The invention is directed to a process and a system for removing sulfur dioxide from a feed gas stream. In the process the feed gas pre-scrubbed. Then SO2 is absorbed from the gas with an absorbing medium. The spent absorbing medium is regenerated. These process steps are interchanged with a caustic treatment in the pre-scrubbing zone in case of a very high SO2 content in the feed gas stream. The system comprises a pre-scrubbing unit, an absorption unit, and a regeneration unit. The system is characterized in that the pre-scrubber unit comprises an inlet for an aqueous solution comprising a strong base. These are a simple, cost-efficient and reliable process and facility for processing gas with a varying SO2 content.

Device (10) for injecting powders into a furnace pipe (500), comprising a chamber (230) connected to a peripheral pipe (220) and, on the other hand, to the said furnace pipe via the said peripheral pipe (220), which comprises a first part (221) of diameter DP1, and a second part (222) of diameter DP2, having a downstream end (222a) and intended to be in communication with the furnace pipe, and a powder conveying pipe (120) which has a diameter DT and a downstream end (121), characterized in that the second part of the peripheral pipe has a length Lthe diameter (DP2) of the second part of the peripheral pipe, and in that the diameter (DT) and the diameter (DP2) are connected by the relationship 0<DP2DT< DT.

A method of reducing selenium contamination in a waste water stream is described herein. The method includes channeling a flue gas stream through an absorber, contacting the flue gas stream with an aqueous alkaline-based slurry, such that any selenium byproduct in the flue gas stream forms a selenium compound within the aqueous alkaline-based slurry, controlling oxidation of the selenium compound in the aqueous alkaline-based slurry, and adding a precipitation agent to the aqueous alkaline-based slurry to cause the selenium compound within the aqueous alkaline-based slurry to precipitate.

A composite material for purifying air includes a porous foam material which is an open-cell polyurethane foam net; and a mixture sprayed on the interior and/or the surface of the porous foam material, the mixture including an absorbent material, a treating agent and an adhesive; wherein the adsorptive material is diatomite, and the treating agent is alkali solution.

A liquid film dust arrester is installed to face a gas flow containing dust and flowing out from a gas discharge pipe. The arrester includes a gas flow blocking unit arranged vis--vis the gas flow, a liquid dispersion unit having a dispersion section arranged at a position near the center of the gas flow blocking unit and upstream relative to the gas flow blocking unit as viewed in the flowing direction of the gas flow so as to face the gas flow blocking unit, a liquid ejection unit having an ejection port disposed vis--vis the dispersion section and configured to eject liquid from the ejection port, and a liquid film forming unit. The dispersion section comprises a smooth surface that causes the ejected liquid to flow and disperse on the smooth surface, and the liquid film is formed to face the gas flow flowing through the flow path.

A combination marine exhaust gas scrubber and ballast disinfection system using seawater/water surrounding a ship to reduce/scrub smoke-stack emissions and produce a disinfected seawater/water for ballast, which can then be periodically or continually discharged back into the seawater/water body without concern for the spread of non-invasive species.

An exhaust gas purification device downstream of a wet desulfurizer for a combustor has a vessel body for intake of exhaust gas from the wet desulfurizer at a lower portion and discharge of the same at an upper end, an auxiliary desulfurizing portion with an injection nozzles for injection of an alkaline solution at a position above an inlet in the vessel body to purify the exhaust gas, bag filters above the injection nozzles to separate particles in the exhaust gas, backwashing nozzles for injection of compressed gas from above the bag filters for backwashing, a drain-receiving tank for reception of drain from the vessel body and a supply pump for supply of the drain in the drain-receiving tank as alkaline solution to the injection nozzles.

A method of spray drying and washing using a spray drying apparatus, includes: spraying dehydrated filtrate from a spray nozzle hung down from a top side of the spray drying apparatus; introducing a part of flue gas into the spray drying apparatus to dry the dehydrated filtrate; wherein a compressed air is introduced into the spray nozzle to facilitate the spraying and into the wash nozzle to perform air purging during the spray drying, and jetting washing liquid from a wash nozzle provided on a side wall of the spray drying apparatus to wash the spray nozzle and an inside of the spray drying apparatus body, wherein the feeding of the dehydrated filtrate to the spray nozzle is stopped during the washing.

Systems and apparatuses for neutralizing acidic compounds in flue gases emitted from a heat recovery coke oven. A representative system includes a spray dry absorber having a barrel that includes a plurality of wall plates that form sidewalls of the barrel. The wall plates include a steel plate and a corrosion resistant alloy cladded to the steel plate and the wall plates are oriented such that the corrosion resistant alloy faces toward and is in fluid communication with an interior area of the barrel. The alloy is resistant to corrosion caused by the acidic compounds in the flue gas and can prevent the steel plate from being corroded by these acidic compounds.

A wet scrubber (14) useful for reducing flue gas sulphur oxides and particulate matter comprising an at least first spray level arrangement (34) arranged horizontally in a wet scrubber tower (16). The at least first spray level arrangement (34) may comprise downwardly, upwardly, and/or combination downwardly and upwardly spraying nozzles (40). Arranged between the nozzles (40) is a plurality of single plates (76, 76A) and/or double plates (82) to direct flue gas flow into absorbent liquid or slurry atomized by the nozzles (40) for flue gas sulphur oxide and particulate matter reduction.