| 1. |
- Areskogh, Dimitri, et al.
(författare)
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Structural modification of commercial lignosulphonates through laccase catalysis and ozonolysis
- 2010
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 32:3, s. 458-466
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Tidskriftsartikel (refereegranskat)abstract
- Lignosulphonates are by-products from the sulphite pulping process, in which lignin is separated from cellulose by the addition of sulphonic acid groups to the alpha-position of lignin, thereby increasing the solubility of lignin in water. The predominant industrial utilisations of lignosulphonates are as dispersants, plasticisers and water-reducing agents in concrete preparation. The ability of lignosulphonates to function as a good plasticisers and water reducers is intimately linked with the purity of the lignosulphonate, its molecular weight and the number of charged groups present in the macromolecule. Currently, lignosulphonates are outrivaled by synthetic plasticisers termed superplasticisers due to their superior properties when used as additives to high-strength concrete. If lignosulphonates are to successfully compete with these superplasticisers, significant modifications are required. This paper describes a two-stage treatment of lignosulphonates in which the molecular weight is increased through laccase oxidation and carboxylic groups are introduced through ozonolysis. The technical significance of the results is also discussed.
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| 2. |
- Arshadi, Mehrdad, et al.
(författare)
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Comparison of fatty and resin acid composition in boreal lodgepole pine and Scots pine for biorefinery applications
- 2013
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 49, s. 535-541
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the potential for Scots- and lodgepole pine for biorefinery applications such as e.g., biodiesel and glue production, wood samples from five different sites in northern Sweden were compared. 21 fatty and 10 resin acids were detected by extraction and GC MS analysis. Total fatty- and resin acid contents of Scots pine varied between 2.4 and 41.4 mg/g. Corresponding concentrations for lodgepole pine were 23 and 26.0 mg/g of dry material. Multivariate models were made with principal component analysis to take advantage of the multivariate correlations between the individual acids. Wood tissue type explained most of the variation in fatty and resin acid content, with heartwood having up to five times the extractive concentration of sapwood. Resin acids were mainly associated with heartwood, while fatty acids were more associated with sapwood. A five-component PLSDA-model distinguished between the two species, mainly due to differences in their hexadecanoic and heptadecanoic acid contents. Heartwood from Scots pine is more suitable for resin extraction while lodgepole pine is a better option for fatty- and resin acid extraction because of the extractives' evenly distribution between wood types. Around 150 kg of fatty acids and 1 ton of resins can be harvested per hectare from a typical mature boreal lodgepole pine stand, for biorefinery use. Systematic fractionation and selection of heartwood and sapwood will likely optimize industrial applications (e.g. biodiesel production) of each fraction. (C) 2013 Elsevier B.V. All rights reserved.
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| 3. |
- Backlund, Ingegerd, et al.
(författare)
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Extractive profiles of different lodgepole pine (Pinus contorta) fractions grown under a direct seeding-based silvicultural regime
- 2014
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 58, s. 220–229-
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to identify and quantify the chemical compounds in the aboveground fractions of lodgepole pine trees (stem top, stem base, bark, branches, needles and cones) grown under a direct seeding-based silvicultural regime, including per hectare-outputs and industrial applications. Plant metabolites were extracted from trees of two sizes from two areas of central-northern Sweden with different climates and analysed by GC MS. The stands were 30 years old and had undergone pre-commercial thinning. The extractive yields for the fractions differed significantly, with the bark having the highest yields (13-20%) and the stem the lowest (0.5-3.5%). Multivariate analysis showed that the extractive profiles of the needles deviated strongly from those of the other fractions, with the needles being particularly rich in wax esters and fatty alcohols. The stemwood mainly contained ketones, terpenes and acids. The cones had a prominent pine scent and were rich in aromatics. The stands examined in this study could produce large quantities of biomass suitable for use in biorefineries without any change in their current management regimes, yielding 2-3 tonnes of crude extractives per hectare. The precise extractive yield depends on the site fertility, tree partitioning and tree size. The extractives obtained can be used for production of, e.g. biodiesel, glue, bioactive food additives, cosmetics, and polymer precursors. Lodgepole pine can be cultivated cost-effectively by direct seeding in dense stands, and advantageously harvested to produce biomass and extractives. It is therefore an appropriate species for the production of biorefinery feedstocks in the boreal region. (C) 2014 Elsevier B.V. All rights reserved.
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| 4. |
- Campolo, Orlando, et al.
(författare)
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Effects of inert dusts applied alone and in combination with sweet orange essential oil against Rhyzopertha dominica (Coleoptera: Bostrichidae) and wheat microbial population
- 2014
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Ingår i: Industrial crops and products (Print). - : ELSEVIER SCIENCE BV. - 0926-6690 .- 1872-633X. ; 61, s. 361-369
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Tidskriftsartikel (refereegranskat)abstract
- The effects of kaolin and diatomaceous earth applied alone and in combinations with sweet orange [Citrus sinensis (L.) Osbeck] peel essential oil against Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and wheat microbial populations were evaluated. Adult beetles reared on durum wheat (cv Simeto) were used to carry out the tests. Five formulations at five application rates were tested. Both insect mortality and progeny production were affected by the treatment, the application rate and the exposure time. C. sinensis essential oil showed a synergistic effect on the mortality of R. dominica, if combined with kaolin, and antagonistic effect when admixed with diatomaceous earth. Yeasts and moulds as well as total mesophilic aerobic bacteria growths were reduced by C sinensis essential oil applied alone more than the other dusts and dust-essential oil-based treatments. Kaolin admixed with C. sinensis peel essential oil might be a viable alternative to the chemical pesticides commonly used in wheat pest management. (C) 2014 Elsevier B.V. All rights reserved.
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| 5. |
- Carrillo Nieves, Danay, et al.
(författare)
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Improvement of biogas production from oil palm empty fruit bunches (OPEFB)
- 2011
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 34:1, s. 1097-1101
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Tidskriftsartikel (refereegranskat)abstract
- Oil palm empty fruit bunches (OPEFB), a waste lignocellulosic material, which is the main byproduct of vegetable oil production industries in Indonesia and Malaysia, was utilized as a source for biogas production. Pretreatments using NaOH as well as phosphoric acid were investigated to improve the biogas production. Clear positive effects of the pretreatments on the yield of methane were observed. The best improvement was achieved when 8% NaOH for 60 min was used for the pretreatment, which resulted in 100% improvement in the yield of methane production. In addition, treatment with phosphoric acid resulted in 40% improvement in the methane yield compared with that of the untreated material. The results showed that the carbohydrate content of OPEFB could be efficiently converted to methane under the anaerobic digestion process. 97% of the theoretical value of methane production was achieved after the pretreatment with NaOH for 60 min. Moreover, the initial rate of methane production was also increased by more than 85% after the treatment with NaOH compared with that of the untreated OPEFB.
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| 6. |
- Du, Xueyu, et al.
(författare)
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Modification of industrial softwood kraft lignin using Mannich reaction with and without phenolation pretreatment
- 2014
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 52, s. 729-735
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Tidskriftsartikel (refereegranskat)abstract
- The amination of industrial softwood kraft lignin was conducted using the Mannich reaction to modify the lignin structure for value-added applications. To understand the reaction mechanism and to quantify the amount of amine groups that were introduced, different types of NMR analyses were performed. The lignin was also pretreated by phenolation to increase its reactivity and the amount of the amine groups that were introduced. The Mannich reaction was very selective at the C-5 position of the guaiacyl units and complete under acidic conditions with similar to 11-fold amounts of reagents of dimethylamine and formaldehyde over either model lignin (4-hydroxy-3-methoxyacetophenone, HMAP) or industrial spruce kraft lignin (LignoBoost lignin, LBL). For LBL, 28 amine groups were introduced over 100 aromatic rings. By weight, the nitrogen content was 2.5%. The animated lignin was found to possess a higher molecular mass, reaching a Mp of 4.9 x 10(3) Da compared to the original 319 x 10(3) Da, and with a considerably increased dispersibility, especially in a dilute aqueous solution of hydrochloric acid (pH = 3), namely 5.2 mg/ml. With a preceding phenolation treatment, which increased the amount of phenolic aromatic rings available for the Mannich reaction, an introduction of 42 amine groups over 100 aromatic rings, or a nitrogen content of 4.8%, was obtained, which caused a further increase of the molecular mass to 5.1 x 10(3) Da (Mp) and of dispersibility in the aqueous solution of hydrochloric acid up to 32.0 mg/ml. The aminated lignins with or without the phenolation pretreatment formed very stable colloidal suspensions in water, with large particle sizes (391 and 39 nm), high zeta potentials (31.6 and 27.2 mV), and large charge densities (1.6 and 1.2 x 10(-7) equiv./ml, respectively). The potential value-added applications of these modified lignins with high amine contents include use as surfactant chemicals, polycationic materials and slow-release fertilisers, among others.
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| 7. |
- Eta, Valerie, et al.
(författare)
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Enhanced mass transfer upon switchable ionic liquid mediated wood fractionation
- 2014
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 55, s. 109-115
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Tidskriftsartikel (refereegranskat)abstract
- The fractionation of lignocellulosic biomass to its major components is the primary step towards the conversion of biomass-based biopolymers to commodity chemicals in the integrated biorefinery process. Wood chips encased in a SpinChem® device and attached to the stirrer of a batch autoclave were used together with switchable ionic liquids (SILs) for the selective fractionation of hemicelluloses and lignin. Stirring of the wood chips in the SpinChem® device facilitated the diffusion of SIL into the chips through forced recirculation and at the same time avoiding mechanical fibrillation. The treatment of birch chips (Betula pendula) with SILs comprising 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU), monoethanolamine (MEA) and CO2 at 120 °C in a SpinChem® device resulted in the fractionation of 82 wt.% hemicelluloses and 90 wt.% lignin, leaving the cellulose-rich non-dissolved material partially fibrillated and softened. The dissolved hemicelluloses and lignin were selectively precipitated using isopropanol and recovered from the spent SIL.
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| 8. |
- Ezekiel, Ngesa, et al.
(författare)
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Effect of temperature and durations of heating on coir fibers
- 2011
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 33:3, s. 638-643
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Tidskriftsartikel (refereegranskat)abstract
- Biocomposites derived from polymeric resin and lignocellulosic fibers may be processed at temperatures ranging from 100 degrees C to 230 degrees C for durations of up to 30 min. These processing parameters normally lead to the degradation of the fiber's mechanical properties such as Young's modulus (E), ultimate tensile strength (UTS) and percentage elongation at break (%EB). In this study, the effect of processing temperature and duration of heating on the mechanical properties of coir fibers were examined by heating the fibers in an oven at 150 degrees C and 200 degrees C for 10,20 and 30 min to simulate processing conditions. Degradation of mechanical properties was evaluated based on the tensile properties. It was observed that the UTS and %EB of heat treated fibers decreased by 1.17-44.00% and 15.28-81.93%, respectively, compared to untreated fibers. However, the stiffness or E of the fibers increased by 6.3-25.0%. Infra red spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to elucidate further the influence of chemical, thermal and microstructural degradation on the resulting tensile properties of the fibers. The main chemical changes observed at 2922, 2851, 1733, 1651, 1460, 1421 and 1370 cm(-1) absorption bands were attributed to oxidation, dehydration and depolymerization as well as volatization of the fiber components. These phenomena were also attributed to in the TGA, and in addition the TGA showed increased thermal stability of the heat treated coir fibers with reference to the untreated counterparts which was most probably due to increased recrystallization and cross linking. The microstructural features including microcracks, micropores, collapsed microfibrils and sort of cooled molten liquid observed on the surface of heat treated coir fibers from the scanning electron microscope (SEM) could not directly be linked to the effect of temperature and durations of heating although such features may have largely account for the lower tensile properties of heat treated coir fibers with reference to untreated ones.
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| 9. |
- García, Ariel, et al.
(författare)
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Dilute sulphuric acid pretreatment and enzymatic hydrolysis of Jatropha curcas fruit shells for ethanol production
- 2014
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 53, s. 148-153
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Jatropha curcas is a promising source of oil for the biodiesel industry, and the shells of its fruits could be considered for ethanol production. In this work, the composition of J. curcas shells is investigated, and the potential of dilute-sulphuric acid pretreatment for improving the enzymatic hydrolysis of cellulose is evaluated. A Box–Behnken experimental design was used for assessing the effect of temperature (110–150 °C), H2SO4 concentration (0.5–2.5%) and pretreatment time (15–45 min) on the formation of sugars during pretreatment and on the enzymatic conversion of cellulose. Cellulose conversions above 80% were achieved both in the separated enzymatic hydrolysis and in the simultaneous saccharification and fermentation of the pretreated materials. Optimal SSF conversions were predicted for pretreatments at low temperature (136 °C) and moderate acid concentrations (1.5%) and reaction time (30 min). The inclusion of an extraction step prior to the pretreatment revealed a further improvement of the enzymatic conversion of cellulose.
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| 10. |
- Goshadrou, Amir, et al.
(författare)
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Bioethanol production from sweet sorghum bagasse by Mucor hiemalis
- 2011
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 34:1, s. 1219-1225
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Tidskriftsartikel (refereegranskat)abstract
- The present work deals with production of ethanol from sweet sorghum bagasse by a zygomycetes fungus Mucor hiemalis. The bagasse was treated with phosphoric acid and sodium hydroxide, with or without ultrasonication, prior to enzymatic hydrolysis by commercial cellulase and β-glucosidase enzymes. The phosphoric acid pretreatment was performed at 50 °C for 30 min, while the alkali treatment performed with 12% NaOH at 0 °C for 3 h. The pretreatments resulted in improving the subsequent enzymatic hydrolysis to 79–92% of the theoretical yield. The best hydrolysis performance was obtained after pretreatment by NaOH assisted with ultrasonication. The fungus showed promising results in fermentation of the hydrolyzates. In the best case, the hydrolyzate of NaOH-ultrasound pretreated bagasse followed by 24 h fermentation resulted in about 81% of the corresponding theoretical ethanol yield. Furthermore, the highest volumetric ethanol productivity was observed in the hydrolyzates of NaOH pretreated bagasse, especially after ultrasonication in pretreatment stage.
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