In this study, Eucalyptus globulus stumpwood samples collected from six different sites in Portugal were evaluated for their ease of pulping, using two delignification processes (kraft and alkaline sulfite-anthraquinonemethanol (ASAM)). Morphologically, the stumpwood included fibers with a mean length of 0.930 mm, diameter of 21.4 μm, lumen width of 9.1 μm, and cell-wall thickness of 6.1 μm. Th...

Kraft lignin, a by-product of the pulp and paper industry, was explored as an adsorbent for six dietary oils and was compared to chitosan, which is widely used in the pharmaceutical market. The dissolution and adsorption efficiency of kraft lignin were tested at an acidic pH corresponding to the stomach, as well as at a basic pH corresponding to the intestine. Results showed that kraft lignin i...

Recent work by Biegler (8) has investigated optimization techniques for sequential, modular flow sheet simulators. This work extends that effort. Successive linear programming coupled with a reduced gradient method gave fast, reliable optimization. A kraft pulping process involving 22 modules and 50 streams was optimized. Compared to the base case, significantly improved operating points were l...

This review analyses the advances of pretreatment with sulfide-containing liquors to modify kraft pulping. In the past several decades, modified kraft pulping has advanced rapidly, based on the principle that high sulfide content at the first stage of cooking would improve both pulp quality and the selectivity of delignification. Pretreatment of wood chips with sulfide-containing liquors (i.e.b...

one of the solutions to increase the applications of lignin molecules is increasing reactive functional groups by chemical modification. adding reactive functional groups into the lignin structures is one the best proposed methods. the aim of this study was to investigate change in structure as well as glass transition temperature (tg) of soda and kraft lignins after hydroxymethylation them wit...

he Technical Association of the Pulp and Paper Industry (TAPPI) sponsored a Paper InT dustry Research Needs workshop at the State University of New York, College of Environmental Science and Forestry in Syracuse, New York, May 26-28,1992, The Pulping and Bleaching Processes Panel identified the major need in kraft black liquor recovery, namely, an affordable, incremental, chemical recovery capa...

The growing demand for rayon and cellulosic products has resulted in the conversion of a number of kraft pulp mills into dissolving pulp mills in recent years. In fact, kraft-based dissolving pulp production fits well into the concept of an integrated forest biorefinery, in particular, the utilization of dissolved organics in the pre-hydrolysis liquor (PHL) for bio-materials and bio-energy purp...

BACKGROUND Despite decades of work and billions of dollars of investments in laboratory and pilot plant projects, commercial production of cellulosic ethanol is only now beginning to emerge. Because of: (1)high technical risk coupled with; (2) high capital investment cost relative to ethanol product value, investors have not been able to justify moving forward with large scale projects on woody...

A new system has been developed for removal of chloride contamination from kraft process liquors. The compact, skid-mounted system which utilizes ion exchange columns only 24 inches in height, is shown to be capable of removing 90-99% of the chloride from a wide variety of sources including dissolved ESP catch, oxidized white liquor, spent bleach scrubber liquors, spent ion exchange demineraliz...

Adam Kraft, Albrecht Dürer’s contemporary in Nuremberg, worked the material of sandstone to provide a comparable experience carved relief about Passion Christ. Both artists began their work Nuremberg around same time, 1490, although older Kraft actually predeceased Dürer by two full decades (1508/1528). But both shared religious sentiment late-medieval art as having goal evoke pious emotions th...