Sugarcane bagasse was delignified with alkali and peracetic acid in a two-stage process to obtain pulps with high yield and low kappa number. The experimental results indicated that alkali pretreatment prior to peracetic acid (PAA) delignification could significantly reduce PAA loading by partially removing lignin and swelling the fibers. An optimum condition for the two-stage delignification w...

The perspective of the article is to explore kraft cooking at the limits of delignification, i.e. what degree of delignification is needed to obtain fibre liberation and what is the maximum degree of delignification possible in the kraft pulping stage. The reasons for the quite narrow boundaries for sufficient and maximum delignification are explained, and the differences between the behaviour ...

This paper describes our efforts focused at defining the formation of diphenylmethane moieties in lignin during conventional kraft and soda pulping conditions. This objective was realized by confirming, initially, the assignment of a P NMR signal as being due exclusively to the presence of phosphitylated diphenylmethane (DPM) phenolic hydroxyl groups. More specifically, softwood milled wood lig...

A biorefinery using the process of hemicellulose pre-extraction and subsequent pulping provides a promising way for the utilization of straw biomass and resolution of problems related to silicon. In this work, hemicellulose was extracted from depithed corn stover with sodium hydroxide solution before soda-AQ pulping. Components of the extracts were quantified by ion chromatography. The paramete...

We evaluated lignin profiles and pulping performances of 2-year-old transgenic poplar (Populus tremula x Populus alba) lines severely altered in the expression of caffeic acid/5-hydroxyferulic acid O-methyltransferase (COMT) or cinnamyl alcohol dehydrogenase (CAD). Transgenic poplars with CAD or COMT antisense constructs showed growth similar to control trees. CAD down-regulated poplars display...

Alkali ratios and cooking time of the alkaline sulfite anthraquinone (AQ) and methanol (ASAM) pulping process of bamboo (Gigantochloa scortechinii) were studied. Bamboo chips were cooked at three different levels of sodium hydroxide and cooking time, namely 14, 16, or 18% for 60, 90, or 120 minutes. Pulping parameters that remained constant were the use of 0.5% ethylene diamine tetraacetic acid...