Abstract: Disclosed is a process for reducing slag in a black liquor recovery boiler, the process comprising: injecting and burning black liquor in a boiler by contacting it with primary air and secondary air; introducing a slag-reducing chemical into the gases above the injection locations through interlaced, tangential or concentric secondary, tertiary, and/or quarternary air ports.

Abstract: Disclosed is a process for reducing slag in a black liquor recovery boiler, the process comprising: injecting and burning black liquor in a boiler by contacting it with primary air and secondary air; introducing a slag-reducing chemical into the gases above the injection locations through interlaced, tangential or concentric secondary, tertiary, and/or quarternary air ports.

Abstract: A slag and corrosion control process is described. The process entails: identifying the location of at least one slagging problem area in a boiler; introducing a slag control chemical comprising magnesium oxide or hydroxide into combustion gases in a location identified as having a slagging problem; identifying the location of at least one corrosion problem area in a boiler; and introducing a corrosion control chemical comprising a sulfate salt, bisulfite salt, sulfuric acid, or sulfur into combustion gases in a location identified as having a corrosion problem. In operation, these slag deposits will be sufficiently friable to be removed by relatively moderate application of physical energy, thus saving time and reducing any damage to the tubes by the cleaning process. The slag deposits are less voluminous and less in weight and are removed quickly. It is an advantage of the invention that slag can be removed with little or no shut down of a boiler.

Abstract: A corrosion control process is described. The process is especially useful in the control of chloride corrosion in waste to energy boilers. Corrosion of high temperature surfaces can be assessed by the monitor and controlled introduction of treatment chemicals by targeted in furnace injection reduces corrosion while maximizing combustion efficiency. A corrosion monitor is also described. Before and following selection of corrosion control chemicals and the locations for targeted in furnace injection, injection regimen and chemical selection and introduction parameters are monitored with the aid of the method and apparatus of the invention to adjust one or more control parameters to reduce corrosion. A preferred method will employ a treatment chemical that comprises an SO2 or SO3 reagent, e.g., sulfuric acid, sulfur, a sulfate salt or a bisulfite salt.