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Jovana Micovic

Bio: Jovana Micovic is an academic researcher from Technical University of Dortmund. The author has contributed to research in topics: Distillation & Nanofiltration. The author has an hindex of 6, co-authored 8 publications receiving 121 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors proposed a four-step design method which can be applied in early process development stages when not all model parameters are available, and demonstrated the feasibility of the approach with the separation of a binary mixture of isomeric aldehydes.
Abstract: Hybrid separations combining distillations and crystallisations have a significant potential for process intensification. To address the large number of degrees of freedom in the design of hybrid separations, a three-step approach is utilised. However, it can only be applied if all parameters for the rigorous modelling of crystallisation and cost functions are known a priori, which is often not the case. In this paper, we propose a four-step design method which can be applied in early process development stages when not all model parameters are available. In the first step, different process variants are generated. In the second step, the variants are evaluated using rigorous models, wherein the unknown model parameters are varied to quantify their influence on the process performance. If hybrid separations appear to be compatible, experiments are performed to determine the unknown parameters in the third step. In the last step, an optimisation is performed to find the optimal process, when necessary in dependence of unknown cost parameters. The developed tools and the feasibility of the approach are illustrated with the separation of a binary mixture of long-chain isomeric aldehydes.

38 citations

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TL;DR: In this article, a new predictive model, based on the Maxwell-Stefan (MS) approach, for prediction of fluxes through dense polymeric OSN membranes was developed to aid the experimental effort.

34 citations

Journal ArticleDOI
TL;DR: In this paper, a four-step design method for combination of organic solvent nanofiltration (OSN) and distillation in a hybrid separation of wide boiling mixtures is presented.
Abstract: Membrane assisted hybrid separations offer tremendous potential for process intensification which aims at increasing resource efficiency as well as decreasing operating and capital costs. Design of such processes is challenging due to large number of degrees of freedom but also due to large experimental effort necessary for membrane screening and for characterising membranes in whole operating range. To address these issues, this paper elaborates a four-step design method for combination of organic solvent nanofiltration (OSN) and distillation in a hybrid separation of wide boiling mixtures. The design method is applied in a case study which is the separation of small amounts of heavy boiler from a mixture containing a mid- and a light-boiler. In the first step, different process options are generated based on heuristics and engineering judgement and screened for feasibility. In the second step, the options are evaluated based on quantitative metrics using rigorous models. In this step the unknown key parameters are identified, and their influences on the process performance are quantified in a detailed a priori process analysis. If hybrid separations with OSN show to be promising when compared to stand-alone distillation, experiments are conducted to (i) identify the best membrane for the operating window in which the hybrid process operates and (ii) to perform model validation and parameterisation in the third step. In the last (fourth) step, an optimisation is performed to identify the best (cost optimal) process using the experimental data gained in step three.

34 citations

Journal ArticleDOI
TL;DR: In this paper, a distilliation/melt crystallization hybrid process is optimized by realistically describing crystallization separation efficiency and by implementing sweating, and the required crystallization models are presented and experimentally validated.
Abstract: Layer melt crystallization is a highly selective method for the separation of narrow boiling mixtures which are difficult to separate with conventional separation techniques like distillation due to low driving forces. Contrawise, layer melt crystallization has the drawback of limited capacity due to the direct connection between crystal product and required cooled surface. Here, the combination of the high throughput distillation and highly selective layer melt crystallization into an integrated hybrid process can lead to enormous benefits. Since the separation efficiency of the crystallization is not predictable, it has to be described with empirical correlation. Here, studies from literature use strongly simplified correlations by, e.g. assuming complete separation. This bears the serious risk of overestimating the efficiency of the hybrid process. Further, the effective post purification step sweating was not implemented into hybrid processes in studies from literature. This study fills this gap in literature. A distilliation/melt crystallization hybrid process is optimized by realistically describing crystallization separation efficiency and by implementing sweating. The required crystallization models are presented and experimentally validated. The optimization of the hybrid process is done with different modelling depths and the results underline impressively the importance of the adequate description of the crystallization separation efficiency.

25 citations

Journal ArticleDOI
TL;DR: In this paper, a hybrid separation combining distillation and crystallization is proposed, which can only be applied if all parameters for the rigorous modeling of crystallization and all cost functions are known a priori.
Abstract: Die Kombination aus Rektifikation und Schmelzekristallisation in einem hybriden Trennverfahren hat groses Potenzial fur die Prozessintensivierung. Allerdings stellt die Auslegung solcher Verfahren aufgrund der Vielzahl struktureller und operativer Freiheitsgrade eine grose Herausforderung dar. Fur die Auslegung hybrider Trennverfahren hat sich eine dreistufige Auslegungsmethode durchgesetzt, die aber nur dann angewendet werden kann, wenn alle Modellparameter fur die Kristallisation a priori bekannt sind. Da dies oft nicht der Fall ist, wird hier eine vierstufige Entwurfsmethode vorgeschlagen. Die Eignung der Methode sowie entwickelte Werkzeuge werden an einem Fallbeispiel der Trennung langkettiger isomerer Aldehyde vorgestellt. Design of hybrid separations is still challenging due to large number of structural and operation degrees of freedom. To design a hybrid separation combining distillation and crystallization, a three-step approach is utilized, which can only be applied if all parameters for the rigorous modeling of crystallization and all cost functions are known a priori. Since this is often not the case in early process development stages, a four-step design method is proposed for that purpose. The developed tools and the feasibility of the approach are shown in a case study of separation of a binary mixture of long-chain isomeric aldehydes.

11 citations


Cited by
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Journal ArticleDOI
TL;DR: Nanofiltration (NF) membranes have come a long way since it was first introduced during the late 80's as mentioned in this paper, and significant development has taken place in terms of the fundamental understanding of the transport mechanism in NF membranes, which has been translated into predictive modeling based on the modified extended Nernst-Planck equation.

1,374 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the green aspects of OSN membrane fabrication, processes development and scale-up as well as the supporting concept of QbD, and solvent recovery technologies are critically assessed and future research directions are given.

263 citations

Journal ArticleDOI
TL;DR: In this article, a review of UMS membranes is presented, highlighting the unique separation capabilities, theories underpinning UMS membrane fabrication, traditional polymeric materials and nanomaterials emerging on the horizon for advanced UMS fabrication and technical applications.

239 citations

Journal ArticleDOI
TL;DR: In this article, a comprehensive overview of the current state-of-the-art technologies of generating membrane materials and corresponding fabrication methods for solvent-resistant nanofiltration membranes made from polymeric materials is presented.
Abstract: When considering energy consumption and environmental issues, solvent-resistant nanofiltration (SRNF) based on polymeric materials emerges as a process for substituting conventional separation processes of organic solutions, such as distillation, which consume high amounts of energy. Because SRNF does not involve phase transition, this process can potentially decrease the energy consumption and solvent waste and increase the yield of active components. Such improvements could significantly benefit a number of fields, such as pharmaceutical manufacturing and catalysis recovery, among others. Therefore, SRNF has gained a lot of attention since the recent introduction of solvent-stable polymeric materials in the manufacture of nanofiltration membranes. The membrane materials and the membrane structures depending on the fabrication methods determine the separation performance of polymeric SRNF membranes. Therefore, this article gives a comprehensive overview of the current state-of-art technologies of generating membrane materials and corresponding fabrication methods for SRNF membranes made from polymeric materials expected to provide the most benefit. The transport mechanisms and the corresponding models of SRNF membranes in organic media are also reviewed to better understand the mass transfer process. Various SRNF applications, such as in pharmaceutical and catalyst, among others, are also discussed. Finally, the difficulties and future research directions to overcome the challenges faced by SRNF processes are proposed. C

120 citations