Patent ID: 6726888
Filing Date: 2004-04-27
Classification: B01D

Abstract:
A method to decrease emissions of nitrogen oxide and mercury while decreasing carbon in fly ash, comprising:selecting a combination of factors from the group consisting of fuel type, fuel staging, air staging and a combustion condition to control a combustion process to generate a flue gas comprising fly ash with enhanced unburned carbon; controlling the combustion process according to the factors to produce the flue gas comprising fly ash with enhanced unburned carbon, NOx and vaporized mercury; removing NOx from the flue gas; allowing the flue gas to cool to a lower temperature to collect fly ash with absorbed mercury; passing the fly ash with absorbed mercury through an ash burnout unit to remove carbon from the fly ash and to produce a mercury-containing exhaust gas; and passing the mercury-containing exhaust gas through a collection unit to capture the mercury.