Active Sensors for Gas-Liquid Mass Transfer Studies in Capillaries

2018 ◽  
Author(s):  
Waldemar Krieger ◽  
Robin Dinter ◽  
Georg Wiese ◽  
Santer zur Horst-Meyer ◽  
Norbert Kockmann
Keyword(s):  
Mass Transfer ◽  
Analytical Methods ◽  
Particle Concentration ◽  
Vision System ◽  
High Surface ◽  
Measurement Techniques ◽  
Volume Ratio ◽  
Life Time ◽  
Industrial Applications ◽  
Taylor Flow

Gas-liquid and gas-liquid-solid reactions in microstructured devices are an active field in scientific research with many industrial applications. High surface-to-volume ratio as well as enhanced heat and mass transfer are advantageous making microstructured devices a promising technology to overcome mass transfer limitations. The implementation of traditional sensors and analytical methods is a drawback when investigating mass transfer phenomena within microstructured devices, since they disturb the flow and reactor characteristics. Offline measurement techniques provide limited insight into flow structure, while noninvasive online measurement techniques either cannot provide local results or require a sophisticated setup. In this work, a noninvasive ultrasonic sensor (SONOTEC, Germany) is used to measure particle concentration and bubble length in Taylor flow. Particle concentration and bubble detection is derived from the ultrasonic signal. Further, an Arduino based slider setup is developed, which is equipped with a computed-vision system to track bubbles in Taylor flow. This setup can be combined with optical analytical methods allowing for investigating the entire life time of a single bubble or liquid slug.

Numerical simulation and experimental investigation of multiphase mass transfer process for industrial applications in China

2019 ◽  
Vol 36 (1) ◽  
pp. 187-214
Author(s):  
Chao Yang ◽  
Guangsheng Luo ◽  
Xigang Yuan ◽  
Jie Chen ◽  
Yangcheng Lu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Transfer Process ◽  
Transport Phenomena ◽  
Measurement Techniques ◽  
Mass Transfer Process ◽  
Industrial Applications ◽  
Economic Benefits ◽  
Distillation Columns ◽  
Stirred Reactors

Abstract This paper presents a comprehensive review of the remarkable achievements by Chinese scientists and engineers who have contributed to the multiscale process design, with emphasis on the transport mechanisms in stirred reactors, extractors, and rectification columns. After a brief review of the classical theory of transport phenomena, this paper summarizes the domestic developments regarding the relevant experiments and numerical techniques for the interphase mass transfer on the drop/bubble scale and the micromixing in the single-phase or multiphase stirred tanks in China. To improve the design and scale-up of liquid-liquid extraction columns, new measurement techniques with the combination of both particle image velocimetry and computational fluid dynamics have been developed and advanced modeling methods have been used to determine the axial mixing and mass transfer performance in extraction columns. Detailed investigations on the mass transfer process in distillation columns are also summarized. The numerical and experimental approaches modeling transport phenomena at the vicinity of the vapor-liquid interface, the point efficiency for trays/packings regarding the mixing behavior of fluids, and the computational mass transfer approach for the simulation of distillation columns are thoroughly analyzed. Recent industrial applications of mathematical models, numerical simulation, and experimental methods for the design and analysis of multiphase stirred reactors/crystallizers, extractors, and distillation columns are seen to garnish economic benefits. The current problems and future prospects are pinpointed at last.

Enhanced Carbon Capture in a Multiport Microscale Absorber

2013 ◽  
Author(s):  
Harish Ganapathy ◽  
Sascha Steinmayer ◽  
Amir Shooshtari ◽  
Serguei Dessiatoun ◽  
Mohamed Alshehhi ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Carbon Capture ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Absorption Efficiency ◽  
Cross Sectional ◽  
Gaseous Mixtures ◽  
Liquid Absorption ◽  
Parametric Studies

Increasing concerns on the effects of global warming leading to climate change has necessitated the development of efficient technologies to separate acid gas components, such as carbon dioxide and hydrogen sulfide, from gaseous mixtures. Microscale technologies have the potential to substantially enhance gas-liquid absorption processes on account of their inherent high surface area to volume ratio. The present work reports the mass transfer characteristics during gas-liquid absorption in a multiport microscale absorber. The reactor was designed to comprise of 15 straight, parallel channels having a hydraulic diameter of 456 micrometer and square cross-sectional geometry. The absorption of CO2 mixed with N2 into aqueous diethanolamine was investigated. The performance of the absorber was characterized with respect to the absorption efficiency and mass transfer coefficient. Parametric studies investigating the effects of the gas and liquid phase superficial velocity were performed and discussed. Additionally, the effect of varying the liquid reactant concentration was investigated and discussed.

A Novel Potentiometric PVC-membrane Cysteamine-Selective Electrode Based on Cysteamine-Phosphomolybdate Ion-Pair

2020 ◽  
Vol 16 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Merve Tumur ◽  
Gulsah Saydan Kanberoglu ◽  
Fatih Coldur
Keyword(s):  
Analytical Methods ◽  
Pharmaceutical Preparations ◽  
Life Time ◽  
Ion Pair ◽  
Pharmaceutical Formulation ◽  
Pvc Membrane ◽  
Selective Electrode ◽  
Potentiometric Response ◽  
Drug Quality Control

Background: Cysteamine is used as an orphan drug in the treatment of cystinosis to prevent long-term cystine accumulation in lysosomes. Dosing in cysteamine treatment is extremely important and overdose may cause some side effects. Up to now, various analytical methods have been used for cysteamine determination. Many of these methods require sophisticated instruments, expert operators, time-consuming measurement procedures and manipulation steps, expensive supplies and long analysis time. Aims and Objective: The present study deals with the development of a potentiometric PVC-membrane cysteamine-selective electrode based on an ion-pair of cysteamine and its application in a pharmaceutical formulation. Methods: Cysteamine (Cys)-Phosphomolybdate (PM) ion-pair was synthesized by mixing the equal volumes of 10-2 M Cysteamine HCl and sodium phosphomolybdate aqueous solutions. The obtained precipitate was used as ionophore in the structure of PVC-membrane. Results and Discussion: The electrode exhibited a linear response in the concentration range of 1.0×10- 1-1.0×10-5 M cysteamine with a slope of 51,7 mV per decade and detection limit of 1.0×10-5 M. The potentiometric response of the electrode was very rapid (5 s), adequately repeatable, stable and selective. pH working range and life-time of the electrode were also determined as 3.0-7.0 and 25 days, respectively. Conclusion: A PVC-membrane cysteamine selective electrode was easily prepared. Cysteamine determination in a pharmaceutical formulation was performed. Analysis results indicated that it can be successfully used in drug quality control laboratories for routine analysis of cysteamine in pharmaceutical preparations alternative to more sophisticated, expensive and time-consuming analytical methods.

scholarly journals A highly thermotolerant laccase produced by Cerrena unicolor strain CGMCC 5.1011 for complete and stable malachite green decolorization

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanhua Yao ◽  
Guimei Zhou ◽  
Yonghui Lin ◽  
Xinqi Xu ◽  
Jie Yang
Keyword(s):  
Malachite Green ◽  
Fermentation Broth ◽  
Nitrogen Sources ◽  
Life Time ◽  
Industrial Applications ◽  
Dynamics Simulation ◽  
Carbon And Nitrogen ◽  
Cdna Sequences ◽  
Cerrena Unicolor ◽  
Future Work

Abstract Laccases are a class of multi-copper oxidases with important industrial values. A thermotolerant laccase produced by a basidiomycete fungal strain Cerrena unicolor CGMCC 5.1011 was studied. With glycerin and peptone as the carbon and nitrogen sources, respectively, a maximal laccase activity of 121.7 U/mL was attained after cultivation in the shaking flask for 15 days. Transcriptomics analysis revealed an expressed laccase gene family of 12 members in C. unicolor strain CGMCC 5.1011, and the gene and cDNA sequences were cloned. A glycosylated laccase was purified from the fermentation broth of Cerrena unicolor CGMCC 5.1011 and corresponded to Lac2 based on MALDI-TOF MS/MS identification. Lac2 was stable at pH 5.0 and above, and was resistant to organic solvents. Lac2 displayed remarkable thermostability, with half-life time of 1.67 h at 70 ºC. Consistently, Lac2 was able to completely decolorize malachite green (MG) at high temperatures, whereas Lac7 from Cerrena sp. HYB07 resulted in accumulation of colored MG transformation intermediates. Molecular dynamics simulation of Lac2 was conducted, and possible mechanisms underlying Lac2 thermostability were discussed. The robustness of C. unicolor CGMCC 5.1011 laccase would not only be useful for industrial applications, but also provide a template for future work to develop thermostable laccases.

scholarly journals Coal Fly Ash Derived Silica Nanomaterial for MMMs—Application in CO2/CH4 Separation

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 78
Author(s):  
Marius Gheorghe Miricioiu ◽  
Violeta-Carolina Niculescu ◽  
Constantin Filote ◽  
Maria Simona Raboaca ◽  
Gheorghe Nechifor
Keyword(s):  
Fly Ash ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Coal Fly Ash ◽  
High Surface ◽  
Industrial Applications ◽  
Mixed Matrix Membranes ◽  
Co2 Removal ◽  
Mcm 41

In order to obtained high selective membrane for industrial applications (such as natural gas purification), mixed matrix membranes (MMMs) were developed based on polysulfone as matrix and MCM-41-type silica material (obtained from coal fly ash) as filler. As a consequence, various quantities of filler were used to determine the membranes efficiency on CO2/CH4 separation. The coal fly ash derived silica nanomaterial and the membranes were characterized in terms of thermal stability, homogeneity, and pore size distribution. There were observed similar properties of the obtained nanomaterial with a typical MCM-41 (obtained from commercial silicates), such as high surface area and pore size distribution. The permeability tests highlighted that the synthesized membranes can be applicable for CO2 removal from CH4, due to unnoticeable differences between real and ideal selectivity. Additionally, the membranes showed high resistance to CO2 plasticization, due to permeability decrease even at high feed pressure, up to 16 bar.

scholarly journals Electrospun Nanofibers for Sensing and Biosensing Applications—A Review

2021 ◽  
Vol 22 (12) ◽  
pp. 6357
Author(s):  
Kinga Halicka ◽  
Joanna Cabaj
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Toxic Metal ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Clinical Diagnostics ◽  
Loading Capacity ◽  
Electrospun Nanofiber ◽  
Sensing Platforms ◽  
Different Types

Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions.

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