Abstract: This invention relates to a control method and apparatus for the coordination of a number of automated liquid-solid separators with an in-line pump between a fluid feed tank and liquid-solid separators. The control method and apparatus develops on-line control signals for the process control of predetermined manipulated process variables. The present invention provides excellent separation control for fluid tanks in which fluid inlet rates vary.

Abstract: A method of producing an alkaline earth nitrate fertilizer composition where a gas stream containing nitrogen oxides is treated to convert the nitrogen oxides to nitric acid and the gas stream then contacted with an aqueous medium containing an alkaline earth compound which reacts with the nitric acid to form an aqueous effluent solution of an alkaline earth nitrate. A portion of the aqueous effluent solution is used to form additional aqueous medium containing an alkaline earth compound for further contact with the gas stream, such that the concentration of alkaline earth nitrate in the aqueous effluent is increased.

Abstract: A process for removing both sulfur dioxide and nitrogen oxides from a gaseous stream where the stream is contacted in a first wet scrubbing unit with an alkaline earth compound to remove sulfur dioxide and humidify the gaseous stream, passing of the humidified gaseous stream to a coronal discharge unit to convert NO.sub.x therein to nitric acid, and then contacting the gaseous stream to a second wet scrubbing unit and contacting the gaseous stream with an alkaline earth compound to remove the nitric acid as an alkaline earth nitrate prior to discharge of the gaseous stream to the atmosphere. The effluent from the first wet scrubbing unit is maintained separate from the effluent from the second wet scrubbing unit during the removal steps so as to provide pure recoverable by-products.

Abstract: A method of removing dioxide and nitrogen oxides from a gaseous stream where an alkaline earth compound is added, either in a wet scrubbing unit which substantially saturates the gaseous stream with water, or to a gaseous stream to which water has been added, and the gaseous stream then exposed to a coronal discharge, with dry calcium hydroxide added which reacts with nitric acid formed by the coronal discharge to form calcium nitrate. Alkaline earth sulfites or sulfates, formed by reaction of the alkaline earth compound with sulfur dioxide are removed from the gaseous stream and calcium nitrate, formed by reaction of injected dry calcium hydroxide with the nitric acid produced are separated from the gaseous stream and the gaseous stream, with sulfur dioxide and nitrogen oxides removed, is discharged to the atmosphere.

Abstract: A method for removing sulfur dioxide and nitrogen oxides from a gaseous stream using a magnesium-enhanced lime scrubbing slurry containing a ferrous chelate where oxidized ferrous chelate is regenerated by electrochemical treatment. The spent scrubbing solution containing ferric chelates is passed as a catholyte, at an acidic pH of 4.0-6.5 through a cathode compartment while an anolyte solution containing magnesium sulfate, at a pH of 1.5 to 6.5 is passed through an anode compartment, the compartments separated by a microporous separator. An electrical current is passed from the cathode compartment to the anode compartment and ferric chelates are regenerated to ferrous chelates.

Abstract: Cement and elemental sulfur are produced by forming a moist mixture of a flue gas desulfurization process waste product containing 80-95 percent by weight calcium sulfate hemihydrate and 5-20 percent by weight calcium sulfate hemihydrate, aluminum, iron, silica and carbon, agglomerating the moist mixture while drying the same to form a feedstock, and calcining the dry agglomerated feedstock in a rotary kiln. Sulfur dioxide produced during the calcination is cooled and contacted with hydrogen and carbon monoxide to reduce the same to elemental sulfur.

Abstract: Cement is produced by forming a moist mixture of a flue gas desulfurization process waste product containing 80-95 percent by weight calcium sulfite hemihydrate and 5-20 percent by weight calcium sulfate hemihydrate, aluminum, iron, silica and carbon, agglomerating the moist mixture while drying the same to form a feedstock, and calcining the dry agglomerated feedstock in a rotary kiln. Sulfur dioxide released from the calcium sulfite hemihydrate and calcium sulfate hemihydrate during calcination may be used to produce sulfuric acid, while heat recovered in the process is used to dry the agglomerating feedstock.

Abstract: An electrode, electrochemical cell, and electrochemical processes are disclosed. The electrode is a porous, multi-layered electrode which can have an element in flexible, strip form wound around a central, usually flat plate core, which core may serve as a current distributor. In any form, each layer can be represented by a very thin, highly flexible metal mesh. This can be a fine, as opposed to a coarse, mesh which has extremely thin strands and small voids. The electrode will have an active coating. For utilizing this electrode, the cell in one form will be a monopolar cell providing upward, parallel electrolyte flow through the porous, multi-layered electrode. A representative cell can have such electrode at least substantially filling an electrode chamber. The cells can be contained in a cell box that will provide the desired flow-through relationship for the electrolyte to the electrode.

Abstract: A process for removing sulfur dioxide and nitrogen oxides from a hot gaseous stream, in a scrubbing unit, by use of an aqueous medium containing calcium and magnesium scrubbing components to remove sulfur dioxide and a ferrous chelate to remove the nitrogen oxide, a portion of the ferrous chelate being oxidized to ferric chelate during the process. The ferric chelate is regenerated to ferrous chelate by contacting the hot gaseous stream, prior to entry into the scrubbing unit, with a prescrubbing aqueous medium containing magnesium scrubbing components for sulfur dioxide, forming bisulfite ions in the aqueous medium.

Abstract: A process for the simultaneous removal of sulfur dioxide and nitrogen oxides from a gaseous stream uses a sorbent containing magnesium ions and sulfite ions for sulfur dioxide removal and a metal chelating agent for nitrogen oxides removal, with the production of an amine disulfonate salt, such as potassium amine disulfonate, as a purified saleable by product.

Abstract: A wet scrubbing method for removal of sulfur dioxide from a gaseous stream uses a magnesium-enhanced lime scrubbing aqueous slurry, where a solids content in the aqueous slurry in a wet scrubbing unit is maintained at an amount of between 13 to 20 percent by weight. A bleed stream is removed from the aqueous scrubbing slurry at a pH of between 4.5-5.6 and fed to an oxidizing unit wherein calcium sulfite is oxidized to gypsum. The gypsum and residual solids in the discharge from the oxidizing unit are separated to produce a clarified solution, which is returned to the wet scrubbing unit.

Abstract: A method of ameliorating acid soils so as to enhance plant growth is provided by adding to soil 0.05 to 20 percent by weight, based on the weight of the soil, of a flue gas desulfurization by-product consisting essentially of 80-99 percent by weight of gypsum (CaSO.sub.4.2H.sub.2 O) and 1-20 percent by weight of magnesium hydroxide (Mg(OH).sub.2).

Abstract: In a process for removing sulfur dioxide from a gas stream using an aqueous solution of magnesium scrubbing components and subsequent oxidation of the magnesium sulfite produced which is regenerated by addition of lime, a pure magnesium hydroxide product is produced using less oxidation energy requirements by passing a further portion of solution from the oxidizing unit to a further oxidizing unit, oxidizing the same to produce an aqueous solution containing less than 130 ppm sulfite, treating the further portion with lime and separating purified magnesium hydroxide therefrom.

Abstract: A method of collecting and conditioning either or both of a fluid bed combustion cyclone or bed ash, from a sulfur-containing petroleum coke combustion, by transferring dry combustion ash, containing anhydrous calcium sulfate and resultant lime to a pneumatic tanker, transferring the tanker with the ash to a storage site, and discharging the dry ash through a mixing pump onto the storage site while adding sufficient water to hydrate anhydrous calcium sulfate and resultant lime in the ash and provide about 7-25 percent by weight excess water in the ash.

Abstract: A horizontal wet scrubbing apparatus and method for removing sulfur dioxide from hot flue gases. The apparatus has a horizontally disposed housing through which the hot flue gases are passed, and at least one liquid injection manifold vertically disposed therein and extending to adjacent a lower wall of the housing for directing an aqueous scrubbing medium parallel to the gas flow, and a flow deflection member adjacent to, and downstream from, the manifold. Aqueous scrubbing medium is collected in reservoirs at the lower wall of the housing and recycled to the injection manifolds. The method provides for injection of aqueous scrubbing medium parallel to the flue gas flow and deflection of the gases, following the injection, by use of packing or baffles to provide intimate contact of the scrubbing medium with the gaseous stream.

Abstract: Sulfur dioxide is removed from a gaseous stream using an aqueous scrubbing medium containing calcium components and magnesium ions, so as to produce a more readily dewatered aqueous calcium sulfite-containing sludge by providing in the aqueous scrubbing medium in an aqueous scrubbing unit an effective amount of at least one amine sulfonate ion of the formula: ##STR1## where R is H or OH, and R' is H or SO.sub.3, with R and R' not both being H. The amine sulfonate ion is preferably provided by adding an amine disulfonate salt having the formula HN(SO.sub.3 X).sub.2 or a hydroxylamine monosulfonate salt having the formula HO--NH--(SO.sub.3 X), when X is an alkali or alkaline earth metal. Or an effluent stream from a scrubbing unit for nitrogen oxides containing a metal chelate and an amine sulfonate may be added to provide the amine sulfonate ion.

Abstract: A process for calcining limestone to lime to produce a low sulfur content lime product, while combusting a sulfur-containing carbonaceous fuel in a rotary kiln to provide heat for the calcination. A finely divided lime hydrate is added to the rotary kiln adjacent the combustion flame, such that the lime hydrate particles react with sulfur-containing contaminants in the hot combustion gases to form lime hydrate-sulfur reaction products, such as calcium sulfate, which are retained in the gaseous flow and removed from the rotary kiln.

Abstract: A compact lime slaker has an inner vessel forming an initial slaking chamber disposed in an outer vessel forming a final slaking chamber, with agitators provided in both chambers. Slaked lime-from the final slaking chamber is pumped to a collection trough where slaked lime and grit are removed therefrom, while a major portion of slaked lime, with grit removed is returned to the final slaking chamber. The slaked lime in the final slaking chamber, at an elevated temperature due to the slaking exotherm, insulates the lime being slaked in the initial slaking chamber and provides heat thereto to aid in the initial slaking. Removal of grit from the portion of slaked lime recycled to the final slaking chamber prevents clogging or attrition of components of the slaker.

Abstract: A method is provided for removing sulfur dioxide from a hot gaseous stream while directly producing .alpha.-hemihydrate gypsum from a scrubber effluent. A portion of an aqueous scrubbing medium containing calcium and magnesium sulfite is removed from a scrubbing unit and passed to a pressurized oxidation vessel where the sulfites are contacted with an oxidizing gas at an elevated temperature to convert calcium sulfite directly to .alpha.-hemihydrate gypsum and magnesium sulfite to magnesium sulfate. The .alpha.-hemihydrate is separated from the aqueous medium removed from the pressurized oxidation vessel.

Abstract: A wet scrubbing process for removing sulfur dioxide from combustion gases uses an aqueous slurry containing calcium components resulting from the slaking of lime, with the slaked lime formed by mixing lime with water containing a calcium sulfur-oxide salt. The presence of the calcium sulfur oxide salt in the slaking water results in a more easily dewatered sludge that is subsequently removed from the wet scrubbing system.