas contactor means contiguous to a bottom of the demister while taking a side stream draw-off from the low pressure drop distillation tray to the circulating pump; feeding an ammonium sulfate solution from a cooling means into a circulating ammonium sulfite-sulfate stream draining from a bottom of the combustion stack while maintaining pH of the circulating ammonia sulfite-sulfate stream at a pH of approximately 6.8 with ammonia addition.
Assignee:
NOV; EDB-92-110615; NOV-92-029030
Patent Number(s):
A; US 5100634
Application Number:
PPN: US 7-589032
OSTI ID:
5151284
Country of Publication:
United States
Language:
English