| 1. |
- Ahlström, Cecilia, et al.
(author)
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Pilot-Scale Protein Recovery from Cold-Pressed Rapeseed Press Cake: Influence of Solids Recirculation
- 2022
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In: Processes. - : MDPI AG. - 2227-9717. ; 10:3
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Journal article (peer-reviewed)abstract
- The agricultural sector is responsible for about 30% of greenhouse gas emissions, and thus there is a need to develop new plant-based proteins with lower climate impact. Rapeseed press cake, a by-product from rapeseed oil production, contains 30% high-quality protein. The purpose of this study was to recover protein from cold-pressed rapeseed press cakes on a pilot scale using a decanter and investigate the effect of recirculation of the spent solids fraction on protein yield. Proteins were extracted under alkaline conditions (pH 10.5) followed by precipitation at pH 3.5. Recirculating the spent solids fraction once increased the accumulated protein yield from 70% to 83%. The efficiency of the recovery process was highest in the first and second cycles. The additional yield after the third and fourth cycles was only 2%. The amino acid composition showed high levels of essential amino acids and was not reduced throughout the recovery process. The glucosinolate and phytate content was reduced in the precipitate after one cycle, although additional process steps are needed to further reduce the phytate content and limit the negative effect on mineral uptake.
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| 2. |
- Ahlström, Cecilia, et al.
(author)
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The Effect of Precipitation pH on Protein Recovery Yield and Emulsifying Properties in the Extraction of Protein from Cold-Pressed Rapeseed Press Cake
- 2022
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In: Molecules. - : MDPI AG. - 1420-3049. ; 27:9
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Journal article (peer-reviewed)abstract
- Rapeseed is the second most cultivated oilseed after soybean and is mainly used to produce vegetable oil. The by-product rapeseed press cake is rich in high-quality proteins, thus having the possibility of becoming a new plant protein food source. This study aimed to investigate how the precipitation pH affects the protein yield, protein content, and emulsifying properties when industrially cold-pressed rapeseed press cake is used as the starting material. Proteins were extracted under alkaline conditions (pH 10.5) with an extraction coefficient of 52 ± 2% followed by precipitation at various pH (3.0-6.5). The most preferred condition in terms of process efficiency was pH 4.0, which is reflected in the zeta potential results, where the proteins' net charge was 0 at pH 4.2. pH 4.0 also exhibited the highest protein recovery yield (33 ± 0%) and the highest protein concentration (64 ± 1%, dry basis). Proteins precipitated at pH 6.0-6.5 stabilized emulsions with the smallest initial droplet size, although emulsions stabilized by rapeseed protein precipitated at pH 5.0-6.0 showed the highest emulsion stability at 37 °C for 21 days, with a limited layer of free oil. Overall, emulsion stabilized by protein precipitated at pH 5.0 was the most stable formulation, with no layer of free oil after 21 days of incubation.
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| 3. |
- Arkell, Anders, et al.
(author)
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Evaluation of membrane performance and cost estimates during recovery of sodium hydroxide in a hemicellulose extraction process by nanofiltration
- 2013
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In: Separation and Purification Technology. - : Elsevier BV. - 1873-3794 .- 1383-5866. ; 118, s. 387-393
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Journal article (peer-reviewed)abstract
- The recovery the alkaline solvent from of a residual stream after the extraction of hemicelluloses in wheat bran was investigated. The solution was withdrawn from an ultrafiltration (UF) process in which hemicelluloses were recovered. The UF permeate, containing mainly NaOH, lignin and mono- and oligosaccharides, was treated by nanofiltration (NF). Seven NF membranes were tested in a parametric study, and the two membranes showing the best performance were further evaluated in a concentration study. The mean flux of a Koch SelRO MPF 36 and a Microdyn-Nadir NP010 membrane was about 200 l/m2 h during concentration to a volume reduction of 0.75. The retention of NaOH was <20%, while the retention of lignin and sugars was about 70% and >95%, respectively. Cost estimates for a NaOH recovery process indicated that an NF plant would have a pay-back time of less than 2 months if the plant was run continuously, and 7 months if it was used 25% of the time.
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| 4. |
- Battestini Vives, Mariona, et al.
(author)
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Low-Molecular-Weight Lignin Recovery with Nanofiltration in the Kraft Pulping Process
- 2022
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In: Membranes. - : MDPI AG. - 2077-0375. ; 12:3, s. 310-310
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Journal article (peer-reviewed)abstract
- Kraft lignin is an underutilized resource from the pulp and paper industry with the potential of being a key raw material for renewable fuels and chemicals. The separation of high-molecular-weight lignin from black liquor by ultrafiltration has been widely investigated, while the permeate containing low-molecular-weight lignin has received little attention. Nanofiltration can concentrate the low-molecular-weight lignin. This work, therefore, evaluates nanofiltration for the separation and concentration of low-molecular-weight lignin from the ultrafiltration permeate. For this study, eight flat polymeric sheet membranes and one polymeric hollow fiber membrane, with molecular weight cut-offs ranging from 100 to 2000 Da, were tested. A parametric study was conducted at 50 °C, 2.5–35 bar, and crossflow velocity of 0.3–0.5 m/s. At a transmembrane pressure of 35 bar, the best performing membranes were NF090801, with 90% lignin retention and 37 L/m2·h, and SelRO MPF-36, with 84% lignin retention and 72 L/m2·h. The other membranes showed either very high lignin retention with a very low flux or a high flux with retention lower than 80%. Concentration studies were performed with the two selected membranes at conditions (A) 50 °C and 35 bar and (B) 70 °C and 15 bar. The NF090801 membrane had the highest flux and lignin retention during the concentration studies. Overall, it was shown that the nanofiltration process is able to produce a concentrated lignin fraction, which can be either used to produce valuable chemicals or used to make lignin oil.
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| 5. |
- Battestini Vives, Mariona, et al.
(author)
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Recovery and Characterization of Low-Molecular-Weight Lignin from Ultrafiltered Kraft Black Liquor
- 2022
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In: <em>10<sup>th</sup> Nordic Wood Biorefinery Conference</em>. - Helsinki. - 9789513887728 ; , s. 218-219
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Conference paper (other academic/artistic)abstract
- Kraft lignin is an aromatic polymer found in black liquor, a side stream of the kraft pulping industry.Usually, lignin is burned in the recovery boiler of the pulp mill as a fuel for energy generation. However,lignin has great potential as a raw material for the production of fossil-free fuels, chemicals, andmaterials. Membrane filtration has been studied in the last decades as a key separation method torecover lignin from black liquor. Further studies to concentrate lignin using membrane filtration arerequired, as well as characterization of the resulting lignin fractions for the development of moleculartailored lignin-based applications.In the present work, nanofiltration (NF) was used to concentrate and recover the low-molecularweightlignin obtained from the permeate of ultrafiltration of kraft black liquor. The concentration wasperformed using a NF090801 polymeric NF membrane (SolSep) with a molecular weight cut-off of 350Da. A transmembrane pressure of 25 bar and 50 °C during the filtration increased the lignin contentfrom 27 to 52 g/l, whereas a transmembrane pressure of 15 bar and 70 °C gave an increase from 18 to45 g/l in lignin content. The lignin fraction recovered in the retentate of the NF step was analyzed bysize-exclusion chromatography to ascertain the molecular weight of the lignin. Moreover, Fouriertransform infrared spectroscopy and thermogravimetric analysis were carried out to evaluate thethermal properties and functionalities of the obtained fractions.
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| 6. |
- Eriksson, Johan, 1987, et al.
(author)
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An atom probe tomography study of the chemistry of radiation-induced dislocation loops in Zircaloy-2 exposed to boiling water reactor operation
- 2021
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 550
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Journal article (peer-reviewed)abstract
- This study is complementary to previous atom probe tomography (APT) studies of irradiation effects in the zirconium alloy Zircaloy-2. Using APT in voltage pulse mode, a difference in morphology was observed between clusters of Fe and Ni and clusters of Fe and Cr in Zircaloy-2 exposed to a high fast neutron fluence in a commercial boiling water reactor. The Fe–Ni clusters were disc-shaped with a diameter of 5–15 nm, whereas the Fe–Cr clusters were spheroidal with a diameter of approximately 5 nm. Both types of clusters appeared to be located at irradiation-induced -type dislocation loops aligned in layers normal to the -direction. The concentration of Fe was higher in the Fe–Cr clusters than in the Fe–Ni clusters. The dilute Fe–Ni clusters, which seem to be segregation of Fe and Ni inside the loops, had formed on all three families of first-order prismatic planes with some deviation from perfect -axis alignment. The Fe–Cr clusters might be very small precipitates with a nucleation associated with the loops.
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| 7. |
- Eriksson, Johan, 1987, et al.
(author)
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Nanoscale chemistry of Zircaloy-2 exposed to three and nine annual cycles of boiling water reactor operation — an atom probe tomography study
- 2022
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 561
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Journal article (peer-reviewed)abstract
- Atom probe tomography was used in this work to study the metal close to the metal/oxide interface in the zirconium alloy Zircaloy-2 exposed to three and nine annual cycles of operation in a commercial boiling water reactor. The two exposure times correspond to before and after the onset of acceleration in corrosion, hydrogen pickup, and growth. The alloying elements Sn, Fe, Cr, and Ni were observed to be redistributed after exposure. After both three and nine cycles, clusters containing Fe and Cr and typically of a spheroidal shape with an approximate diameter of 5 nm were observed to be located in layers presumed to be layers of -loops. On average, the cluster number density was slightly higher after nine cycles, with larger and more Cr-rich clusters. However, there were large grain-to-grain variations, which were larger than the differences between the two exposure times. Ni was only occasionally observed in the clusters. Sn was observed to be slightly enriched in the Fe–Cr clusters, but the Sn concentration was higher between than inside the layers of clusters. After nine cycles, clusters of Sn were detected in regions that were depleted of Fe and Cr. Enrichment of Sn, Fe, and Ni at features that appeared to be -component loops was observed after nine cycles, whereas no such features were observed after three cycles. Enrichment of Sn and Fe, and small amounts of Cr and Ni, was observed at grain boundaries after both exposure times. After three cycles, a partially dissolved second phase particle of Zr(Fe,Cr)2 type that contained about ten times more Cr than Fe was observed.
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| 8. |
- Eriksson, Johan, 1987, et al.
(author)
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Solute Concentrations in the Matrix of Zirconium Alloys Studied by Atom Probe Tomography
- 2023
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In: ASTM Special Technical Publication. - 0066-0558. ; STP1645, s. 149-172
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Conference paper (peer-reviewed)abstract
- This work indicates that the matrix content of the alloying elements iron, chromium, and nickel in as-produced commercial Zircaloy-2-type materials is lower than what has been indicated by many previous studies. Atom probe tomography in voltage pulse mode was used to study the matrix content of solutes in Zircaloy-2 of type LK3/L and a similar model alloy, called Alloy 2, of the same heat treatment. Both alloys were analyzed in the as-produced state and after reactor exposure. In the as-produced materials, the concentrations of iron, chromium, and nickel were all below the detection limits of around 10 wt. ppm. After reactor exposure, these alloying elements were observed to reside in clusters at loops, and the matrix content (including clusters) of iron had increased to about 1,200 wt. ppm in the fueled region of the rod and to about half that value in the plenum region. The chromium content in the fueled region was approximately 100 wt. ppm, and the nickel content was approximately 200 wt. ppm. In the plenum region, the content of these elements was lower. However, due to an uneven distribution of clusters, there was a wide scatter in the measured concentrations in the irradiated materials. Additionally, the matrix concentrations of solute elements in (nonirradiated) Zircaloy-2 were investigated for a series of samples subjected to a annealing at 770◦C followed by cooling at different rates. From these measurements, the solubilities at 770◦C were estimated to be around 65 wt. ppm for chromium, at least 37 wt. ppm for iron, and below 9 wt. ppm for nickel. Slow cooling resulted in virtually no iron, chromium, or nickel in the matrix. The concentration of aluminum in the matrix was observed to be between 10 and 20 wt. ppm for all a-annealed samples and for the as-produced materials of commercial heat treatment.
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| 9. |
- Karlsson, Johan, 1984, et al.
(author)
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Atomically resolved tissue integration
- 2014
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 14:8, s. 4220-4223
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Journal article (peer-reviewed)abstract
- In the field of biomedical technology, a critical aspect is the ability to control and understand the integration of an implantable device in living tissue. Despite the technical advances in the development of biomaterials, the elaborate interplay encompassing materials science and biology on the atomic level is not very well understood. Within implantology, anchoring a biomaterial device into bone tissue is termed osseointegration. In the most accepted theory, osseointegration is defined as an interfacial bonding between implant and bone; however, there is lack of experimental evidence to confirm this. Here we show that atom probe tomography can be used to study the implant-tissue interaction, allowing for three-dimensional atomic mapping of the interface region. Interestingly, our analyses demonstrated that direct contact between Ca atoms and the implanted titanium oxide surface is formed without the presence of a protein interlayer, which means that a pure inorganic interface is created, hence giving experimental support to the current theory of osseointegration. We foresee that this result will be of importance in the development of future biomaterials as well as in the design of in vitro evaluation techniques.
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| 10. |
- Karlsson, Johan, 1984, et al.
(author)
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Localized controlled drug delivery from mesoporous implants
- 2014
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In: Technical Proceedings of the 2014 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2014. Washington, DC, United States, 15-18 June 2014. - 9781482258271
-
Conference paper (peer-reviewed)abstract
- Mesoporous materials possess both a well-defined topography on the nanometer scale, and they may serve as hosts for drugs. In this work, titanium implants coated with mesoporous TiO2 thin films have been evaluated both in vitro and in vivo. Material characterization showed that, long-range ordered mesoporous TiO2, with a pore-size of 6 nm, and a narrow pore-size distribution were obtained. An in vivo study demonstrated that the films were robust enough to withstand the implantation procedure. The in vitro apatite formation experiments showed that formation of apatite was higher on the mesoporous surface compared to its nonporous counterpart. In a separate in vivo study, two osteoporosis drugs, alendronate (ALN) and raloxifene (RLX), were immobilised into the nanoporous oxide films. The in vitro drug release tests carried out showed a sustained release of both drugs. The osteogenic response after 28 days of implantation of the drug-loaded implants showed a significantly improved bone fixation.
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