Chemical Pulping of Steam‐Exploded Mixed Hardwood Chips

Abstract

We determined the pulping yields for steam-exploded and untreated mixed hardwood chips for kraft pulping processes with and without anthraquinone and/or polysulphide. The pulp yield from steam-exploded chips was 1 -3% lower than from untreated chips under similar conditions. The benefit of kraft pulping with anthraquinone and/or polysulphide was found to be more pronounced for the exploded chips than for the untreated chips.

Biobleaching of Eucalyptus globulus kraft pulps: Comparison between pulps obtained from exploded and non-exploded chips

“…Also, recent reports have shown that the cooking liquor diffuses more freely into the open structure of exploded chips which leads to easier and shorter kraft pulping (Ahvazi et al, 2007;Martin-Sampedro et al, 2010). Moreover, hemicelluloses removed during the steam explosion pre-treatment can be further converted into value-added products such as ethanol, polymers and other chemicals (Li et al, 2010).…”

Integration of kraft pulping on a forest biorefinery by the addition of a steam explosion pretreatment

“…From all these results, it can be concluded that, under the same cooking conditions, the steam exploded chips cooked faster and more efficiently than the untreated chips, or alternatively, they could be pulped at a lower temperature and/or with lower active alkali, while maintaining the same production rate (Ahvazi et al 2007;San Martin 1995;Wafa Al-Dajani et al 2009). With the first option, the cooking time could be reduced, increasing the production rate of the pulp mill.…”

“…The most common commercial procedure for extracting hemicelluloses is pre-steaming to release natural wood acids (autohydrolysis) followed by water extraction or acid hydrolysis with small amounts of mineral acids (sulfuric acid or hydrochloric acid). Compared to these processes, steam explosion not only allows the recovery of wood components without their degradation (Avellar and Glasser 1998;Britt 1970), but also leaves a solid residue (exploded chips) that is expected to be pulped more easily than those obtained conventionally due to the open structure of the exploded chips that might encourage an efficient diffusion of cooking liquor into the fibers (Ahvazi et al 2007). Therefore, taking into account the advantages of the steam explosion pretreatment, it can be concluded that this process could be used as an efficient pretreatment in pulping, increasing the total revenue stream for the pulp industry and converting the pulp mill into an integrated forest biorefinery (Ragauskas et al 2006;Van Heiningen 2006).…”

“…Although some studies have assessed the pre-extraction of hemicelluloses before kraft pulping (Li et al 2010;Wafa Al-Dajani et al 2009;San Martin et al 1995;Ahvazi et al 2007), few of them have evaluated the potential of steam explosion to this end. Therefore, deeper research would be needed to evaluate not only the effect of steam explosion pretreatment on kraft pulping, but also the potential recovery of sugars from the liquid fraction generated during this pretreatment.…”

Enzymatic hydrolysis of steam-exploded sugarcane bagasse by adding natural Sapindus peel

“…2) were investigated. It has been suggested that the increased porosity and the removal of hemicelluloses increase the accessibility of the pre-treated material (Ahvazi et al 2007;Yang et al 2004). As it can be observed, higher hydrolysis yields were obtained after steam pre-treatment compared to steam explosion pre-treatments.…”