Positive and negative aspects of soda/anthraquinone pulping of hardwoods.
The positive aspects of the non-sulfur soda/anthraquinone (SAQ) process are mostly tied to improved energy efficiency while lower pulp brightness after bleaching is its most significant drawback. A credible method that quantifies bleachability as well as an approach that solves the problem for SAQ pulps from hardwoods will be described. A straight line correlation (R2=0.904) was obtained between O2 kappa number and final light absorption coefficient (LAC) value after standardized OD0EpD1 bleaching of nine hardwood kraft pulps from three laboratories and one pulp mill. The bleachability of pulps from four different soda processes catalyzed by anthraquinone (AQ) and 2-methylanthraquinone (MAQ) was compared to that of conventional kraft pulps by comparing O2 kappa number decrease and final LAC values. It was observed that a mild hot water pre-hydrolysis improved the bleachability of SAQ pulps to a level equal to that of kraft.
Francis
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RC
Faculty of Paper and Bioprocess Engineering/Empire State Paper Research Institute, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York 13210, USA. francis@syr.edu
Bolton
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TS
Abdoulmoumine
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N
Lavrykova
N
N
Bose
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SK
D000880:Anthraquinones / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D008031:Lignin / Q000378:metabolism; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010209:Paper; D012972:Sodium Hydroxide / Q000737:chemistry*; D028561:Transition Elements / Q000032:analysis; D014867:Water / Q000737:chemistry; D014934:Wood / Q000737:chemistry*
D000880:Anthraquinones; D017610:Calcium Compounds; D010087:Oxides; D028561:Transition Elements; D014867:Water; D000431:Ethanol; C004569:soda lime; D012972:Sodium Hydroxide; D008031:Lignin; D010100:Oxygen