75 results found
Yeo J, Peeva L, Chung S, et al., 2021, Liquid Phase Peptide Synthesis via One‐Pot Nanostar Sieving (PEPSTAR), Angewandte Chemie, Vol: 133, Pages: 7865-7874, ISSN: 0044-8249
Kim JH, Cook M, Peeva L, et al., 2020, Low energy intensity production of fuel-grade bio-butanol enabled by membrane-based extraction, Energy and Environmental Science, Vol: 13, Pages: 4862-4871, ISSN: 1754-5692
Widespread use of biofuels is inhibited by the significant energy burden of recovering fuel products from aqueous fermentation systems. Here, we describe a membrane-based extraction (perstraction) system for the recovery of fuel-grade biobutanol from fermentation broths which can extract n-butanol with high purity (>99.5%) while using less than 25% of the energy of current technology options. This is achieved by combining a spray-coated thin-film composite membrane with 2-ethyl-1-hexanol as an extractant. The membrane successfully protects the micro-organisms from the extractant, which, although ideal in other respects, is a metabolic inhibitor. In contrast to water, the extractant does not form a heterogeneous azeotrope with n-butanol, and the overall energy consumption of for n-butanol production is 3.9 MJ kg-1, substantially less than other recovery processes (17.0 – 29.4 MJ kg-1). By (a) extracting n-butanol from the fermentation broth without a phase change, (b) breaking the heterogeneous azeotrope relationship (less energy consumption for distillation), and (c) utilizing a small volume ratio of extractant : fermentation broth (1:100, v/v), the need for high energy intensity processes such as pervaporation, gas stripping or liquid-liquid extraction is avoided. The application of this perstraction system to continuous production of higher alcohols is developed and shown to be highly favourable.
Sultan Z, Graça I, Li Y, et al., 2019, Membrane fractionation of liquors from lignin-first biorefining, ChemSusChem, Vol: 12, Pages: 1203-1212, ISSN: 1864-5631
For the purposing of each lignin fraction in the lignin liquors, the development of separation strategies to fractionate the lignin streams by MW ranges constitutes a timely challenge to be tackled. Herein, membrane separation was applied to the refining of lignin streams obtained from a lignin-first biorefining process based on H-transfer reactions catalyzed by Raney Ni, using 2-propanol as a part of the lignin extraction liquor and as an H-donor. A two-stage membrane cascade was considered to separate and concentrate the monophenol-rich fraction from the CUB liquor. Building on the experimental results, an economic evaluation of the potential of membrane separation for the refining of lignin streams was undertaken. The membrane performance represents the bottleneck of the costs associated with the separation process. Accordingly, we present a detailed analysis of future developments in the performance required to debottleneck the utilization of membrane separation for lignin refining.
Cook M, Gaffney P, Peeva L, et al., 2018, Roll-to-roll dip coating of three different PIMs for Organic Solvent Nanofiltration, Journal of Membrane Science, Vol: 558, Pages: 52-63, ISSN: 0376-7388
PIM-1, PIM-7, and PIM-8 composite membranes have been fabricated for Organic Solvent Nanofiltration (OSN) on two different support membranes. Both support membranes, PAN and crosslinked Ultem 1000, displayed pore sizes within the range of 20–25 nm as characterised by gas liquid porometry. PIM layers of < 500 nm thickness were formed from dip coating on a roll-to-roll pilot line. The resultant composite membranes exhibited typical MWCOs in the region of 500–800 g mol−1. The quality of coating obtained on the crosslinked Ultem 1000 support membrane was consistently higher for all three PIMs than that obtained on the PAN membrane. The PIM composite membranes coated on to crosslinked Ultem 1000 were stable in a wider range of solvents than those on the PAN support. OSN testing in a model system with isomeric alkane solutes verified that manipulated changes to the molecular architecture of the polymer backbone resulted in a higher separation factor between straight and branched alkane isomers.
Mitev D, Radeva E, Peshev D, et al., 2018, PECVD modification of nano & ultrafiltration membranes for organic solvent nanofiltration, JOURNAL OF MEMBRANE SCIENCE, Vol: 548, Pages: 540-547, ISSN: 0376-7388
Peshev D, Mitev D, Peeva L, et al., 2018, Valorization of spent coffee grounds - A new approach, SEPARATION AND PURIFICATION TECHNOLOGY, Vol: 192, Pages: 271-277, ISSN: 1383-5866
Cook M, Peeva L, Livingston A, 2018, Solvent-Free Coating of Epoxysilicones for the Fabrication of Composite Membranes, Industrial & Engineering Chemistry Research, Vol: 57, Pages: 730-739, ISSN: 0888-5885
Solventless coated epoxysilicone composite membranes have been prepared from a UV curable epoxysilicone polymer for organic solvent nanofiltration. Coatings were conducted solventless on a roll-to-roll pilot line using a forward gravure coating technique, and applied on a polyacrylonitrile or cross-linked poly(ether imide) support. Cross-linking of the poly(ether imide) support membrane with propanediamine enhanced the adhesion properties of the epoxysilicone selective layer. Penetration of the coating solution into the porous support membrane was confirmed using scanning electron microscopy with energy-dispersive X-ray spectroscopy. Membranes fabricated using two different gravure heads have been studied, with submicrometer siloxane layer thicknesses achieved. The separation performance of the membranes is observed to be independent of the thickness. It has been possible to achieve membranes with a molecular weight cut-off < 500 g mol–1 in hydrocarbon solvents. Benefits of the fabrication include the ability to UV cross-link under air, elimination of solvent-based coating, and the feasibility of achieving uniform, submicrometer coatings at large scale manufacturing. These membranes comprise a further step toward greener and safer membrane production.
Peeva LG, Marchetti P, Livingston AG, 2018, Nanofiltration operations in nonaqueous systems, Comprehensive Membrane Science and Engineering: Second Edition, Pages: 36-78, ISBN: 9780444637963
Nanofiltration is a pressure-driven membrane process used to remove solutes with molecular weight in the range of 200-2000 g mol-1, typically from aqueous streams. A relatively recent innovation is the extension of nanofiltration (NF) processes to organic solvents (OSs)-an emerging technology referred to as organic solvent nanofiltration (OSN). Separation of molecules present in OSs by NF has great potential in industries ranging from refining to fine chemical and pharmaceutical synthesis, and OSN is currently an area of intensive investigation. This article summarizes the most recent developments in the field of OSN.
Peeva L, Livingston A, 2018, Nanofiltration in the pharmaceutical and biopharmaceutical technology, Current Trends and Future Developments on (Bio-) Membranes: Membrane Processes in the Pharmaceutical and Biotechnological Field, Pages: 97-121, ISBN: 9780128136072
Separation processes account for up to 40%-70% of both capital and operating costs in many industries including fine chemical, pharmaceutical, and biopharmaceutical industries, and there is a constant search for efficient and economical separation methods. Membrane separations have been investigated already for many years as an alternative to conventional separation processes (e.g., distillation). Despite many proven success stories, multiple challenges still remain, hampering wider application of membranes. One such challenge is the imperfect separation provided by membranes and their inability to fully discriminate between solutes even with significant differences in their molecular size. In this chapter, we will focus our attention on how the imperfect separation gridlock might be resolved via multistage membrane processes operated in batch and continuous mode. Examples will be presented for typical separation challenges faced by the pharmaceutical industry such as purification, fractionation, solvent recovery, and solvent exchange.
Vogelsang D, Dreimann JM, Wenzel D, et al., 2017, Continuously Operated Hydroamination - Toward High Catalytic Performance via Organic Solvent Nanofiltration in a Membrane Reactor, Industrial & Engineering Chemistry Research, Vol: 56, Pages: 13634-13641, ISSN: 0888-5885
Still, the hydroamination of dienes to form allylic amines is a challenging task in a continuous operation. Herein, we present the performance of a membrane reactor by the implementation of a continuously operated hydroamination reaction of β-myrcene with morpholine. Via application of a poly ether–ether–ketone (PEEK) membrane, operation at elevated temperatures was possible in an integrated reaction/separation unit. First, the kinetics of the hydroamination reaction and relevant membrane characteristics were determined under optimized reaction conditions. Afterward, these results were incorporated in a reactor/separator model to predict the process behavior. With this, catalyst replenishment was adjusted resulting in stable continuous operation. In the end an increase of the turnover number from 460 to 5135 compared to a batch process was achieved. The desired geranyl amines were obtained in very good yields higher than 80%, while an excellent conversion of β-myrcene above 93% was reached in a long-time stable process.
Marchetti P, Peeva L, Livingston A, 2017, The Selectivity Challenge in Organic Solvent Nanofiltration: Membrane and Process Solutions, ANNUAL REVIEW OF CHEMICAL AND BIOMOLECULAR ENGINEERING, VOL 8, Vol: 8, Pages: 473-497, ISSN: 1947-5438
Peeva LG, Marchetti P, Livingston AG, 2017, 2.3 Nanofiltration Operations in Nonaqueous Systems, Comprehensive Membrane Science and Engineering, Publisher: Elsevier, Pages: 36-78
Peeva LG, Da Silva Burgal J, Heckenast Z, et al., 2016, Continuous consecutive reactions with inter-reaction solvent exchange by membrane separation, Angewandte Chemie International Edition, Vol: 55, Pages: 13576-13579, ISSN: 1433-7851
Pharmaceutical production typically involves multiple reaction steps with separations between successive reactions. Two processes which complicate the transition from batch to continuous operation in multistep synthesis are solvent exchange (especially high‐boiling‐ to low‐boiling‐point solvent), and catalyst separation. Demonstrated here is membrane separation as an enabling platform for undertaking these processes during continuous operation. Two consecutive reactions are performed in different solvents, with catalyst separation and inter‐reaction solvent exchange achieved by continuous flow membrane units. A Heck coupling reaction is performed in N,N‐dimethylformamide (DMF) in a continuous membrane reactor which retains the catalyst. The Heck reaction product undergoes solvent exchange in a counter‐current membrane system where DMF is continuously replaced by ethanol. After exchange the product dissolved in ethanol passes through a column packed with an iron catalyst, and undergoes reduction (>99 % yield).
Burgal JDS, Peeva L, Livingston A, 2016, Negligible ageing in poly(ether-ether-ketone) membranes widens application range for solvent processing, JOURNAL OF MEMBRANE SCIENCE, Vol: 525, Pages: 48-56, ISSN: 0376-7388
Da Silva Burgal J, Peeva L, Livingston AG, 2016, Towards improved membrane production: using low-toxicity solvents for the preparation of PEEK nanofiltration membranes, Green Chemistry, Vol: 18, ISSN: 1744-1560
In this work it is shown that PEEK membranes are “green” from the production point of view when compared with commercial polyimide (PI) based organic solvent nanofiltration (OSN) membranes. Green metrics (E-factor and solvent intensity) and waste cost were used in order to assess the environmental burden of PEEK membranes: the solvent intensity of PEEK membranes is 8.3 vs. 35–224 for PI based membranes, and the waste cost for PEEK membranes is 46 £ kg−1 of polymer vs. 1019 £ kg−1 of polymer (bench scale) and 189 £ kg−1 of polymer (industrial scale) for PI based membranes. Scaling-up of PEEK membranes to spiral-wound modules was successfully achieved with permeances between 0.26 L h−1 m−2 bar−1 and 0.47 L h−1 m−2 bar−1 for THF, and molecular weight cut-offs (MWCO) of ∼300 g mol−1. As a final assessment, the solvent intensity and environmental burden associated with permeating a THF flow of 100 L h−1 using PEEK membranes was also assessed. The results showed a waste cost of 1.4 £ m−2 of membrane, significantly lower than PI based membranes.
Adi VSK, Cook M, Peeva LG, et al., 2016, Optimization of OSN Membrane Cascades for Separating Organic Mixtures, Editors: Kravanja, Bogataj, Publisher: ELSEVIER SCIENCE BV, Pages: 379-384
Mitev D, Radeva E, Peshev D, et al., 2016, PECVD polymerised coatings on thermo-sensitive plastic support, Conference on Light in Nanoscience and Nanotechnology (LNN), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Da Silva Burgal J, Peeva L, Marchetti P, et al., 2015, Controlling molecular weight cut-off of PEEK nanofiltration membranes using a drying method, Journal of Membrane Science, Vol: 493, Pages: 524-538, ISSN: 0376-7388
In this research paper we report two ways of controlling the molecular weight cut-off (MWCO) of PEEK membranes prepared via phase inversion and subsequent drying. The two methods explored were the change of polymer concentration in the dope solution – 8 wt. %, 10 wt. % and 12 wt. %-and the variation of solvent filling the pores prior to drying – e.g. water, methanol, acetone, tetrahydrofuran and n-heptane. The results show that it is possible to vary the MWCO from 295 g.mol−1 to 1400 g.mol−1 by varying these parameters. A statistical analysis based on a genetic algorithm showed that the Hansen solubility parameter, polarity and their interactions with molar volume were likely to be the most important parameters influencing the performance of PEEK membranes when drying from different solvents. In addition, the drying temperature also proved to have an effect on the membrane performance-the higher the temperature the higher the rejection and the lower the permeance.
Burgal JDS, Peeva LG, Kumbharkar S, et al., 2015, Organic solvent resistant poly(ether-ether-ketone) nanofiltration membranes, JOURNAL OF MEMBRANE SCIENCE, Vol: 479, Pages: 105-116, ISSN: 0376-7388
Peeva L, Burgal JDS, Valtcheva I, et al., 2014, Continuous purification of active pharmaceutical ingredients using multistage organic solvent nanofiltration membrane cascade, CHEMICAL ENGINEERING SCIENCE, Vol: 116, Pages: 183-194, ISSN: 0009-2509
Siddique H, Bhole Y, Peeva LG, et al., 2014, Pore preserving crosslinkers for polyimide OSN membranes, JOURNAL OF MEMBRANE SCIENCE, Vol: 465, Pages: 138-150, ISSN: 0376-7388
Campbell J, Peeva LG, Livingston AG, 2014, Controlling Crystallization via Organic Solvent Nanofiltration: The Influence of Flux on Griseofulvin Crystallization, CRYSTAL GROWTH & DESIGN, Vol: 14, Pages: 2192-2200, ISSN: 1528-7483
Siddique H, Rundquist E, Bhole Y, et al., 2014, Mixed matrix membranes for organic solvent nanofiltration, JOURNAL OF MEMBRANE SCIENCE, Vol: 452, Pages: 354-366, ISSN: 0376-7388
Ferguson S, Ortner F, Quon J, et al., 2014, Use of Continuous MSMPR Crystallization with Integrated Nanofiltration Membrane Recycle for Enhanced Yield and Purity in API Crystallization, CRYSTAL GROWTH & DESIGN, Vol: 14, Pages: 617-627, ISSN: 1528-7483
Peeva L, Da Silva Burgal J, Livingston AG, 2014, Organic solvent nanofiltration in continuous catalytic reactions
Peeva L, Da Silva Burgal J, Livingston AG, 2014, Organic solvent nanofiltration in continuous catalytic reactions
Peeva L, da Silva Burgal J, Vartak S, et al., 2013, Experimental strategies for increasing the catalyst turnover number in a continuous Heck coupling reaction, Journal of Catalysis, Vol: 306, Pages: 190-201, ISSN: 0021-9517
Peeva L, Arbour J, Livingston A, 2013, On the Potential of Organic Solvent Nanofiltration in Continuous Heck Coupling Reactions, ORGANIC PROCESS RESEARCH & DEVELOPMENT, Vol: 17, Pages: 967-975, ISSN: 1083-6160
Siddique H, Peeva LG, Stoikos K, et al., 2013, Membranes for Organic Solvent Nanofiltration Based on Preassembled Nanoparticles, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, Vol: 52, Pages: 1109-1121, ISSN: 0888-5885
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