Størker Moe - Academia.edu (original) (raw)

Papers by Størker Moe

Food Polysaccharides and Their Applications, 2006

Journal of Wood Chemistry and Technology, 2000

Hydrobiologia, 1993

The effective molecular weight cut-off values of dialysis membranes for carrageenan and alginate ... more The effective molecular weight cut-off values of dialysis membranes for carrageenan and alginate oligosaccharides were evaluated by gel permeation chromatography and nuclear magnetic resonance spectroscopy. For the different membranes tested, i.e. Medicell, Spectra Por 1000D and 3500D, the porous sizes are analogous to tri-and tetrasaccharides. A simple dialysis can be used to recover the majority of the oligosaccharides produced by a carrageenase or an alginate lyase digestion.

A revised method for analysis of carbohydrates in pulps is presented. The method utilizes commerc... more A revised method for analysis of carbohydrates in pulps is presented. The method utilizes commercially available enzyme preparations for enzymatic hydroly- sis of the pulp, followed by acid hydrolysis for com- plete cleavage of oligomers that are still present. Quantification of monosaccharides in the hydrolysate was performed by HPLC using a Pb-sulphonate/poly- mer column and deionized water as the mobile

Carboxymetyl celluloses (CMCs) were prepared from both cotton linter cellulose and spruce sulfite... more Carboxymetyl celluloses (CMCs) were prepared from both cotton linter cellulose and spruce sulfite specialty cellulose samples. The resulting carboxymethyl celluloses were investigated by viscometric measurements and by 1 H- and 13C-NMR spectroscopy. There was no detectable difference between the two types of raw material, neither in viscosity stability during carboxymethylation, nor in the extent of the substitution reaction. Under the

There is still some uncertainty about the mechanism of increased bleachability by interstage acti... more There is still some uncertainty about the mechanism of increased bleachability by interstage activation of two- stage oxygen delignification (the OxO process). To possibly help in understanding the chemistry of the OxO process, residual lignin in kraft pulp bleached by oxygen and peracetic acid was extracted by the diox- ane/water acidolysis method. The content of functional groups in the extracted

A linear correlation has been found between the beatability and the hemicellulose content of Scan... more A linear correlation has been found between the beatability and the hemicellulose content of Scandinavian softwood laboratory pulps. In addition to increasing yield, especially of hemicellulose, additives like polysulfide and/or anthraquinone can thus improve the beatability of softwood pulps. At similar hemicellulose content, pulps manufactured from Norway spruce (Picea abies) is still better than pulps manufactured from Scots pine (Pinus

Wood Science and Technolgoy, May 28, 2015

Ethanol derived from biomass has the potential to be a renewable transportation fuel that can rep... more Ethanol derived from biomass has the potential to be a renewable transportation fuel that can replace gasoline. This work was carried out to establish an optimized ethanol organosolv pretreatment of Norway spruce (Picea abies) for
bioethanol production (63 wt% EtOH, pH 3.5 in aqueous phase, 170–240 degree C, 90 min) utilizing hydrolytic enzymes in the saccharification step. To test the generality of the method, a series of ethanol organosolv pretreatments were also performed on sugarcane bagasse (50 wt% EtOH, pH 3.5 in aqueous phase, 155–210 degree C, 90–120 min). The degree of delignification increased with increasing temperature during pretreatment, and the fastest increase was observed with sugarcane bagasse. The pretreatments were carried out in a batch mode. The maximum degree of delignification of *65 % was reached at *235 degree C for Norway spruce, while sugarcane bagasse reached *80 % at *210 degree C. Cellulose was subjected to degradation (5–10 % points) at these temperatures. Subsequent enzymatic hydrolysis (30 FPU/g cellulose, 32 pNPGU/g cellulose, 50 degree C, 48 h) of ethanol
organosolv-pretreated biomass achieved complete conversion for both raw materials at the highest degrees of delignification.

Carbohydrate compositions of softwood kraft pulps manufactured with anthraquinone or polysulfide ... more Carbohydrate compositions of softwood kraft pulps manufactured with anthraquinone or polysulfide addi- tion or H2S impregnation have been determined. The yield increase was mainly due to increased glucoman- nan retention, and the yield of xylan was constant within experimental errors. Carbohydrate yield loss was linearly dependent on cooking time for one single type of pulping process. For anthraquinone, the yield

Ozonation of the cellulose model compound cellobiose (4-O-β-D-glucopyranosyl-D-glucose) was perfo... more Ozonation of the cellulose model compound cellobiose (4-O-β-D-glucopyranosyl-D-glucose) was performed under pressurized contions and at atmospheric pres- sure. Ozonation at atmospheric conditions showed a strong preference for oxidation at the reducing end yielding cellobionic acid as the main product. Only after extended ozonation could other reaction products be observed. Ozonation of cellobiose under pressurized conditions yielded a less specific reaction.

A large number of kraft pulps has been manufactured with or without additives like anthraquinone,... more A large number of kraft pulps has been manufactured with or without additives like anthraquinone, polysulfide or H2S impregnation. Carbohydrate analysis of the pulps showed that the main mechanism for yield increase by additives is increased retention of glucomannan. On the other hand, the retention of cellulose was somewhat affected by the use of anthraquinone and higher kappa number. Xylan

A promising method for maximizing the yield of kraft pulp seems to be cooking to kappa numbers be... more A promising method for maximizing the yield of kraft pulp seems to be cooking to kappa numbers between 40 and 45 with the addition of polysulfide and anthraquinone (PS/AQ) to the kraft cooking liquor, followed by oxygen delignification to kap- pa numbers around 22 and subsequent bleaching with more spe- cific bleach chemicals. The bleachability of the oxygen delignified high-yield

IEEE/LEOS International Conference on Optical, 2000

The NEXUS market analysis for microsystems 1996-2000 states that a large growth in the market for... more The NEXUS market analysis for microsystems 1996-2000 states that a large growth in the market for microsystems for environmental monitoring is expected. One important product is reliable low cost gas sensors. IR absorption systems are attractive for this application, because of their excellent reliability, selectivity, and sensitivity. However, high production costs have limited the widespread use of these systems. In

The performance of the preflotation stage of the Norske Skog Skogn DIP mill has been studied over... more The performance of the preflotation stage of the Norske Skog Skogn DIP mill has been studied over the first year of operation. Process conditions have covered a wider range of process parameters than would normally be expected in an established mill. The main factor affecting free ink removal and filler yield was the process water hardness, and there was a

Ozone has high affinity for lignin and is gaining acceptance as a bleaching agent for chemical pu... more Ozone has high affinity for lignin and is gaining acceptance as a bleaching agent for chemical pulps. A reaction with pulp carbohydrates leading to depolymerisation is ozone's main disadvantage. In this study, products from the reaction between ozone and the cellulose model compounds, glucose and cellobiose, were investigated by 1 HNMR-and 13 CNMRspectroscopy. Oxidation of C1, giving gluconic acid and it's lactones was the favored pathway for ozonation of glucose, but glucuronic acid was also formed. The ozonation of cellobiose yielded a small amount of glucose, no other monomer products was identified, indicating that cleavage of the glycosidic bond was not the main reaction. _________________________________________________

The amount and origin of charged groups in fines from different parts of the fibre wall have been... more The amount and origin of charged groups in fines from different parts of the fibre wall have been determined. In order to produce the different fines, chips from mainly Norway spruce were refined in a pilot refiner. Most of the fines were removed from the pulp by washing before further refining. This procedure was executed four successive times, and the fibre wall thickness of the long fibre fraction was measured after each refining stage. The fines produced in the first refining stage had less fibrillar material and a higher amount of charged groups than the last fractions. The amount of charged groups was measured both by chemical analysis and polymer adsorption. Three uronic acids were responsible for 80- 90% of the charge, measured in terms of the adsorption of a small cationic polymer for the fines fractions.

Journal of Polymers and the Environment, 2011

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigat... more The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s -1 was identified. The study shows a hysteresis loop in the shear rate-viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s -1 .

Journal of Liquid Chromatography & Related Technologies, 2000

ABSTRACT Two types of hydrophilic macroporous monodisperse particles (MMP) based on poly(styrene-... more ABSTRACT Two types of hydrophilic macroporous monodisperse particles (MMP) based on poly(styrene-co-divinylbenzene) have been investigated for use as column material for size exclusion chromatography (SEC) analysis of cellulose dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). The particles appeared inert to the mobile phase and no adsorption of cellulose could be detected. Favorable chromatographic properties associated with monosized particles such as low back pressures and high flow rates were obtained. Two MMP columns of different pore size distributions coupled in series, allowed separation of cellulose in the molecular weight range 104–107 g/mole. The particles were suitable for SEC of cellulose samples dissolved in 0.5% LiCl/DMAc and the reproducibility and long term stability were superior to that of a comparable commercial SEC column.

Journal of Carbohydrate Chemistry, 2002

Mild ozonation of cellobiose in acetic acid almost exclusively favors oxidation of the reducing e... more Mild ozonation of cellobiose in acetic acid almost exclusively favors oxidation of the reducing end, thus yielding 4-O-β-d-glucopyranosyl-d-gluconic acid (“cellobionic acid”). This compound can be quantitatively separated from the substrate by preparative HPLC using acetonitrile/phosphate buffer on an aminopropyl silica column. The product was identified using one and two dimensional NMR techniques. C and H NMR chemical shifts are reported.†Current