A. Keskin et Gj. Kubes, KINETICS OF NEUTRAL SULFITE SEMICHEMICAL AND NEUTRAL SULFITE SEMICHEMICAL-ANTHRAQUINONE PULPING, Journal of wood chemistry and technology, 14(1), 1994, pp. 103-117
Delignification rate expressions for neutral sulfite semichemical (NSS
C) and neutral sulfite semichemical anthraquinone (NSSC-AQ) pulping of
black spruce have been developed. The rates take into account the eff
ects of temperature and reaction times on the rates of delignification
. NSSC in this study is defined by an alkali ratio [sodium sulfite/(so
dium sulfite + sodium carbonate)] of 0.60 (expressed as sodium oxide)
giving a final pulp yield between 55 and 60 %. NSSC-AQ is identical to
NSSC with the addition of anthraquinone. Reaction temperature and pul
ping chemical concentrations were held essentially constant in all kin
etic experiments. Isothermal experiments were conducted in the tempera
ture range between 165 and 180-degrees-C. A concentration of 150 g/L s
odium sulfite with a liquor to wood ratio 62 were used.