Organic acid solutions, sulfite oxidation

Current processes for the manufacture of trinitrotoluene (TNT) produce atmospheric and water pollution that is only partly relieved by mechanical clean-up methods. TNT is currently produced from toluene by successive mono-, di-, and trinitrations with mixed aqueous nitric and sulfuric acids in the first two steps and anhydrous mixed acid in the last. Each stage in the current process is conducted at elevated temperatures, and side reactions in the overall process directly produce thousands of pounds of oxides of nitrogen, sulfuric acid aerosols, and volatile nitro organic products (such as tetranitromethane and nitroaro-matics). These pollutants derive from the thermal decomposition of the aqueous nitric acid solutions, from oxidative side reactions that produce as many as 40 by-product compounds, and from formation of unsymmetrlcal "meta" Isomers. Since symmetrical TNT is inevitably accompanied by meta isomers as well as oxidation products, the crude material is treated with sodium sulfite solutions to remove the undesirable Isomers and nitroaromatics by derivatization. The spent sulfite solution, known as "red water, is then disposed of by combustion to an inorganic ash. Itself a disposal problem. 

A considerable amount of work has been done on the oxidation of sulfite and bisulfite anions in aqueous solutions (25). In this paper the discussion is limited to oxidation of calcium sulfite (9), which has received much less attention than oxidation of sodium salts. The attention here is on the oxidation of calcium sulfite, catalyzed by metal ions in the presence of organic acid buffers, occuring in solid-liquid-gas slurry reactors. The organic acid buffers not only moderate pH changes during the reaction, but also inhibit the rate of chemical reaction (10). 

DISODIUM SULFITE (7757-83-7) React with water, steam, or acids, forming corrosive acid solution and sulfur oxide fumes. Incompatible with oxidizers, lead diacetate, mercury(I) chloride, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, organic anhydrides, isocyanates, vinyl acetate. 

There are four sources for the anions contained in this solution. Chloride, nitrate, and fluoride usually originate from the production water, sulfate and sulfite are oxidation products of endogenous sulfur, thiosulfate is formed as a product of the reaction of H2S with cyanide, and organic acids are products of the thermal degradation of MDEA. The extremely high retention time for thiosulfate of... 

Biphasic basic oxidation using technical grade (50-60%) 3-chloroperbenzoic acid affords this oxaziridine in - 4 hr In a 2-L, three-necked, Morton-flask equipped with a mechanical stirrer was placed 22.6 g (0.083 mol) of crude (+)-[(7,7-dimethoxycamphoryl)sulfonyl]imine, 42.6 g (0.13 mol) of 3-chloroperoxybenzoic acid (50-60%) in 450 mL of methylene chloride, and 450 mL of saturated potassium carbonate solution. The reaction mixture was stirred vigorously until the oxidation was complete as indicated by TLC (Note 27) at which time 500 mL of water was added, the organic layer was separated and the aqueous layer was extracted with methylene chloride (2 x 500 mL). The combined organic extracts were washed with saturated sodium sulfite (300 mL) and water (300 mL), and dried over anhydrous magnesium sulfate. 

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