| 1. |
- Aguilera, Adriana Freites, et al.
(författare)
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Screening of ion exchange resin catalysts for epoxidation of oleic acid under the influence of conventional and microwave heating
- 2019
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 94:9, s. 3020-3031
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Tidskriftsartikel (refereegranskat)abstract
- Background: For many chemical systems, it is of great importance to find a durable, active and efficient catalyst that improves the process performance. Epoxidation of oleic acid with peracetic acid (Prilezhaev oxidation) was carried out in an isothermal loop reactor in the presence of heterogeneous catalysts. The kinetic experiments conducted under microwave heating (MW) were compared with identical experiments carried out under conventional (conductive/convective) heating. Extensive screening of heterogeneous catalysts was conducted and the influence of microwave irradiation on the reaction kinetics was studied. Several ion exchange resins were screened to explore their applicability and activity in the epoxidation of oleic acid. The perhydrolysis reaction (peracetic acid formed in situ from acetic acid and H2O2) was promoted with the use of various solid acid catalysts: Amberlite IR-120, Amberlyst 15, Smopex®, Dowex 50x8-100, Dowex 50x8-50, Dowex 50x2-100 and Nafion™.Results: From the selected group of catalysts, Dowex 50-x8100 and Dowex 50x8-50 produced the highest yield of epoxidized oil. Only minor differences in the reactant conversion and the product yield were found in the experiments carried out under microwave exposure compared to the conventionally heated experiments in the presence of several ion exchange resins.Conclusions: The catalytic effect was much more prominent than the microwave effect, because the solid acid catalysts enhanced the slow step of the process, the perhydrolysis of acetic acid. The catalytic effect was very dominant and a considerable improvement of the oleic acid conversion and the epoxide yield was observed in the presence of the top-performing catalysts.
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| 2. |
- Almeida, Joao, et al.
(författare)
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Increased tolerance and conversion of inhibitors in lignocellulosic hydrolysates by Saccharomyces cerevisiae
- 2007
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 82:4, s. 340-349
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Forskningsöversikt (refereegranskat)abstract
- During hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance during the fermentation step. Among the microorganisms that have been evaluated for lignocellulosic hydrolysate ethanol fermentation, the yeast Saccharomyces cerevisiae appears to be the least sensitive. In order to overcome the effect of inhibitors, strategies that include improvement of natural tolerance of microorganism and use of fermentation control strategies have been developed. An overview of the origin, effects and mechanisms of action of known inhibitors on S. cerevisiae is given. Fermentation control strategies as well as metabolic, genetic and evolutionary engineering strategies to obtain S. cerevisiae strains with improved tolerance are discussed.
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| 3. |
- Axelsson, Anders, et al.
(författare)
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Performance of batch and continuous reactors with co-immobilized yeast and beta-galactosidase
- 1991
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 52:2, s. 227-241
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Tidskriftsartikel (refereegranskat)abstract
- The anaerobic fermentation of deproteinized whey with beta-galactosidase coimmobilized with Saccharomyces cerevisiae in calcium alginate gel beads for the production of ethanol has been studied in a continuous horizontal packed bed reactor (HPBR). The results are compared with batch experiments in a stirred tank reactor. The immobilized yeast cells are exposed to conditions that vary with time and location in the reactor, making a true steady state impossible. In spite of a very low specific growth rate-of the order of 0.01 h-1 in the first section of the HPBR-the yeast cell growth, accompanied by bead expansion in this section, was high enough to create a cell concentration gradient along the reactor. The continuous reactor is preferable to the batch reactor as the galactose conversion is more efficient. The highest volumetric productivity obtained in the HPBR was 125 mol ethanol m-3 h-1 (6 g ethanol dm-3 h-1) at a substrate concentration of 164 mol m-3 lactose (56 g dm-3) and a dilution rate of 0.21 h-1, corresponding to a space velocity of 0.51 dm3 dm-3 gel h-1. The ethanol yield from consumed glucose and galactose was 80%. The ethanol yield from lactose was only 70%, as only 75% of the galactose was consumed while all the lactose and glucose were converted.
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| 4. |
- Axelsson, Anders, et al.
(författare)
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Simulation of batch and continuous reactors with co-immobilized yeast and β-galactosidase
- 1991
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 52:4, s. 481-497
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Tidskriftsartikel (refereegranskat)abstract
- A reaction-diffusion model was used to simulate a co-immobilized system utilizing the numerical method of orthogonal collocation. The production of ethanol from deproteinized whey using beta-galactosidase co-immobilized with Saccharomyces cerevisiae in calcium alginate gel beads was chosen as a model system. Calculated concentrations of lactose, glucose, galactose and ethanol were compared with experimental data for a batch reactor and a continuous horizontal packed-bed reactor. The mathematical model has been used to analyse the influence of internal and external mass transfer for the continuous reactor. The external mass transfer was shown to be of minor importance. The introduction of baffles decreased the backmixing in the horizontal packed-bed reactor. Internal mass transfer was found to be the main cause of the reduction in the apparent reaction rate. Thus, much of the expected increase in reaction rate is diminished by mass transfer hindrance when the cell concentration is increased.
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| 5. |
- 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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| 6. |
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| 7. |
- Chen, Genqiang, et al.
(författare)
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Scale-up of production of bacterial nanocellulose using submerged cultivation
- 2018
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 93:12, s. 3418-3427
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: More extensive utilization of bacterial nanocellulose (BNC) is severely restricted by the low efficiency and small scale of the traditional static cultivation. Submerged fermentation in stirred-tank reactors (STRs) is potentially favourable for large-scale production of BNC, but scale-up of cultivation remains challenging. Even though the STR is most commonly used for submerged cultivation in the fermentation industry, there are few previous attempts to scale-up production of BNC to pilot scale using an STR. Furthermore, the question of how scale-up of submerged cultivation affects the properties of the BNC has received very little attention. RESULTS: Four strains were compared in 250-mL shake flasks. Strain DHU-ATCC-1 displayed the highest volumetric productivity, 0.56 g L−1 d−1, and was then cultivated in a 400-mL STR, showing a similar productivity of 0.55 g L−1 d−1. Scale-up using a 75-L STR pilot bioreactor resulted in enhancement of the BNC production rate from 0.056 g d−1 in the shake flasks to 17.3 g d−1 in the 75-L STR, although the productivity decreased to 0.43 g L−1 d−1. During scale-up from shake flasks to 400-mL STR and further on to 75-L STR, the BNC fibers formed more bundles, whereas the fiber diameter decreased from 25.6 to 21.7 nm. The BNC from the 75-L STR exhibited a higher degree of polymerization, specifically 3230, higher degree of crystallinity, specifically 83%, larger crystallites, and improved strength including higher tensile energy absorption index and superior stretch at break. CONCLUSION: It is possible to enhance BNC production, and maintain or improve its properties when scaling up submerged cultivation in STRs.
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| 8. |
- Cimander, C., et al.
(författare)
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Online monitoring of a bioprocess based on a multi-analyser system and multivariate statistical process modelling
- 2002
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 77:10, s. 1157-1168
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Tidskriftsartikel (refereegranskat)abstract
- Multivariate statistical process control (MSPC) was for the first time applied to analyse data from a bioprocess on-line multi-analyser system consisting of an electronic nose (EN), a near-infrared spectroscope (NIRS), a mass spectrometer (MS) and standard bioreactor probes. One hundred and fifty sensor signals from the electronic nose, 1050 wavelength signals from the NIRS, carbon dioxide evolution rate calculated from mass spectrometer signals and standard bioreactor data (eg amount of substrate fed) were interrogated for their ability to model a bioprocess using MSPC. The models obtained were validated on a recombinant Escherichia coli fed-batch process for tryptophan production. Limiting trajectories were defined in the MSPC models for warning, action, and process experience with respect to biomass and tryptophan concentrations. The results showed the capacity and robustness of MSPC models for monitoring with multi-analysers and allowed a comparison of the different analysers' suitability for this kind of data processing. Furthermore, the results demonstrate that MSPC models provide a functional and versatile framework for coping with large information flows and are also suited to a variety of other bioprocessing monitoring and control tasks. ⌐ 2002 Society of Chemical Industry.
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| 9. |
- Cirne, Dores, et al.
(författare)
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Effects of bioaugmentation by an anaerobic lipolytic bacterium on anaerobic digestion of lipid-rich waste
- 2006
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 81:11, s. 1745-1752
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Tidskriftsartikel (refereegranskat)abstract
- The effect of bioaugmentation with an anaerobic lipolytic bacterial strain on the anaerobic digestion of restaurant lipid-rich waste was studied in batch experiments with a model waste containing 10% lipids (triolein) under two sets of experimental conditions: (A) methanogenic conditions, and (B) initially acidogenic conditions in the presence of only the lipolytic strain biomass (4 days), followed by methanogenic conditions. The bioaugmenting lipolytic strain, Clostridium lundense (DSM 17049(T)), was isolated from bovine rumen. The highest lipolytic activity was detected at the beginning of the experiments. A higher methane production rate, 27.7 cm(3) CH4(STP) g(-1) VSadded day(-1) (VS, volatile solids) was observed in experiment A with the presence of the bioaugmenting lipolytic strain under methanogenic conditions. The highest initial oleate concentration, 99% of the total oleate contained in the substrate, was observed in the experiments with the bioaugmenting lipolytic strain under treatment A conditions; the levels of palmitate and stearate were also higher until day 15, indicating that the bioaugmentation strategy improved the hydrolysis of the lipid fraction. In general, the results indicated that degradation of the long chain fatty acids (LCFAs) controlled the digestion process. (c) 2006 Society of Chemical Industry.
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| 10. |
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| 11. |
- Davidsson, Paul, et al.
(författare)
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Software agents for bioprocess monitoring and control
- 2002
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 77:7, s. 761-66
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Tidskriftsartikel (refereegranskat)abstract
- We argue for the appropriateness of using software agents for the monitoring and control of bioprocesses. Different approaches to the design of individual agents as well as complete multi-agent systems are discussed. This is followed by a brief discussion of a number of successful agent-based monitoring and control applications from different domains. We conclude by discussing the advantages and disadvantages of agent technology for monitoring and control of bioprocesses. © 2002 Society of Chemical Industry.
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| 12. |
- Diaz-Morales, Oscar, et al.
(författare)
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Catalytic effects of molybdate and chromate–molybdate films deposited on platinum for efficient hydrogen evolution
- 2023
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 98:5, s. 1269-1278
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Sodium chlorate (NaClO3) is extensively used in the paper industry, but its production uses strictly regulated highly toxic Na2Cr2O7 to reach high hydrogen evolution reaction (HER) Faradaic efficiencies. It is therefore important to find alternatives either to replace Na2Cr2O7 or reduce its concentration.RESULTS: The Na2Cr2O7 concentration can be significantly reduced by using Na2MoO4 as an electrolyte co-additive. Na2MoO4 in the millimolar range shifts the platinum cathode potential to less negative values due to an activating effect of cathodically deposited Mo species. It also acts as a stabilizer of the electrodeposited chromium hydroxide but has a minor effect on the HER Faradaic efficiency. X-ray photoelectron spectroscopy (XPS) results show cathodic deposition of molybdenum of different oxidation states, depending on deposition conditions. Once Na2Cr2O7 was present, molybdenum was not detected by XPS, as it is likely that only trace levels were deposited. Using electrochemical measurements and mass spectrometry we quantitatively monitored H2 and O2 production rates. The results indicate that 3 μmol L−1 Na2Cr2O7 (contrary to current industrial 10–30 mmol L−1) is sufficient to enhance the HER Faradaic efficiency on platinum by 15%, and by co-adding 10 mmol L−1 Na2MoO4 the cathode is activated while avoiding detrimental O2 generation from chemical and electrochemical reactions. Higher concentrations of Na2MoO4 led to increased oxygen production.CONCLUSION: Careful tuning of the molybdate concentration can enhance performance of the chlorate process using chromate in the micromolar range. These insights could be also exploited in the efficient hydrogen generation by photocatalytic water splitting and in the remediation of industrial wastewater.
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| 13. |
- Eivazihollagh, Alireza, et al.
(författare)
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Electrochemical recovery of copper complexed by DTPA and C12-DTPA from aqueous solution using a membrane cell
- 2018
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 93:5, s. 1421-1431
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDThe electrochemical recovery of copper from DTPA and C12-DTPA (a surface-active derivative of DTPA) complex solutions was investigated in a membrane flow cell. Electrolysis time, solution flow rate, applied current density, and solution pH were evaluated.RESULTSThe chelating surfactant C12-DTPA can promote the kinetics of copper electrodeposition more than DTPA depending on the experimental conditions. At a current density of 30 A m–2, a solution flow rate of 0.6 L min–1, and pH 10 after 180 min treatment, the copper recovery and current efficiency were 50% and 43.3%, respectively, in the Cu(II)-DTPA system and about 65% and 53.6%, respectively, in the Cu(II)-C12-DTPA system. The differences in the amount of recovery could be explained in terms of differences in the diffusion of copper complexes with DTPA and C12-DTPA to the cathode, as well as their solution behavior and pH-dependent conditional stability constants (log10 K’CuDTPA3-).CONCLUSIONElectrochemical methods could be effectively combined with foam flotation for the chelating surfactant C12-DTPA, to recover copper and C12-DTPA. This makes the overall treatment more sustainable, and can be helpful in complying with the increasingly stringent environmental regulations
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| 14. |
- Eivazihollagh, Alireza, et al.
(författare)
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Influences of the operational variables on electrochemical treatment of chelated Cu(II) in alkaline solutions using a membrane cell
- 2017
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 92:6, s. 1436-1445
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDThe electrochemical recovery of copper and chelating agent from their complex solution using a membrane flow cell was investigated. The parameters electrolysis time, solution pH, current density, and temperature were investigated.RESULTSElectrochemical investigation indicated that chelating ligands can be recovered by the electrodeposition of copper ions on the cathode. For copper and EDTA recovery, the results indicated that recovery efficiency was affected by time, current density, and temperature. The recovery process was not influenced by pH in the range studied (pH 8–12), which can be explained by the low variation in the conditional stability constant, i.e. Δlog10 K' ≤ 0.7, over the pH range. However, when NTA, EDTA, and DTPA were compared, the results indicated that the recovery efficiency decreased as the conditional stability constant of the chelating agent–Cu(II) complex increased. The maximum current efficiency of copper and EDTA recovery after 5 h of treatment was approximately 85%, whereas the recovery was 80% of the initial concentration (0.05 mol L−1) at a current density of 1 A dm−2, temperature of 333 K, and pH of 10.CONCLUSIONRelatively high recovery efficiency makes the process fairly sustainable and hinders the discharge of copper ions and chelating ligands as pollutants into the environment.
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| 15. |
- Endrodi, Balázs, et al.
(författare)
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Suppressed oxygen evolution during chlorateformation from hypochlorite in the presenceof chromium(VI)
- 2019
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 94:5, s. 1520-1527
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chromium(VI) is a crucial electrolyte component in industrial chlorate production. Due to its toxicity, iturgently needs to be abandoned and its functions fulfilled by new solutions. In the industrial production of sodium chlorate,homogeneous decomposition of the hypochlorite intermediate to chlorate is a key step. As a competing loss reaction,hypochlorite can decompose to oxygen. How chromium(VI) affects these reactions is not well understood.RESULTS: This work shows, for the first time, that chromium(VI) selectively accelerates the chlorate formation from hypochloriteboth in dilute and concentrated, industrially relevant solutions. The effect of the ionic strength and the specific contributionof different electrolyte components were systematically studied. By simultaneously measuring the concentration decayof hypochlorite (UV–vis spectroscopy) and the oxygen formation (mass spectrometry), both the rate and the selectivity of thereactions were evaluated.CONCLUSION: In the presence of chromium(VI) the hypochlorite decomposition is described by the sum of an uncatalyzedand a parallel catalyzed reaction, where oxygen only forms in the uncatalyzed reaction. When removing chromium(VI),the homogeneous oxygen formation increases, causing economic and safety concerns. The need for a catalyst selectivefor chlorate formation is emphasized.
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| 16. |
- 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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| 17. |
- 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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| 18. |
- 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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| 19. |
- 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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| 20. |
- Guo, Xiang, et al.
(författare)
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Production of bacterial nanocellulose and enzyme from [AMIM]Cl-pretreated waste cotton fabrics : effects of dyes on enzymatic saccharification and nanocellulose production
- 2016
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 91:5, s. 1413-1421
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Dyed used cotton textiles is a waste material associated with environmental problems. In this study, waste dyed cotton fabrics were used as feedstock for production of bacterial nanocellulose (BNC) with Gluconacetobacter xylinus and production of enzymes with Trichoderma reesei via enzymatic saccharification.RESULTS Reactive dyes caused almost no inhibition of the cellulase activity at a concentration of 5 g L-1, but decreased the BNC production at concentrations higher than 1 g L-1. The BNC yield reached 12.8 g L-1 with cotton hydrolysate, which was 48% higher than with glucose-based medium. The spent fermentation broth after BNC harvest was subsequently utilized for enzyme production. Cellulase activities produced by T. reesei reached 5.3 U mL(-1) with spent detoxified purple bed sheet (PBS) hydrolysate, and 8.2 U mL(-1) with 2-fold diluted spent PBS hydrolysate, which was almost the same or higher than with glucose medium (5.6 U mL(-1)). The xylanase activities (60.2 U mL(-1) and 88.0 U mL(-1)) obtained with the two media were 3-4 times higher than that obtained with glucose medium (21.0 U mL(-1)).CONCLUSION This approach could contribute to economical conversion of cellulosic waste to two high value-added microbial products, while also providing new raw materials for a more sustainable textile industry.
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| 21. |
- Hashemzehi, Mojgan, et al.
(författare)
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Modelling and optimization of main independent parameters for biodiesel production over a Cu0.4Zn0.6Al2O4 catalyst using an RSM method
- 2021
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 97:1, s. 111-119
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Tidskriftsartikel (refereegranskat)abstract
- In this research, the modeling of Cu0.4Zn0.6Al2O4 catalysts performance and optimizing of esterification reactions were considered by the central composite design (RSM) response method. The main independent parameters of temperature, the ratio of alcohol to oil, the amount of catalyst and time duration have been considered for setting the esterification process. To access the maximum activity in the esterification process, the optimum conditions are estimated at 10.42 the molar ratio of alcohol to oil, 2.98 wt.% for the amount of catalyst at the temperature of 163.37 degrees C and within 4.15 hrs. Under these conditions, the conversion will be above 97.94%. These conditions have been applied to adjust the process of transesterification of waste cooking oil. The reusability of the Cu0.4Zn0.6Al2O4 nanocatalyst in the esterification reaction was investigated in this study. Employed statistical techniques and developed models can be employed as a useful tool for design, prediction, and optimization of the biodiesel production process with effective performance for various industrial applications. (c) 2021 Society of Chemical Industry (SCI).
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| 22. |
- Hochschorner, Elisabeth, et al.
(författare)
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Environmental Life Cycle Assessment of a pre- fragmented high explosive grenade
- 2006
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 81:3, s. 461-475
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Tidskriftsartikel (refereegranskat)abstract
- Organisations today face increasing environmental constraints, e.g. in the form of legal and customer requirements; the defence sector is no exception. There is a need to evaluate and limit environmental effects of defence activities and materiel. In this study we used quantitative Life Cycle Assessment (LCA) and a method for simplified LCA (the Material, Energy, Chemicals and Others (MECO) method) to assess the environmental impacts of a grenade. The aims of the study are to identify aspects in the grenade's life-cycle that have the largest environmental impact, suggest improvement possibilities, make a comparison between different approaches for waste management of munitions, and to perform a demonstrative case for the application of LCA to munitions. Significant environmental aspects of the grenade's life-cycle include use of metals, use of fossil fuels, and detonation outdoors. The study shows that an LCA can be used to analyse environmental impacts from munitions. The simplified LCA gave information that is complementary to the quantitative LCA.
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| 23. |
- Hoyer, Kerstin, et al.
(författare)
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Production of fuel ethanol from softwood by simultaneous saccharification and fermentation at high dry matter content
- 2009
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 84:4, s. 570-577
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The production of bio-ethanol from softwood is considered a promising alternative to fossil fuels in Sweden. In order to make fuel ethanol economically competitive with fossil fuels, it is important to reduce the production cost, which can be done by increasing the dry matter content of the fermentation medium, thus reducing the energy demand in the final distillation of the fermentation broth. Running simultaneous saccharification and fermentation l at higher dry matter content has, however, been found to decrease the ethanol yield. RESULTS: The use of different stirrer types and stirring speeds in the present study has shown to have an influence on the final ethanol yield in SSF with 10% water-insoluble solids (WIS). Also, higher concentration of pretreatment hydrolysate, i.e., with increased inhibitor concentration, at the same WIS resulted in a decreased ethanol yield. However, despite stirring problems and high inhibitor concentration, ethanol was produced at 12% WIS with an ethanol yield in the SSF step of 81% of the theoretical based on the content of fermentable sugars in the fermentor. CONCLUSION: The decrease in ethanol yield in SSF at high dry matter content has been shown to be a combined effect of increased mass transfer resistance and increased inhibitor concentration in the fermentation broth. (c) 2008 Society of Chemical Industry
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| 24. |
- Hulst, A C, et al.
(författare)
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Immobilized Plant Cells: Respiration and Oxygen Transfer
- 1985
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660 .- 0264-3421 .- 1935-1828. ; 35:3, s. 198-204
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Tidskriftsartikel (refereegranskat)abstract
- The influence of support material (calcium alginate, x-carrageenan and agarose), cell loading and, in case of alginate, bead diameter on the rate of respiration of immobilised plant cells (Daucus carota) was investigated. No significant differences were observed between the three supports and no loss of respiration activity occurred as result of immobilisation per se. The results show further that above a critical combination of cell loading and bead diameter limitations of the rate of respiration by diffusion of oxygen increases with increasing loading and diameter.
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| 25. |
- Jogi, Ramakrishna, et al.
(författare)
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Biocrude production through hydro‐liquefaction of wood biomass in supercritical ethanol using iron silica and iron Beta zeolite catalysts
- 2019
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 94:11, s. 3736-3744
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In the production of biofuels from lignocellulosic material, biocrude plays a key role. The present work deals with the biocrude production through hydrothermal liquefaction (HTL) of birch wood in supercritical ethanol over 5 wt. % Fe‐H‐Beta‐150 (SiO2 to Al2O3 ratio of 150) or 5 wt. % Fe‐SiO2 catalyst.RESULTS: The liquid and solid products were characterized with various analytical techniques such as GC‐MS, GC‐FID, SEC, ICP‐MS, p‐XRD, SEM, and solid‐state 13C MAS NMR respectively. The results revealed that 5 wt. % Fe‐H‐Beta‐150, a strongly Brønsted acidic catalyst, enhanced the biocrude formation when compared with a non‐acidic 5 wt. % Fe‐SiO2 catalyst. Hemicellulose and lignin degradation occurred resulting in formation of mainly sugars, acids‐esters and phenolic compounds in liquid phase. The gaseous atmosphere of hydrogen also enhanced the degradation of biomass. The biocrude yield from birch was 25 wt. % over 5 wt. % Fe‐H‐Beta‐150. The Brønsted acidic catalyst gave higher dissolution efficiency and its clear catalytic effect was observed in comparison to non‐acidic 5 wt. % Fe‐SiO2. The degradation level of lignin in presence of 5 wt. % Fe‐H‐Beta‐150 was high 68 wt. % aromatic products were formed, while only 38 wt. % was obtained with 5 wt. % Fe‐SiO2.CONCLUSIONS: Hydrogen atmosphere enhances the fractionation of birch wood when compared to argon atmosphere. 5 wt. % Fe‐H‐Beta‐150 catalyst enhanced very strongly the degradation of hemicellulose and lignin in biomass to sugars and acid‐esters as well as phenolic compounds, respectively compared to the non‐acidic 5 wt. % Fe‐SiO2 catalyst.
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| 26. |
- 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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| 27. |
- Krauklis, Andrejs, et al.
(författare)
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FeOOH and Mn8O10Cl3 modified zeolites for As(V) removal in aqueous medium
- 2017
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley-Blackwell. - 0268-2575 .- 1097-4660. ; 92:8, s. 1948-1960
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Arsenic in drinking water poses serious potential health risks in more than 30 countries with total affected population of around 100 million people. The present study is devoted to the development of innovative sorbents based on zeolite materials for As(V) sorption by modifying raw materials with iron oxyhydroxide and manganese oxychloride. Natural clinoptilolite and synthetic zeolite A were modified in order to obtain improved sorption of As(V). Sorption properties of newly developed sorbentswere studied. Zeolites containing natural clinoptilolite are chosen due to relatively lowcost and their broad use in industrial production as well as characteristic large surface area. RESULTS: Results obtained indicate that modification of zeolites with FeOOH and Mn8O10Cl3 significantly improves the As(V) sorption capacity of newly developed materials. As(V) sorption on FeOOH-modified aluminosilicates follows the Langmuir model, while on unmodified aluminosilicates it is described by the Freundlich model. As(V) sorption kinetics on both modified and unmodified materials most precisely can be described by Lagergren's pseudo-second-order kinetic model. Elevated As(V) concentration on the surface of Mn8O10Cl3 crystals and amorphous FeOOH indicates these compounds as responsible for sorption increase. CONCLUSION: Developed sorbents show improved performance in comparison with their unmodified counterparts, with a dramatic increase in As(V) sorption capacity up to 99.3 times in the case of FeOOH-modified calcium zeolite A. These materials have great potential for As(V) removal in aqueousmedium. (C) 2017 Society of Chemical Industry
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| 28. |
- Larsson, Madeleine, et al.
(författare)
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Anaerobic digestion of wastewater from the production of bleached chemical thermo-mechanical pulp : higher methane production for hardwood than softwood
- 2017
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 2:1, s. 140-151
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chemical thermo-mechanical pulp (CTMP) mills holds a large biomethane potential in their wastewater. Their broadened market has involved increased bleaching and utilisation of different raw materials. Therefore, the main aim of this study was to obtain and maintain a stable anaerobic digestion (AD) process, with a high methane yield and total organic carbon (TOC) reduction, when digesting CTMP wastewater, from different production protocols including shifts in raw material and bleaching. A lab-scale upflow anaerobic sludge bed (UASB) reactor was used for the tests.RESULTS: The variations in raw material (aspen, birch and spruce) and consequently in TOC-loading (3.6-6.6 kg TOC m-3 and day-1) did not affect the UASB process negatively. Methane production values from 360 to 500 NmL g TOC-1 were obtained, with the highest yield for wastewater from the production of birch- followed by aspenand spruce pulp. The acetic acid and fTOC reduction ranged 90 to 95% and 61 to 73%, respectively.CONCLUSIONS: The stable process performance maintained during shifts in raw material for pulp production show that AD is feasible for CTMP mills with a diversified product portfolio. Furthermore, the increased use of hardwood and bleaching will most likely increase their potential as a biomethane producer.
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| 29. |
- Le, Ha V., et al.
(författare)
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Stepwise conversion of methane to methanol on Cu and Fe/zeolites prepared in solid state: the effect of zeolite type and activation temperature
- 2023
-
Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 1097-4660 .- 0268-2575. ; 98:11, s. 2716-2725
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Grand efforts have been recently devoted to the development of catalysts based on the excellent performance of Cu- and Fe-dependent enzymes in methanotrophic bacteria for the partial oxidation of methane to methanol under ambient conditions. As a continuation of the study on the stepwise manner for this conversion over zeolite-based catalysts, in this work, the effects of zeolite topology and activation temperature on the catalytic performance of Cu- and Fe-containing zeolites were investigated. RESULTS: Cu species exchanged in the medium-pore zeolites (mordenite, ZSM-5, and ferrierite) afforded better methanol production, while large-pore zeolites (zeolite β and zeolite γ) were inappropriate to accommodate active Cu sites. Notably, Cu/silicalite-1 containing CuO species was also reactive to methane after the activation in O2, yielding a minor methanol amount. Furthermore, the activity of Fe/mordenite towards the methanol in the O2-assisted procedure was reported for the first time but with a much lower yield as compared to that of Cu/mordenite. The methanol yield over Cu/mordenite increased with the activation temperature because increasing the activation temperature favored the Cu-exchange degree with a higher priority at the side pockets as compared to the main channels of mordenite, as evidenced from infrared analysis. CONCLUSION: The selective oxidation of methane to methanol by O2 via a stepwise manner can be obtained over both ion-exchanged Cu species and well-dispersed CuO nanoparticles with better activity being recorded for the former. The activity of Cu-exchanged zeolites was considerably dependent on the zeolite topology and the charge-balancing position of the Cu2+ cations.
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| 30. |
- Mamma, Diomi, et al.
(författare)
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Effect of adsorption characteristics of a modified cellulase on indigo backstaining
- 2004
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 79:6, s. 639-644
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Tidskriftsartikel (refereegranskat)abstract
- The effect of limited proteolysis (digestion) of a commercial cellulase preparation (Ecostone((R)) L350) on backstaining with indigo was investigated. The influence of protease (papain) concentration on limited proteolysis of cellulase preparation was studied, applying different ratios of papain/cellulase (w/w). Changes in adsorption on Avicel cellulose of the non-digested compared with the papain-digested Ecostone((R)) L350 were examined using the Langmuir adsorption isotherm. The non-digested Ecostone((R)) L350 exhibited stronger interaction to Avicel cellulose compared with the digested form, while the maximum efficiency of cellulase adsorption to Avicel cellulose decreased after digestion. When papain-digested Ecostone((R)) L350 was applied on cotton fabrics during the dyeing procedure with indigo, a reduction of indigo backstaining was obtained compared with the non-digested Ecostone((R)) L350.
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| 31. |
- Mandenius, Carl-Fredrik, et al.
(författare)
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Mini-review: soft sensors as means for PAT in the manufacture of bio-therapeutics
- 2015
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 90:2, s. 215-227
-
Forskningsöversikt (refereegranskat)abstract
- This mini-review discusses how soft sensors can contribute to accomplish FDAs process analytical technology (PAT) ambitions in the manufacture of bio-therapeutics. Focus is on applications with protein-based drugs (proteins, antibodies), but also gene therapy vectors as well as cell cultures are considered where chemical and bio-analytical as well as mathematical and statistical methods are used as tools. An overview of existing soft sensor alternatives and how these can be configured to meet typical industrial needs is provided. It is noted how several of these needs coincide with the PAT regulatory incentives but do also address process economic aspects of bio-therapeutic manufacture. Evaluation of soft sensor alternatives is highlighted in relation to the production targets, quality attributes and the specification of these as well as shortcomings and needs for further improvements.
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| 32. |
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| 33. |
- 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
-
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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| 34. |
- Moreno, David, 1986, et al.
(författare)
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Exploring laccase and mediators behavior during saccharification and fermentation of steam-exploded wheat straw for bioethanol production
- 2016
-
Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 1097-4660 .- 0268-2575. ; 91:6, s. 1816-1825
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Laccases represent a very powerful tool to improve biorefining processes from lignocellulosic feedstocks. These enzymes are being investigated not only for potential use as pretreatment agents in bioethanol production, mainly as a delignifying agent, but also as a biotechnological tool for removal of inhibitors (mainly phenols) of subsequent fermentation processes. RESULTS: In this work, the treatment of the water insoluble solids (WIS) fraction from steam-exploded wheat straw with Pycnoporus cinnabarinus laccase and different laccase-mediator systems (LMS) did not decrease the lignin content, resulting in lower glucose recoveries during the subsequent saccharification. In combination with an alkaline extraction, the treatment with laccase/LMS produced no synergistic effect enhancing the delignification or saccharification of WIS. In contrast, laccase reduced the soluble phenols (95% of the total phenols identified) of the whole slurry from steam-exploded wheat straw, improving the yeast performance during the fermentation and enhancing the ethanol yields. CONCLUSIONS: The efficiency of P. cinnabarinus laccase with or without mediators as a delignifying agent on steam-exploded wheat straw for bioethanol production was not observed, whereas its detoxification ability was shown. Thus, new laccases or designing laccases with ability to delignify and detoxify simultaneously needs to be explored in order to produce major ethanol global yields.
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| 35. |
- Nair, Ramkumar B., et al.
(författare)
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Optimizing dilute phosphoric acid pretreatment of wheat straw in the laboratory and in a demonstration plant for ethanol and edible fungal biomass production using Neurospora intermedia.
- 2016
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660.
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND : A method is described that uses dil. phosphoric acid for wheat straw pretreatment and subsequent ethanol and fungal biomass prodn. with the edible fungus Neurospora intermedia. Dil. phosphoric acid pretreatment of wheat straw was optimized at a lab. scale, and the results were validated in a biorefinery demonstration plant for the first time. The various conditions for the dil. acid pretreatment include such factors as phosphoric acid concns. (0.5-3.0% w/v), temp. (150-210 °C), and reaction time (5-20 min). RESULTS : The optimal pretreatment conditions were detd. as an acid concn. of 1.75% (w/v) at a temp. of 190 °C for 15 min, based on the max. enzymic digestibility with the min. inhibitor release. The efficiency of enzymic polysaccharide hydrolysis was 36% for untreated straw and 86% for straw pretreated with dil. phosphoric acid. Scale up of the pretreatment at a biorefinery demonstration plant improved the process, with the subsequent efficiency of polysaccharide hydrolysis being 95% of the theor. max. Ethanol fermn. of enzymically hydrolyzed wheat straw using N. intermedia showed an improvement in the ethanol yield from 29% (with untreated straw) to 94% (with dil. phosphoric acid pretreated straw) of the theor. max. CONCLUSION : This study opens up an alternative strategy for the efficient use of wheat straw for the prodn. of ethanol and edible fungal biomass in existing wheat-to-ethanol plants.
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| 36. |
- Nazir, Muhammad Tahir, et al.
(författare)
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Production of filamentous fungal biomass with increased oil content using olive oil as a carbon source
- 2022
-
Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660.
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDVegetable oil is more difficult for microorganisms to degrade compared with carbohydrates and protein. Oil-rich waste creates serious environmental and health concerns if it remains untreated. The aim of the work reported here was to evaluate the effects on the nutritional composition of filamentous fungal biomass by growing it in pure olive oil as a carbon source.RESULTSThe growth of different filamentous fungal strains (Aspergillus oryzae, Neurospora intermedia and Rhizopus oryzae) was investigated in pure olive oil. A pre-germination stage of either glucose or yeast extract was necessary for successful fungal growth in olive oil. A. oryzae showed superior performance in comparison with N. intermedia and R. oryzae in terms of biomass growth. The obtained biomass from A. oryzae and N. intermedia was analyzed for protein, fat, ash and alkali-insoluble material, where the presence of olive oil had a steering effect on biomass growth (16 g L−1 with oil versus 4 g L−1 without oil). Nutritional composition of the fungal biomass of A. oryzae contained 0.33% fat and 48% protein when cultivated in medium without olive oil supplementation, while 31% fat and 14% protein contents were observed in the presence of olive oil-containing medium. Similar trends for fat and protein contents were observed for the biomass of N. intermedia. Moreover, microscopy confirmed the presence of oil globules inside the fungal cells.CONCLUSIONSFat composition of fungal biomass can be steered through addition of olive oil, which increases the versatility of the produced biomass for various applications, namely in feed, food and biofuel production.
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| 37. |
- Nilsson, BK, et al.
(författare)
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Diffusion rates in a dense matrix of methane-producing microorganisms
- 1989
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 44:4, s. 255-260
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Tidskriftsartikel (refereegranskat)abstract
- The diffusion rate of a species, in a dense matrix of methane-producing microorganisms, was determined experimentally. To this end, a specially designed diaphragm diffusion cell was utilized. The experimental results revealed that the effective diffusion coefficient in a microorganism matrix was 22–33% of the diffusion coefficient in pure water.
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| 38. |
- Okoli, Chuka, et al.
(författare)
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Application of magnetic iron oxide nanoparticles prepared from microemulsions for protein purification
- 2011
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 86:11, s. 1386-1393
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Magnetic nanoparticles are of immense interest for their applications in biotechnology. This paper reports the synthesis of magnetic iron oxide nanoparticles from two different water-in-oil microemulsion systems (ME-MIONs), their characterization and also their use in purification of coagulant protein. RESULTS: ME-MIONs have demonstrated to be an efficient binder in the purification of Moringa oleifera protein when compared with the superparamagnetic iron oxide nanoparticles prepared from coprecipitation in aqueous media. The size and morphology of the ME-MIONs were studied by transmission electron microscopy (TEM) while the structural characteristics were studied by X-ray diffraction (XRD). The microemulsion magnetic iron oxide nanoparticles (ME 1-MION and ME 2-MION) obtained have a size range 7-10 nm. The protein and ME-MIONs interaction was investigated by Fourier transform infrared spectroscopy (FT-IR); the presence of three peaks at 2970, 2910 and 2870 cm(-1) respectively, confirms the binding of the protein. The purification and molecular weight of the coagulant protein was 6.5 kDa as analyzed by SDS-PAGE. CONCLUSION: The ME-MIONs have the advantage of being easily tailored in size, are highly efficient as well as magnetic, cost effective and versatile; they are, thus, very suitable for use in a novel purification technique for protein or biomolecules that possess similar characteristics to the Moringa oleifera coagulant protein.
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| 39. |
- Palmarola Adrados, Beatriz, et al.
(författare)
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Pretreatment of barley husk for bioethanol production
- 2005
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 80:1, s. 85-91
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the optimization of steam pretreatment of barley husk for high pentose and hexose recovery in the subsequent enzymatic hydrolysis step, as well as high ethanol yield, following simultaneous saccharification and fermentation. The parameters optimized in the steam pretreatment step were residence time (5-15 min), temperature (190-215 degreesC), and concentration of the acid catalyst (0 or 0.5% H2SO4). A microwave oven was employed for screening of the optimal conditions to obtain the highest sugar yield following combined pretreatment and enzymatic hydrolysis. The final optimization of the pretreatment prior to enzymatic hydrolysis was performed on a larger scale, in a steam pretreatment unit. Simultaneous saccharification and fermentation was carried out following steam pretreatment on 5 and 10% dry matter steam-pretreated slurries. Fermentability tests were performed to determine the effect of by-products (ie furfural and 5-hydroxymethyl furfural) in the bioconversion of glucose to ethanol by baker's yeast. The maximum glucose yield, 88% of the theoretical, was obtained following steam pretreatment with 0.5% H2SO4 at 200degreesC for 10 min. Under these conditions, a sugar to ethanol conversion of 81% was attained in simultaneous saccharification and fermentation. (C) 2004 Society of Chemical Industry.
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| 40. |
- Pappenreiter, Magdalena, et al.
(författare)
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Product sieving of mAb and its high molecular weight species in different modes of ATF and TFF perfusion cell cultures
- 2023
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 98:7, s. 1658-1672
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tangential flow filtration (TFF) systems are widely used cell retention devices in perfusion cultures, but significant challenges occur with their prolonged operation. A well-known and common issue includes membrane fouling, which leads to reduced permeate flow and increased product retention. The fouling behavior in hollow fibers have been studied widely and the application of alternating flow profiles, cell lysis, shear stress, and membrane pore size have been found to be major contributors to this phenomenon. RESULTS: In this work, different process set ups and conditions were tested using magnetic levitation pumps for low shear TFF systems in small-scale perfusion bioreactors (200 mL). A novel concept based on the application of reverse flow across the hollow fiber using two magnetically levitating pumps was validated with a Chinese Hamster Ovary cells (CHO) cell line producing a recombinant monoclonal antibody. Product sieving could be improved by 30% when a dynamic recirculation flow was applied. Furthermore, minimal product retention was achieved by reversing the flow of two alternating pumps with short cycle times. Besides this, a correlation was found between the passage of high molecular weight species to the harvest stream of the perfusion process and the flow direction, as well as the degree of product sieving. CONCLUSION: TFF with a reverse flow is a valuable alternative to an alternating tangential flow (ATF) system for overcoming antibody retention and it can be used at various scales and at a constant bioreactor volume. The comparison of ATF and TFF showed differences in product yield and purity and is, therefore, an important point for process design.
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| 41. |
- Parawira, Wilson, et al.
(författare)
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Volatile fatty acid production during anaerobic mesophilic digestion of solid potato waste
- 2004
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 79:7, s. 673-677
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Tidskriftsartikel (refereegranskat)abstract
- The production of volatile fatty acids by anaerobic digestion of solid potato waste was investigated using a batch solid waste reactor with a working capacity of 2 dm(-3) at 37degreesC. Solid potato waste was packed into the digester and the organic content of the waste was released by microbial activity by circulating water over the bed, using batch loads of 500g or 1000 g potato waste. The sequence of appearance of the volatile fatty acids was (acetic, propionic); (n-butyric); (n-valeric, iso-valeric, caproic); (iso-butyric). After 300 h digestion of potato waste on a small scale, the fermentation products were chiefly (mg g(-1) total VFAs): acetic acid (420), butyric acid (310), propionic acid (140) and caproic acid (90), with insignificant amounts of iso-butyric acid, n-valeric and iso-valeric acids. When the load of potato solids was increased, the volatile fatty acid content was similar, but butyric acid constituted 110 mg g(-1) and lactic acid 400 mg g(-1) of the total volatile fatty acids. The maximum soluble chemical oxygen demand (COD) achieved under the experimental conditions used was 27 and 37 g COD dm(-3) at low and high loadings of potato solids, respectively. The total volatile fatty acids reached 19 g dm(-3) of leachate at both loads of potato solid waste. Gas production was negligible, indicating that methanogenic activity was effectively inhibited. (C) 2004 Society of Chemical Industry.
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| 42. |
- Pavankumar, Asalapuram Ramachandran, et al.
(författare)
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Identification of Moringa oleifera protein responsible for the decolorization and pesticide removal from drinking water and industrial effluent - an in silico and in situ evaluation
- 2015
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 90:8, s. 1521-1526
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Tidskriftsartikel (refereegranskat)abstract
- Natural products are always in demand, especially in the food and water treatment industry, to reduce health hazards caused by the prolonged use of chemicals. Though crude seed extract of Moringa oleifera (MOCE) is used for decolouration, the protein responsible for such activity is not fully known. In this study, in silico analysis of Moringa oleifera coagulant protein (MOCP; a predominant oligomeric protein in MOCE) was undertaken to check its molecular interactions with water and soil pollutants, in order to identify the protein accountable for such activities. The molecular docking studies of MOCP with azo dyes like congo red, tartrazine) and a pesticide (dichlorodiphenyltrichloroethane) revealed a strong binding affinity (-5.66, -5.33 and -5.04, respectively, kJ mol(-1)) between the protein and the pollutants through hydrogen bonding and electrostatic interactions. Further, these results were verified in situ with MOCP, a recombinant form of MOCP (MOCRP) and MOCE against congo red (100 mg L-1) and revealed the dye removal efficiency of 63.8%, 65.7%, and 72.3%, respectively. While the jar test results of synthetic coloured water and industrial textile effluent containing congo red showed 51.6% and 58.3%. Hence, we believe that the MOCP is responsible for multiple activities of MOCE and suggest its prospective use for large-scale treatment of drinking water and industrial effluents.
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| 43. |
- Sarkar, P, et al.
(författare)
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Screen-printed biosensor for allergens
- 2005
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley andamp;amp; Sons, Ltd. - 0268-2575 .- 1097-4660. ; 80:12, s. 1389-1394
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Tidskriftsartikel (refereegranskat)abstract
- Allergen levels in indoor environments, leading to many diseases, eg asthma, rhinitis and conjunctivitis, affect a large and increasing fraction of the population. A quite effective and inexpensive method of a rough but very rapid overall assessment of total allergen level in the environment has been developed. The method involved estimation of protein in allergen extracts by screen-printed electrodes using two different techniques. The biosensor comprised a rhodinised carbon working electrode, a silver/silver chloride reference electrode and a carbon counter electrode. In the first method the enzyme protease reacted with allergen protein to release amino acid, which produced hydrogen peroxide in the presence of amino acid oxidase. This was detected amperometrically. The second method used potassium bromide as electrolyte and the electrode was subjected to dual potential. Bromine, released due to electrolysis at higher potential, was consumed by the allergen protein at lower potential. In the first method, a unique technique was used to microencapsulate the enzyme protease and immobilise it on the surface of the electrode by in-situ polymerisation to avoid contact with the amino acid oxidase. A total of seven allergens were tested and the results gave a good correlation with the standard protein measurement method. Environmental specimens from indoors, schools and workplaces can be evaluated for the aeroallergens produced by dust mites, animal hairs, cockroach debris, pollens, etc as a means of determining the exposure risk. (c) 2005 Society of Chemical Industry.
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| 44. |
- Sifontes Herrera, Víctor A, et al.
(författare)
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Sugar hydrogenation over a Ru/C catalyst
- 2011
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Society of Chemical Industry. - 0268-2575 .- 1097-4660. ; 86:5, s. 658-668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In recent years, exploitation of renewable resources has gained considerable attention. In this respect, polyols derived from the hydrogenation of sugar molecules are versatile molecules with a variety of uses, such as low-caloric sweeteners. The hydrogenation of D-maltose, D-galactose, L-rhamnose and L-arabinose was carried out on a finely dispersed Ru/activated carbon catalyst with the objective of studying the kinetics of the production of the corresponding polyols. The reactions were carried out in a stirred tank reactor at temperatures ranging from 90 to 130 °C and hydrogen pressures from 40 to 60 bar. RESULTS: Sugar conversions up to 100% were achieved. Some by-product formation affecting the quality of the selectivity was also observed at elevated operating conditions. The catalyst was characterized by scanning electron microcopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectrometry (ICP-OES) and nitrogen physisorption. Kinetic models based on the Langmuir Hinshelwood assumptions were proposed for the reactions and a nonlinear regression was performed to obtain the numerical values of the kinetic parameters. CONCLUSIONS: The kinetic models predicted well the sugar hydrogenation process and the kinetic parameters were established. The model can be used to predict the behaviour of batchwise operating slurry reactors. Copyright © 2011 Society of Chemical Industry
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| 45. |
- Sims, Cassie, et al.
(författare)
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Feeding the future : developing the skills landscape in the agri-food sector
- 2022
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 97:3, s. 549-557
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Tidskriftsartikel (refereegranskat)abstract
- The agri-food sector and supply chain is a foundational component of society and is required for healthy populations across the globe. Feeding the world, not only with enough calories, but with nutritious food that has been sustainably sourced and processed, is a continuous and developing challenge. Despite this, careers in research and development opportunities in the agri-food sector have less visibility in comparison to other sectors, and we argue that agri-food remains under-represented in education and training, from school through to higher education. In this perspective, we explore how diversity in people, skills and education contributes to the agri-food sector, and how fostering this diversity could help to solve some of the big challenges faced in 2021 and beyond. Specific focus is given to education and training schemes, and the lack of agri-food topics in relevant science degrees.
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| 46. |
- Soudham, Venkata Prabhakar, et al.
(författare)
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Enzymatic hydrolysis of Norway spruce and sugarcane bagasse after treatment with 1-allyl-3-methylimidazolium formate
- 2013
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 88:12, s. 2209-2215
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Enzymatic hydrolysis of cellulose in lignocellulosic materials suffers from slow reaction rates due to limited access to enzyme adsorption sites and to the high crystallinity of the cellulose. In this study, an attempt was made to facilitate enzymatic hydrolysis by pretreatment of cellulosic materials using the ionic liquid (IL) 1-allyl-3-methylimidazolium formate ([Amim][HCO2]) under mild reaction conditions. The effect of the IL was compared with that of thermochemical pretreatment under acidic conditions. RESULTS: The lignocellulosic substrates investigated were native and thermochemically pretreated Norway spruce and sugarcane bagasse. Microcrystalline cellulose (Avicel) was included for comparison. The IL treatments were performed in the temperature range 45-120°C and, after regeneration and washing of the cellulosic substrates, enzymatic saccharification was carried out at 45°C for 72h. After 12h of hydrolysis, the glucose yields from regenerated native spruce and sugarcane bagasse were up to nine times higher than for the corresponding untreated substrates. The results also show positive effects of pretreatment using [Amim][HCO2] on the hydrolysis of xylan and mannan. Conclusion: The present work demonstrates that both native wood and agricultural residues are readily soluble in [Amim][HCO2] under gentle conditions, and that pretreatment with ionic liquids such as [Amim][HCO2] warrants further attention as a potential alternative to conventional pretreatment techniques.
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| 47. |
- Ståhl, Stefan, et al.
(författare)
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Affinity proteins and their generation
- 2013
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 88:1, s. 25-38
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Forskningsöversikt (refereegranskat)abstract
- Engineered affinity proteins have, together with antibodies and antibody derivatives, become indispensable tools in many areas of life science and with an increasing number of applications. The need for high-throughput methods for generation of these different affinity proteins is evident. Today, combinatorial protein engineering is the most successful strategy to generate novel affinity proteins of non-immunoglobulin origin. In this approach, high-complexity combinatorial libraries are constructed from which affinity proteins are isolated using appropriate selection methods, thus circumventing the need for detailed knowledge of the protein structure and the binding mechanism that is necessary in more rational approaches. Since the introduction of the phage display technology, several alternative selection systems have been developed for this purpose. This review presents briefly some of the more commonly used affinity proteins, and gives an overview of the different methods and challenges related to the generation of library diversity and the selection methods available for the isolation of affinity proteins with desired properties.
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| 48. |
- Svensson, Mattias, et al.
(författare)
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Straw bed priming enhances the methane yield and speeds up the start-up of single-stage, high-solids anaerobic reactors treating plant biomass
- 2006
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 81:11, s. 1729-1735
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Tidskriftsartikel (refereegranskat)abstract
- A simple and potentially inexpensive implementation of a high-solids reactor is a single-stage, stratified bed reactor, in which the bed is made up of the plant biomass fed into the system. In the present study, the stratified bed was started up for a period of four weeks by either direct feeding of sugar beet leaves at four different feeding rates, or by introducing a straw bed primer which was batch digested without feeding. During weeks five to six both systems were fed with sugar beet leaves at such a rate that the total amount of beet leaves added at the end of week six was the same in each of the four corresponding pairs of straw and 'no-straw' reactors. Straw bed priming enhanced the methane yield of the sugar beet leaves, with 0.33-0.37 in 3 kg(-1) VSadded (volatile solids) accumulated at average solid retention times as short as 11-25 days, while the 'no-straw' reactors had lower yields at longer average solid retention times. The levels and speciation of the organic acids suggested that both the rate and extent of the anaerobic digestion of the sugar beet leaves added in the straw reactors were improved. At the highest loading rate, the straw reactor failed, while the 'no-straw' reactor did not. It is hypothesised that the microbial biomass was better established in the straw reactors than in the 'no-straw' reactors.
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| 49. |
- Turan, Meltem, et al.
(författare)
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Polynomial approaches in improving accuracy of probability distribution estimation using the method of moments
- 2024
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 99:5, s. 1056-1068
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Determination of a probability density function (PDF) is an area of active research in engineering sciences as it can improve process systems. A previously developed polynomial method-of-moments-based PDF estimation model has been applied in the research to produce accurate approximations to both standard and more complex PDF. A model with a different polynomial basis than a monomial is still to be developed and evaluated. This is the work that is undertaken in this study.RESULTS: A set of standard PDF (Normal, Weibull, Log Normal and Bimodal) and more complex distributions (solutions to the Smoluchowski coagulation equation and Population Balance equation) were approximated by the method-of-moments using Chebyshev, Hermite and Lagrange polynomial-based density functions. Results show that Lagrange polynomial-based models improve the fit compared to monomial based-modeling in terms of RMSE and Kolmogorov-Smirnov test statistic estimates. The Kolmogorov-Smirnov test-statistics decreased by 19% and the RMSE values were improved by around 85% compared to the standard monomial basis when using Lagrange polynomial basis.CONCLUSION: This study indicates that the procedure using Lagrange polynomials with method-of-moments is a more reliable reconstruction procedure that calculates the approximate distribution using lesser number of moments, which is desirable.
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| 50. |
- Winestrand, Sandra, et al.
(författare)
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Oxalate decarboxylase of Trametes versicolor : biochemical characterization and performance in bleaching filtrates from the pulp and paper industry
- 2012
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Ingår i: Journal of chemical technology and biotechnology (1986). - : Wiley. - 0268-2575 .- 1097-4660. ; 87:11, s. 1600-1606
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oxalate decarboxylase (ODC) from acid-induced cultures of the white-rot fungus Trametes versicolor was purified and characterized with respect to its biochemical properties and the possibility to utilize the enzyme for treatment of process water with the intention to prevent problems with calcium-oxalate scaling in the pulp and paper industry. RESULTS: Purified T. versicolor ODC was identified by tandem mass spectrometry. As estimated by using SDS-PAGE, the molecular mass was 69 kDa, and 60 kDa after deglycosylation with N-glycosidase F. The pH optimum was 2.5 and the temperature optimum was 4045 degrees C. The effects of ten potential inhibitors in industrial filtrates were examined. The enzyme was sensitive to low concentrations (0.1 mmol L-1) of chlorite and sulfite. T. versicolor ODC exhibited activity in 16 filtrates collected from mechanical pulping and kraft pulping. It had higher activity than ODC from Aspergillus niger in all of the filtrates and higher activity than oxalate oxidase from barley in all filtrates except two. CONCLUSIONS: The investigation shows basic biochemical properties of T. versicolor ODC and indicates that the enzyme may be useful for treatment of industrial filtrates under acidic conditions. Copyright (c) 2012 Society of Chemical Industry
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