Mechanical pulping process effect

The compressors to be covered in this book are those using mechanical motion to effect the compression. These types of compressors are commonly used in the process and gas transport/distribution industries. A partial list of these industries includes chemical, petrochemical, refinery, pulp and paper, and utilities. A few typical applications are air separation, vapor extraction, refrigeration, steam recompression, process and plant air. 

There are a number of full-scale activated sludge plants that are in operation in countries such as the United States, Canada, and Finland, which treat effluents from Kraft, sulfite, TMP, CTMP, and newsprint mills [22]. SchneU et al. [70] reported the effectiveness of a conventional activated sludge process operating at an alkaline-peroxide mechanical pulping (APMP) plant at Malette Quebec, Canada. The full-scale plant achieved 74% reduction in filterable COD and nearly complete elimination of BOD5, resin acids, and fatty acids in the whole mill effluent. The treated effluent tested nontoxic as measured by a Microtox assay. Saunamaki [71] reported... 

The degradation of o -D-glucose at 419K initiated by irradiation at doses of 2-10 Mrad proceeds by a chain mechanism to yield carbonyl compounds. A study of the effect of nitrates, phosphites, chlorides, and sulphates of polyvalent cations on the rate of degradation of D-glucose by sulphur dioxide solution (simulating the pulping process of wood) has shown that they all... 

Investigations of variation in fiber began some years ago. Using polymeric isocyanate treatment, Maldas, Kokta, and Daneault reported the differences in mechanical properties between aspen, spruce, and birch, and between sawdust, cotton fiber, and fiber from paper pulp processing." Typically, aspen and birch provided better properties than softwood spruce. At 30 percent loading, the highest modulus at 1 percent strain was found with two types of treated pulp, followed by cotton fiber, and then treated sawdust. The effects of isocyanate treatment were more dramatic with sawdust. 

Caro s acid is effective ia delignifying wood pulp (qv) made by chlorine-free bleaching sequences. When conditions are carefully controlled, the mechanical properties of the final paper (qv) are not impaired. These processes were developed ia the 1980s and commercialized ia the 1990s (68). 

Mechanism of Anthraquinone Acceleration. The mechanism for the dual function of AQ has been the subject of much research (29). Anthraquinone is an effective pulping accelerator in very small quantities and functions as a catalyst in the process. It is generally accepted that AQ functions in a complex redox sequence. 

High-yield chemical pulps can be produced by the soda, kraft, or sulfite processes, in which chemical use and digestion time and/or temperature are suitably reduced to effect a milder cook than used for full chemical pulps. Mechanical defibrators are used to complete the separation of wood fibers not accomplished by the chemical action... 

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