| 1. |
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34th EMS Summer School : Membranes in Biorefineries
- 2017
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Proceedings (redaktörskap) (refereegranskat)abstract
- The EMS Summer School “Membranes in Biorefineries” is related to Annex XVII of the Industrial Energy Related Technologies and Systems (IETS)Implementing Agreement: “Membrane Filtration for Energy-efficient Separation of Lignocellulosic Biomass Components” co-ordinated by the Department of Chemical Engineering at Lund University, Sweden.The IETS Implementing Agreement is an initiative within IEA (International Energy Agency). The mission of IETS is to foster international co-operation among OECD and non-OECD countries for accelerated research and technology development of industrial energy-related technologies and systems. In doing so, IETS seeks to enhance knowledge of cost-effective new industrial technologies and system layouts that enable increase productivity and better product quality while improving energy efficiency and sustainability.
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| 2. |
- Al-Rudainy, Basel, et al.
(författare)
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Galactoglucomannan Recovery with Hydrophilic and Hydrophobic Membranes: Process Performance and Cost Estimations
- 2019
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 9:8
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we compared the GR51PP (hydrophobic/polysulfone) membrane with a series of hydrophilic (regenerated cellulose) membranes with the aim of increasing the retention of products and decreasing membrane fouling. The raw material used was a sodium-based spent sulfite liquor from the sulfite pulping process of spruce and pine. The results show that the hydrophilic membranes were superior to the hydrophobic membranes in terms of higher fluxes (up to twice the magnitude), higher product retentions and less fouling (up to five times lower fouling). The fouling was probably caused by pore blocking as observed in earlier studies. However, the hydrophilic membranes had a lower affinity for lignin, which was indicated by the lower retention and fouling. This also resulted in a separation degree, which was higher compared with the hydrophobic membrane, thus yielding a higher galactoglucomannan (GGM) purity. 2D HSQC NMR results show that no major structural differences were present in the hydrophilic and hydrophobic retentates. A techno-economical evaluation resulted in the RC70PP being chosen as the most cost-efficient membrane in terms of flux and product recovery.
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| 3. |
- Battestini Vives, Mariona, et al.
(författare)
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Low-Molecular-Weight Lignin Recovery with Nanofiltration in the Kraft Pulping Process
- 2022
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 12:3, s. 310-310
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Battestini Vives, Mariona, et al.
(författare)
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Recovery and Characterization of Low-Molecular-Weight Lignin from Ultrafiltered Kraft Black Liquor
- 2022
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Ingår i: <em>10<sup>th</sup> Nordic Wood Biorefinery Conference</em>. - Helsinki. - 9789513887728 ; , s. 218-219
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)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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| 5. |
- Bildyukevich, Alexandr V., et al.
(författare)
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Correlation between membrane surface properties, polymer nature and fouling in skim milk ultrafiltration
- 2020
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 605
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Tidskriftsartikel (refereegranskat)abstract
- The fouling of the membranes in skim milk ultrafiltration with the nominal molecular weight cut-off (MWCO) of 100 kDa fabricated from different polymers (polysulfone (PSF), polysulfonamide (PSA), aromatic polyamide (PA), polyacrylonitrile (PAN), cellulose acetate (CA) and regenerated cellulose (RC)) was studied. The membrane structure and physical-chemical properties of the selective layer were analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (θ, °) measurements, free surface energy measurements and bovine serum albumin (BSA) adsorption. Additionally, the flux of the skim milk at the constant product concentration, protein adsorption, resistance of the gel layer of the membranes were determined. It was found that according to the decrease in water contact angle of the membrane selective layers membranes can be arranged in the series as follows: PSF > PSA > PA > PAN > CA > RC. It was revealed that there was no direct correlation between the membrane hydrophilicity and the protein adsorption. It was noted, that the studied membranes featured significantly different hydraulic resistances of the protein gel-layer, which can be considered as a secondary dynamic membrane. Comparison of the parameters – water contact angle and polar component of the free surface energy of the membrane selective layer, and normalized dipole moment of the membrane polymers - with the adsorption values of the proteins during ultrafiltration proves that the protein adsorption to the membrane surface increases with an increase in hydrophobicity and polarity of the membrane. The high protein adsorption by the moderately hydrophilic PAN membrane is due to the contribution of the high normalized dipole moment of the polymer. In the case of the polar RC-100 membrane, the influence of the membrane polarity was shown to be counter-balanced by its high hydrophilicity. The study highlights the impact of the physical-chemical properties and structure of the membrane on the protein gel-layer and thus their importance in membrane fouling control in dairy applications.
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| 6. |
- Bildyukevich, Alexandr V., et al.
(författare)
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Effect of molecular weight of polyacrylic acid (PAA) on polyethersulfone membrane structure and performance
- 2019
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Ingår i: ; , s. 88-88
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Konferensbidrag (refereegranskat)abstract
- The novel method of modification of polyethersulfone (PES) ultrafiltration membranes is proposed. This method involves the use of aqueous solutions of polyacrylic acid (PAA) of different molecular weights (Mn=5.1×103 g·mol–1, Mn=490×103 g·mol–1) as a coagulant in non-solvent induced phase inversion process (NIPS). Addition of PAA (0.05–1.5 wt%) to the coagulation bath leads to marked changes in permeability and hydrophilicity of the surface of membrane selective layer. When the coagulation bath contains 0.5 wt% of PAA (Mn=5.1×103 g·mol–1) the rejection coefficient for polyvinulpyrrolidone (PVP К-30, Mn=40 kDa) decreases from 95% (for pristine PES membrane) to 80% (for membrane modified by PAA) and pure water flux (PWF) increases from 55 to 150 l·m-2·h-1. The presence of 0.1 wt% PAA (Mn=490×103 g·mol–1) in the coagulation bath results in an increase in PWF up to 220 l·m-2·h-1 and a decrease in rejection coefficient down to 35%. Water contact angles of the surface of the selective layer of modified membranes decreased down to 33o, for membranes, modified with PAA of higher molecular weights, and down to 43o for for membranes, modified by PAA with lower molecular weight (Mn=5.1×103 g·mol–1). The presence of PAA on the surface of PES membranes is confirmed by the FTIR spectroscopy. The membranes obtained by using PAA solution were pH-sensitive and pH-reversible, while the PWF of the initial membranes did not respond to the pH of feed solution. The SEM analysis of the structure of the membranes reveals marked difference in the morphology along cross section between the pristine and modified membranes. The suppression of macrovoids formation in the supporting layer of membrane with an increase in the concentration of PAA in the coagulation bath was noted. Fouling resistance behavior was studied using bovine serum albumin (BSA) solution in phosphate buffer. It was found that PAA addition to the coagulation bath enhances the fouling resistance of the modified membranes. The best fouling resistance with respect to BSA fouling is observed for the membranes with maximum hydrophilicity.This work was supported by the Belarusian Republican Foundation for Fundamental Research, Grant No. X18MС-018 and STINT Grant no. IB 2017-7377.
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| 7. |
- Burts, Katsiaryna S., et al.
(författare)
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Development of Antifouling Polysulfone Membranes by Synergistic Modification with Two Different Additives in Casting Solution and Coagulation Bath: Synperonic F108 and Polyacrylic Acid
- 2022
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- This study deals with the development of antifouling ultrafiltration membranes based on polysulfone (PSF) for wastewater treatment and the concentration and purification of hemicellulose and lignin in the pulp and paper industry. The efficient simple and reproducible technique of PSF membrane modification to increase antifouling performance by simultaneous addition of triblock copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol (Synperonic F108, Mn =14 × 103 g mol−1) to the casting solution and addition of polyacrylic acid (PAA, Mn = 250 × 103 g mol−1) to the coagulation bath is proposed for the first time. The effect of the PAA concentration in the aqueous solution on the PSF/Synperonic F108 membrane structure, surface characteristics, performance, and antifouling stability was investigated. PAA concentrations were varied from 0.35 to 2.0 wt.%. Membrane composition, structure, and topology were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The addition of PAA into the coagulation bath was revealed to cause the formation of a thicker and denser selective layer with decreasing its pore size and porosity; according to the structural characterization, an interpolymer complex of the two additives was formed on the surface of the PSF membrane. Hydrophilicity of the membrane selective layer surface was shown to increase significantly. The selective layer surface charge was found to become more negative in comparison to the reference membrane. It was shown that PSF/Synperonic F108/PAA membranes are characterized by better antifouling performance in ultrafiltration of humic acid solution and thermomechanical pulp mill (ThMP) process water. Membrane modification with PAA results in higher ThMP process water flux, fouling recovery ratio, and hemicellulose and total lignin rejection compared to the reference PSF/Synperonic F108 membrane. This suggests the possibility of applying the developed membranes for hemicellulose concentration and purification.
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| 8. |
- Burts, K.S., et al.
(författare)
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Development of polysulfone ultrafiltration membranes with enhanced antifouling performance for the valorisation of side streams in the pulp and paper industry
- 2022
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 632
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Tidskriftsartikel (refereegranskat)abstract
- One-stage method of polysulfone (PSf) membrane modification by the addition of polyacrylic acid (PAA, Mn = 250 kg·mol−1) to the coagulation bath during membrane preparation via non-solvent induced phase separation (NIPS) was proposed. The effect of PAA concentration on the membrane structure, hydrophilicity, zeta potential, separation performance and antifouling stability in ultrafiltration of lysozyme, polyvinylpyrrolidone (PVP K-30, Mn = 40 kg mol−1) and humic acid model solutions as well as thermomechanical pulp mill process (ThMP) water was studied. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), measurements of the tangential flow streaming potential and water contact angle were used for membrane characterization. It was found that addition of PAA into coagulation bath resulted in decreasing pore size and porosity of the selective layer as well as the formation of a thicker and denser selective layer. Water contact angle of the modified membranes was found to decrease significantly and zeta potential of the selective layer was shown to become more negative in the studied pH range 3–10, all compared to the reference membrane. It was revealed that pure water flux (PWF) decreased and lysozyme and PVP K-30 rejection increased with the increase in PAA concentration in the coagulation bath. It was found that membranes modified with PAA demonstrated better antifouling stability in ultrafiltration of humic acid solution and ThMP process water. Modified membranes were found to have higher flux, fouling recovery ratio and hemicelluloses rejection in ThMP process water ultrafiltration compared to the reference PSf membrane that allows application of these membranes for hemicelluloses concentration and purification.
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| 9. |
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Current Trends and Future Developments on (Bio-) Membranes
- 2024
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Current Trends and Future Developments on (Bio-) Membranes: Engineering with Membranes discusses various aspects of membrane engineering. This includes, but is not limited to, the role of membranes in food production, treatment and recovery, their applications in electrochemical processes and devices, in drug delivery and in ionic materials, such as salts, acids and bases, recovery. In addition, this book approaches the above topics in a different angle than the existing publications, i.e., reviews technical difficulties, environmental challenges and economic analysis. Membranes are one of the technologies which can affect various aspects of engineering dealing with feeds and products. Membranes demonstrate selective purifying properties, hence, membranes can help in the removal of various pollutants onsite and without the need of adding extra units and apparatuses. Besides that, membranes help reactions shift forward and make the whole process more efficient.
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| 10. |
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| 11. |
- Danielsson, Sverker, et al.
(författare)
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A novel approach for applied membrane filtration on processing flows
- 2012
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Konferensbidrag (refereegranskat)abstract
- Membrane filtration technique shows exclusively properties for optimized filtration for a given size, from micrometer to nanometer scales compared to other industrial filtration. However, there is a trade off in flux that has delayed the implementation of the membrane techniques for a wider range of applications. For a specific flow in a process stream, the limited flux through the membrane means large membrane area is demanded, that results in a return of investments not accepted by industry. On the other hand, as the energy prices increases and environmental issues become more and more important as design parameters, the membrane techniques will due to its excellent separation performance be of interest, and from a life cycle analysis (LCA) a feasible approach.In this project the process flows in pulp and paper sector, and in particular the waste water treatment, are studied based on membrane technology. The purpose is to obtain a procedure to evaluate the membrane technique so that the results are guiding for extended studies. Two different representative integrated mills have been in focus, one thermo-mechanical pulp mill and one kraft pulp mill. The waste water streams that result in challenges for treatment process and that due to membrane filtration give reject / accept of greater values are studied. The possible benefit is two-fold the waste can be used as a resource of added valued products and the energy demanding waste water treatment decreases.A membrane filtration equipment from Alfa Laval LabStak M20 was used in this study on different streams for a pulp and paper mill. In this unit several membranes can be tested at the same time in order to briefly evaluate a type of membrane which suitable for the prevailing conditions, ranging from RO, NF, UF and MF depending on molecular weight cut-off (MWCO) and pore size. The volume concentrations factor (VFC) ranged from 1-4 in this study and the reduced TOC indicates satisfactory results. As pointed out, a trade off in decrease flux during filtration was in the order of 20%, to be considered in process design. The result gives indication of feasible way to use membrane filtration techniques as a tool for creating new business opportunities and elucidate the potential in reducing the water and energy consumption. The technique is demonstrated to gained parameters of importance for the pulp and paper sector. However, also applicable for other industry sectors when dealing with large scale processing flows
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| 12. |
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| 13. |
- Elhamarnah, Yousef, et al.
(författare)
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Investigating the impact of stormwater fouling on polysulfone ultrafiltration membranes modified with deep eutectic solvents
- 2023
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Ingår i: Journal of Water Process Engineering. - 2214-7144. ; 56, s. 104362-104362
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we evaluate the performance of modified polysulfone (PSF) ultrafiltration (UF) membranes, which incorporate deep eutectic solvents (DES), in treating stormwater laden with natural organic matter e.g. chemical oxygen demand (COD) and total suspended solids (TSS). We also aim to understand how these organic substances, e.g. COD, TSS, from the water source contribute to the fouling of the synthesized membranes. PSF membranes were synthesized using a non-solvent induced phase separation technique and integrated with varying concentrations of ChCl:FR (Choline Chloride: D-(−)-Fructose) 1:1 DES. The surface and porous structures of the membranes were characterized through Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurements, scanning electron microscopy (SEM), and mechanical testing. The UF performance of these membranes was assessed and compared with different commercially available UF flat sheet membranes in terms of pure water permeability and antifouling behavior against collected stormwater from a sedimentation pond. Furthermore, the study evaluated the quality of the permeate based on parameters such as COD, turbidity, TSS, pH, and conductivity and compared the permeate quality of a pilot-scale ceramic UF membrane unit. The findings indicate that the inclusion of DES in the polysulfone membrane structure enhances the membranes' antifouling properties and permeability. This research offers valuable insights into the role of DES in the formation of polysulfone UF membranes and their potential for practical use e.g. sedimented stormwater.
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| 14. |
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Engineering aspects of membrane separation and application in food processing
- 2017
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Engineering Aspects of Membrane Separation and Application in Food Processing presents an overview and introduction to a wide range of membrane processes, their unique characteristics and challenges. In the food industry, as in many industries, membranes have an environmental advantage over conventional processes that they displace, because they are less energy intensive. The processing at near-ambient conditions also retains flavors and nutritional value. These advantages, together with significant reductions in the cost of membrane modules, augers well for their future not only in the dairy industry but in other parts of the food industry, such as alcohol processing, animal product processing, and fruit and vegetable processing. Chapters address a wide range of membranes separations in the food and beverage industries, and applications are provided that will be of value not only to food engineers but also to process engineers working in other areas. The processing of food is now a highly interdisciplinary science, and anyone concerned with food processing will benefit from reading this book and understanding what membrane processes of the twenty-first century have to offer.
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| 15. |
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Engineering with Membranes 2019 : Membranes for a sustainable future
- 2019
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Proceedings (redaktörskap) (refereegranskat)abstract
- The focus of this edition of ‘Engineering with Membranes' will be on ‘Membranes for a sustainable future'. Thus, the current conference will emphasize how membrane processes can help to achieve the 17 sustainability goals developed by the United Nations. The conference, thus welcomes papers dedicated to the sustainable manufacturing, design and application of membrane and membranes processes. In particular papers related to the development and integration of membranes processes in the food, biorefinery and biotech industry are welcomed. The conference schedule is designed to provide an inspiring event with key speeches combined with oral and poster presentations but also time and space for meetings and stimulating discussions.
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| 16. |
- Essalhi, Mohamed, et al.
(författare)
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The potential of salinity gradient energy based on natural and anthropogenic resources in Sweden
- 2023
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents assessment of natural and anthropogenic sources of blue energy within Swedish territory to identify suitable spots for implementing new projects. The natural energy potential of salinity gradients was found to be higher in southwest Sweden, and a national energy resource potential of 2610.6 MW from seawater/river water mixing will be reduced to a technical potential ranging from 1044.3 MW to 1825.4 MW considering technical and environmental constraints. It has been found that the theoretical extractable energy potential in Sweden is equivalent to 13% of the total electricity consumption and 6.2% of the total final energy consumption by energy commodities.Anthropogenic water sources were also highlighted as promising low and high-concentration solutions for SGE extraction. Gotland was identified as an attractive location for generating salinity gradient power. The total salinity gradient power obtainable by mixing municipal wastewater with seawater in Sweden was estimated to be 11.8 MW. The most promising site for this process was determined to be Gryaab AB Ryaverket in Gothenburg, which accounted for 45.8% of the total national potential from anthropogenic sources.
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| 17. |
- Field, Robert, et al.
(författare)
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Membrane separation processes an overview
- 2017
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Ingår i: Engineering Aspects of Membrane Separation and Application in Food Processing. - 9781420083644 - 9781420083637 ; , s. 3-40
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Bokkapitel (refereegranskat)abstract
- The food industry, which is a major worldwide industry, is going through a revolution. Changing lifestyles and expectations, such as demand for fewer additives, have placed new demands on the industry, which can only be met by new technology. At the same time, the producers in this very large industry have a further challenge, namely, that of the countervailing power of the retailer. Some years ago, J.K. Galbraith forecasted that the rise of purchasing power by large conglomerates would match the monopoly power of the producing industries. In the food industry, this has already occurred, and even 25 years ago in the United Kingdom, five or six major retailers controlled nearly 80% of the UK market (Field and Howell, 1989). Thus, it is essential that producers design, install, and maintain first-class production systems.
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| 18. |
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| 19. |
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| 20. |
- Gonzalez-Perez, Alfredo, et al.
(författare)
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Functional channel membranes for drinking water production
- 2018
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 10:7
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Forskningsöversikt (refereegranskat)abstract
- Drinking water production utilities rely on, among other processes, different filtration technologies like bank filtration and slow sand filters, as well as pressure, roughing, or rapid gravity filters that, together with low- and high-pressure operating membranes, help to ensure high quality drinking water for millions of customers all over the world. The global market of membrane separation technologies is projected to reach USD 11.95 Billion by 2021, encompassing water treatment, wastewater treatment, food and beverage processing, industrial gas processing, and pharmaceutical and biomedical applications. In addition to the current, polymer-based membrane separation technologies, new promising strategies using embedded functional motifs, water and ion channels, are expected to play a key role in the next generation of membranes for separation purposes, which are of paramount relevance for drinking water production utilities. In this review, we summarize the different strategies for developing new advanced membranes with a wide variety of functional motifs, like biological and artificial water and ion channels, and their possible impact on drinking water applications.
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| 21. |
- Hey, Tobias, et al.
(författare)
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Direct membrane filtration of municipal wastewater in Norway
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Real raw municipal wastewater is treated abiotic in combination of chemical and mechanical treatment with microfiltration as the final treatment step. This rather new treatment concept is described as direct membrane filtration and has been tested in a smaller scale in Sweden. The presented concept in this study is significantly larger (386 times) and is built in Norway to compare both studies performed in Sweden and Norway. The expected outcome is high carbon and phosphorus removal which makes it very interesting for wastewater treatment in the Norwegian but also European (< 10 000 PE) perspective. Furthermore, the concepts potential is to treat wastewater energy neutral due to high carbon rejection and a Finish study showed high >99 % removal of microplastics which is a world-wide hot topic. The presented direct membrane filtration concept is claimed to be the largest tested concept within Scandinavia.
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| 22. |
- Hliavitskaya, Tatsiana, et al.
(författare)
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Development of antifouling ultrafiltration PES membranes for concentration of hemicellulose
- 2020
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 1097-4628 .- 0021-8995. ; 138:17
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Tidskriftsartikel (refereegranskat)abstract
- A new approach for one‐stage facile membrane modification during non‐solvent induced phase separation (NIPS)‐process is proposed. The novelty of this study is that cheap and commercially available anionic high molecular polyacrylamide‐based flocculant (AHMPF) is applied for the first time as an additive to coagulation bath (CB). The series of polyethersulfone membranes were prepared using 0.05–0.3 wt% AHMPF aqueous solution as CB at different temperatures (25–50°C) via NIPS. The effect of AHMPF concentration on the structure, composition and hydrophilicity of membranes was investigated. The separation and antifouling performance were evaluated during filtration of bovine serum albumin (BSA) solution and thermomechanical pulp mills process water (ThMP) in order to concentrate hemicellulose. The successful immobilization of AHMPF into the structure of membranes selective layer (not bottom layer) was confirmed by FTIR spectroscopy. It was established that despite the similar rejection of hemicellulose (88.8–93%) and lignin (20–21.4), modified membranes demonstrate 3–8 times higher flux and 2 times higher FRR (43.8% for reference membrane and 86.5% for modified one) in ThMP ultrafiltration. The developed membrane was found to be highly efficient in hemicellulose concentration and purification in pulp industry.
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| 23. |
- Hliavitskaya, Tatsiana, et al.
(författare)
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Modification of PES ultrafiltration membranes by cationic polyelectrolyte Praestol 859: Characterization, performance and application for purification of hemicellulose
- 2020
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Ingår i: Chemical Engineering Research and Design. - : Elsevier BV. - 0263-8762. ; 162, s. 187-199
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Tidskriftsartikel (refereegranskat)abstract
- Novel approach for membrane modification to improve separation performance and antifouling stability was proposed. It involves using of 0.1–0.3 wt.% aqueous solutions of Praestol 859 (cationic polyelectrolyte based on copolymer of acrylamide and 2-acryloxyethyltrimethylammonium chloride) as coagulants upon membrane preparation via non-solvent induced phase separation. It was shown that the addition of small amounts (0.1–0.3 wt.%) of Praestol 859 into the coagulation bath leads to an increase in membrane pure water flux from 51 up to 68 L m−2 h−1 without decreasing membrane retention. Contact angle for modified membranes decreased from 64° down to 55°. Immobilization of Praestol 859 on the surface of a selective membrane layer was confirmed by FTIR spectroscopy. It was found that the addition of Praestol 859 into the coagulation bath suppressed the macrovoid formation in the membranes supporting layer due to the decrease of “solvent-non-solvent” exchange rate which is attributed to the significant increase of viscosity of the coagulation bath. The separation performance of modified membranes for fractionation of thermomechanical pulp mill process water, for concentration and purification of hemicellulose for further processing was studied. It was found that membrane modification by Praestol 859 leads to 2–6 times increase of flux, increase of fouling recovery ratio and improvement of cleaning efficiency without decreasing membrane rejection with regard to hemicelluloses (91.5–93%) and lignin (21–22%) as reference components.
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| 24. |
- Hummel, Dell, et al.
(författare)
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Membrane glucose demudding by a decanter-membrane synergy process: A development update
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Rotary vacuum filters (RVFs) with adiatomaceous earth (kieselguhr) coatings as filter aid are the most established technology for the removal of the so-called mud fraction after liquefaction and saccharification in the production of starch-based sweeteners. The RVFs is an open process which is further associated with the use of filters resulting in an increasing disposal challenge. Based on this there is a demand from the industry for alternative demudding solutions. Since about 2005 Alfa Laval is working on development and introduction of a new concept for demudding – a synergy process consisting of a decanter and a membrane unit. The initial large scale pilot tests were carried out in 2008 focusing on low DE wheat-based sweetener - DE45 and maltose. These tests proved that the basic principles of the concept were working and were in line with previous experience on starch-based sweetener demudding using decanters and membranes independently. The decanter before the ultrafiltration unit removed over 95% of the mud fraction and the subsequent ultrafiltration unit polished the sweeteners to a quality higher than achieved by existing RVFs with regard to turbidity and colour removal. Hence, this concept was found to be not only suitable to replace the RVFs but also to have the potential to lower downstream processing costs. Based on these tests and previous experience two full-scale demudding systems were installed for corn-based sweetener in 2011. The first system operates on low DE sweetener - DE40 – 45 and maltose - and the second system works on higher DE sweetener - DE95. Both systems operate 24h/7days per week. In order to achieve this the membrane systems are operating with sequential cleaning – one of the five loops of the membrane plant is in cleaning/maintenance mode, while the other four loops are in production mode. The membranes installed in the plant are dedicated ultrafiltration membranes for demudding with a high hydrophilicity. Compared to conventional membranes used for demudding, this particular membrane has a relatively low MW cut-off which provides a high removal of turbidity and colour without significant impact on the Brix in polished permeate stream compared to the original feed stream plus a resistance against retrograded starch. Further, in order to improve increase plant capacity the module design was optimised to the requirements of the application. Most recently Alfa Laval optimised the performance of the synergy process for DE96 wheat-based sweeteners on large pilot-scale. Overall, Alfa Laval has developed over the years a comprehensive knowledge base covering wheat- and corn-based sweeteners from low DEs (40+) to high DEs (95/96). Current development work is focusing on the optimisation of the performance parameters and the extrapolation of the achieved to other starch sources.
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| 25. |
- Jiang, Yuan, et al.
(författare)
-
The influence of different ultrafiltration set-ups on the mineral partitioning between skim milk streams
-
Ingår i: International Journal of Dairy Technology. - 1364-727X.
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, the partitioning of minerals in ultrafiltration (UF) streams of skim milk using cross-flow (CF-UF) and dead-end (DE-UF) was investigated using 50 kDa membrane at different temperatures (5, 10, 25, 35, 55°C). CF-UF showed higher protein retention (6.02–10.9%) compared with DE-UF (3.44–4.70%), along with more retention of calcium, with values ranging from 29.8 to 41.5 and 57.8 to 112 mM for DE-UF and CF-UF, respectively. Ionic calcium in permeates varied less for CF-UF (2.48–1.18 mM) than for DE-UF (3.11–0.98 mM). The insights provided in this study can be exploited to tailor adjustments of minerals in milk streams using UF.
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| 26. |
- Jönsson, Ann-Sofi, et al.
(författare)
-
Costs for membrane cleaning – an economic assessment
- 2016
-
Konferensbidrag (refereegranskat)abstract
- Cleaning is an inevitable, and often costly, part of most membrane filtration plants. The economic assessment of cleaning costs is often rather arbitrary when researchers design and estimate costs of a membrane plant in a new application. Severity of fouling, operation conditions, cleaning agents and cleaning frequency all influence the costs for membrane cleaning. In addition to the costs of the cleaning process itself, cleaning also affects membrane lifetime, membrane performance during filtration and process down time. The cleaning procedure and cleaning frequency varies from one application to another and most cleaning studies are therefore trial-and-error investigations. Temperature, time, concentration and type of cleaning agent must be adapted to the conditions in each individual application. Furthermore, in some cases it is necessary to use a sequence of different cleaning agents. The influence of cleaning conditions on costs for membrane cleaning is illustrated in this work.
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| 27. |
- Knozowska, Katarzyna, et al.
(författare)
-
Membrane assisted processing of acetone, butanol, and ethanol (ABE) aqueous streams
- 2021
-
Ingår i: Chemical Engineering and Processing - Process Intensification. - : Elsevier BV. - 0255-2701. ; 166
-
Tidskriftsartikel (refereegranskat)abstract
- Downstream processing of ABE fermentation broth is challenging issue. In this work, results of the application of both hydrophobic and hydrophilic commercial membranes during the pervaporation of ABE aqueous mixtures were investigated and presented. Hydrophobic pervaporation experiments were performed using ABE-water mixtures containing 0-5 wt% of organics in feed, using commercial membranes: POMS, PEBAX, and PervapTM4060. Separation factor and Pervaporation Separation Index were employed to discuss hydrophobic pervaporation results. PervapTM4060 membrane revealed the best separation performance in the removal of ABE components from diluted aqueous mixtures mimicking the fermentation broth, resulting in two-phase permeate containing ca. 34 wt% of organics. The subsequent liquid-liquid phase separation resulted in the organic phase containing 62 wt% of ABE. Hydrophilic pervaporation experiments were performed in contact with ABE-water system initially comprising 38 wt% of water applying both the PervapTM4100 PVA based polymeric membrane and modified silica ceramic one. Application of hydrophilic membranes allowed for the complete dewatering of ABE-water mixtures. Eventually, the combination of membrane separation processes (microfiltration, hydrophobic pervaporation, hydrophobic thermopervaporation, membrane distillation, and hydrophilic pervaporation) enhanced by the liquid-liquid phase separation was suggested for the recovery and dehydration of ABE aqueous mixture.
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| 28. |
- Kruse, Micha, et al.
(författare)
-
Membrane processes for a sustainable future: Moving from C2/C3 chemistry to biotechnogical processes
- 2018
-
Konferensbidrag (refereegranskat)abstract
- The global society has started a journey from using fossil-based raw material to the utilisation of climate-smart sustainable raw materials. Biorefineries have been identified as one of the backbones of the new bioeconomy using fermentation processes to convert biomass to biofuels and –chemicals and thus replacing the conventional C2/C3 chemistry with biotechnological processes. In current petro-chemical refineries distillation is the dominating separation concept as most compounds are volatile. However, in contrast to petro-chemical compounds, most compounds derived from biomass are non-volatile. Molecular weight, charge and solubility are therefore the main separation characteristics of extracted biomass compounds, which makes membrane processes a natural key separation technique in current and future biorefinery concepts either as stand-alone units or as process synergies in combining with other separation technologies such as evaporators or high speed separators. Since the 1970ies, the conventional membrane processes microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) have established themselves in the production of classic fermentation products such as enzymes, antibiotics and organic acids. While, in current biorefineries membrane processes are used from the feedstock preparation to recovery of the fermentation products. This presentation will not only review some of the established membrane applications in fermentation processes and biorefineries but it will also provide some insight related to the latest applications of membranes in fermentation processes and biorefineries realised on industrial scale using different raw materials. Furthermore, the presentation will final provide an outlook related to membrane applications in lignocellulose-based and agriculture residual based biorefineries. Overall, this presentation will show that membrane processes as stand-alone units and as process synergies are not only established in classic fermentation processes but they are also core to the development of current and future biorefinery concepts.
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| 29. |
- Lipnizki, Frank, et al.
(författare)
-
Anwendungspotenzial von Membranprozessen im Konzept der Lignocellulose-Bioraffinerien
- 2021
-
Ingår i: Chemie Ingenieur Technik. - : Wiley. - 1522-2640 .- 0009-286X. ; 93
-
Tidskriftsartikel (refereegranskat)abstract
- The pulp and paper industry is one of the most important industrial sectors worldwide and has great potential to be a cornerstone for the future bioeconomy, especially for lignocellulosic biorefineries. The potential of membrane processes in this transformation is shown in three examples from the fields of Kraft / Sulphate, Sulphite and thermomechanical pulping. In addition, the challenges of membrane fouling and cleaning with regard to the pulp industry are discussed and an outlook on future developments of membranes in biorefineries is given.
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| 30. |
- Lipnizki, Frank
(författare)
-
Applications of Membrane Technology in the Food Industry - An approach to reduce food processing costs and to improve food quality
- 2012
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Over the last two decades, the global market for membrane technology in the food industry increased to a market volume of about € 800 - 850 million and is now the second biggest industrial market for membranes after water and wastewater treatment including desalination. The key membrane technologies in the food industry are the pressure driven membrane processes microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). The success of membrane technology in the food and beverage market is directly linked to some of the key advantages of membrane processes over conventional separation technologies. Among these ad¬vantages are:• Gentle product treatment due to moderate temperature changes during processing. • High selectivity based on unique separation mechanisms compared with e.g. sieving, solution-diffusion or ion exchange mechanism.• Compact and modular design for ease of installation and extension. • Lower energy consumption compared to condensers and evaporators.In the first part of the presentation will provide an overview of the key membrane technologies in the food industry – MF, UF, NF and RO. The second part of the presentation will look on selected applications of membrane processes in the food industry taking into account food processing costs and food quality.
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| 31. |
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| 32. |
|
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| 33. |
- Lipnizki, Frank, et al.
(författare)
-
Beer Clarification
- 2016
-
Ingår i: Encyclopedia of Membranes. - 9783662443231 - 9783662443248
-
Bokkapitel (populärvet., debatt m.m.)
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| 34. |
- Lipnizki, Frank, et al.
(författare)
-
Beer Dealcoholization
- 2016
-
Ingår i: Encyclopedia of Membranes. - 9783662443231 - 9783662443248
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 35. |
- Lipnizki, Frank, et al.
(författare)
-
Beer Maturation
- 2016
-
Ingår i: Encyclopedia of Membranes. - 9783662443231 - 9783662443248
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
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| 36. |
- Lipnizki, Frank, et al.
(författare)
-
Bulk Biotech Industry
- 2016
-
Ingår i: Encyclopedia of Membranes. - 9783662443231 - 9783662443248
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 37. |
- Lipnizki, Frank, et al.
(författare)
-
Changing an industry with membrane technology – Converting pulp mills to bio-refineries
- 2017
-
Konferensbidrag (refereegranskat)abstract
- The pulp and paper industry is one of the most important industrial sectors worldwide and has a great potential to be the nucleus for the future bio-economy. Today’ pulp industry is mainly focusing on the production of cellulose fibres and electricity, while its future potential includes the production of bio-chemicals, bio-fuels and advanced materials. In order to fulfil their future role, pulp mills will have to adjust their concepts and convert to ligno-cellulosic bio-refineries. Key to these new concepts is the efficient separation of the wood components: cellulose, hemicellulose, lignin plus extractives as raw material for further processing. In particular, the pressure-driven membrane processes microfiltration, ultrafiltration, nanofiltration and reverse osmosis have been identified as high potential technologies to separate of these wood components. The first applications of membrane technology in the pulp industry can actually be dated back to the 1970ies but while membrane technology experienced significant growth in other sectors, it remained a niche technology in the pulp industry. The first part of the presentation will identify potential positions of membrane technology in the concepts of ligno-cellulosic bio-refineries ranging from the separation of lignin from cooking liquor over the extraction and purification of hemicellulose to the purification of platform chemical derived from fermentation of hemicellulose and/or cellulose. The second part of the presentation will discuss the barriers of membrane technology in the pulp industry. Main focus will be thus on scale-up and integration challenges of membrane processes in the pulp industry and fouling/cleaning issues related to pulp applications - both important factors in enabling membrane technology for the pulping industry. Overall, this presentation will demonstrate that membrane technology can play a major role in the conversion of the current pulping industry into bio-refineries and it will highlight approaches enabling the successful integration of membrane technology into this industry.
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| 38. |
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| 39. |
|
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| 40. |
- Lipnizki, Frank, et al.
(författare)
-
Development of hydrophilic membranes for challenging separation applications
- 2016
-
Konferensbidrag (refereegranskat)abstract
- Membrane fouling and its control is one of the most critical parameters in the application of membrane processes. The degree of fouling depends on the application and on industrial scale, fouling is often observed as reduction in plant capacity over time. One approach to reduce fouling for the pressure driven processes microfiltration and ultrafiltration is to use hydrophilic membranes. This paper will show two examples of the development and use of hydrophilic membranes – ETNA and UFX membranes - for challenging microfiltration and ultrafiltration applications and will provide an overview on recent and future developments regarding hydrophilic membranes. The ETNA membrane is a surface-modified PVDF membrane with permanently hydrophilic properties on a polypropylene support. One of the key application areas for this membrane is the separation of oil-water mixtures, an application area which is driven by the increasing demand for efficient oil-water separation, e.g. produced water in the oil and gas industry, process water in the petrochemical industry and bilge water in the marine industry.The UFX membrane is a permanently hydrophilic polysulphone based membrane reinforced on a polypropylene support. The membrane has established itself as the standard for concentration and purifications of industrial enzymes but it should also have potential in the concept of future biorefineries in particular for the concentration and purification of hemicellulose. One current trend is the use of cellulose, a sustainable membrane material, which can either be used directly, or as regenerated cellulose, e.g. the European NanoSelect project which is aiming at the development of low fouling and adsorption membranes based on cellulosic fibrils, and the development of a new generation of regenerated cellulose membranes by Alfa Laval is in progress.Overall, the development and availability of hydrophilic membranes can reduce the fouling challenges in a wide range of industries.
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| 41. |
- Lipnizki, Frank, et al.
(författare)
-
Einsatz von Pervaporation-Bioreaktor-Hybridprozessen in der Biotechnologie
- 1998
-
Ingår i: Chemie-Ingenieur-Technik. - : Wiley. - 0009-286X .- 1522-2640. ; 70:12, s. 1587-1595
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Pervaporation is a membrane separation process with considerable innovative possibilities in the area of biotechnology. Above all, the combination of bioreactor and pervaporation has potential in the longer term as an alternative to conventional batch processes. This article considers the state of the art of pervaporation/bioreactor hybrid processes. The possible applications of such hybrid processes are discussed and compared with conventional processes. It becomes apparent that the use of pervaporation/bioreactor hybrid processes can avoid product inhibition and greatly enhance the productivity of biotechnological processes.
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| 42. |
- Lipnizki, Frank, et al.
(författare)
-
Exploring the structure-properties relationship of novel polyamide thin film composite membranes
- 2015
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Polysulfone (PSf) is a traditional material widely used for manufacturing microfiltration and ultrafiltration membranes by non-solvent induced phase separation (NIPS) process. However, the hydrophobic nature of PSf makes the membranes prone to protein fouling. In order to create non fouling surfaces and further decrease the pore size, the membrane pores can be modified by different strategies as atom transfer radical polymerization [1]. However, these strategies are not adopted by industry due to either cost or technical challenges. This contribution presents the preparation of asymmetric membranes by in situ interfacial polymerization (IP) of thin films (TF) on the PSf support surface in order to form a new polyamide (PA) layer [2]. The new PA is hydrophilic and negatively charged, and has prospects in application such as removal of bacteria and heavy metal ions from waste water. The pore size of the barrier layer can be controlled by adjusting the cross-linking degree and chemical composition of the PA network. This work is an attempt to prepare a new PA TF composite membrane and investigate the effect of different amines’ structures on the final membrane properties. Characterization of the PA surface morphology and chemical structure includes scanning electron microscopy, atomic force microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and streaming potential measurements. Rhodamine B cannot stain the TF composite membrane surface unlike the virgin PSf surface. Furthermore, the water flux decreases from 220 L/h/m²/bar for the PSf membrane to 1.5 L/h/m²/bar for the TF composite membrane. It is therefore concluded that a dense PA TF forms on the porous PSf support after the IP. In order to confirm the antifouling properties, bovine serum albumin/phosphate-bufered saline solution was tested as a model solution to measure flux recovery. References[1] Han-Bang Dong, You-Yi Xu, Zhuan Yi, Jun-Li Shi, Modification of polysulfone membranes via surface-initiated atom transfer radical polymerization, Applied Surface Science, 255, (2009), 8860-8866.[2] Yu Jun Song, Patricia Sun, Lawrence L. Henry, Benhui Sun, Mechanism of structure and performance controlled thin film composite membrane formation via interfacial polymerization process, Journal of Membrane Science, 251, (2005) 67-79.
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| 43. |
- Lipnizki, Frank, et al.
(författare)
-
Fouling and cleaning in the food and bioprocess industry: Key aspects in membrane plant operation
- 2017
-
Konferensbidrag (refereegranskat)abstract
- 1. INTRODUCTIONFrom the early days of membrane technology fouling has been identified as the most important parameter for the slow integration of technology in the industry [1]. Since then significant progress has been achieved in the field of fouling and cleaning of membranes which are still both key aspects in membrane plant operation in the food and bioprocess industry with a significant impact on membrane plants capital (CAPEX) and operating expenditures (OPEX) and thus the sustainability of membrane processes. The aim of this presentation is to demonstrate the relationship between fouling, pre-treatment, operating conditions and cleaning and how on this background industrial membrane processes can be optimized from a techno-economical point of view. The first part of the presentation will introduce the challenges of cleaning and fouling in the food and bioprocess industry. The second part will demonstrate different approaches to reduce fouling and improve cleaning, while the final part will focus on an application study utilizing approaches to optimize fouling and cleaning and thus OPEX and CAPEX for industrial application in the starch-based sweetener industry. 2. FOULING AND CLEANING CHALLENGESIn the food and bioprocess industry cleaning is an integrated part of the daily plant operation and due to hygienic considerations one cleaning cycle per day will be often required. In many cases the selection of cleaning cycle length, number of cleaning steps and cleaning frequency is quite arbitrary in particular for new applications. Each cleaning cycle is combined with production downtime of either parts or the complete membrane plant and thus the plant design has to compensate for downtime, e.g. a 4-hour cleaning cycle per day requires 17% additional membrane area. Furthermore, each cleaning cycle consists typically of 3 – 4 chemical/enzymatic cleaning steps plus flushing steps in between and at least carried out once per day. Apart from the downtime aspect, each cleaning cycle is associated with costs for cleaning agents, water, heating and electricity. In addition, cleaning has a negative impact on membrane lifetime. Therefore optimizing plant design and operation together with cleaning cycle length, number of cleaning steps and cleaning frequency can improve both plant OPEX and CAPEX significantly. 3. APPROACHES TO MINIMISE FOULING AND CLEANING The initial step to reduce fouling and thus the need of cleaning is to identify the fouling materials and sources. Based on this often optimizing the pre-treatment can lead to significant reductions in fouling, e.g. in the fruit juice industry membrane fouling can be significantly reduced by enzymatic degradation of starches and pectin before clarification of the juice, while in the fermentation industry sufficient pre-filtration with a self-cleaning strainer can reduce the risk of fouling and module blockage. Apart from understanding of the fouling materials it is important to identify the fouling mechanisms. Depending on the fouling mechanism e.g. complete pore blockage, partial pore blockage or cake filtration remedies to minimize the fouling can be considered. Approaches to minimize fouling are e.g. constant transmembrane pressure operation for milk filtration, vibrating modules for recovery of beer from tank bottoms or rotating modules for white water recovery in the paper industry. Since often fouling cannot be complete avoided despite best efforts or a hygienic requirement, cleaning is an inevitable part of plant operation. It is crucial that temperature, time, concentration and type of cleaning agents are adapted to the individual application and membranes used. One consideration to improve the cleaning process is to move from one comprehensive daily cleaning to two shorter cleanings. Using this approach for e.g. animal blood concentration reduces overall cleaning time and increases the overall plant capacity. 4. APPLICATION STUDY: STARCH-BASED SWEETENER INDUSTRYIn the starch-based sweetener production, the removal of impurities from the sweeteners after liquefaction and saccharification of the starch is a crucial step in the process. The impurity phase consists of retrograded starch, proteins and fat. In the past open tubular ceramic microfiltration modules and hybrid processes consisting of high speed separators and microfiltration have established themselves for the sweetener purification. Recently a new process consisting of a decanter and ultrafiltration spiral wound modules has been developed. Key aspects of this new process are a self-cleaning strainer before the ultrafiltration membranes to minimize fouling, the utilization of low fouling regenerated cellulose membranes to optimize membrane operations between cleaning cycles combined with an optimized cleaning method to maintain membrane performance. The overall concept resulted not only in higher sweetener quality but also in lower CAPEX and OPEX compared to established membrane based approaches. 5. OUTLOOK AND CONCLUSIONSOverall this presentation will highlight the importance of fouling and cleaning and their impact on CAPEX and OPEX of membrane plants. The approaches proposed can help to optimize the performance of membrane processes and thus support the long-term sustainability of membrane processes in the different industries.
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| 44. |
- Lipnizki, Frank, et al.
(författare)
-
Hemicellulose isolation from thermomechanical pulp mill process water using UF: Optimisation and economics
- 2008
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Every year, 100,000 tons of dissolved hemicelluloses are discharge unused with wastewater from thermomechanical pulp mills around the world. Isolation of these hemicelluloses from the wastewater would not only reduce the treatment costs for the pulp mills but would also provide an excellent raw material for high value applications such as oxygen barriers in food packaging. The isolation of the hemicelluloses can be combined with polishing of the waste-water by using different filtration processes. The initial step in this combination is either a drum filter or a microfiltration treatment to remove solid residues from the wastewater followed by ultrafiltration to concentrate the hemicelluloses. The permeate from the ultra-filtration can then be further polished by reverse osmosis before recycling. The focus of this paper is on the optimisation of the ultrafiltration step concentrating on the membrane selection and its impact on the process economics. The membrane selection includes the newly developed commercial UFX5 pHt membrane (Alfa Laval, Denmark) based on hydrophilised polyethersulfone. The feed studied in this paper is process water from the thermomechanical pulp mill Stora Enso Kvarnsveden (Sweden). The temperature of this process stream is 75°C. To reduce the need for cooling and preserve the energy, temperature tolerance is an important membrane selection parameter. Further, since the process water contains resin and lignin, which tend to foul membranes, the hydrophilicity of the membrane is another important selection parameter. Based on this, five membranes with molecular weight cut-offs (MWCOs) between 1 – 10 kD were pre-selected: (1) a hydrophilised fluoro polymer membrane ETNA01PP, MWCO: 1 kD, (2) a hydrophilised fluoro polymer membrane ETNA10PP, MWCO: 10 kD, (3) a hydro¬philised polyethersulfone membrane UFX5 pHt, MWCO: 5 kD (all Alfa Laval, Denmark), (4) a regenerated cellulose membrane UC005, MWCO: 5 kD, and (5) a polyethersulfone membrane UP005, MWCO: 5 kD (all Microdyn-Nadir, Germany). The ETNA01PP, ETNA10PP, and UC005 are limited to a temperature of 60/55°C and to a pH range of 1 to 11, whereas the UP005 and UFX5 pHt can be operated up to 75°C and in a pH range from 1 to 14/13. In the initial study, a small flat test module was used to study the pure water fluxes and the fouling behaviour of the membranes related to octanoic acid, a fouling substance which represents a significant number of small hydrophobic substances. Based on this, ETNA01PP, ETNA10PP, and UFX5 pHt were selected for further experiments in 2.5” spiral wound modules using process water from Kvarnsveden pulp mill. In these experiments, among others the flux decline with increasing concentration of hemicelluloses at different transmembrane pressures and cross-flow velocities as well as the retention of hemicelluloses under these conditions were studied. The experimental results of ETNA10PP, ETNA01PP and UFX5 pHt were then used as basis for the development of a full-scale system to treat a feed stream of 100 m3/h with an initial feed temperature of 60/75ºC. Both investment and operating costs were analysed as well as the impact of retention and operating conditions on the ultrafiltration process. It was revealed that operating temperature and membrane selection/retention had an impact on both the investment and operating costs. In conclusion, the results show that ultrafiltration is an attractive process unit in the hemicelluloses isolation process.
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| 45. |
- Lipnizki, Frank, et al.
(författare)
-
High temperature applications of spiral wound modules for UF and NF
- 2004
-
Ingår i: ; , s. 20-20
-
Konferensbidrag (refereegranskat)abstract
- The most common modules for ultrafiltration (UF) and nanofiltration (NF) are spiral wound elements due to their low investment, easy replacement and high packing density. Operating at high temperatures greater than 70°C, the use of spiral wound modules is, however, often limited. In the past ceramic membranes have been considered as the only viable option to operate at these temperatures. However, ceramic membranes are still associated with high investment costs. To overcome past restrictions, improved polymeric membranes and spiral wound modules are now available. These new UF and NF modules are manufactured of temperature stable materials, which allow operating at operation temperature greater than 75 °C. Despite the availability of these membranes and modules, the influence of the high temperature on the mass transfer performance of the membranes is not fully understood. The aim of this paper is therefore to introduce this new generation of membrane modules and to provide further inside in the mass performance of polymeric membranes at high temperatures. Finally, the use of these membranes will be demonstrated in case study on the concentration of carrageenan, highly viscous sulphated polysaccharides, with UF at 90ºC.
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| 46. |
- Lipnizki, Frank
(författare)
-
Hybrid Processes and Process Synergies: Optimisation and Integration of Membrane Processes
- 2004
-
Ingår i: ; , s. 623-623
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Membrane processes are often competing directly with conventional separation processes. The aim of this study is to highlight the potentials of combinations of membrane processes and conventional separation processes by the means of hybrid processes and process synergies. The concepts of hybrid processes and process synergies will be introduced and defined supported by industrial examples, e.g. the combination of pervaporation and distillation as a hybrid process to dehydrate alcohols [1] and the combination of reverse osmosis and evaporation as a process synergy to concentrate fruit juices. The advantages and potentials of hybrid processes and process synergies will be highlighted in a study focusing on the clarification and concentration of apple juice. For the concentration step, a combination of centrifugation and ultrafiltration as a hybrid process is proposed. The centrifuge removes the larger solids, while the ultrafiltration unit is used for the final clarification. In order to maximise the yield of the process, the retentate stream from the ultrafiltration unit is recycled before centrifugation. For the concentration step, a combination of reverse osmosis and evaporation as a process synergy is considered. The reverse osmosis unit will pre-concentrate the juice to up to 25ºBrix and then it is passed to an evaporator for final evaporation up to 75ºBrix. Both process combinations will be evaluated from a technical and economical point of view and compared with stand-alone units.
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| 47. |
- Lipnizki, Frank
(författare)
-
Integration of cross-flow filtration in the beverage industry
- 2005
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The market for membrane technology in the food and beverage industries increased during the last two decades to a market volume of about € 150 million and is now the second biggest industrial market for membranes after municipal water treatment in Europe. The aim of this study is to highlight new application concepts for membrane processes either by replacing conventional separation processes or by combining membrane processes with conventional separation technologies to achieve optimised solutions. The first part of this work demonstrates potential applications in the fruit juice industry. In this industry, kieselguhr filtration or ultrafiltration is used to clarify apple juice by removing suspended solids or other high molecular solids such as proteins and starch. A new concept combining a high-speed separator with spiral wound ultrafiltration modules will be proposed as an alternative to kieselguhr filtration or ultrafiltration as stand alone unit. Further, for the concentration of apple juice a combination of reverse osmosis and evaporation will be discussed in comparison to only evaporation. The focus in the second part of this work is on the brewing industry. In the traditional brewing process clarification of beer after fermentation and maturation is achieved by a separator followed by kieselguhr filtration. Microfiltration will be introduced as a replacement for kieselguhr filtration to clarify the beer by removing yeast, micro-organisms and haze without affecting the taste. Another novel use of cross-flow microfiltration in breweries is the recovery of beer from tank bottoms. After fermentation, yeast with 1.5 to 2 % of the total beer volume settles at the bottom of the fermentation vessels. By using microfiltration the beer, which would be lost if not recovered, can be separated from the yeast. Overall this work demonstrates the potential of membrane processes in the beverage industry and the importance of process optimisation and integration.
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| 48. |
- Lipnizki, Frank
(författare)
-
Integration of cross-flow filtration in the fruit juice industry
- 2005
-
Ingår i: ; , s. 142-142
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The market for membrane technology in the food and beverage industries increased during the last two decades to a market volume of about € 150 million and is now the second biggest industrial market for membranes after municipal water treatment in Europe. The aim of this study is to highlight new application concepts for membrane processes either by replacing conventional separation processes or by combining membrane processes with conventional separation technologies to achieve optimised solutions. The first part of this work demonstrates potential applications in the fruit juice industry. In this industry, kieselguhr filtration or ultrafiltration is used to clarify apple juice by removing suspended solids or other high molecular solids such as proteins and starch. A new concept combining a high-speed separator with spiral wound ultrafiltration modules will be proposed as an alternative to kieselguhr filtration or ultrafiltration as stand alone unit. Further, for the concentration of apple juice a combination of reverse osmosis and evaporation will be discussed in comparison to only evaporation. The focus in the second part of this work is on the brewing industry. In the traditional brewing process clarification of beer after fermentation and maturation is achieved by a separator followed by kieselguhr filtration. Microfiltration will be introduced as a replacement for kieselguhr filtration to clarify the beer by removing yeast, micro-organisms and haze without affecting the taste. Another novel use of cross-flow microfiltration in breweries is the recovery of beer from tank bottoms. After fermentation, yeast with 1.5 to 2 % of the total beer volume settles at the bottom of the fermentation vessels. By using microfiltration the beer, which would be lost if not recovered, can be separated from the yeast. Overall this work demonstrates the potential of membrane processes in the beverage industry and the importance of process optimisation and integration.
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| 49. |
- Lipnizki, Frank, et al.
(författare)
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Key aspects of membrane plant operations related to fouling and cleaning in the food industry
- 2018
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Ingår i: Fouling and Cleaning in Food Processing 2018 : The food-water-energy challenge - The food-water-energy challenge.
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Konferensbidrag (refereegranskat)abstract
- Fouling is one the most important challenges to apply membrane technology on industrial scale in the food industry. Despite significant progress in understanding and preventing fouling and in developing appropriate membrane cleaning protocols, both fouling and cleaning remain key challenges in membrane plant operation in the food industry with a significant impact on membrane plants capital (CAPEX) and operating expenditures (OPEX) and thus the sustainability of membrane processes. The goal of this presentation is to show a relationship between fouling, pre-treatment, operation conditions and cleaning and how this can impact industrial membrane processes from a techno-economical point of view. The first part of the presentation will analyze the state-of-the-art of membrane cleaning in the food industry. The impact of e.g. number of cleaning cycle per day, cleaning cycle length and cleaning chemicals as well as type of cleaning chemicals and water quality will be discussed with regard to their impact on membrane plant OPEX and CAPEX. In the subsequent part of the presentation different approaches to reduce fouling and minimize the need for cleaning will be highlighted. The focus will be on the impact of pre-treatment but also on membrane module and membrane selection. The final part of the presentation will be an application study related to the removal of impurities e.g. retrograded starch, proteins and fat in the production of starch-based sweetener after liquefaction and saccharification of the starch. For this production step - which is often referred to as demudding - a new concept has been developed consisting of a decanter and membranes. The application study will demonstrate how the membrane part of the process was adjusted to overcome some serious fouling and thus capacity challenges encountered during the start-up of the first installation. The resulting new concept did not only control the fouling and minimized the cleaning but it also resulted in an improved sweetener quality. Overall the presentation will show approaches to reduce fouling and cleaning in order to support the long-term sustainability of membrane processes in the food industry.
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| 50. |
- Lipnizki, Frank, et al.
(författare)
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Meeting the challenges: Membrane processes for water recovery from oily and PVC wastewater
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The demand for water recovery in the industry is increasingly important partly due to water shortage and partly due to tightening of regulatory requirements. In this paper water recovery solutions for two challenging types of wastewater - oily and polyvinylchloride (PVC) wastewater - are presented. The first part of the presentation analyses the operation and performance of a membrane unit operated in an oily waste treatment facility. The facility handles mainly bilge water and industrial oil waste with low concentration of suspended solids. The waste is pre-treated in skimmer tank followed by a band filter before entering an ultrafiltration unit with polymeric membranes. At the entrance of the ultrafiltration unit the oily wastewater contains approx. 1000 ppm emulsified oil, which is then separated into an oil-rich stream which is recycled to the skimmer tank and a permeate stream with less than 2 ppm oil sufficient for direct discharge. The second part of the presentation focuses on the recovery and reuse of water in the polyvinylchloride (PVC) production. In the PVC production approx. 2.0 - 2.5 m3 of demineralised water is required per ton PVC. In today’s installations 20% of the water used is lost during drying of the PVC or as sealing water. The remaining water is recovered by the PVC decanter. 20 – 25% of the water recovered by the PVC decanter is used for flushing of the facilities, while 75 – 80% is currently discharged to biological treatment. A new concept based on reverse osmosis does not only remove the residual PVC particles but also the inhibitors and conductivity down to levels allowing the direct recycle of decanter water to the polymerisation step and thus reducing water consumption and water treatment costs – both in-take and discharge cost - significantly. Overall, the case studies presented will demonstrate how membranes can handle even challenging industrial wastewaters at minimal energy costs.
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