Ethanol‐water pulping: Cooking variables optimization

Abstract

The ethanol-based pulping of Eucalyptus globulus by the &CELL@ process was studied to determine the optimum cooking conditions. In the first set of experiments the influence of chip size, chip impregnation, liquor-to-wood ratio and cooking additives was studied. Once the more convenient values for these variables were established according to kappa number, yield and viscosity, a surface response method was used to determine the influence of cooking temperature, cooking time and ethanol concentration on autocatalyzed pulping process. The developed models indicate that a high screened pulp yield (56%) and acceptable kappa number (23) and viscosity (1030 mL/g) can be obtained when cooking conditions are around 185OC, 110 min and 50% of ethanol. ~~~~~On a etudie le procae de mise en pite a base d'ethanol d'Eucalypm globulus par le procede ALCELL@ afin de determiner les conditions de cuisson optimales. Dans la premiere serie d'expkriences, l'influence de la taille des copeaux, de l'impregnation des copeaux, du rapport liquiddois et des additifs de cuisson, a ete etudiee. Apres avoir etabli les valeurs pertinentes pour ces variables en fonction du nombre kappa, du rendement et de la viscosite, on a eu recours a une methode de reponse de surface pour determiner l'influence de la tempkrature de cuisson, du temps de cuisson et de la concentration en ethanol sur le procede de mise en pate autocatalyd. Les modeles mis au point indiquent qu'un haut rendement en pite tamisee (56%) ainsi qu'un nombre kappa (23) Keywords organosolv pulping, ethanol pulping, Eucal~pm ghbulus pulping, optimum conditions, response surface design.he kraft process has long been the dominant method for T producing pulp. The main reasons for this domination of the kraft process are its versatility in dealing with Merent raw materials coupled with high pulp quality and efficient recovery of energy and cookmg chemicals. However, capital intensiveness, extensive pollution control requirements, and large minimum economical mill size are well-known disadvantages.Organosolv processes, which use organic solvents either exclusively or as one of the pulping liquor components, have received great attention for development as a commercial process (Stockburger, 1993). Among their advantages are low capital cost, small scale for economically attractive operation, significantly low environmental impact and the production of by-products of potentially significant commercial interest (Kuqi et aL, 1994). A wide range of organic solvents has been proposed for the delignification of lignocellulosic raw materials, either as solvents as such or combined with water, ethanol and methanol being the most used (Johansson et al., 1987). Thus, of the four processes that have operated at pilot plant or commercial scales, three of them use either ethanol or metanol (&CELL@, Organocell and ASAM; see Stockburger, 1993) and one uses formic acid (MILOX@; see Seisto et al., 1997).The pulping media in organosolv processes can be acidic or alkaline, depending on the chemicals and addit...

Ethanol‐based pulping from Cynara cardunculus L

“…Similar behavior was reported for the ethanol-water and methanol-water delignification of Eucalyptus globulus. 17,21 In the better conditions observed for delignification (run 10), the kappa numbers of the pulps obtained have values similar to those reported for the kraft, soda and soda-anthraquinone pulping of cardoon. 4 -6 Likewise, they are also close to those found for the ethanol-water pulping of E globulus 17 and other non-wood species.…”

“…17,21 In the better conditions observed for delignification (run 10), the kappa numbers of the pulps obtained have values similar to those reported for the kraft, soda and soda-anthraquinone pulping of cardoon. 4 -6 Likewise, they are also close to those found for the ethanol-water pulping of E globulus 17 and other non-wood species. 16 The pulps with low kappa number are obtained at the expense of an important loss in pulp yield, as can be seen in Fig 3, where the relationship between total yield and kappa number is shown for all the pulping runs carried out.…”

“…17 The high rejects content obtained in this work, even at very low kappa numbers, can indicate that removal of lignin from the medium lamella is difficult, which seems to be characteristic of cardoon. Thus, the rejects contents found in this work are similar to those reported for soda-anthraquinone and kraft pulping of cardoon.…”

Bioconversion of hybrid poplar to ethanol and co-products using an organosolv fractionation process: Optimization of process yields

“…Historically, the organosolv process has been investigated largely from the perspective of paper production (Diaz et al, 2004;Gilarranz et al, 1998;Jimenez et al, 2004;van Heiningen, 1996, 1997), but several studies have also involved analysis of the lignin fraction extracted during pulping (Hepditch and Thring, 1997;Liu et al, 2000;Lora et al, 1993), including demonstration of its potential for manufacture of various industrial co-products such as adhesives or biodegradable polymers (Boocock and Balatinecz, 1992;Kubo and Kadla, 2004;Thring et al, 1997). Generation of high-quality lignin and other potentially valuable co-products (e.g., furfural and acetic acid) from woody feedstocks may be critical to otherwise marginally cost-effective biorefinery schemes for fuel ethanol production (Pan et al, 2005).…”

Modeling and Optimization of Eucalyptus globulus Bark and Wood Delignification using Response Surface Methodology

“…Nevertheless, optimization studies have been done for other species and other delignification processes (Gominho et al 2001;Vanderghem et al 2012;Dong and Fricke 1996;Gilarranz et al 1998;Ligero et al 2008).…”