The objective of this study was to evaluate different pretreatment methods prior to oxygen delignification on extractives removal and O-delignification selectivity. Four different pretreatment methods were used including ultrasonic treatment, hot water soaking, soda addition-preheating, and applying a high-shear mechanical pretretament. Acacia mangium and mixed hardwood (MHW) kraft pulps were u...

We develop a general framework to prove Krafttype inequalities for prefix-free permutation codes for source coding with various notions of permutation code and prefix. We also show that the McMillan-type converse theorem in most of these cases does not hold, and give a general form of a counterexample. Our approach is more general and works for other structures besides permutation codes. The cl...

Kraft lignin (KL) was thermally treated at 500 to 1000 °C in an inert atmosphere. Carbon nanostructure parameters of thermally treated KL in terms of amorphous carbon fraction, aromaticity, and carbon nanocrystallites lateral size (La), thickness (Lc), and interlayer space (d002) were analyzed quantitatively using X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron ...

An integrated picture of the distribution of functional groups should be provided as a function of molecular size within residual kraft lignins. With this goal we developed a reliable and reproducible method for determination of the molecular weight and molecular weight distribution of residual kraft lignins (RKLs) over the whole delignification range. In general, our data indicate that for rel...

The effect of hardwood admixture (15-25% birch or aspen) in kraft cooking on the strength properties of the fully bleached pulp was investigated. Results obtained from both laband mill-processed ECF bleached pulps showed that adding 15-25% birch or aspen to the production of fully bleached softwood kraft pulp had a minor effect on the strength properties. No significant effect was observed for ...

In this study, several kraft pulps were produced by kraft pulping of fastgrowing Eucalyptus with a wide range of cooking conditions. The dependences between pulp yields and some pulp properties, namely, kappa number, HexA contents, and cellulose viscosities, were well investigated. It was found that kraft pulp yields linearly decreased with the reduction of HexA-free kappa number in two differe...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Hanna Hörhammer Name of the doctoral dissertation A larch biorefinery producing pulp and lactic acid Publisher School of Chemical Technology Unit Department of Forest Products Technology Series Aalto University publication series DOCTORAL DISSERTATIONS 143/2014 Field of research Biorefineries Manuscript submitted 6 June 2014 D...