| 1. |
- Azwar, Edwin, et al.
(författare)
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Liquefied biomass derived plasticizer for polylactide
- 2013
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 88:5, s. 897-903
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The valorization of renewable agro-industrial residues and their further utilization for production of polymers and polymer additives is a highly attractive alternative for replacement of oil-based materials. RESULTS: Liquefied wood flour and rice bran derived esters were synthesized and evaluated as novel green plasticizers for polylactide (PLA). The liquefied wood flour ester (PWF) showed good miscibility with PLA and good plasticization efficiency as shown by differential scanning calorimetry (DSC) and tensile testing. Tensile strain at break increased from a few percent for pure PLA to over 100 and 300% for the materials containing 10 and 30 wt-% of PWF. The addition of PWF accelerated the hydrolysis rate of PLA as shown by faster weight loss during aging in water and faster formation of water-soluble lactic acid oligomers, which was shown by electrospray ionization mass spectrometry (ESI-MS) analysis of the migrants. The liquefied rice bran based product (PRB) was not miscible with PLA and it did not improve the elongation at break of PLA. Rice bran is generally rich in arabinoxylans with only secondary less reactive alcohol groups. The larger number of un-reacted hydroxyl-groups in PRB was confirmed by Fourier transform infrared (FTIR) spectroscopy and could explain the immiscibility with PLA. CONCLUSIONS: The results demonstrate that the synthesized liquefied wood flour derived plasticizer could have great potential as a biobased polylactide plasticizer.
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| 2. |
- Carrasco, Cristhian, et al.
(författare)
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Arabinosylated phenolics obtained from SO2-steam-pretreated sugarcane bagasse
- 2012
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575. ; 87:12, s. 1723-1726
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Tidskriftsartikel (refereegranskat)abstract
- A pentose-rich hydrolysate fraction obtained by extraction of steam-pretreated sugarcane bagasse was analysed with regard to dissolved phenolics. The liquid obtained after steam pretreatment (2% SO2 (w/w) at 190 degrees C for 5 min) was divided into two parts: one containing dissolved compounds originating from hemicellulose (with xylose as the dominating compound), and the other containing predominantly dissolved compounds originating from lignin. Using nuclear magnetic resonance, the main dissolved compounds originating from lignin were identified as the glycosylated aromatics, 5-O-(trans-feruloyl)-L-Arabinofuranose and 5-O-(trans-coumaroyl)-L-Arabinofuranose, together with p-coumaric acid and small amounts of more common free phenolics such as p-hydroxybenzaldehyde, p-hydroxybenzoic acid and vanillin. The phenolic compounds were analysed and quantified using reversed-phase high-performance liquid chromatography. The findings show that SO2 steam explosion opened up new degradation pathways during lignin degradation. Copyright (c) 2012 Society of Chemical Industry
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| 3. |
- Enman, Josefine, et al.
(författare)
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Growth promotive conditions for enhanced eritadenine production during submerged cultivation of Lentinus edodes
- 2012
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 87:7, s. 903-907
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mycelium of the medicinal mushroom shiitake, Lentinus edodes, is a potential source for production of the blood cholesterol reducing compound eritadenine. To increase the mycelial biomass and in turn the production of eritadenine, a potential growth promoting substance in the form of a water extract of distillers dried grains with solubles (DDGS) was added to the culture media.Results: The hot water extract of DDGS was shown to considerably increase the growth of shiitake mycelia in bioreactor cultivations; the mycelial yield was 2-3 times higher than in the control, and the highest final biomass concentration obtained was 3.4 g L -1. Further, by using shake flask cultures as inoculums the bioreactor cultivation time could be reduced by 1 week for some of the experiments. The highest final titer of eritadenine in the present study was 25.1 mg L -1, which was about 2 times higher than in the control, and was also obtained when a water extract of DDGS was added to the culture medium.Conclusion: It was demonstrated that a water extract of DDGS promoted the growth of shiitake mycelia in bioreactor cultivations, along with enhanced eritadenine production.
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| 4. |
- Forgács, Gergely, 1983, et al.
(författare)
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Metahne Production from citrus waste: Process development and cost estimation
- 2012
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 1097-4660 .- 0268-2575. ; 87:2, s. 250-255
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Tidskriftsartikel (refereegranskat)abstract
- AbstractLignocellulosic biomass can be utilized to produce ethanol, a promising alternative energy source for the limited crude oil. There are mainly two processes involved in the conversion: hydrolysis of cellulose in the lignocellulosic biomass to produce reducing sugars, and fermentation of the sugars to ethanol. The cost of ethanol production from lignocellulosic materials is relatively high based on current technologies, and the main challenges are the low yield and high cost of the hydrolysis process. Considerable research efforts have been made to improve the hydrolysis of lignocellulosic materials. Pretreatment of lignocellulosic materials to remove lignin and hemicellulose can significantly enhance the hydrolysis of cellulose. Optimization of the cellulase enzymes and the enzyme loading can also improve the hydrolysis. Simultaneous saccharification and fermentation effectively removes glucose, which is an inhibitor to cellulase activity, thus increasing the yield and rate of cellulose hydrolysis.
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| 5. |
- Galanakis, Charis M., et al.
(författare)
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Recovery and preservation of phenols from olive waste in ethanolic extracts
- 2010
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 85:8, s. 1148-1155
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The current trend of upgrading undervalued agricultural by-products involves the recovery of natural antioxidants. The purpose of this study was to recover phenols from fresh olive mill wastewater (OMW) with their dispersion in 85 mL ethanol per 100 mL and to investigate the effect of processing parameters on the phenol content and antioxidant capacity of the extracts. Moreover, all these characteristics were monitored over a period of 18 weeks in order to examine their preservation inside the ethanolic medium. RESULTS: Extraction time (30-120 min) was not critical for the process, while a pre-treatment step with the addition of ethanol in lower concentrations (20 mL per 100 mL or less) seems to affect negatively the recovery of the phenols in the final (85 mL per 100 mL) ethanolic medium. A pre-heating step of OMW at 50-60 degrees C as well as 80 degrees C resulted in reduction of the phenol concentrations and antioxidant activities of the extracts, probably due to the generation of enzymatic and non-enzymatic reactions, respectively. Nevertheless, extracts from the heat treated samples generally preserved their phenol characteristics as well as ferric ions reduction ability and indeed increased their radical scavenging activity during storage. CONCLUSION: Extraction of the phenols was mainly governed by their solubilization in the hydro-ethanolic mixture as well as the thermal pre-treatment of OMW. Results can be utilized to optimize the recovery and preservation of phenols from OMW in hydro-ethanolic mixtures. (C) 2010 Society of Chemical Industry
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| 6. |
- Gerlach, Inga, et al.
(författare)
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Virtual bioreactor cultivation for operator training and simulation: application to ethanol and protein production
- 2013
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Ingår i: Journal of chemical technology and biotechnology (1986). - : WILEY-BLACKWELL, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA. - 0268-2575 .- 1097-4660. ; 88:12, s. 2159-2168
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDDuring recent years several computer-based operator training simulators (OTS) have been developed that are suitable for the virtual training of operators and other professionals. In the field of bioprocess engineering OTS are rarely used. Furthermore, the effects of using training simulators in bioprocess applications have not been evaluated. less thanbrgreater than less thanbrgreater thanRESULTSThe OTS BioProcessTrainer was applied to bioreactor operations for two biological processes, Saccharomyces cerevisiae, for ethanol production, and recombinant Escherichia coli, for production of green fluorescence protein (GFP). The simulator used a multi-shell model platform that described the biological and physical conditions of the bioreactor for the two bioprocess systems. The simulator enabled the user to plan, operate and control the processes in real or accelerated time. The training resulted in improved ability to manage the whole bioreactor procedure for the two processes. less thanbrgreater than less thanbrgreater thanCONCLUSIONThe study showed that the simulator can be an efficient tool for training of operation, optimization and control of bioprocesses. The mathematical model framework of the simulator can be adapted to a variety of industrial bioprocesses. Thus, it appears likely that this type of OTS may serve as a useful resource in industry for training and continuing education of plant operators and engineers.
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| 7. |
- Jogunola, Olatunde, et al.
(författare)
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Kinetic studies of alkyl formate hydrolysis using formic acid as a catalyst
- 2012
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Elsevier. - 0268-2575 .- 1097-4660. ; 87:2, s. 286-293
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The hydrolysis of methyl formate is the major industrial process forthe production of formic acid. The aim of the work is to determine the reaction kinetics quantitatively in the presence of formic acid catalyst, develop a mathematical model for the reaction system and estimate the kinetic parameters for the purpose of optimization.RESULTS: Liquid phase hydrolysis kinetics of alkyl formates (ethyl and methyl formate) was studied in an isothermal batch reactor at 80-110oC and 20 bar nitrogen pressure. The catalyst of choice was formic acid. The reaction rate was enhanced but the formic acid product yield was slightly suppressed relative to the uncatalysed system. A kinetic model comprising mass balances and rate equations was developed and the kinetic and equilibrium parameters included in the rate equations were estimated from the experimental data with non-linear regression analysis.CONCLUSION: The model was able to predict the experimental results successfully.Furthermore, the results obtained were compared quantitatively with an earlier model involving alkyl formate hydrolysis in a neutral aqueous solution.
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| 8. |
- Jonstrup, Maria, et al.
(författare)
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Decolorization of textile dyes by Bjerkandera sp BOL 13 using waste biomass as carbon source
- 2013
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575. ; 88:3, s. 388-394
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phanerochaete chrysosporium, Trametes versicolor and Bjerkandera sp BOL13 were compared for decolorization of azo dyes supplied individually or as a mixture. The dye decolorization was also evaluated during continuous treatment under non-sterile conditions using a lignocellulosic growth substrate. RESULTS: Bjerkandera sp BOL13 showed the highest dye decolorization potential. This fungus was also found to support high decolorization of Remazol Red RR at an initial pH of 4-6 and when using straw as co-substrate. The fungus was evaluated for Remazol Red RR decolorization in a continuously fed packed-bed bioreactor operated under non-sterile conditions with 3 days of hydraulic retention time. When glucose was supplied as growth-substrate, decolorization efficiencies of 65-90% were maintained for 12 days in a bioreactor packed with wooden material. The decolorization efficiency was lower when glucose was not fed to the fungus or when a plastic material was used as packing. Higher manganese peroxidase and laccase activities were also recorded when the wood packing was used. Contamination caused a drop in decolorization efficiency after 17-19 days operation. CONCLUSIONS: The potential of Bjerkandera sp BOL13 for decolorization of azo dyes under non-sterile conditions using lignocellulosic growth substrates was demonstrated. Research is needed to reduce contamination under non-sterile conditions. (c) 2012 Society of Chemical Industry
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| 9. |
- Mirahmadi, K., et al.
(författare)
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Alkaline Pretreatment of Spruce and Birch to Improve Bioethanol and Biogas Production
- 2010
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Ingår i: BioResources. - : Wiley. - 1930-2126 .- 1930-2126. ; 5:2, s. 928-938
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Tidskriftsartikel (refereegranskat)abstract
- Alkaline pretreatment with NaOH under mild operating conditions was used to improve ethanol and biogas production from softwood spruce and hardwood birch. The pretreatments were carried out at different temperatures between minus 15 and 100 degrees C with 7.0% w/w NaOH solution for 2 h. The pretreated materials were then enzymatically hydrolyzed and subsequently fermented to ethanol or anaerobically digested to biogas. In general, the pretreatment was more successful for both ethanol and biogas production from the hardwood birch than the softwood spruce. The pretreatment resulted in significant reduction of hemicellulose and the crystallinity of cellulose, which might be responsible for improved enzymatic hydrolyses of birch from 6.9% to 82.3% and spruce from 14.1% to 35.7%. These results were obtained with pretreatment at 100 degrees C for birch and 5 degrees C for spruce. Subsequently, the best ethanol yield obtained was 0.08 g/g of the spruce while pretreated at 100 degrees C, and 0.17 g/g of the birch treated at 100 degrees C. On the other hand, digestion of untreated birch and spruce resulted in methane yields of 250 and 30 l/kg VS of the wood species, respectively. The pretreatment of the wood species at the best conditions for enzymatic hydrolysis resulted in 83% and 74% improvement in methane production from birch and spruce.
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| 10. |
- Mohsenzadeh, A., et al.
(författare)
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Alkali pretreatment of softwood spruce and hardwood birch by NaOH/thiourea, NaOH/urea, NaOH/urea/thiourea, and NaOH/PEG for improve of ethanol and biogas production
- 2012
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons Ltd.. - 0268-2575 .- 1097-4660. ; 87:8, s. 1209-1214
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Tidskriftsartikel (refereegranskat)abstract
- Alkali-dissolution pretreatment of softwood spruce and hardwood birch to improve ethanol and biogas production was investigated. The pretreatments were carried out at different temperatures between − 15 and 80 °C with NaOH/thiourea (7/5.5 wt%), NaOH/urea (7/12 wt%), NaOH/urea/thiourea (7/8/6.5 wt%), and NaOH/PEG (7/1 wt%) aqueous solutions. The pretreated materials were then subjected to enzymatic hydrolysis for 72 h. The pretreatments by NaOH/thiourea at − 15 °C improved the hydrolysis yields of spruce from 11.7% to 57% of theoretical yield, and for birch from 23.1% to 83% of theoretical yield. The enzymatic hydrolysis and fermentation of these pretreated materials by NaOH/thiourea with baker's yeast resulted in 54.0% of theoretical yield compared with 10.9% for untreated spruce and 80.9% of theoretical yield compared with 12.9% for untreated birch. Furthermore, anaerobic digestion of pretreated materials resulted in 0.36 L g−1 VS methane compared with 0.23 L g−1 VS for untreated birch, and 0.21 L g−1 VS compared with 0.03 L g−1 VS for untreated spruce.
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