| 1. |
- Bondesson, Pia-Maria, et al.
(författare)
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Optimizing Ethanol and Methane Production from Steam-pretreated, Phosphoric Acid-impregnated Corn Stover.
- 2015
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 1559-0291 .- 0273-2289. ; 175:3, s. 1371-1388
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Tidskriftsartikel (refereegranskat)abstract
- Pretreatment is of vital importance in the production of ethanol and methane from agricultural residues. In this study, the effects of steam pretreatment with phosphoric acid on enzymatic hydrolysis (EH), simultaneous saccharification and fermentation (SSF), anaerobic digestion (AD) and the total energy output at three different temperatures were investigated. The effect of separating the solids for SSF and the liquid for AD was also studied and compared with using the whole slurry first in SSF and then in AD. Furthermore, the phosphoric acid was compared to previous studies using sulphuric acid or no catalyst. Using phosphoric acid resulted in higher yields than when no catalyst was used. However, compared with sulphuric acid, an improved yield was only seen with phosphoric acid in the case of EH. The higher pretreatment temperatures (200 and 210 °C) resulted in the highest yields after EH and SSF, while the highest methane yield was obtained with the lower pretreatment temperature (190 °C). The highest yield in terms of total energy recovery (78 %) was obtained after pretreatment at 190 °C, but a pretreatment temperature of 200 °C is, however, the best alternative since fewer steps are required (whole slurry in SSF and then in AD) and high product yields were obtained (76 %).
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| 2. |
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| 3. |
- Kruse, Micha, et al.
(författare)
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Membrane processes for a sustainable future: Moving from C2/C3 chemistry to biotechnogical processes
- 2018
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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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| 4. |
- 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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| 5. |
- Lipnizki, Frank, et al.
(författare)
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Membrane-based oil-water separation: Membranes, concepts and case studies
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 1. IntroductionThe demand for efficient oil-water separation is driven by the tightening of discharge limits for e.g. produced water in the oil and gas industry, process water in the petrochemical industry and bilge water in the marine industry. The global produced water production alone is over 71 billion bbl/a – 8.4 billion m3/a [1]. Among the different technologies, particularly ultrafiltration with polymeric membranes can be used to reduce oil in water down to less than 1 ppm leading to an energy-efficient and compact approach for the industry. The first part of the presentation will introduce the ETNA membrane for oil-water separation. The second part will review different oil-water separation technologies with focus on ultrafiltration-based synergy processes, while the final part will present two case studies on industrial oil-water separation processes. 2. Oil-water separation membranesThe membranes chosen for oil-water separation are the ETNA01PP and ETNA10PP membranes (Alfa Laval Nakskov A/S, Denmark) with a molecular weight cut-off of 1,000 and 10,000 Dalton, respectively. Both membranes are surface-modified PVDF membranes on a polypropylene support and are permanently hydrophilic. The hydrophilic surface of these membranes increases the retention of hydrophobic compounds such as oil and thus reduces membrane fouling [2].3. Membrane-based oil-water separation conceptsThe most common technologies in the industry for oil-water separation are skimmers (gravity/density), coalescers (coalescence) and centrifugal separators (centrifugation/density). Skimmers, centrifugal separators and coalescers are very efficient separation processes for initial oil-water separation but their final oil-in-water levels are commonly higher than the level of less than 1 ppm which is achievable by ultrafiltration. Since the industry often requires high oil recovery combined with low oil content in the discharge water, the optimal solution is often a process combination consisting of a conventional separation technology followed by ultrafiltration and thus different ultrafiltration-based oil-water separation concepts will be reviewed.4. Case studies: Industrial scale oil-water separation The potential of ultrafiltration-based concepts will be highlighted in two case studies. The first plant has a capacity of 40,000 tons/a treating bilge water and industrial oil waste with low suspended solids concentration. The process set-up consists of a skimmer, high speed centrifugal separators and paper band filter plus ultrafiltration. The second plant has a capacity of 80,000 tons/a handling oily waste from ships, petrochemical facilities or offshore industry with higher levels of suspended solids. In the process set-up, decanter centrifuges, high speed separators and evaporation are used in combination with ultrafiltration. Both process set-ups result in an oil-rich phase with more than 98% oil and a water rich-phase with less than 2 ppm oil. 5. Conclusion and outlookOverall, this paper shows that ultrafiltration-based oil-water separation concepts can achieve both high oil concentrations combined with very low residual oil in the water phase and offer therefore an excellent alternative for current and future oil-water separation challenges.
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| 6. |
- Lipnizki, Frank, et al.
(författare)
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Membrane processes in biorefineries based on lignocellulosic biomass: Membrane opportunities in the production and water loop
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Biorefineries are the backbone of “white biotechnology”, the 3rd wave of biotechnology which aims to replace classic C2/C3 chemistry by biotechnological processes. In analogy to petrorefineries biorefineries aim at the integrated and simultaneous production of bulk products, as e.g. biofuels, or biopolymers, heat and power, using biomass. In order to avoid any competition with food production the focus in recent years is on lignocellulosic biomass such as wood and agricultural residues as raw material for biorefineries. One of the key success factors of biorefineries is the integration of high-selective low energy separation processes such as membrane processes either as stand-alone units or as process synergies, e.g. the combination of membrane processes with separators or evaporators. Key applications of membrane processes can be found in the production and water loop of biorefineries. The first part of the presentation will focus on the production loop. In the initial step of the biorefinery the lignocellulosic biomass needs ideally to be separated into its three key components: hemicelluloses, lignin and cellulose. This can either be done by appropriate pre-treatment methods with e.g. heat or chemical treatment, or by utilizing suitable process/waste streams from pulp mills. In particular the pressure-based membrane processes microfiltration, ultrafiltration, nanofiltration and reverse osmosis have been proven to be suitable for the concentration and purification of these key components. Hemicelluloses can be concentrated and purified by ultra- and nanofiltration for the production of barrier films and coatings. Lignin, either as ligninsulfonate from the sulfite pulping process, or lignin in black liquor of the kraft pulping process, can be concentrated and classified by ultrafiltration to be used e.g. as binding agent. The cellulosic part can be hydrolyzed to sugars. After hydrolysation the sugars can be purified by a decanter-ultrafiltration process and then - if required - concentrated by reverse osmosis before fermentation. In order to prevent product inhibition during the fermentation a micro- or ultrafiltration unit can be directly integrated into the fermentation of the biofuel/biochemical. In the subsequent step residual sugars can be separated from the biofuel/biochemical by nanofiltration or reverse osmosis. Furthermore, pervaporation and vapor permeation might be used in combination with distillation in the final concentration step. The second part of the presentation will focus on the water loop. This section will cover the upgrading of in-take water by a cascade of ultrafiltration followed by reverse osmosis as well as the recycling of water in processes such as evaporator condensate polishing by reverse osmosis. Furthermore the opportunities of using a membrane bioreactor for end-of-pipe treatment in biorefineries will be discussed. Overall, it will be demonstrated that membrane processes as highly selective and energy-saving separation processes have the potential to become key units of operation in the concept of biorefineries. The contents of the presentation will be supported by application and case studies.
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| 7. |
- Lipnizki, Frank, et al.
(författare)
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New concepts for the starch and starch-based sweetener industry
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 1. IntroductionBoth the development of nowadays membrane technology and nutritive sweeteners started in the middle of the 20th century. The development of the asymmetric membranes using phase inversion was pioneered by Loeb and Sourirajan in the 1960-ies, while the discovery of glucose isomerase was a milestone in the commercialisation of high fructose corn syrup in the beginning of the 1970-ies. The use of membranes in the sweetener industry started in the 1980-ies with DDS Filtration, now Alfa Laval Business Centre Membranes, as one of the pioneering companies. The aim of this presentation is to give an update on recent developed membrane concepts for the starch and starch-based sweetener industry and it will focus on three novel concepts: (1) water recovery from the 3-phase starch decanter by reverse osmosis in the wheat starch production to improve the overall water balance, (2) demudding of starch-based sweeteners with a decanter-ultrafiltration process replacing rotatory vacuum filters and improving product quality and (3) the use of a membrane bioreactor (MBR) in the wastewater treatment plant of starch factories. 2. Water recovery from 3-phase starch decanter using ultrafiltrationThe first focus application is related to the wheat starch extraction. In the process, the wheat flour is mixed with water and then separated by a 3-phase decanter resulting in an A-starch fraction, a gluten and B-starch fraction, and a fraction consisting of solubles and pentosanes. In order to optimise the water consumption it is possible to apply UF for concentrating the solubles and pentosanes and recovering water for recycling in the process i.e. dough preparation. Applying this concept reduces the water consumption by approx. 20% resulting in reduction of water from 2.4 m3 water/ton flour to 2 m3 water/ton flour for a wheat starch line and from 1.7 m3 water/ton flour to 1.3 m3 water/ton flour for a wheat gluten line. It should be noted that this concept does not only improve the overall water balance for the starch extraction but reduces also the energy required for the concentration of the soluble/pentosane fraction by evaporation. An application study for the treatment of 56 m3/h soluble/pentosane fraction from a wheat starch decanter will be presented. 3. Demudding of starch-based sweeteners by a decanter – ultrafiltration synergy process After the after liquification and saccarfication of the starch the resulting starch-based sweeteners needs to be polished. This demudding step is conventionally done with rotary vacuum filters using kieselguhr as filter aid. Alternatively, a decanter – ultrafiltration synergy process has been developed. This closed process avoids potentially hazardous filter aids, limits the exposure of the sweeteners to the outer atmosphere and achieves higher product qualities than the conventional approach. A case study of a low DE 42 – 50 line and a high DE95 line for the demudding of corn-based sweeteners will be shown. 4. Membrane bioreactor for wastewater treatment in starch factoriesDespite efforts to reduce the water consumption in the starch and starch-based sweetener industry and close the water loop as much as possible often some effluents streams are generated which have to be removed from the process and discharged. In the last 20 years, membrane bioreactors (MBRs) combining activated sludge treatment with a filtration through an MF/UF membrane, either submerged in the biology or in a side-stream, have established themselves in a wide range of industries and it can be foreseen that MBRs will also establish themselves in the area of the starch and starch-based sweetener industry. In particular combining MBRs with NF/RO polishing could result in water stream suitable direct recycling or blending with in-take water streams. A case study related to the wastewater treatment plant of a modified potato starch producer using Alfa Laval’s hollow sheets MBR modules will be used to highlight the potential of this emerging technology. 5. Conclusions and outlookOverall, membrane processes have their potential in the starch and starch-based sweetener as highly selective and energy-saving separation processes and these new applications will support this trend. R&D efforts are currently focusing on the optimisation of these new applications and on the increased further integration of membrane technologies in the starch and starch-based sweetener production plus starch-based biorefineries aiming at the optimal utilisation of the starch containing crops.
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