Pulp Bleaching Process

Titanium is being employed in the bleaching industry where the good corrosion resistance of the material makes it particularly suitable for equipment in both textile and paper pulp bleaching processes. In the dye-stuffs industry, the inertness of titanium eliminates any products of corrosion which might cause discoloration of the products. A similar situation can also exist in areas like the plastics, pharmaceuticals, and food-stuffs industries. 

New Chemistry, Including Pulp Bleaching Processes, of the Golden-Aged, Water-Soluble Compound, Tris(hydroxymethyl)phosphine... 

Acedox [Acetic oxidation] A pulp-bleaching process using peracetic acid as the oxidant. Developed by Eka Nobel in 1994 and first commercialized, in combination with Lignox, in Sweden in 1995. 

AhlStage [Ahlstrom stage] A pulp-bleaching process that economizes on oxidizing agents by first destroying hexenuronic acid derivatives that would otherwise consume them. They are destroyed by hydrolysis with dilute sulfuric acid. Developed by Ahlstrom Machinery Corporation, Finland, in 1996. 

DegOX [Degussa oxidation] A pulp-bleaching process developed by Degussa. The active species is peroxomonosulfuric acid (Caro s acid). The first full-scale commercial trial was held in 1994. 

ECF [Elemental chlorine free] A generic term for pulp-bleaching processes which use chlorine dioxide and other oxidants in place of elemental chlorine. See also TCF. 

EnZone [Enzyme ozone] A pulp bleaching process using the enzyme xylanase in combination with oxygen, ozone, and hydrogen peroxide. Invented by K.-E. L. Eriksson at the University of Georgia and piloted in 1998. 

GreenOx A pulp-bleaching process developed by Kemira in Finland. 

Lignox [Lignin oxidation] A pulp-bleaching process using hydrogen peroxide as the oxidant, and a chelating agent. Developed in Sweden in 1990 by Eka Nobel. See also Acetox. 

Macrox A pulp-bleaching process using hydrogen peroxide. 

Oxypro (2) A family of pulp-bleaching processes developed by Air Products and Chemicals. Piloted in 1995 at Pittsfield, MA. Oxypro 0R is for processing mixed office waste papers it uses molecular oxygen, optionally hydrogen peroxide, sodium hydroxide, and a stabilizer. First commercialized in Scotland in 1994. 

Prenox A pulp-bleaching process using nitrogen dioxide and oxygen instead of chlorine. Developed by AGA, Sweden. 

Sapoxal A pulp-bleaching process used in the paper industry. The bleaching agent is oxygen and the process is operated under alkaline conditions. 

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). 

Solv-X A pulp-bleaching process which prevents the transition-metal catalyzed side reactions of hydrogen peroxide which would otherwise occur. 

SRP [Sulfonation-Reduction-Peroxide] A pulp-bleaching process which combines reduction with sodium borohydride and oxidation with hydrogen peroxide. Developed by Atochem in 1991 and licensed to Morton International, Chicago. 

Figure 1 Steps involved in the pulping and pulp bleaching processes (from Ref. 2).

Fig. 6.18. Wood pulp bleaching process usingTAML activators and hydrogen peroxide.

Green liquor A papermaking process that uses a mixture of sodium hydroxide and sodium carbonate. GreenOx A pulp-bleaching process developed by Kemira in Finland. 

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