Modeling the absorption of SO2 in a spray scrubber using the penetration theory

Adsorption of SOx by oxide materials: A review

In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m–3), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5–6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca2+. In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very...

Sulfate Formation Enhanced by a Cocktail of High NOx, SO2, Particulate Matter, and Droplet pH during Haze-Fog Events in Megacities in China: An Observation-Based Modeling Investigation.

Evaporite mineral solution mining process and apparatus comprising the steps of undercutting a bed or massive deposit by in-air jetting with an aqueous solution followed by solution mining of the mineral above the undercut with monitoring and control to cease the solution mining when the roof rock is adequately exposed to maintain a stable roof and stable pillar support. The resulting cavity exhibits steeply angled, nearly vertical sidewalls, flared upwardly and outwardly only 10° to 15° from the vertical plane normal to the edges of the undercut as compared to 45° typical for morning glory cavities. A first plan vertical production well is drilled with a sump provided substantially adjacent to the floor rock. A second horizontal well is developed up dip to intersect and communicate with the production well. The air jet tool mechanism provides horizontal, slightly upwardly inclined jets (0°-15°) which cut the mineral laterally on both sides of the tool which is gradually withdrawn up dip as the undercut progresses. The tool also includes and EMR ranging system, preferably a radar system, and a MWD unit to transmit data to the surface. This permits undercut width control to develop a substantially rectangular undercut profile. The subsequent controlled solution mining provides a substantially rectangular room throughout the entire horizontal length which provides improved mineral recovery, steeply angled pillar wall profiles controlled roof span and increased dissolution rate. The method and apparatus is applicable to beds having dips from 0°-90° and multiple beds with or without partings.

Method and apparatus for solution mining

The present invention generally relates to the field of pharmaceutical sciences. More specifically, the present invention includes apparatus and devices for the preparation of pharmaceutical formulations containing large diameter synthetic membrane vesicles, such as multivesicular liposomes, methods for preparing such formulations, and the use of specific formulations for therapeutic treatment of subjects in need thereof. Formation and use of the pharmaceutical formulations containing large diameter synthetic membrane vesicles produced by using the apparatus and devices for therapeutic treatment of subjects in need thereof is also contemplated.

Method for formulating large diameter synthetic membrane vesicles

Method for disposal of water soluble sodium sulfur oxide-containing wastes resulting from industrial processes producing fly and/or bottom ash from fossil fuel utilization and waste or excess sodium sulfur oxide compounds, particularly disposal of sodium sulfite and/or sodium sulfate resulting from wet or dry sodium alkali scrubbing of tail or flue gases to reduce SO x emissions therefrom as from smelters, power plants, paper plants, glass plants and industrial boiler operations Process involves mixing sodium sulfur oxide wastes with an alumina and silica-containing fly ash and/or bottom ash, forming an agglomerate, such as a pellet or briquette, and sintering in the range of about (1000°-2300°F) The resultant sintered particle shows lower solubility than the current standard of calcium sulfate, being 10sup -2 to 10sup -4 as soluble as the starting sodium sulfur oxides, has increased density (as high as 23 g/l), and reduced volume as compared to the dry fly ash or sodium sulfur oxide wastes, and fixes heavy metals Fly ash leaching and dusting problems are substantially overcome Sodium sulfur oxides include sodium sulfite, sulfate, bisulfite, bisulfate, thiosulfite, persulfite (pyrosulfite), thiosulfate, persulfate (pyrosulfate), and mixtures thereof Sintered particle may be disposed of by known landfill techniques, or used as an aggregate for mulch, road beds, concrete, asphalt or the like

Sodium sulfur oxides wastes disposal process

Improved combination wet absorber/spray-dry dry wastes collection air pollution control process and apparatus therefor, employing aqueous solutions of sodium or ammonium alkali sorbents injected in an absorber through which SO x -containing flue or process gases containing fly ash are passed. Fly ash is collected in the absorber wherein the alkali reacts with the SO x to form sodium and ammonium sulfur oxide salts liquor containing collected fly ash in slurry form, which is passed back upstream and injected into a spray dryer through which the gases pass. The heat of the gases in the spray dryer dries the slurry to a powder of salts and fly ash which is removed. The spray dryer simultaneously provides some added preliminary SO x removal.

Air pollution control process and apparatus

Process for insolubilizing water soluble wastes from alkaline sodium or ammonium type sulfur dioxide control systems used in conjunction with industrial or power plants. The sodium or ammonium sulfite or sulfate wastes are reacted in solution with ferric ions and sulfuric acid to produce an insoluble basic, hydrous or anhydrous, sodium and/or ammonium hydroxy ferric sulfate or sulfite compounds of the generic type Mv (Na, NH4)w Fex (SOu)y (OHz)nH2 O, wherein M is selected from an alkali metal other than sodium, or an authigenic metal or other cation present in industrial or power plant wastes, v is selected from zero to six, w is selected from zero to five, x is selected from zero to six, y is selected from one to five, u is 3 and/or 4, z is selected from zero to 12, and n is selected from zero to 20. Principal end product compounds include Natrojarosite, Ammoniojarosite, Metasideronatrite, Sideronatrite, Depegite, Rosarite, Iriite, and mixtures thereof. The reaction takes place at an acid pH in a temperature ranging from about 50°-300° F. and may occur in single or multi-stage reactors. Air and/or bacterial activation at a pH of less than about 5.5 may be employed. The end product basic, sodium and/or ammonium hydroxy ferric sulfate and sulfite compounds are water insoluble as compared to the standard in the industry, CaSO4, and may be disposed of by simple landfill without the water pollution hazards inherent with landfilling of wet or dry sodium or ammonium sulfite and/or sulfate baghouse or wet scrubber wastes. The process also uses, and conversely can dispose of, other pollutants as reactants, such as hot waste water from power plant ash tanks, waste sulfuric acid, pickle liquior, acid mine water (blackwater), iron slag or scrap, or gob or pyrite leachate as part of an integrated, multiple-pollutant disposal process.

Process for insolubilizing potentially water pollutable wastes from sodium or ammonium type sulfur dioxide air pollution control systems

Process for control of SOx emissions from copper smelter operations involving pyrometallurgical reduction of copper ores to elemental copper in which the gases from reverberatory furnaces, roasters, and/or converters are scrubbed with a sodium alkali sorbent to produce sodium sulfate and sulfite wastes. The cleaned flue gases are exhausted to the atmosphere. The waste sodium sulfate/sulfite material is then reacted with excess acid from the smelter acid plant and ferrous ion-rich barren solution from the associated cement copper operations to produce co-precipitated double salts of sodium ferric hydroxy-disulfates and/or sulfites (SFH), having low water solubility and being suitable for landfill type disposal without posing serious water pollution problems. This disposes of the sodium sulfite/sulfate waste materials from the air pollution control process and also strips the barren solution of iron prior to its recycle to heap or dump leaching operations. The reduction of ferrous iron concentrations in the recycle barren solution tends to reduce the opportunity for iron hydroxides to be formed in the dump thereby increasing production of copper from aqueous sulfuric acid type leaching operations.

Process for control of SOx emissions from copper smelter operations

Experiments were conducted to determine the influence of nitrogen oxides on the solid phase oxidation of sulfite to sulfate in slaked lime slurries from lime/limestone scrubbing systems. Nitric oxide is observed to act as an inhibitor and nitrogen dioxide as a promoter of the oxidation of sulfite. Nitric oxide present at the same concentration as nitrogen dioxide is unable to inhibit the oxidative influence of the latter. At a mole ratio of 12:1, the promotive action of nitrogen dioxide is offset, and the total oxidation is no greater than it would be without the presence of nitric oxide. Oxidation inhibition merits consideration as a way to avoid sulfate scaling in such scrubbing systems. (1 diagram, 1 graph, 6 references, 1 tables)

Harvey S. Rosenberg

Papers

Sodium sulfur oxides wastes disposal process

Air pollution control process and apparatus

Process for insolubilizing potentially water pollutable wastes from sodium or ammonium type sulfur dioxide air pollution control systems

Process for control of SOx emissions from copper smelter operations

Nitrogen oxides (NOx) influence on sulfite oxidation and scaling in lime/limestone flue gas desulfurization (FGD) systems.