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The effect of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids – A pore network study

Krzysztoforski Jan, Khayrat Karim, Henczka Marek, Jenny Patrick

Chemical and Process Engineering

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2021

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Vol. 42, nr 4

349-–368

EN

The role of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids was investigated numerically. As a specific process to be modelled, cleaning of porous membranes, contaminated with soybean oil, using supercritical carbon dioxide as the cleaning fluid (solvent) was considered. A 3D pore-network model, developed as an extension of a 2D drying model, was used for performing pore scale simulations. The influence of various process parameters, including the coordination number of the pore network, the computational domain size, and the external flow mass transfer resistance, on the strength of the capillary pumping effect was investigated. The capillary pumping effect increases with increasing domain size and decreasing external flow mass transfer resistance. For low coordination numbers of the pore network, the capillary pumping effect is not noticeable at macro scale, while for high coordination numbers, the opposite trend is observed – capillary pumping may influence the process at macro scale. In the investigated system, the coordination number of the pore network seems to be low, as no capillary pumping effects were observed at macro scale during experimental investigation and macro-scale modelling of the membrane cleaning process.

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Teaching chemical engineering in Europe – developments, dilemmas and practical examples

Stankiewicz Andrzej, Henczka Marek, Molga Eugeniusz

Chemical and Process Engineering

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2021

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Vol. 42, nr 4

321–-335

EN

This perspective paper focuses on the changes in teaching chemical engineering in Europe triggered by new challenges and megatrends observed in the chemical and related industries. Among the new teaching areas to address those challenges and megatrends, process intensification, digitalization and advanced materials are expected to play the most important role and are discussed in more detail. The discussion on incorporation of those new areas in the university curricula is illustrated with a comparison of educational approaches to the chemical engineering teaching at two universities – Delft University of Technology and Warsaw University of Technology. The aim of this paper is to focus the attention of university teachers and potential decision makers on the most important challenges for contemporary teaching of chemical engineering.

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Application of porogenes in production of porouspolymers by supercritical foaming

Sawicka Katarzyna, Kosowska Katarzyna, Henczka Marek

Chemical and Process Engineering

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2019

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Vol. 40, nr 1

115–-122

EN

Biocomposite foam scaffolds of poly(ε-caprolactone) (PCL) with different porogenes were producedwith batch foaming technique using supercritical carbon dioxide (scCO2)as a blowing agent. Inperformed experiments composites were prepared from graphene-oxide (nGO), nano-hydroxyapatite(nHA) and nano-cellulose (nC), with various concentrations. The objective of the study was to explorethe effects of porogen concentration and foaming process parameters on the morphology and me-chanical properties of three-dimensional porous structures that can be used as temporary scaffolds intissue engineering. The structures were manufactured using scCO2as a blowing agent, at two variousfoaming pressures (9 MPa and 18 MPa), at three different temperatures (323 K, 343 K and 373 K) fordifferent saturation times (0.5 h, 1 h and 4 h). In order to examine the utility of porogenes, a number oftests, such as static compression tests, thermal analysis and scanning electron microscopy, have beenperformed. Analysis of experimental results showed that the investigated materials demonstrated highmechanical strength and a wide range of pore sizes. The obtained results suggest that PCL porousstructures are useful as biodegradable and biocompatible scaffolds for tissue engineering.