Desulfurization processes, solution

The latter reaction has been studied numerous times because of its relevance for the autoxidation of hydrogen sulfide in seawater and other aqueous systems [112, 113]. 8ince the polysulfide ions can be further oxidized to elemental sulfur which precipitates from the solution, these reactions are the basis for several industrially important desulfurization processes (e.g., the 8tretford, 8ulfolin, Lo-Cat, 8ulFerox, and Bio-8R processes) [114] ... 

Shell s microbiological desulfurization process is carried out by mixing coal with an aqueous biocatalyst solution [158], The coal considered in this invention concerns bituminous coal containing inorganic sulfur (pyritic).This process seems to be applicable to refinery pet-coke, which contains sulfur in the form of inorganic sulfides. Nowadays, when coke has become one of the major products of heavy oil and bitumens refining, such desulfurization processes might have potential uses. 

CONOSOX A complex flue-gas desulfurization process using potassium carbonate solution as the wet scrubbing medium. The product potassium bisulfite is converted to potassium thiosulfate and then reduced with carbon monoxide to potassium carbonate for re-use. The sulfur is recovered as hydrogen sulfide, which is converted to elemental sulfur by the Claus process. Developed by the Conoco Coal Development Company and piloted in 1986. 

Dowa A flue-gas desulfurization process in which the sulfur dioxide is absorbed in a basic aluminum sulfate solution. The product solution is oxidized with air and reacted with limestone to produce gypsum. Developed by the Dowa Mining Company, Japan, in the early 1980s. In 1986 it was in use in nine plants in Japan and the United States. 

Dual Alkali A flue-gas desulfurization process. The sulfur dioxide is absorbed in aqueous sodium hydroxide and partially oxidized, and this liquor is then treated with calcium hydroxide to regenerate the scrubbing solution and precipitate calcium sulfate. Developed by Combustion Equipment Associates and Arthur D. Little. 

E-SOX A flue-gas desulfurization process. The gas is contacted with calcium hydroxide or sodium hydroxide solution in a spray drier, and the resulting particles are trapped in an elec-tostatic precipitator. Developed and piloted by the U.S. Environmental Protection Agency. 

Formate (2) A flue-gas desulfurization process. Potassium formate solution reduces the sulfur dioxide to thiosulfate, and then to hydrosulfide. 

Ionics A flue-gas desulfurization process using aqueous sodium hydroxide. The resulting sodium sulfate solution is electrolyzed to yield sodium hydroxide, sodium bisulfate, sulfuric acid, oxygen, and hydrogen. 

Ispra Mark 13A A flue-gas desulfurization process developed at the Joint Research Centre of the European Community at Ispra, Italy, from 1979. It uses a novel electrochemical method to regenerate the solution used for absorbing the sulfur dioxide. The products are concentrated sulfuric acid and hydrogen. The absorbent is a dilute aqueous solution of sulfuric and hydrobromic acids, containing a small amount of elemental bromine. Sulfur dioxide reacts with the bromine thus ... 

SOXAL A flue-gas desulfurization process, basically similar to the Wellman-Lord process but regenerating the bisulfite solution in a membrane electrochemical cell. Developed by Allied Signal Group and piloted at the Florida Power Light Company, Miami, FL, in 1991. A larger demonstration plant was planned for Dunkirk, New York. 

Solution Equilibria in Aqueous Flue Gas Desulfurization Processes... 

Cansolv A flue-gas desulfurization process based on the selective absorption of sulfur dioxide in a proprietary, thermally regenerable, organic amine-based solution. Developed by Union Carbide Corporation the first plant was originally planned for startup at Newburgh, IN, in 1994, although the process was abandoned in 1993. Now licensed by Cansolv Technologies Inc. See HS. 

Kurabo A flue-gas desulfurization process involving scrubbing with an acidic solution of ammonium sulfate. The product is gypsum. Used in Japan. 

The thermodynamic properties of gases, liquids, solids and aqueous solutes of interest for desulfurization processes are tabulated for temperatures from 298 K to temperatures as high as 1000 K when possible. Major emphasis has been placed on aqueous lime or limestone scrubbing, but the data can also be used for high temperature gas processes and for N0 processes. 

Limestone (CaCC>3) dissolution is an important phenomenon in stack gas desulfurization processes using limestone slurry to absorb SC>2 and produce CaSC>3/CaS04 waste solids (1). The rate of dissolution directly determines the need for excess limestone and interacts strongly with SC>2 removal and scale-free operation in the absorber. There is a need to know the dependence of dissolution rates on both solution composition and the type and grind of limestone. This paper presents a mass transfer model and... 

Sulfo and hydroxy carboxylic acids are attractive as buffer additives because the additional hydrophilic groups make both the buffer and its degradation products nonvolatile in aqueous solution. Keller (21) patented the use of sulfosuccinic acid in a flue gas desulfurization process using H2S regeneration. 

In the industrial practice of gas treating, removal of one or more components of a gas stream by means of a chemically rea tive liquid is almost always accompanied by a process which r generates the rich liquid solution by stripping out the absorbed gas. The only important exception is flue gas desulfurization, where, often the product of the reaction (usually calcium sulfite and sulfate) is simply disposed of as waste however, also for flue gas desulfurization processes where a regeneration step is inclu ed, such as the Wellman-Lord process, are in common industrial use. 

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