Pulp and paper chemical

Cellulose is not only the most abundant organic substance available, it is a major component of woody plants and is constantly replaceable. Its conversion to paper products is the function of the pulp and paper industries, which manufacture thousands of useful items from cellulose. 

Before paper can be made from wood, the cellulose fibers must be freed from the matrix of lignin that cements them together. The fibers may be separated by mechanical procedures or by solution of the lignin by various chemicals. The pulp thus formed has its fibers recemented together to form paper when suitable additives are used. 

All processes used for pulping have the same goal, and that is the release the fibrous cellulose from its surrounding lignin while keeping the hemi-celluloses and celluloses intact, thereby increasing the yield of useful fibers. The fibers thus obtained are naturally colored and must be bleached before they can be used for paper. 

There are many processes and variations of basic processes that can be used for making pulp from wood. The major processes are the kraft process (also known as the sulfate process), the groundwood and thermomechanical process, semichemical process, and the sulfite process. The kraft process remains dominant. 

An essential factor in the kraft process has been the recovery of the spent liquor from the cooking process. The black liquor removed from the 

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Pulp and Paper Chemical and coatings preparation Stock dilution and consistency control Addition of bleaching chemicals... 

Hydrogen peroxide applications include commercial bleaching dye oxidation, the manufacture of organic and peroxide chemicals. Hydrogen peroxide is also used in pulp and paper chemical synthesis, textiles, and environmental control, including municipal and industrial water treatment. 

Regional Marketing Manager Pulp and Paper Chemicals, Connell Bros. Co. Ltd.,... 

In general, the solid solution austenitic phase (y) with high chromium content (12 % - 20 %) is responsible about the excellent corrosion performance of austenitic alloys. This advantage allows these alloys to use in biomedical, food and chemical, pulp and paper chemical, petrochemical, heat exchange and nuclear power plant industries [1-4], However, most of these applications are suffering from their relatively low hardness and poor tribological properties. 

Multicompartment dmm filters range in size from about 1 m to over 100 m they are widely used in mineral and chemical processing, in the pulp and paper industry, and in sewage and waste materials treatment. 

J. Casey, ed.. Pulp and Paper Chemistry and Chemical Technology, Vol. 1, 3rd ed., John Wiley Sons, Inc., New York, 1980. 

Lists of the manufacturers of each type of product used by the paper industry are available (6). Surveys of chemical suppHers for the U.S. and Canadian pulp and paper industries have been pubHshed (7). 

Sulfur, another inorganic petrochemical, is obtained by the oxidation of hydrogen sulfide 2H2S + O2 — 2H2 0 + 2S. Hydrogen sulfide is a constituent of natural gas and also of the majority of refinery gas streams, especially those off-gases from hydrodesulfurization processes. A majority of the sulfur is converted to sulfuric acid for the manufacture of fertilizers and other chemicals. Other uses for sulfur include the production of carbon disulfide, refined sulfur, and pulp and paper industry chemicals. 

Uses are estimated to be manufacture of hydrosulfites and other chemicals, 40% pulp and paper, 23% food and agriculture (mainly corn processing), 14% water and waste treatment, 9% metal and ore refining, 6% oil recovery and refining, 4% and miscellaneous, including sulfonation of oils and as a reducing agent or antioxidant, 4% (270,271). 

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