Abstract: When using soda ash reagent in an SBS injection system, various impurities from various possible sources can form suspended solid particles and also form scale that may foul the filtration screens, piping, reagent storage tanks, and instrumentation in the injection system. A system and method are disclosed in which a chelating agent cleaning process removes existing scale, or alternatively, prevents the particles and scale from forming. Various embodiments operate in batch or continuous modes or a combination of both.

Abstract: A scrubber system is provided which enables a substantially horizontal flow path for the gas which is being subjected to scrubbing. Among other advantages, this permits operation of the absorber with a differential pressure of zero or less. Scrubber composition spray means are positioned in the horizontal gas flow path for spraying an aqueous scrubber composition in a direction which is generally cocurrent with said gas flow. The system is free of means which spray the scrubber composition in directions countercurrent to said gas flow.

Abstract: An improved magnesium-enhanced lime flue gas desulfurization system is provided which produces the high sulfur dioxide removal level of previous magnesium-enhanced lime flue gas desulfurization systems and additionally produce waste solids that have significantly better properties and are more easily dewatered than the solids produced by known systems. The magnesium-enhanced lime flue gas desulfurization system of the present invention includes a crystallizer-clarifier reaction tank (CCRT) which receives scrubber effluent and functions as a combined reaction tank and thickener. Clear liquor from the CCRT is sent to a scrubber to scrub the flue gas, and a portion of the CCRT--thickened solids are directed to a high pH premix slurry tank (PMST) where the crystallization environment can be controlled by reagent addition and pH. The PMST contents are circulated to the CCRT and are separated to produce a waste solids fraction that is easily dewatered.

Abstract: An improved wet magnesium-enhanced lime flue gas desulfurization system and process are provided. The magnesium-enhanced lime slurry process for removing sulfur dioxide from flue gas to produce gas that is substantially free from sulfur dioxide and calcium and sulfite-containing waste solids is modified to include the addition of process reagents to a separate premix slurry tank which has a controlled, high pH. The addition of slurry formed from the scrubber effluent to the premix slurry tank is controlled to maintain the pH above 10. The premix slurry tank mixture is circulated to a reaction tank for reaction with the scrubber effluent to produce large crystal, easily dewatered waste solids.

Abstract: An improved magnesium-enhanced lime flue gas desulfurization system and process are provided which produce the high sulfur dioxide removal level of previous magnesium-enhanced lime flue gas desulfurization systems and additionally produce waste solids that have significantly better properties and are more easily dewatered than the solids produced by known systems. The magnesium-enhanced lime flue gas desulfurization system of the present invention includes a crystallizer-clarifier reaction tank (CCRT) which receives scrubber effluent and functions as a combined reaction tank and thickener. Clear liquor from the CCRT is sent to a scrubber to scrub the flue gas, and a portion of the CCRT-thickened solids are directed to a high pH premix slurry tank (PMST) where the crystallization environment can be controlled by reagent addition and pH. The PMST contents are circulated to the CCRT and are separated to produce a waste solids fraction that is easily dewatered.