Pulp production

Pulp production and per capita consumption of paper and board for 1992 is shown in Table 8. The United States, Canada, Sweden, Finland, and Norway make up the North American and Scandinavian (NORSCAN) countries and produced about 63% (22.8 million tons) of the world output. Market share is growing for producers in Latin and South America, Western Europe, Asia, and Africa. These areas provide low cost pulp from state-of-the-art mills. Mills in the third world countries often enjoy the benefits of plentiful, fast-growing tree species, such as eucalyptus and tropical pines, and lower operating and labor costs (3). 

The United States is the largest importer of pulp, in 1993 importing 5.5 million tons, principally bleached and semibleached kraft pulp. It is also the largest producer of pulp, paper, and aUied products. Table 9 shows U.S. pulp production for 1983—1992. 

The kraft process has become the dominant process for pulp production throughout the world, primarily because of the recovery of the pulping chemicals. A schematic diagram of the kraft pulping process, with the location of atmospheric emission sources, is shown in Fig. 6-11. 

I.4. Polyterpene resins. Terpene resins are obtained from natural terpene monomers obtained from naval stores, paper pulp production, and citrus juice production. Terpenes are found in almost all living plants, and the turpentine oil from pine trees is the most important source. 

In the pulp and paper industry, the main gas emissions are from the pulp production. The main sources of emission are in the soda recovery boiler, lime kiln, evaporation plant, and bark combustion boiler. 

Pulp production from recovered paper or paperboard without deinking processes to produce tissue, paperboard, molded products, and construction papers... 

Table 21.3 presents an overview of wood pulping types by the method of fiber separation, resultant fiber quality, and percent of 1998 U.S. pulp production.1112 Many mills perform multiple pulping processes at the same site, most frequently nondeink secondary fiber pulping and paper-grade kraft... 

Process Category Fiber Separation Method Fiber Quality Examples % of Total 1998 U.S. Wood Pulp Production... 

Semichemical pulping comprised 6% of U.S. pulp production in 1993.1 Semichemical pulp is often very stiff, making this process common in corrugated container manufacture. This process primarily uses hardwood as furnish. 

Mechanical pulping accounted for 9% of U.S. pulp production in 2000.1 Mechanically produced pulp is of low strength and quality. Such pulps are used principally for newsprint and other nonpermanent paper goods. Mechanical pulping uses physical pressures instead of chemicals to separate furnish fibers. The processes include the following ... 

U.S. Department of Energy, Forest Products Project Fact Sheet Closed-Cycle Bleach Kraft Pulp Production, Office of Industrial Technologies, Washington, October 2000. 

Alliance for Environmental Technology, Trends in World Bleached Chemical Pulp Production 1990-2000, January 2001. Available at http //www.aet.org/reports/market/aet trends 2000.html. 

Marttila et al. (1995) also examined the relationship between daily exposure to malodorous sulfur compounds (measured as total reduced sulfur [TRS]) from pulp production and experience of symptoms in a small population living in the vicinity of a pulp mill. The major components of the malodorous sulfur compounds are hydrogen sulfide, methyl mercaptan, and methyl sulfides. This work was initiated due to the observation that an unusually high short-term exposure to malodorous sulfur compounds (maximum 4-hour concentrations of hydrogen sulfide at 135 g/m3 [96 ppb]) led to a considerable increase in the occurrence of ocular, respiratory, and neuropsychological symptoms (Haahtela et al. 

Pulp production enzymes, 10 304-305 Pulp stabilization, sulfur dioxide in, 23 667 Pulpstone grinding wheels, 1 19 Pulp, sugar beet, 23 458 Pulpwood species, 21 2t properties of, 21 3t... 

Year World pulp production from virgin fibre (million tonnes) World paper and board consumption (million tonnes) Recycled fibre usage (million tonnes) Recycled fibre usage (%)... 

Table 1.3 World-wide hardwood, softwood and non-wood pulp production (1988).

These pressures have worked their way through the chain and now we have no chlorine consumption in pulp production in Europe and a much diminished consumption of chlorine in the HFC precursors. In addition the solvents sector saw a reduction in the demand for chlorine as many solvent applications changed. 

Wood chips are processed in mild chemical liquor and subjected to mechanical refining using disc refiners. Semichemical pulping liquors have variable composition ranging from sodium hydroxide alone, alkaline sulfite (sodium sulfite - - sodium carbonate), mixtures of sodium hydroxide and sodium carbonate, to Kraft green or white liquors [3]. Sodium sulfite/ sodium carbonate liquor is most commonly used and the pulp product obtained thereafter is referred to as neutral sulfite semichemical (NSSC) pulp. 

PULP (Wood) PRODUCTION AND PROCESSING. Pulps can be defined as fibrous products derived from cellulosic fiber-contaiumg materials and used in the production of hardboard, fiberboard, paperboard, paper, and molded-pulp products. With suitable chemical modification, pulps can be used in Hie manufacture of rayon, cellulose acetate, and other familiar products. Pulps can be produced from any material containing cellulosic fiber but in North America and several other regions of the world, wood is the predominant source of pulp. This description is confined to the production and processing of wood pulp,... 

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