NORDIC PULP & PAPER RESEARCH JOURNAL
Home » Volume 31, 2016 » Issue No. 4
BIOREFINERY
Combustion properties of spruce black liquor droplets: Sulfur-free pulping and influence of hot-water pretreatment
Chengcong Chen, Raimo Alén, Joni Lehto and Hannu Pakkanen, University of Jyväskylä, Jyväskylä, Finland
Abstract
Hot-water pretreatment of lignocellulosics prior to sulfur-free alkaline pulping is an interesting approach for recovering value-added carbohydrate- and lignin-derived materials. This paper investigated the chemical composition variations and combustion properties of the black liquors (BLs) from three different cooking processes: two sulfur-free soda-anthraquinone (soda-AQ) and oxygen-alkali (O2-NaOH) cooks and kraft cook, before and after hot-water pretreatment of the spruce sawdust. Relatively less aliphatic acids but more lignin were present in the BLs after hot-water pretreatment as cooking time prolonged. In general, the burning time decreased as follows: soda-AQ BL > O2-NaOH BL  kraft BL. With the same cooking time, the increase in the total burning time for soda-AQ BLs compared with kraft BLs was 11-17% (without pretreatment) and 25-39% (with pretreatment). Compared to kraft BLs with the same cooking time, the swelling for soda-AQ and O2-NaOH BLs decreased by 8-25% and 4-23%, respectively.
Keywords
Black liquor, Combustion properties, Hot-water pre-treatment, Spruce, Sulfur-free pulping
Pages
531-540
DOI
10.3183/NPPRJ-2016-31-04-p531-540
Price
22 EUR (excl. VAT) Buy PDF
Nordic Pulp & Paper Research Journal (NPPRJ) is an international scientific magazine covering science and technology for the areas of wood or bio-mass constituents, pulp and paper and including new fiber-based materials, recovery and by-products from pulping processes, bio-refining and energy issues. Articles meeting required scientific standards are accepted from any continent.
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ISSN: 0283-2631