Several additives have been used in research and on an
industrial scale to improve the pulp yield and to increase
the rate of delignification. One such additive is 1,4-
dihydro- 9,10-dihydroxyanthracene (DDA), also called soluble
anthraquinone. This chemical is widely used in Japan and
some other countries, especially with the...
Douglas-fir wood chips from Oregon were pulped with kraft
green liquor to produce semi-chemical pulps with properties suitable
for the manufacture of corrugating medium. The effects of five cooking
variables were studied, chemical charge, chip size, bark content
of chips, pulping temperature, and liquor sulfidity. The combinations
of levels of...
Non-process elements are present in all kraft
recovery systems. Non-process elements are defined as
those elements which are not essential to the chemical
process, i.e., are neither active pulping chemicals (e.g.,
NaOH and Na₂S in the kraft process), nor compounds present
as a result of incomplete conversion of makeup chemicals...
Fume, sub-micron aerosal particles in the combustion gases, have been identified
as a cause of extensive plugging and fouling in the heat transfer section of a kraft
recovery boiler in kraft pulp mills. After the deposition on the heat transfer surface,
fume deposits will undergo the sintering process which causes...
Production of dry particles made of titanium dioxide powder and black liquor is
the first step in a newly proposed black liquor treatment process (Frederick et. al., 1992).
This work investigates the granulation processes in a fluidized bed granulator of titanium
dioxide and black liquor. Experiments are performed in a...
Most metal ions have negative impacts on pulp mill operations. The concentrations of metal ions on pulp fibers and in washwaters rise significantly with increased wastewater recycling. The development of technology to remove these metal ions requires an understanding of how metal ions are bound to pulp components. It is...
A survey of the pulping literature indicated
that although the kinetics of the Kraft Pulping
process has been studied in detail , very few studies
have been reported for Alkaline Sulfite /
Anthraquinone (ASAQ) pulping process. There is no
existing rate model for this pulping process. Hence,
the objectives of...
Semi chemical pulping processes, using both acid and neutral sulfite liquors, were ap!)lied to the following six Arkansas Delta hardwoods: black willow, southern cottonwood, American elm, sugarberry, green ash, and bitter pecan. Pulping conditions for yields of 75 to 80 percent were determined and the properties of both the pulps...
Parallel solutions for two classes of linear programs are
presented. First we parallelized the two-phase revised simplex
algorithm and showed that it is possible to get linear improvement in
performance. The simplex algorithm is the best known algorithm for
solving linear programs, and we claim our result is the best...
This work is part of a larger project dealing with
nonprocess element (NPE) behaviour in chemical pulping
processes. Nonprocess elements are defined as those
elements which are not essential to the chemical
process, i.e. are neither active pulping chemicals
(e.g., NaOH and Na2S in the kraft process), nor
compounds present...