The power boiler is a suitable location to dispose of all three types of noncondensible gases (NCG). The strong NCG and stripper off gas are typically injected into the boiler separately through a dedicated nozzle with two ports. The dilute gas may be injected into the boiler in a number of ways including with the primary combustion air, as overfire air, or through a separate port with or without an auxiliary burner.

Operating parameters of a boiler need to be considered when choosing one as the point of disposal. The cold end temperature of the boiler needs to be reviewed to insure that the gas temperature will remain above the acid dew point of the gas. The availability of the boiler is important as well as the volume of dilute NCG compared to the combustion air. Most important is the stack emissions and whether or not the addition of sulfur containing gas will cause a sulfur dioxide emission issue.

Prior to combustion in the boiler all types of NCG are passed through a mist eliminator for removal of droplets and each line is protected by a flame arrester. Depending upon the location for introduction of dilute NCG into the boiler it may be appropriate to preheat the NCG to minimize its impact on the boiler operation. In addition to the normal NCG system interlocks, the ability to burn the NCG gases in the boiler is tied to the steam generation in the boiler. This insures adequate combustion temperatures.