A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operatio... more A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm(3) μm day(-1) m(-2) kPa(-1) at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the films' tensile performance was directly controlled by the ratio of SWH to cocomponent.
Tobacco Smoke Chemistry. 4. A Mass Spectral Study of Alkyl 3-Hydroxy-4-pyrones Jan Arnarp, Jacek ... more Tobacco Smoke Chemistry. 4. A Mass Spectral Study of Alkyl 3-Hydroxy-4-pyrones Jan Arnarp, Jacek Bielawski, Britt-Marie Dahlin, Olof Dahlman, Curt R. Enzell and Tore Pettersson Reserca AB, Box 17007, S-104 62 Stockholm, Sweden Arnarp, J., Bielawski, J., Dahlin, ...
In the present study, hardwood and softwood pulps were characterized by employing Fourier transfo... more In the present study, hardwood and softwood pulps were characterized by employing Fourier transform infrared photoacoustic spectroscopy (FT-IR-PAS). The pulp samples examined originated from Swedish sulfite and kraft pulp mills, which utilize different cooking processes and modern bleaching technologies. Partial least-squares (PLS) analysis was used to correlate the spectral data obtained with the kappa (K) numbers and carbohydrate compositions of the pulp samples determined by enzymatic hydrolysis and subsequent capillary zone electrophoresis. Using four principal components, the present PLS model based on photoacoustic FT-IR spectra could explain 85% of the variance in the X matrix and 81% of the variance in the Y matrix. The FT-IR-PAS technique in combination with PLS was found to accurately predict the contents of carbohydrates, i.e., xylose, glucose, mannose, arabinose, galactose, and hexenuronic acid residues, as well as the content of lignin measured in terms of K numbers and...
An efficient method for determining the carbohydrate composition of extractive-free delignified w... more An efficient method for determining the carbohydrate composition of extractive-free delignified wood and pulp is described here. The polysaccharides in the sample are first hydrolyzed using a mixture of commercially available preparations of cellulase and hemicellulase. The reducing saccharides in the hydrolysate thus obtained are subsequently derivatized with 4-aminobenzoic acid ethyl ester and thereafter quantitated by capillary zone electrophoresis (CZE) in an alkaline borate buffer with monitoring of the absorption at 306 nm. All reducing sugars (i.e., neutral monosaccharides and uronic acids) which occur as structural elements in the polysaccharides of wood and pulp can be quantitated in a single such analytical run, which can also determine the contents of 4-deoxy-beta-L-threo-hex-4-enopyranosyluronic acid (HexA) residues present in pulps obtained from alkaline processes. CZE analyses were performed using linear regression of standard curves over a concentration range spanning approximately three orders of magnitude. Carbohydrate constituents constituting approximately 0.1% of the dry mass of the sample could be quantitated. The overall precision of this analytical procedure--involving enzymatic hydrolysis, derivatization and CZE--was good (RSD=2.2-7.5%), especially considering the heterogeneity of the wood and pulp samples. The total yield of carbohydrates (93-97%) obtained employing the procedure developed here was consistently higher than that obtained upon applying the traditional procedure for carbohydrate analysis (85-93%) (involving acid hydrolysis and gas chromatographic analysis) to the same pulps. The trisaccharide HexA-xylobiose was the only HexA-containing saccharide detected using the conditions for enzymatic hydrolysis developed here (i.e., 30 h incubation at pH 4 and 40 degrees C); whereas mixtures of HexA-xylobiose and HexA-xylotriose were obtained when the incubation was performed at pH 5 or 6.
... Douwe Hoornstra1, Olof Dahlman2, Elina Ja¨ a¨ skela¨ inen1, Maria A. Andersson1, Assi Weber3,... more ... Douwe Hoornstra1, Olof Dahlman2, Elina Ja¨ a¨ skela¨ inen1, Maria A. Andersson1, Assi Weber3, Birgit Aurela3, Henry Lindell4 and Mirja S. Salkinoja ... Lhuguenot, J.-C., Mäki-Paakkanen, J., Savo-lainen, M., Severin, I., Stammati, A.-L., Turco, L., Weber, A., von Wright, A., Zucco ...
... Carina Flodin, Emma Johansson, Hans ... Two types of samples were analyzed: (i) lignin ma... more ... Carina Flodin, Emma Johansson, Hans ... Two types of samples were analyzed: (i) lignin materials isolated by acidic solvolysis of fresh and decaying spruce wood, birch leaves, peat moss (Sphagnum), and meadow grass and (ii) high molecular weight organic matter leached ...
An oxidative degradation method was used to study the occurrence of aromatically bound halogens i... more An oxidative degradation method was used to study the occurrence of aromatically bound halogens in high mo-lecular weight organic matter isolated from natural waters and bleached-kraft mill effluents. Gas chromatographic analysis of the degradation products revealed that mono- ...
A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operatio... more A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm(3) μm day(-1) m(-2) kPa(-1) at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the films' tensile performance was directly controlled by the ratio of SWH to cocomponent.
The molecular properties of hemicelluloses located in the surface and inner layers of fibers pres... more The molecular properties of hemicelluloses located in the surface and inner layers of fibers present in hardwood and softwood pulps, together with the effects of different bleaching processes on these properties, have been investigated in this study. In order to separate ...
O-acetylated glucomannans were isolated from aspen and birch wood employing two different procedu... more O-acetylated glucomannans were isolated from aspen and birch wood employing two different procedures and thereafter subjected to carbohydrate analysis by NMR spectroscopy and MALDI mass spectrometry. In one of the isolation procedures, acetone-extracted aspen or birch wood meal was extracted with dimethyl sulfoxide and then with hot water. Fractionation of the hemicellulose-containing extracts by size-exclusion chromatography was subsequently performed. In the other procedure, fractional precipitation with ethanol was used to isolate glucomannans from lyophilized process water produced by mechanical pulping of aspen. The aspen and birch glucomannans are O-acetylated at the C-2 or C-3 position of some of the mannose residues (random distribution), with a degree of acetylation of approx 0.3. In both cases the degree of polymerization was approx 16, indicating that low-molecular mass fractions of the glucomannans in hardwood have been isolated here.
A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operatio... more A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm(3) μm day(-1) m(-2) kPa(-1) at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the films' tensile performance was directly controlled by the ratio of SWH to cocomponent.
Tobacco Smoke Chemistry. 4. A Mass Spectral Study of Alkyl 3-Hydroxy-4-pyrones Jan Arnarp, Jacek ... more Tobacco Smoke Chemistry. 4. A Mass Spectral Study of Alkyl 3-Hydroxy-4-pyrones Jan Arnarp, Jacek Bielawski, Britt-Marie Dahlin, Olof Dahlman, Curt R. Enzell and Tore Pettersson Reserca AB, Box 17007, S-104 62 Stockholm, Sweden Arnarp, J., Bielawski, J., Dahlin, ...
In the present study, hardwood and softwood pulps were characterized by employing Fourier transfo... more In the present study, hardwood and softwood pulps were characterized by employing Fourier transform infrared photoacoustic spectroscopy (FT-IR-PAS). The pulp samples examined originated from Swedish sulfite and kraft pulp mills, which utilize different cooking processes and modern bleaching technologies. Partial least-squares (PLS) analysis was used to correlate the spectral data obtained with the kappa (K) numbers and carbohydrate compositions of the pulp samples determined by enzymatic hydrolysis and subsequent capillary zone electrophoresis. Using four principal components, the present PLS model based on photoacoustic FT-IR spectra could explain 85% of the variance in the X matrix and 81% of the variance in the Y matrix. The FT-IR-PAS technique in combination with PLS was found to accurately predict the contents of carbohydrates, i.e., xylose, glucose, mannose, arabinose, galactose, and hexenuronic acid residues, as well as the content of lignin measured in terms of K numbers and...
An efficient method for determining the carbohydrate composition of extractive-free delignified w... more An efficient method for determining the carbohydrate composition of extractive-free delignified wood and pulp is described here. The polysaccharides in the sample are first hydrolyzed using a mixture of commercially available preparations of cellulase and hemicellulase. The reducing saccharides in the hydrolysate thus obtained are subsequently derivatized with 4-aminobenzoic acid ethyl ester and thereafter quantitated by capillary zone electrophoresis (CZE) in an alkaline borate buffer with monitoring of the absorption at 306 nm. All reducing sugars (i.e., neutral monosaccharides and uronic acids) which occur as structural elements in the polysaccharides of wood and pulp can be quantitated in a single such analytical run, which can also determine the contents of 4-deoxy-beta-L-threo-hex-4-enopyranosyluronic acid (HexA) residues present in pulps obtained from alkaline processes. CZE analyses were performed using linear regression of standard curves over a concentration range spanning approximately three orders of magnitude. Carbohydrate constituents constituting approximately 0.1% of the dry mass of the sample could be quantitated. The overall precision of this analytical procedure--involving enzymatic hydrolysis, derivatization and CZE--was good (RSD=2.2-7.5%), especially considering the heterogeneity of the wood and pulp samples. The total yield of carbohydrates (93-97%) obtained employing the procedure developed here was consistently higher than that obtained upon applying the traditional procedure for carbohydrate analysis (85-93%) (involving acid hydrolysis and gas chromatographic analysis) to the same pulps. The trisaccharide HexA-xylobiose was the only HexA-containing saccharide detected using the conditions for enzymatic hydrolysis developed here (i.e., 30 h incubation at pH 4 and 40 degrees C); whereas mixtures of HexA-xylobiose and HexA-xylotriose were obtained when the incubation was performed at pH 5 or 6.
... Douwe Hoornstra1, Olof Dahlman2, Elina Ja¨ a¨ skela¨ inen1, Maria A. Andersson1, Assi Weber3,... more ... Douwe Hoornstra1, Olof Dahlman2, Elina Ja¨ a¨ skela¨ inen1, Maria A. Andersson1, Assi Weber3, Birgit Aurela3, Henry Lindell4 and Mirja S. Salkinoja ... Lhuguenot, J.-C., Mäki-Paakkanen, J., Savo-lainen, M., Severin, I., Stammati, A.-L., Turco, L., Weber, A., von Wright, A., Zucco ...
... Carina Flodin, Emma Johansson, Hans ... Two types of samples were analyzed: (i) lignin ma... more ... Carina Flodin, Emma Johansson, Hans ... Two types of samples were analyzed: (i) lignin materials isolated by acidic solvolysis of fresh and decaying spruce wood, birch leaves, peat moss (Sphagnum), and meadow grass and (ii) high molecular weight organic matter leached ...
An oxidative degradation method was used to study the occurrence of aromatically bound halogens i... more An oxidative degradation method was used to study the occurrence of aromatically bound halogens in high mo-lecular weight organic matter isolated from natural waters and bleached-kraft mill effluents. Gas chromatographic analysis of the degradation products revealed that mono- ...
A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operatio... more A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm(3) μm day(-1) m(-2) kPa(-1) at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the films' tensile performance was directly controlled by the ratio of SWH to cocomponent.
The molecular properties of hemicelluloses located in the surface and inner layers of fibers pres... more The molecular properties of hemicelluloses located in the surface and inner layers of fibers present in hardwood and softwood pulps, together with the effects of different bleaching processes on these properties, have been investigated in this study. In order to separate ...
O-acetylated glucomannans were isolated from aspen and birch wood employing two different procedu... more O-acetylated glucomannans were isolated from aspen and birch wood employing two different procedures and thereafter subjected to carbohydrate analysis by NMR spectroscopy and MALDI mass spectrometry. In one of the isolation procedures, acetone-extracted aspen or birch wood meal was extracted with dimethyl sulfoxide and then with hot water. Fractionation of the hemicellulose-containing extracts by size-exclusion chromatography was subsequently performed. In the other procedure, fractional precipitation with ethanol was used to isolate glucomannans from lyophilized process water produced by mechanical pulping of aspen. The aspen and birch glucomannans are O-acetylated at the C-2 or C-3 position of some of the mannose residues (random distribution), with a degree of acetylation of approx 0.3. In both cases the degree of polymerization was approx 16, indicating that low-molecular mass fractions of the glucomannans in hardwood have been isolated here.
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