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Systems of two immiscible liquid phases—aqueous phase (i.e., distilled water (dH2O) or phosphate-buffered saline (PBS)) and liquid perfluorochemical (i.e., perfluorodecalin (PFD))—were subjected to wave-assisted agitation, i.e., oscillatory rocked, in a disposable bag-like container in a ReadyToProcess WAVETM25 bioreactor, to recognize oxygen transfer effects and effectivity of the surface aeration. According to the DoE methodology, values of the volumetric liquid-side mass transfer (kLa) coefficient for dH2O, PBS, dH2O-PFD, and PBS-PFD systems were determined for the whole range of operating parameters of the WAVE 25 bioreactor. A significantly higher maximal value of kLa was found for waving dH2O than for dH2O-PFD (i.e., 0.00460 s−1 vs. 0.00331 s−1, respectively) compared to more equal maximal values of kLa reached for PBS and PBS-PFD (0.00355 s−1 vs. 0.00341 s−1, respectively). The interface development factor (f) depended on the interfacial area a, and the enhancement factor (EPFD), depending on kLa, was introduced to quantitatively identify the mass transfer effects in the systems of waving two immiscible liquids. The phase of PFD was identified as the reservoir of oxygen. Dimensional correlations were proposed for the prediction of the kLa coefficient, in addition to the f and EPFD factors. The presented correlations, and the set of kLa values, can be directly applied to predict oxygen transfer effects reached under continuous oscillatory rocked systems containing aqueous phase and liquid perfluorochemical.
Kamil Wierzchowski; Paweł Sobieszuk; Maciej Pilarek. Oxygen Transfer Effects in a Two-Phase System of an Aqueous Phase and Liquid Perfluorochemical Subjected to Continuous Wave-Assisted Agitation in Disposable Bioreactor. Energies 2021, 14, 4381 .
AMA StyleKamil Wierzchowski, Paweł Sobieszuk, Maciej Pilarek. Oxygen Transfer Effects in a Two-Phase System of an Aqueous Phase and Liquid Perfluorochemical Subjected to Continuous Wave-Assisted Agitation in Disposable Bioreactor. Energies. 2021; 14 (14):4381.
Chicago/Turabian StyleKamil Wierzchowski; Paweł Sobieszuk; Maciej Pilarek. 2021. "Oxygen Transfer Effects in a Two-Phase System of an Aqueous Phase and Liquid Perfluorochemical Subjected to Continuous Wave-Assisted Agitation in Disposable Bioreactor." Energies 14, no. 14: 4381.
(1) The generation of nanobubbles by electrolysis is an interesting method of using electrical energy to form bubble nuclei, effectively creating a multiphase system. For every process, the effectiveness of nanobubble generation by electrolysis depends on various process parameters that impact should be determined. (2) In this work, the electrolytic generation of hydrogen and oxygen bubbles was performed in a self-built setup, in which a Nafion membrane separated two chambers. The generation of bubbles of both gases was investigated using Box–Behnken experimental design. Three independent variables were salt concentration, current density, and electrolysis time, while the dependent variables were Sauter diameters of generated bubbles. An ANOVA analysis and multivariate regression were carried out to propose a statistical and power model of nanobubble size as a process parameter function. (3) The generation of bubbles of hydrogen and oxygen by electrolysis showed that different factors or their combinations determine their size. The results presented in this work proved to be complementary to previous works reported in the literature. (4) The Sauter diameter of bubbles increases with salt concentration and stays constant with increasing current density in investigated range. The proposed correlations allow the Sauter diameters of nanobubbles generated during electrolysis to be predicted.
Karol Ulatowski; Radosław Jeżak; Paweł Sobieszuk. Impact of Process Parameters on the Diameter of Nanobubbles Generated by Electrolysis on Platinum-Coated Titanium Electrodes Using Box–Behnken Experimental Design. Energies 2021, 14, 2542 .
AMA StyleKarol Ulatowski, Radosław Jeżak, Paweł Sobieszuk. Impact of Process Parameters on the Diameter of Nanobubbles Generated by Electrolysis on Platinum-Coated Titanium Electrodes Using Box–Behnken Experimental Design. Energies. 2021; 14 (9):2542.
Chicago/Turabian StyleKarol Ulatowski; Radosław Jeżak; Paweł Sobieszuk. 2021. "Impact of Process Parameters on the Diameter of Nanobubbles Generated by Electrolysis on Platinum-Coated Titanium Electrodes Using Box–Behnken Experimental Design." Energies 14, no. 9: 2542.
Nanobubble dispersions have been intensively studied in recent years. Their expanding applications include a wide range of industrial and biochemical processes. Nanobubble-saturated water intensifies the growth of bacteria, animal cell lines, plants, and animals. However, their influence on yeast growth has not been investigated. Yeast is an important microorganism in the biotechnology and food industries. Intensified growth of yeasts would be beneficial for basic and industrial purposes. In this study, the possibility of culturing Saccharomyces cerevisiae with oxygen nanobubbles as the sole source of oxygen was investigated. Batch, sequential batch, and semi-batch cultures were grown with the addition of oxygen nanobubbles, along with classical aeration of the bioreactor. The results were compared to batch cultures without nanobubble addition. Biomass, substrate, and oxygen profiles were determined throughout the time of culture. The Monod and Tsao–Hanson models were used to describe yeast growth. The balance of the bioreactor culture was determined using MATLAB software. The comparison of balance and kinetic parameters demonstrated a higher maximum specific growth rate of yeast in nanobubble cultures than in cultures without nanobubble addition.
Paweł Sobieszuk; Alicja Strzyżewska; Karol Ulatowski. Investigation of the possibility of culturing aerobic yeast with oxygen nanobubble addition and evaluation of the results of batch and semi-batch cultures of Saccharomyces cerevisiae. Chemical Engineering and Processing - Process Intensification 2020, 159, 108247 .
AMA StylePaweł Sobieszuk, Alicja Strzyżewska, Karol Ulatowski. Investigation of the possibility of culturing aerobic yeast with oxygen nanobubble addition and evaluation of the results of batch and semi-batch cultures of Saccharomyces cerevisiae. Chemical Engineering and Processing - Process Intensification. 2020; 159 ():108247.
Chicago/Turabian StylePaweł Sobieszuk; Alicja Strzyżewska; Karol Ulatowski. 2020. "Investigation of the possibility of culturing aerobic yeast with oxygen nanobubble addition and evaluation of the results of batch and semi-batch cultures of Saccharomyces cerevisiae." Chemical Engineering and Processing - Process Intensification 159, no. : 108247.
This article presents the review of the research papers concerning nanobubble generation. In main section of this article, numerous methods of nanobubble generation have been discussed pinpointing the differences in results obtained in similar experimental setups. Different generation methods have been tabularized to present the composition of phases, the diameter of generated bubbles as well as the commentary concerning discrepancies within one method. The number of nanobubble applications in environmental processes is increasing in the last years, however the thorough investigation of their generation methods is not covered in literature. This review article is gathering knowledge about nanobubble generation methods and is comparing results obtained by different research teams. It should lay foundation for future research concerning nanobubbles, what will lead to increasing the efficiency of various environmental processes, including wastewater flotation, metal recovery and soil and groundwater remediation.
Karol Ulatowski; Paweł Sobieszuk. Gas nanobubble dispersions as the important agent in environmental processes – generation methods review. Water and Environment Journal 2020, 34, 772 -790.
AMA StyleKarol Ulatowski, Paweł Sobieszuk. Gas nanobubble dispersions as the important agent in environmental processes – generation methods review. Water and Environment Journal. 2020; 34 (S1):772-790.
Chicago/Turabian StyleKarol Ulatowski; Paweł Sobieszuk. 2020. "Gas nanobubble dispersions as the important agent in environmental processes – generation methods review." Water and Environment Journal 34, no. S1: 772-790.
Lecithin-based hydroxyapatite (HAp-LE) precipitation allows synthesis of biocompatible nanosized particles. In our previous paper regarding this process, we concluded that the concentration of lecithin gives control over the size and morphology of such particles. In this paper, a special emphasis is put on the analysis of initial pH value and reaction temperature to optimize lecithin-based synthesis conditions of the uniform spherical nanoparticles. We obtained HAp-LE in the presence of lecithin with reagent's initial pH value: 8, 9, 10 and in the reaction temperature range 24–80 °C to assess the influence of selected factors on morphology in HAp-LE precipitation process. According to scanning electron microscopy and nanoparticle tracking analysis, a pH of 10 and any synthesis temperature results in the spherical HAp-LE particles with the size around 100 nm. What is more, Fourier-transform infrared spectroscopy results indicate B-type hydroxyapatite in the precipitate. According to X-ray diffraction, mostly hydroxyapatite was obtained, but it differed in samples crystallinity because of the initial pH of synthesis. The results show that to obtain homogeneous, spherical particles, a lecithin-based synthesis should be conducted at pH 10 at any synthesis temperature.
Joanna Latocha; Michał Wojasiński; Paweł Sobieszuk; Stanisław Gierlotka; Tomasz Ciach. Impact of morphology-influencing factors in lecithin-based hydroxyapatite precipitation. Ceramics International 2019, 45, 21220 -21227.
AMA StyleJoanna Latocha, Michał Wojasiński, Paweł Sobieszuk, Stanisław Gierlotka, Tomasz Ciach. Impact of morphology-influencing factors in lecithin-based hydroxyapatite precipitation. Ceramics International. 2019; 45 (17):21220-21227.
Chicago/Turabian StyleJoanna Latocha; Michał Wojasiński; Paweł Sobieszuk; Stanisław Gierlotka; Tomasz Ciach. 2019. "Impact of morphology-influencing factors in lecithin-based hydroxyapatite precipitation." Ceramics International 45, no. 17: 21220-21227.
The focus of this work was to examine the stability of gas nanobubbles in water. The generation of nanobubbles was carried out in two porous-membrane modules for two distinct values of liquid flow rate. Gas phase was nitrogen or oxygen, and the liquid phase was distilled water. Samples of nanodispersions were stored for 10 to 35 days. Half of them were stored open and other half closed to ensure or deny contact with the atmosphere, respectively. During storage Sauter diameter and zeta potential of nanobubbles were measured. Additionally, in the case of oxygen the dissolved gas concentration was measured. The result shows that stability and size of nanobubbles did not depend on whether samples were left open or closed. Obtained nanobubbles were stable for over a month and their Sauter diameter approached the value in the range 250-350 nm from different initial sizes. Additionally, the average zeta potential of nanobubbles in stable dispersions was between -10mV and -15mV in pure water without any frother additions. Furthermore, the discussion of reasons of stability of bubbles was carried out.
Karol Ulatowski; Paweł Sobieszuk; Andrzej Mróz; Tomasz Ciach. Stability of nanobubbles generated in water using porous membrane system. Chemical Engineering and Processing: Process Intensification 2018, 136, 62 -71.
AMA StyleKarol Ulatowski, Paweł Sobieszuk, Andrzej Mróz, Tomasz Ciach. Stability of nanobubbles generated in water using porous membrane system. Chemical Engineering and Processing: Process Intensification. 2018; 136 ():62-71.
Chicago/Turabian StyleKarol Ulatowski; Paweł Sobieszuk; Andrzej Mróz; Tomasz Ciach. 2018. "Stability of nanobubbles generated in water using porous membrane system." Chemical Engineering and Processing: Process Intensification 136, no. : 62-71.
We combine a wet chemical precipitation method and 3D-printing technology in the design of a process for the continuous production of hydroxyapatite nanoparticles (10–30 nm). Our goal was to create a simple technology for the precipitation of hydroxyapatite (HAp) with properties mimicking natural bone. To influence HAp precipitation and to obtain nanosized particles, an additive of nontoxic surfactant lecithin (LE) was applied. HAp-LE particles were produced in two Y-shaped continuous reactors of different lengths, operating at atmospheric pressure and room temperature. The products obtained were characterized in terms of their crystal structure (XRD), chemical composition (FTIR), morphology of nanoparticles (SEM) and particle size distribution (DLS, NTA). A new application of chemical oxygen demand (COD) analysis was proposed to determine the quantity of lecithin in HAp-LE powders. For both reactors, process parameters such as the concentration of lecithin and the aging conditions of the product were investigated. We obtained carbonated HAp with a spherical shape, and found that the aging temperature has the most significant influence on the properties of HAp-LE (crystallinity, crystallite size, and particle size). The influence of lecithin concentration on the particle size is non-monotonic. The obtained HAp-LE exhibits properties similar to those of natural hydroxyapatite.
Joanna Latocha; Michał Wojasiński; Klaudia Jurczak; Stanisław Gierlotka; Paweł Sobieszuk; Tomasz Ciach. Precipitation of hydroxyapatite nanoparticles in 3D-printed reactors. Chemical Engineering and Processing - Process Intensification 2018, 133, 221 -233.
AMA StyleJoanna Latocha, Michał Wojasiński, Klaudia Jurczak, Stanisław Gierlotka, Paweł Sobieszuk, Tomasz Ciach. Precipitation of hydroxyapatite nanoparticles in 3D-printed reactors. Chemical Engineering and Processing - Process Intensification. 2018; 133 ():221-233.
Chicago/Turabian StyleJoanna Latocha; Michał Wojasiński; Klaudia Jurczak; Stanisław Gierlotka; Paweł Sobieszuk; Tomasz Ciach. 2018. "Precipitation of hydroxyapatite nanoparticles in 3D-printed reactors." Chemical Engineering and Processing - Process Intensification 133, no. : 221-233.
The knowledge of a volumetric liquid-side mass transfer coefficient (kLa) characterizing the oxygen transfer in bioreactor working at defined operating parameters, is a fundamental principle for establishing the aeration strategy for aerobic bioprocesses. The design of experiments (DoE) methodology has been applied for distinguishing relevant from irrelevant operating parameters, and for prediction of characteristics of oxygen mass transfer effects, in the whole range of values of operating parameters accessible in setup of ReadyToProcess WAVE™25 (WAVE 25; GE Healthcare) bioreactor equipped with 2 dm3 disposable culture bag. Due to DoE-aided analysis, rocking speed (ω), rocking angle (α) and volumetric flow of gas phase through the culture bag (QG) have been indicated as the operating parameters robustly impacting on the value of the kLa coefficient. All relevant operational parameters, i.e. ω, α and QG, exerted monotonically increasing influence on kLa. Otherwise, the influence of volume of liquid poured into culture bag (VL) and oxygen partial pressure in applied gas phase (p1) on kLa proved to be negligible. Two original correlations have been proposed to generalize the experimental results and to estimate the kLa coefficient values possible to be reached in the WAVE 25: the dimensional correlation defining the kLa coefficient, as well as the dimensionless correlation that defines Sherwood number and integrating the originally-defined Reynolds number for the liquid phase that is subjected to wave-induced mixing. The validity of results predicted by both correlations has been verified by acceptable level of the relative errors.
Maciej Pilarek; Paweł Sobieszuk; Kamil Wierzchowski; Katarzyna Dąbkowska. Impact of operating parameters on values of a volumetric mass transfer coefficient in a single-use bioreactor with wave-induced agitation. Chemical Engineering Research and Design 2018, 136, 1 -10.
AMA StyleMaciej Pilarek, Paweł Sobieszuk, Kamil Wierzchowski, Katarzyna Dąbkowska. Impact of operating parameters on values of a volumetric mass transfer coefficient in a single-use bioreactor with wave-induced agitation. Chemical Engineering Research and Design. 2018; 136 ():1-10.
Chicago/Turabian StyleMaciej Pilarek; Paweł Sobieszuk; Kamil Wierzchowski; Katarzyna Dąbkowska. 2018. "Impact of operating parameters on values of a volumetric mass transfer coefficient in a single-use bioreactor with wave-induced agitation." Chemical Engineering Research and Design 136, no. : 1-10.
Paweł Sobieszuk; Anna Zamojska-Jaroszewicz; Łukasz Makowski. Influence of the operational parameters on bioelectricity generation in continuous microbial fuel cell, experimental and computational fluid dynamics modelling. Journal of Power Sources 2017, 371, 178 -187.
AMA StylePaweł Sobieszuk, Anna Zamojska-Jaroszewicz, Łukasz Makowski. Influence of the operational parameters on bioelectricity generation in continuous microbial fuel cell, experimental and computational fluid dynamics modelling. Journal of Power Sources. 2017; 371 ():178-187.
Chicago/Turabian StylePaweł Sobieszuk; Anna Zamojska-Jaroszewicz; Łukasz Makowski. 2017. "Influence of the operational parameters on bioelectricity generation in continuous microbial fuel cell, experimental and computational fluid dynamics modelling." Journal of Power Sources 371, no. : 178-187.
Measurements of hydrogen solubility in various nitrobenzene-aniline mixtures were conducted in an autoclave reactor with a stirrer and control of temperature. The solubility of hydrogen was measured at 7 different values of temperature (30 °C, 40 °C, 50 °C, 90 °C, 130 °C, 170 °C, 210 °C, respectively), 3 values of stirrer rotation speed (1200 rpm, 1600 rpm, 2000 rpm, respectively) and a range of pressure of 20 ‒ 30 bar. Moreover, pure aniline, pure nitrobenzene and their mixtures with different concentrations were used. In the next step, values of Henry’s constant were calculated. Based on experimental data a dependence of Henry’s constant on temperature for pure aniline and pure nitrobenzene was proposed. Additionally, for each temperature correlations between Henry’s constant and aniline’s concentration in mixture of nitrobenzene-aniline were found.
Aleksandra Srebniak; Manfred Kraut; Oliver Görke; Paweł Sobieszuk. Measurements of Hydrogen Solubility in Nitrobenzene/Aniline Mixtures. Chemical and Process Engineering 2017, 38, 241 -248.
AMA StyleAleksandra Srebniak, Manfred Kraut, Oliver Görke, Paweł Sobieszuk. Measurements of Hydrogen Solubility in Nitrobenzene/Aniline Mixtures. Chemical and Process Engineering. 2017; 38 (2):241-248.
Chicago/Turabian StyleAleksandra Srebniak; Manfred Kraut; Oliver Görke; Paweł Sobieszuk. 2017. "Measurements of Hydrogen Solubility in Nitrobenzene/Aniline Mixtures." Chemical and Process Engineering 38, no. 2: 241-248.
The paper presents an investigation of mass transfer in gas-liquid annular flow in a microreactor. The microreactor had a meandered shape with a square cross-section of the channel (292×292 μm, hydraulic diameter 292 μm) and 250 mm in length. The rate of CO2 absorption from the CO2/N2 mixture in NaOH (0.1 M, 0.2 M, 0.7 M, 1.0 M and 1.5 M) water solutions was measured. Two velocities of gas flow and two velocities of liquid flow were used. In two cases a fully developed annular flow at the beginning of the channel was observed, whilst in two cases annular flow was formed only in about 2/3 of the microchannel length. Based on the measurements of CO2 absorption rate, the values of volumetric liquid - side mass transfer coefficients with the chemical reaction were determined. Then physical values of coefficients were found. Obtained results were discussed and their values were compared with the values predicted by literature correlations.
Paweł Sobieszuk; Karolina Napieralska. Investigations of mass transfer in annular gas-liquid flow in a microreactor. Chemical and Process Engineering 2016, 37, 55 -64.
AMA StylePaweł Sobieszuk, Karolina Napieralska. Investigations of mass transfer in annular gas-liquid flow in a microreactor. Chemical and Process Engineering. 2016; 37 (1):55-64.
Chicago/Turabian StylePaweł Sobieszuk; Karolina Napieralska. 2016. "Investigations of mass transfer in annular gas-liquid flow in a microreactor." Chemical and Process Engineering 37, no. 1: 55-64.
Gas-liquid microreactors find an increasing range of applications both in production, and for chemical analysis. The most often employed flow regime in these microreactors is Taylor flow. The rate of absorption of gases in liquids depends on gas-side and liquid-side resistances. There are several publications about liquid-side mass transfer coefficients in Taylor flow, but the data about gas-side mass transfer coefficients are practically non existent. We analysed the problem of gas-side mass transfer resistance in Taylor flow and determined conditions, in which it may influence the overall mass transfer rate. Investigations were performed using numerical simulations. The influence of the gas diffusivity, gas viscosity, channel diameter, bubble length and gas bubble velocity has been determined. It was found that in some case the mass transfer resistances in both phases are comparable and the gas-side resistance may be significant. In such cases, neglecting the gas-side coefficient may lead to errors in the experimental data interpretation.
Paweł Sobieszuk; Filip Ilnicki; Ryszard Pohorecki. Contribution of Liquid- and Gas-Side Mass Transfer Coefficients to Overall Mass Transfer Coefficient in Taylor Flow in a Microreactor. Chemical and Process Engineering 2014, 35, 35 -45.
AMA StylePaweł Sobieszuk, Filip Ilnicki, Ryszard Pohorecki. Contribution of Liquid- and Gas-Side Mass Transfer Coefficients to Overall Mass Transfer Coefficient in Taylor Flow in a Microreactor. Chemical and Process Engineering. 2014; 35 (1):35-45.
Chicago/Turabian StylePaweł Sobieszuk; Filip Ilnicki; Ryszard Pohorecki. 2014. "Contribution of Liquid- and Gas-Side Mass Transfer Coefficients to Overall Mass Transfer Coefficient in Taylor Flow in a Microreactor." Chemical and Process Engineering 35, no. 1: 35-45.
This article presents a critical mini-review of research conducted on bioelectrochemical reactors with emphasis placed on microbial fuel cells (MFC) and microbial electrolysis cells (MEC). The principle of operation and typical constructions of MFCs and MECs were presented. The types of anodes and cathodes, ion-selective membranes and microorganisms used were discussed along with their limitations.
Paweł Sobieszuk; Anna Zamojska-Jaroszewicz; Andrzej Kołtuniewicz. Harvesting Energy and Hydrogen from Microbes. Chemical and Process Engineering 2012, 33, 603 -610.
AMA StylePaweł Sobieszuk, Anna Zamojska-Jaroszewicz, Andrzej Kołtuniewicz. Harvesting Energy and Hydrogen from Microbes. Chemical and Process Engineering. 2012; 33 (4):603-610.
Chicago/Turabian StylePaweł Sobieszuk; Anna Zamojska-Jaroszewicz; Andrzej Kołtuniewicz. 2012. "Harvesting Energy and Hydrogen from Microbes." Chemical and Process Engineering 33, no. 4: 603-610.
The aim of this study was to determine the solubility of CO2 in perfluorodecalin (PFD) which is frequently used as efficient liquid carrier of respiratory gases in bioprocess engineering. The application of perfluorinated liquid in a microsystem has been presented. Gas-liquid mass transfer during Taylor (slug) flow in a microchannel of circular cross section 0.4 mm in diameter has been investigated. A physicochemical system of the absorption of CO2 from the CO2/N2 mixture in perfluorodecalin has been applied. The Henry’s law constants have been found according to two theoretical approaches: physical (H = 1.22·10-3 mol/m3Pa) or chemical (H = 1.26·10-3 mol/m3Pa) absorption. We are hypothesising that the gas-liquid microchannel system is applicable to determine the solubility of respiratory gases in perfluorinated liquids.
Paweł Sobieszuk; Maciej Pilarek. Absorption of Co2 into Perfluorinated Gas Carrier in the Taylor Gas–Liquid Flow in a Microchannel System. Chemical and Process Engineering 2012, 33, 595 -602.
AMA StylePaweł Sobieszuk, Maciej Pilarek. Absorption of Co2 into Perfluorinated Gas Carrier in the Taylor Gas–Liquid Flow in a Microchannel System. Chemical and Process Engineering. 2012; 33 (4):595-602.
Chicago/Turabian StylePaweł Sobieszuk; Maciej Pilarek. 2012. "Absorption of Co2 into Perfluorinated Gas Carrier in the Taylor Gas–Liquid Flow in a Microchannel System." Chemical and Process Engineering 33, no. 4: 595-602.
The pressure drop in microreactors for the gas - liquid Taylor flow was measured for 4 different microreactor geometries and 3 different gas - liquid systems. The results have been compared with the existing literature correlations. A selection of the best correlations has been made.
Paweł Cygański; Paweł Sobieszuk; Ryszard Pohorecki. Pressure drop in two-phase gas-liquid (Taylor) flow in microreactors. Chemical and Process Engineering 2012, 33, 369 -384.
AMA StylePaweł Cygański, Paweł Sobieszuk, Ryszard Pohorecki. Pressure drop in two-phase gas-liquid (Taylor) flow in microreactors. Chemical and Process Engineering. 2012; 33 (3):369-384.
Chicago/Turabian StylePaweł Cygański; Paweł Sobieszuk; Ryszard Pohorecki. 2012. "Pressure drop in two-phase gas-liquid (Taylor) flow in microreactors." Chemical and Process Engineering 33, no. 3: 369-384.
Paweł Sobieszuk; Anna Zamojska-Jaroszewicz; Krystian Frahn. Investigations of bioelectrochemical cell for hydrogen and methane production. New Biotechnology 2012, 29, S44 .
AMA StylePaweł Sobieszuk, Anna Zamojska-Jaroszewicz, Krystian Frahn. Investigations of bioelectrochemical cell for hydrogen and methane production. New Biotechnology. 2012; 29 ():S44.
Chicago/Turabian StylePaweł Sobieszuk; Anna Zamojska-Jaroszewicz; Krystian Frahn. 2012. "Investigations of bioelectrochemical cell for hydrogen and methane production." New Biotechnology 29, no. : S44.
Over the last ten to fifteen years, microreaction technology has become of increased interest to both academics and industrialists for intensification of multiphase processes. Amongst the vast application possibilities, fast, highly exothermic and/or mass transfer‐limited gas‐liquid reactions benefit from process miniaturization. Recent studies of hydrodynamics and mass transfer in gas‐liquid microreactors with closed and open microchannels, e.g., falling‐film microreactors, are reviewed and compared. Special attention is paid to Taylor or slug flow in closed channels, as this regime seems to be most adapted for practical engineering applications.
Pawel Sobieszuk; Joelle Aubin; Ryszard Pohorecki. Hydrodynamics and Mass Transfer in Gas-Liquid Flows in Microreactors. Chemical Engineering & Technology 2012, 35, 1346 -1358.
AMA StylePawel Sobieszuk, Joelle Aubin, Ryszard Pohorecki. Hydrodynamics and Mass Transfer in Gas-Liquid Flows in Microreactors. Chemical Engineering & Technology. 2012; 35 (8):1346-1358.
Chicago/Turabian StylePawel Sobieszuk; Joelle Aubin; Ryszard Pohorecki. 2012. "Hydrodynamics and Mass Transfer in Gas-Liquid Flows in Microreactors." Chemical Engineering & Technology 35, no. 8: 1346-1358.
The interfacial area in the Taylor (slug) gas–liquid flow in a microchannel was measured by the Danckwerts' (chemical) method, using CO2 absorption from the CO2/N2 mixture into KHCO3/K2CO3 buffer solutions, containing NaOCl as a catalyst. The rate of absorption was determined and the Danckwerts' plots were constructed. Reasonable agreement with the geometrical area measured photographically was obtained. This fact allowed to determine for the first time the mass transfer coefficients separately for liquid film and liquid caps. A correlation for the calculation of mass transfer coefficients has been proposed.
Paweł Sobieszuk; Ryszard Pohorecki; Paweł Cygański; Jacek Grzelka. Determination of the interfacial area and mass transfer coefficients in the Taylor gas–liquid flow in a microchannel. Chemical Engineering Science 2011, 66, 6048 -6056.
AMA StylePaweł Sobieszuk, Ryszard Pohorecki, Paweł Cygański, Jacek Grzelka. Determination of the interfacial area and mass transfer coefficients in the Taylor gas–liquid flow in a microchannel. Chemical Engineering Science. 2011; 66 (23):6048-6056.
Chicago/Turabian StylePaweł Sobieszuk; Ryszard Pohorecki; Paweł Cygański; Jacek Grzelka. 2011. "Determination of the interfacial area and mass transfer coefficients in the Taylor gas–liquid flow in a microchannel." Chemical Engineering Science 66, no. 23: 6048-6056.
Mass transfer in some gas–liquid systems may be significantly enhanced by the Marangoni effect. In the case of a falling film microreactor (FFMR) for gas–liquid reactions, the question whether the interfacial tension driven cells would develop in the limited space of a microchannel remains unsolved. One way of approaching this problem is to measure the mass transfer rate in a microreactor using a system known to exhibit the Marangoni effect in the macroscale, and to compare this rate with the value determined for the analogous process without this effect. Gas–liquid mass transfer in a FFMR with 29 microchannels (0.6 mm width each) was investigated. CO2 was absorbed from a CO2/N2 gaseous mixture into an aqueous solution of NaOH, and the liquid side mass transfer coefficient as well as the gas side mass transfer coefficient were measured. Then the possibility of appearance of the Marangoni effect was investigated using aqueous monoethanolamine (MEA) solution. The existence of the cellular convection was observed. The enhancement of the overall rate of the mass transfer depends on both gas and amine concentrations.
Paweł Sobieszuk; Ryszard Pohorecki; Paweł Cygański; Manfred Kraut; Frank Olschewski. Marangoni effect in a falling film microreactor. Chemical Engineering Journal 2010, 164, 10 -15.
AMA StylePaweł Sobieszuk, Ryszard Pohorecki, Paweł Cygański, Manfred Kraut, Frank Olschewski. Marangoni effect in a falling film microreactor. Chemical Engineering Journal. 2010; 164 (1):10-15.
Chicago/Turabian StylePaweł Sobieszuk; Ryszard Pohorecki; Paweł Cygański; Manfred Kraut; Frank Olschewski. 2010. "Marangoni effect in a falling film microreactor." Chemical Engineering Journal 164, no. 1: 10-15.
Gas–liquid mass transfer in a falling film microreactor (FFMR) with 29 microchannels (0.6 mm width each) was investigated. CO2 was absorbed from a CO2/N2 gaseous mixture into a NaOH aqueous solution and the liquid-side mass transfer coefficient and the gas-side mass transfer coefficient were measured. The influence of gas concentration on the value of gas-side mass transfer coefficient has been discussed.
Paweł Sobieszuk; Ryszard Pohorecki. Gas-side mass transfer coefficients in a falling film microreactor. Chemical Engineering and Processing: Process Intensification 2010, 49, 820 -824.
AMA StylePaweł Sobieszuk, Ryszard Pohorecki. Gas-side mass transfer coefficients in a falling film microreactor. Chemical Engineering and Processing: Process Intensification. 2010; 49 (8):820-824.
Chicago/Turabian StylePaweł Sobieszuk; Ryszard Pohorecki. 2010. "Gas-side mass transfer coefficients in a falling film microreactor." Chemical Engineering and Processing: Process Intensification 49, no. 8: 820-824.