Controlling Non-Condensable Gases with a Flameless Thermal Oxidizer System, 1996 Environmental Conference Proceedings

The typical method for controlling non-condensable gas (NCG) releases at a Kraft mill is combustion in the mill’s lime kiln. During periods when the lime kiln is out of service a secondary means of treating the NCGs is required for operation of the mill without violating applicable air regulations and permit limits. Following an extensive evaluation of options, a flameless thermal oxidizer (FTO) system was selected and installed at Georgia-Pacific’s Monticello, MS Mill as a back-up system to treat the NCGs during kiln outage periods. The system is comprised of a gas inlet train, a flameless thermal oxidizer for H2 S and volatile organic compound (VOC) destruction, a quench/wet scrubber for SO2 removal, and a stack. The oxidizer utilizes a preheated packed bed that is supplemented during operation with natural gas to maintain temperature in the primary oxidation zone in excess of 1600°F. The system has been shown to be capable of achieving high destruction and removal efficiencies (DREs) and very low SO2 and H2 S emissions. This paper addresses environmental and permitting considerations, design of the thermal oxidizer system, system control methodology, startup challenges and experiences, resultant system improvements, and performance data.