Mathieson process

Sulfur Dioxide Reductant. The Mathieson process uses sulfur dioxide, sodium chlorate, and sulfuric acid to produce chlorine dioxide gas with a much lower chlorine content. The sulfur dioxide gas reductant is oxidized to make sulfuric acid, reducing the overall acid requirement of the process. Air is used to dilute the chlorine dioxide produced by this process. The exit gases flow through a scmbber to which chlorate is added in order to remove any unreacted sulfur dioxide. Spent Hquor, containing some unreacted chlorate, sulfuric acid, and sodium sulfate, continuously overflows from this process. 

Small amounts of chlorine, amounting from 1 to 5% of the chlorine dioxide, ate present in the chlorine dioxide gas product from the Mathieson process. The purity of the chlorine dioxide gas can be increased at the expense of higher chlorate content in the spent Hquor if NaCl is not used in the reactor and a small amount of sulfur dioxide gas is present in the generator chlorine dioxide product gas stream. 

Exit gases from the Mathieson process are passed through a scrubber to remove any unreacted sulfur dioxide. The Solvay process uses sodium chlorate and sulfuric acid, with methanol as the reducing agent. Products from this process are chlorine dioxide, formic acid, and carbon dioxide. In improved Solvay processes, sulfuric acid demand is reduced by crystallizing out the by-products sodium sulfate, sodium sesquisulfate, or sodium bisulfate (Kaczur and Cawlfield 1993 Vogt et al. 1986). 

A process based on a nickel catalyst, either supported or Raney type, is described ia Olin Mathieson patents (26,27). The reduction is carried out ia a continuous stirred tank reactor with a concentric filter element built iato the reactor so that the catalyst remains ia the reaction 2one. Methanol is used as a solvent. Reaction conditions are 2.4—3.5 MPa (350—500 psi), 120—140°C. Keeping the catalyst iaside the reactor iacreases catalyst lifetime by maintaining a hydrogen atmosphere on its surface at all times and minimises handling losses. Periodic cleaning of the filter element is required. 

Chlorine dioxide, discovered in 1811 by Davy, was prepared from the reaction of potassium chlorate with hydrochloric acid. Early experimentation showed that chlorine dioxide exhibited strong oxidizing and bleaching properties. In the 1930s, the Mathieson Alkali Works developed the first commercial process for preparing chlorine dioxide from sodium chlorate. By 1939, sodium chlorite was established as a commercial product for the generation of chlorine dioxide. 

Dihydrostreptomycin sulfate may be prepared from streptomycin sulfate by catalytic hydrogenation (Merck, Pfizer, Cyanamid), electrolytic reduction (Schenley, Olin Mathieson), or by sodium boro hydride reduction (Bristol), or by isolation from a fermentation process (Takeda). 

Cominco [Consolidated Mining Smelting Company] A process for absorbing sulfur dioxide from smelting operations. The sulfur dioxide is absorbed in an aqueous solution of ammonium sulfite regeneration is by acidification with sulfuric acid. The ammonium sulfate byproduct is sold. Operated at the Cominco smelter at Trail, Canada, and at other smelters and sulfuric acid plants in the United States. Licensed by the Olin Mathieson Corporation. The name has been applied also to a lead extraction process. 

Mathieson (1) A process for making chlorine dioxide gas by passing sulfur dioxide, diluted with air, into aqueous sodium chlorate and sulfuric acid. The product is absorbed in water. Operated in the United States on a large scale for pulp-bleaching. 

Mathieson (2) A process for making calcium hypochlorite dihydrate by mixing sodium hypochlorite and calcium chloride. Invented by A. George and R. B. MacMullin at the Mathieson Alkali Works, New York, in the 1920s. See also Perchloron. 

Perchloron A process for making calcium hypochlorite, similar to the Mathieson (2) process but using more chlorine and yielding a more readily filterable material. Developed by the Pennsylvania Salt Manufacturing Company. The name is also used in Germany as a product name for calcium hypochlorite. 

Solvay (2) A pulp-bleaching process using chlorine dioxide, generated by reducing sodium chlorate with methanol. In 1962, 20 paper mills in the United States were using this process. See also Mathieson (1). 

Warmuth, M.K., Liao, )., Ratsch, G., Mathieson, M., and Purr A, S. Active learning with support vector machines in the drug discovery process./. Chem. Inf. Comput. Sci. 2003, 43, 667-673. 

The process for the manuf of this proplnt was developed ca 1935 by Fred 01sen,Director of Research, Western Cartridge Co, Division of Olin Industries,Inc(now called Olin Mathieson Chemical Corp),East Alton,111. The process bears little resemblance to conventional methods of manufg proplnts and results in a product that is unique in the expls industry. The proplnt consists of small spheres, not target than 0.030 in diam. Ellipsoids can be obtained by flattening the spheres by mechanical devices Manuf of ball proplnt consists essentially of the following operations, as described in Refs 1-4 ... 

Warmuth MK, Rasch G, Mathieson M, Liao J, Lemmen C. Active learning in the drug discovery process. In Dietterich TG, Becher S and Ghahramani Z, editors. Advances in Neural Information Processing Systems 2002 14 1449-56. 

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