Sulfur dioxide uses for

Hydrogen sulfide is recovered from the scmbbing solution under vacuum, hence the name. It is then either oxidized with air and the sulfur dioxide used for making sulfuric acid, or converted to elemental sulfur by the Claus process. The process is suitable only for gases not containing ammonia. Developed by Krupp Koppers, Germany. Three units were being built in 1993. 

The addition of 20-30 mg/1 ascorbic acid prevents the formation of colloidal turbidity (called chill haze) in beer, and also prevents adverse changes in flavour due to the oxidation that occurs during pasteurisation and storage. The use of ascorbic acid in winemaking can reduce the amount of sulfur dioxide used for fumigation. 

A smaller but important use for sulfur dioxide is for stabilization of pulp (qv) brightness after hydrogen peroxide bleaching of mechanical pulps. Sulfur dioxide neutralizes the alkalinity and destroys any excess hydrogen peroxide, which if left in the pulp would cause it to lose brightness. 

The ancient process of stoving is stiU occasionally used to bleach wool and silk with sulfur dioxide. In this process, wet fabrics are hung in chambers of burning sulfur or sulfur dioxide gas for at least 8 h. The fabrics are then washed with sodium sulfite to remove excess sulfur dioxide. Fabric so treated may have unpleasant odors, and the original color eventually returns, but the process is simple and inexpensive. 

Cofiring biomass has environmental benefits in addition to lowering greenhouse gases. Since biomass has little or no sulfur, sulfur dioxide (SOj) emissions are less when biomass fuels are used. In the United States, power plants have allowable sulfur dioxide levels for each gigawatt of power produced. If they produce less than the allowable amount of sulfur dioxide, they receive credits with which they can trade on the open market. The price for these sulfur dioxide credits is about 70 to 200 per ton. 

When this is done, the calcium hydroxide is included in the melting furnace slag, and the unspent calcium carbide is either used or oxidized in the melting furnace. Little testing has been done to determine the actual fate of the sulfur. Most of it may be included in the slag, but it may also be emitted to the air as sulfur dioxide, or, for foundries with wet emission control systems, it may be dissolved in the water. 

Two Automated Methods for Measuring Trace Levels of Sulfur Dioxide Using Translation Reactions... 

The last one (6.2 g, 18.4 mmol) was converted into 3,4-dihydro-4-hydroxy-2-(2-methoxy)ethyl-2H-thieno[3,2-e]-l,2-thiazine-6-sulfonamide 1,1-dioxide (4.87 g, 77%) m.p. 187°C by using the reaction with n-butyl lithium in anhydrous THF at -40°C for 40 min, and then bubbling sulfur dioxide gas for 20 min after which time the mixture was warmed to room temperature. After 30 min at room temperature the mixture was concentrated the residue was dissolved in water, cooled (0°C), sodium acetate trihydrate was added followed by hydroxylamine-O-sulfonic acid. The reaction mixture was stirred at room temperature for 18 h after which time was basified with solid sodium bicarbonate and extracted with ethyl acetate. 

The sulfur dioxide problem for example can be solved in a number of ways. The easiest way is by the use of intermittent control systems. However, EPA and Congress refuse to approve of this method. As a result, the requirements for low sulfur coal are increased by ten times over what they would be if intermittent control systems were allowed. The insistance upon the use of scrubbers is going to increase the cost of electricity by billions of dollars per year—all to be paid by the ultimate customers. ... 

Example 9-2 Olson and Schuler determined reaction rates for the oxidation of sulfur dioxide, using a packed bed of platinum-on-alumina catalyst pellets. A differential reactor was employed, and the partial pressures as measured from bulk-stream compositions were corrected to fluid-phase values at the catalyst surface by the methods described in Chap. 10 (see Example 10-1). The total pressure was about 790 mm Hg. 

At the Ronnskar works of Boliden AB in Sweden, which include both a copper and a lead smelter, a cyclic process using water as the absorbent concentrates sulfur dioxide both to produce liquid sulfur dioxide and for feed to acid plants (20, 21). The process is reported to give an absorption efficiency of about 98% on gas containing 2% sulfur dioxide. Water is not normally a favorable solvent for such an application but can be used in this case because it is available at a low temperature, less than 5°C for most of the year. Recovery of sulfur dioxide from the complete smelter is to be increased from 90 to 95% by applying water-cooled collecting hoods and waste heat boilers to all the copper converters (20). 

Manocha and Bahl (1980) [198] state that during the stabilization of a copolymer in O2, dehydrogenation and polymerization occur simultaneously, whereas in air, dehydrogenation precedes polymerization. Bahl, Mathur and Kundra (1980) [199] used a sulfur dioxide atmosphere for stabilization. 

Polyamine sulfone n. A water-soluble copolymer of diallylamine monomer and sulfur dioxide, used as a paint additive, antistatic agent, synthetic-fiber modifier, and polishing agent for metal platings. 

Vas (1949) studied the kinetics of the addition of glucose and bisulfite under controlled conditions probably best suited for conclusions in fruit juice treatments with sulfur dioxide, using concentrations of glucose far in excess of the sulfur dioxide contents. For such conditions the system would be expected to behave in a pseudomonomolecular manner, since the proportion of change of glucose from beginning to end of the reaction would be very small. However, values for ki at 20° C. and ki at 20 C. 

Sulfonamide 114 can be considered the proper substrate for the key enantioselective carboamination step, where it has been treated with the Cu(II)-(/ )-Ph-Box ligand in the presence of Mn02 and PhCFa solvent to afford sultam 115 in moderate yield. After the removal of sulfur dioxide using Li metal, pyrrolidine product 116 was obtained. Product 116 after subsequent intramolecular C-N cyclization... 

To circumvent the use of highly toxic sulfur dioxide gas, Willis and coworkers explored amine-S02 complexes as sulfur dioxide surrogates. Willis demonstrated that l,4-diazabicyclo[2.2.2]octane (DABCO)-bis sulfur dioxide (DABSO, Figure 13.2) is a useful replacement for sulfur dioxide gas for the formation of sulfonamides from Grignard reagents (Scheme 13.15). DABSO is commercially available and may be prepared quantitatively from DABCO and sulfur dioxide. 

Example 4.4 Butadiene sulfone (or 3-sulfolene) is an intermediate used for the production of solvents. It can be produced from butadiene and sulfur dioxide according to the reaction ... 

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