A novel approach for calculating packed column height based on new correlation of mass transfer coefficient

Abstract The calculation of column’s height plays an important role in packed columns precise design. This research is based on experimentally measurement of mass transfer coefficients in different heights of packed column to predict its height. The objective of presented work is to introduce a novel conceptual method to predict column height via new correlation for mass transfer coefficient. As the mass transfer coefficient is decreased with increase of column height, the HTU’s are not constant figures along the column so this new approach is called increasing HTU’s. The results of the proposed idea were compared with other correlations and the conventional method i.e. constant HTU’s. Since the results are in very good agreement with experimental data comparing to conventional method, it seems this approach can be a turning point in design of all differential columns like packed columns. Making use of this method is suggested for design of differential columns.

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Mass Transfer Enhancement for CO2 Absorption in Structured Packed Absorption Column

Journal of the chemical society of pakistan ◽

10.52568/000803/jcsp/41.05.2019 ◽

2019 ◽

Vol 41 (5) ◽

pp. 820-820

Author(s):

Pongayi Ponnusamy Selvi and Rajoo Baskar Pongayi Ponnusamy Selvi and Rajoo Baskar

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Gas Flow ◽

Aqueous Ammonia ◽

Volume Flow Rate ◽

Packed Column ◽

Operating Conditions ◽

Co2 Absorption ◽

Absorption Column

The acidic gas, Carbon dioxide (CO2) absorption in aqueous ammonia solvent was carried as an example for industrial gaseous treatment. The packed column was provided with a novel structured BX-DX packing material. The overall mass transfer coefficient was calculated from the absorption efficiency of the various runs. Due to the high solubility of CO2, mass transfer was shown to be mainly controlled by gas side transfer rates. The effects of different operating parameters on KGav including CO2 partial pressure, total gas flow rates, volume flow rate of aqueous ammonia solution, aqueous ammonia concentration, and reaction temperature were investigated. For a particular system and operating conditions structured packing provides higher mass transfer coefficient than that of commercial random packing.

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Film Cooling Downstream of a Row of Discrete Holes With Compound Angle

Journal of Turbomachinery ◽

10.1115/1.1344905 ◽

2000 ◽

Vol 123 (2) ◽

pp. 222-230 ◽

Cited By ~ 48

Author(s):

R. J. Goldstein ◽

P. Jin

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Film Cooling ◽

Transfer Coefficients ◽

Cooling Effectiveness ◽

Mass Transfer Coefficients ◽

Cooling Performance ◽

Film Cooling Effectiveness ◽

Compound Angle

A special naphthalene sublimation technique is used to study the film cooling performance downstream of one row of holes of 35 deg inclination angle and 45 deg compound angle with 3d hole spacing and relatively small hole length to diameter ratio (6.3). Both film cooling effectiveness and mass/heat transfer coefficients are determined for blowing rates from 0.5 to 2.0 with density ratio of unity. The mass transfer coefficient is measured using pure air film injection, while the film cooling effectiveness is derived from comparison of mass transfer coefficients obtained following injection of naphthalene-vapor-saturated air with that of pure air injection. This technique enables one to obtain detailed local information on film cooling performance. General agreement is found in local film cooling effectiveness when compared with previous experiments. The laterally averaged effectiveness with compound angle injection is higher than that with inclined holes immediately downstream of injection at a blowing rate of 0.5 and is higher at all locations downstream of injection at larger blowing rates. A large variation of mass transfer coefficients in the lateral direction is observed in the present study. At low blowing rates of 0.5 and 1.0, the laterally averaged mass transfer coefficient is close to that of injection without compound angle. At the highest blowing rate used (2.0), the asymmetric vortex motion under the jets increases the mass transfer coefficient drastically ten diameters downstream of injection.

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Dufour and Soret effects on Al2O3-water nanofluid flow over a moving thin needle: Tiwari and Das model

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-03-2020-0177 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Cited By ~ 1

Author(s):

Iskandar Waini ◽

Anuar Ishak ◽

Ioan Pop

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Skin Friction ◽

Temporal Stability ◽

Physical Parameters ◽

Transfer Coefficients ◽

Nanofluid Flow ◽

Content Type

Purpose This paper aims to examine the effect of Dufour and Soret diffusions on Al2O3-water nanofluid flow over a moving thin needle by using the Tiwari and Das model. Design/methodology/approach The governing equations are reduced to the similarity equations using similarity transformations. The resulting equations are programmed in Matlab software through the bvp4c solver to obtain their solutions. The features of the skin friction, heat transfer and mass transfer coefficients, as well as the velocity, temperature and concentration profiles for different values of the physical parameters, are analysed and discussed. Findings The non-uniqueness of the solutions is observed for a certain range of the physical parameters. The authors also notice that the bifurcation of the solutions occurs in which the needle moves toward the origin (λ < 0). It is discovered that the first branch solutions of the skin friction coefficient and the heat transfer coefficients increase, but the mass transfer coefficient decreases in the presence of nanoparticle. Additionally, the simultaneous effect of Dufour and Soret diffusions tends to enhance the heat transfer coefficient; however, dual behaviours are observed for the mass transfer coefficient. Further analysis shows that between the two solutions, only one of them is stable and thus physically reliable in the long run. Originality/value The problem of Al2O3-water nanofluid flow over a moving thin needle with Dufour and Soret effects are the important originality of the present study. Besides, the temporal stability of the dual solutions is examined for time.

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ABSORBSI H2S MENGGUNAKAN LARUTAN Fe-EDTA DALAM PACKED COLUMN

EKUILIBIUM ◽

10.20961/ekuilibrium.v10i2.2236 ◽

2011 ◽

Vol 10 (2) ◽

Author(s):

Endang Kwartiningsih ◽

Arif Jumari

Keyword(s):

Mass Transfer ◽

Liquid Phase ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Gas Phase ◽

Reaction Rate ◽

Packed Column ◽

Reaction Rate Constant ◽

Absorption Process ◽

Edta Solution

Abstract: Gas purification from the content of H2S using Fe-EDTA (Iron Chelated Solution) gave several advantages. The advantages were the absorbent solution can be regenerated that means a cheap operation cost, the separated sulfur was a solid that is easy to handle and is save to be disposal to environment. This research was done by simulation and experimental. The simulation step was done by mathematical model arrangement representing the absorption process in packed column through mass transfer arrangement such as mass transfer equations and chemical reaction. The experimental step was done with the making of Fe-EDTA solution from FeCl2 and EDTA. Then Fe-EDTA solution was flown in counter current packed column that was contacted with H2S in the methane gas. By comparing gas composition result of experiment and simulation, the value of mass transfer coefficient in gas phase ( kAga), mass transfer coefficient in liquid phase (kAla) and the reaction rate constant ( k) were found. The values of mass transfer coefficient in liquid phase (kAla) were lower than values of mass transfer coefficient in gas phase (kAga) and the reaction rate constant (k). It meant that H2S absorption process using Fe-EDTA absorbent solution was determined by mass transfer process in liquid phase. The higher flow rate of absorbent, the higher value of mass transfer coefficient in liquid phase. The smaller packing diameter, the higher value of mass transfer coefficient in liquid phase.From analysis of dimension, the relation of dimensionless number between Sherwood number and flow rate of absorbent, packing diameter was Keywords: chemical reaction, Fe-EDTA, H2S absorption, mass transfer

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Liquid-liquid mass transfer studies in various stirred vessel designs

Reviews in Chemical Engineering ◽

10.1515/revce-2014-0049 ◽

2015 ◽

Vol 31 (4) ◽

Cited By ~ 2

Author(s):

Reza Afshar Ghotli ◽

Abdul Raman Abdul Aziz ◽

Shaliza Ibrahim

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Interfacial Area ◽

Operating Conditions ◽

Experimental Results ◽

Dispersed Phase ◽

Transfer Coefficients ◽

Mass Transfer Coefficients ◽

Wide Range

AbstractA general review on correlations to evaluate mass transfer coefficients in liquid-liquid was conducted in this work. The mass transfer models can be classified into continuous and dispersed phase coefficients. The effects of drop size and interfacial area on mass transfer coefficient were investigated briefly. Published experimental results for both continuous and dispersed phase mass transfer coefficients through different hydrodynamic conditions were considered and the results were compared. The suitability and drawbacks of these correlations depend on the operating conditions and hydrodynamics. Although the results of these models are reasonably acceptable, they could not properly predict the experimental results over a wide range of designs and operating conditions. Therefore, proper understanding of various factors affecting mass transfer coefficient needs to be further extended.

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Correction Factors for Determining the Mass Transfer Coefficients

Strojnícky casopis – Journal of Mechanical Engineering ◽

10.2478/scjme-2021-0022 ◽

2021 ◽

Vol 71 (2) ◽

pp. 109-120

Author(s):

Gužela Štefan ◽

Dzianik František

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Correction Factors ◽

Industrial Equipment ◽

Transfer Coefficients ◽

Mass Transfer Coefficients ◽

Industrial Operations ◽

The Given

Abstract A number of industrial operations are linked to mass transfer. The mass transfer coefficient value is necessary to know when designing the industrial equipment in which mass transfer occurs. There are various mass transfer coefficients, as well as equations for their calculation. However, the value of these coefficients determined according to these equations often has to be corrected for the given conditions. The aim of the article is to state the conversion relations - the correction factors enabling the calculation of the mass transfer coefficients values corresponding to the given conditions.

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Dinamika tetes dalam kolom isian

Jurnal Teknik Kimia Indonesia ◽

10.5614/jtki.2008.7.1.1 ◽

2018 ◽

Vol 7 (1) ◽

pp. 710

Author(s):

Danu Ariono ◽

Dwiwahju Sasongko ◽

Priyono Kusumo

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Size Distribution ◽

Droplet Size ◽

Droplet Diameter ◽

Mass Transfer Rate ◽

Packed Column ◽

Droplet Size Distribution ◽

Droplet Dynamics

To date, evaluation of the performance of liquid-liquid extraction in packed columns has not been able to produce satisfactory results, because the correlations used in this evaluation are empirical in nature, with a very limited range of validity. One of the causes of this limitation is the use of the assumption that the dynamics of liquid dispersed in droplets is constant (in terms of shape, dimensions, and numbers), so that the mass transfer interfacial area and mass transfer coefficient in the column are assumed to be constant. In reality, dynamics of droplets in a column is not constant, due to the imbalance between droplet coalescence and disintegration. For a given droplet diameter, there is an increase in numbers of droplets due to coalescence of smaller droplets, and a decrease in numbers of droplets due to disintegration into smaller droplets. These coalescence and disintegration phenomena may be caused by various factors, including the existence of packings which impede the flow of droplets. These phenomena impact the mass transfer rate from continuous to dispersed phase, and vice versa, due to a variation in the interfacial contact area and mass transfer coefficient. The observation of droplet dynamics from droplet formation until its motion through void spaces between packings is a critical factor in developing a model that can describe the performance of the packed column. The dynamics of droplets is influenced by various operational and physical variables. A droplet dynamics experiment has been undertaken, aimed at obtaining the droplet size distribution at specific heights along the column. This distribution is to be used to develop mass transfer coefficient correlations in the continuous and dispersed phases.Keywords: droplet size distribution, packed column Abstrak Evaluasi unjuk kerja ekstraksi cair-cair dalam kolom isian (packed column) hingga saat ini belum dapat memberikan hasil yang memuaskan karena korelasi-korelasi yang digunakan masih bersifat empiris serta daerah keberlakuannya sangat terbatas. Salah satu penyebab keterbatasan berlakunya korelasi tersebut ialah penggunaan anggapan bahwa dinamika cairan yang terdispersi dalam bentuk tetesan bersifat konstan (bentuk, ukuran serta jumlahnya), sehingga harga luas perpindahan massa dan harga koefisien perpindahan massa dalam kolom dianggap tetap. Kenyataannya dinamika tetesan dalam kolom tidak konstan akibat adanya tetesan yang bergabung dan pecah dalam jumlah yang tidak sama. Pada suatu harga diameter tetesan tertentu, ada penambahan jumlah tetesan akibat penggabungan tetesan tetesan yang ukurannya lebih kecil serta adanya pengurangan jumlah tetesan akibat pecahnya tetesan menjadi tetesan-tetesan yang lebih kecil. Peristiwa penggabungan dan pemecahan tetesan dapat disebabkan berbagai faktor temasuk adanya isian yang menghalangi gerakan tetesan. Kejadian tersebut akan mempengaruhi laju proses perpindahan massa dari fasa kontinyu ke fasa terdispersi atau sebaliknya, karena adanya variasi luas permukaan kontak serta koefisien perpindahan massanya. Pengamatan dinamika tetesan mulai saat pembentukan tetes hingga pergerakannya saat melewati sela-sela isian merupakan faktor penting dalam membangun model yang dapat menggambarkan unjuk kerja kolom isian. Dinamika tetesan tersebut dipengaruhi oleh berbagai variabel operasi dan variabel fisik. Eksperimen dinamika fetes yang dilakukan diarahkan untuk memperoleh distribusi ukuran tetes pada posisi ketinggian tertentu dan distribusi tersebut akan digunakan untuk pengembangan korelasi koefisien perpindahan massa difasa dispersi danfasa kontinyu.Kata kunci: distribusi ukuran tetes, kolom isian.

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An Experimental Study of Mass Transfer coefficient of CO2 absorption using Different Amines in a Packed Column

Egyptian Journal of Chemistry ◽

10.21608/ejchem.2020.29899.2641 ◽

2020 ◽

Vol 0 (0) ◽

pp. 0-0

Author(s):

Zahraa Abd ◽

salih Rushdi

Keyword(s):

Mass Transfer ◽

Experimental Study ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Packed Column ◽

Co2 Absorption

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Experimental Investigation of Enhanced Absorption of Carbon Dioxide in Diethanolamine in a Microreactor

ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2013-73162 ◽

2013 ◽

Cited By ~ 3

Author(s):

Harish Ganapathy ◽

Amir Shooshtari ◽

Serguei Dessiatoun ◽

Mohamed Alshehhi ◽

Michael M. Ohadi

Keyword(s):

Carbon Dioxide ◽

Mass Transfer ◽

Natural Gas ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Absorption Efficiency ◽

Optimum Operating ◽

Transfer Coefficients ◽

Mass Transfer Coefficients ◽

Liquid Absorption

Natural gas in its originally extracted form comprises carbon dioxide and hydrogen sulfide as small, but non-negligible fractions of its dominant component, methane. Natural gas in the above form is typically subjected to a sweetening process that removes these acid gases. Microscale technologies have the potential to substantially enhance mass transport phenomena on account of their inherently high surface area to volume ratio. The present work reports the mass transfer characteristics during gas-liquid absorption in a microreactor. The absorption of CO2 mixed with N2 into aqueous diethanolamine was investigated in a single straight channel having a hydraulic diameter of 762 micrometer and circular cross-sectional geometry. The performance of the reactor was characterized with respect to the absorption efficiency and mass transfer coefficient. Close to 100% absorption efficiency was obtained under optimum operating conditions. Shorter channel lengths were observed to yield enhanced values of mass transfer coefficient on account of the improved utilization of the liquid reactants’ absorption capacity for a given reactor volume. In comparison to the 0.5 m long channel, the mass transfer coefficients with the 0.3 m and 0.1 m channels were higher on an average by 35.2% and 210%, respectively. Parametric studies investigating the effects of phase superficial velocity, liquid and gas phase concentration were performed. The mass transfer coefficients achieved using the present minichannel reactor were 1–3 orders of magnitude higher than that reported using conventional gas-liquid absorption systems.

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