scholarly journals DESIGN OF A PACKED-BED ABSORPTION COLUMN CONSIDERING FOUR PACKING TYPES AND APPLYING MATLAB

2016 ◽  
Vol 29 (2) ◽  
pp. 83-104 ◽  
Author(s):  
A. Pérez Sánchez ◽  
E. J. Pérez Sánchez ◽  
R. Segura Silva
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Gas Phase ◽  
Phase Transfer ◽  
Packed Bed ◽  
Design Parameters ◽  
Microsoft Excel ◽  
Absorption Column ◽  
Transfer Unit ◽  
Gaseous Stream

In the present work, a packed bed absorption column is designed to recover certain amounts of ethanol contained in a gaseous stream. Four packing types (50-mm metal Hiflow® rings, 50-mm ceramic Pall® rings, 50-mm metal Top Pak® rings and 25-mm metal VSP® rings) are considered in order to select the most appropriate one in terms of column dimensions, pressure drop and mass-transfer results. Several design parameters were determined including column diameter (D), packing height (Z), overall mass-transfer coefficient (Km) and gas pressure drop (P/Z), as well as the overall number of gas-phase transfer units (NtOG), overall height of a gas-phase transfer unit (HtOG) and the effective surface area of packing (ah). The most adequate packing to use for this absorption system constitutes the 25-mm metal VSP® rings, since it provided the greatest values of Km (0.325 kmol/m3.s), and ah (169.57 m-1), as well as the lowest values of both Z (0.6 m) and HtOG (0.145 m), meaning that it will supply the higher mass-transfer conditions with the lowest column dimensions. The influence of both gas mixture (QG) and solvent (mL) feed flowrates on D, Z, Km, P/Z, NtOG and HtOG was also evaluated for the four packing considered. The design methodology was solved using computing software MATLAB® version 7.8.0.347 (R2009a) (Math Works, 2009), and also Microsoft Excel®.D

scholarly journals Experimental Evaluation of Sulfur Dioxide Absorption in Water Using Structured Packing

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Rosa-Hilda Chavez ◽  
Nicolas Flores-Alamo ◽  
Javier de J. Guadarrama
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Nuclear Research ◽  
Packed Bed ◽  
Performance Model ◽  
Two Phase ◽  
Average Deviation ◽  
Absorption Column ◽  
Structured Packing ◽  
Transfer Unit

An experimental study of hydrodynamic and mass transfer processes was carried out in an absorption column of 0.252 m diameter and 3.5 m of packed bed height developed by Mexican National Institute of Nuclear Research (ININby its acronym in Spanish) of stainless steel gauze corrugated sheet packing by means of SO2-air-water systems. The experiments results include pressure drop, flows capacity, liquid hold-up, SO2composition, and global mass transfer coefficient and mass transfer unit height by mass transfer generalized performance model in order to know the relationship between two-phase countercurrent flow and the geometry of packed bed. Experimental results at loading regimen are reported as well as model predictions. The average deviation between the measured values and the predicted values is±5% of 48-data-point absorption test. The development of structured packing has allowed greater efficiency of absorption and lower pressure drop to reduce energy consumption. In practice, the designs of equipment containing structured packings are based on approximations of manufacturer recommendations.

scholarly journals Gas-phase mass transfer coefficient of CO2 in different alkanolamine solutions within packed-bed absorption column

2020 ◽  
Author(s):  
P. Vaewhongs ◽  
K. Photein ◽  
R. Nimchareon ◽  
T. Limlertchareonwanit ◽  
K. Minakanishtha ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Phase ◽  
Packed Bed ◽  
Absorption Column

Influence of the Cross Sectional Area of a Separation Column Using Structured Packing

2003 ◽  
Author(s):  
Rosa H. Cha´vez ◽  
Javier de J. Guadarrama ◽  
Osbaldo Pe´rez ◽  
Abel Herna´ndez-Guerrero
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Separation Efficiency ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Structured Packing ◽  
Separation Column ◽  
Transfer Unit ◽  
The Cross

In order to determine the dimension of a separation column, hydrodynamic and mass transfer models are necessary to evaluate the pressure drop and the height of the global mass transfer unit, respectively. Those parameters are a function of the cross sectional area of the column. The present work evaluates the dependency of the pressure drop and height of the global transfer unit with respect to the cross sectional area of the column, using an absorption column with high efficiency structured packing, in order to recover SO2 in the form of NaHSO3, as an example. An optimization was done applying Two Film model which is based on the number of global mass transfer units of both gas and liquid, involving the separation efficiency in terms of the height of a global transfer unit. Structured packing, geometrically heaped in a separation column, has been achieving wider acceptance in the separation processes due to their geometric characteristics that allow them to have greater efficiency in the separation processes. Three different structured packing were evaluated in this work. The results show how ININ packing is one of the packings does the best work having the highest separation efficiency because it has the lowest height of the global mass transfer unit and Mellapak packing has the largest capacity because it manages the largest liquid and gas flows. An analysis is done with respect to the pressure drop through the system for all packings considered, and a discussion is presented for each hydrodynamic and mass transfer parameter studied.

MONOPHASIC REACTION WITH A PACKED BED MICROREACTOR: CHARACTERIZATION OF MASS TRANSFER AND REACTION

2020 ◽  
Vol 20 (06) ◽  
pp. 2050033
Author(s):  
YAO CHEN ◽  
XUEYE CHEN
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Catalytic Reaction ◽  
Conversion Rate ◽  
Packed Bed ◽  
Particle Radius ◽  
Channel Structure ◽  
Clear Change

In this paper, the monophasic catalytic reaction in the microreactor is studied. Several factors that may affect the catalytic reaction are discussed, including the pressure drop, the size of catalyst particles, and the channel structure. Finally, some important conclusions can be reached. The change of pressure drop has an effect on the reaction. For example, the C3H6 conversion rate is 62.88% when the pressure drop is 8[Formula: see text]atm, and the C3H6 conversion rate is 61.78% when the pressure drop is 11[Formula: see text]atm. The effect of the change particle radius is not obvious on the reaction. Enhancing the mixing of substances before entering the reaction domain is helpful to the catalytic reaction. There are different substances concentration in catalyst particles at different positions in microreactors. But from the surface to the inside of catalyst particles, the substances concentration has a clear change rule.

Treatment of source-separated urine by a combination of bipolar electrodialysis and a gas transfer membrane

2006 ◽  
Vol 53 (3) ◽  
pp. 139-146 ◽  
Author(s):  
W. Pronk ◽  
M. Biebow ◽  
M. Boller
Keyword(s):  
Mass Transfer ◽  
Gas Phase ◽  
Ammonium Phosphate ◽  
Low Ph ◽  
Bubble Columns ◽  
Gas Transfer ◽  
Additional Mass ◽  
Hydrophobic Membrane ◽  
Bipolar Membranes ◽  
Transfer Unit

Urine contains nutrients which can be applied usefully as a fertiliser in agriculture, but the relatively high pH can lead to ammonia evaporation. Electrodialysis with bipolar membranes was combined with an additional mass transfer unit in order to render a product containing ammonium and phosphate at a low pH. In one case, the additional mass transfer unit consisted of bubble columns placed in acid and basic concentrate streams, connected with a circulating gas phase. In the other case, the unit consisted of a gas-filled (hydrophobic) membrane placed in between the circulating acid and basic concentrate streams. The results showed that ammonia was transferred through the gas phase, but also carbonate, which is present in stored urine originating from the hydrolysis of urea. Although the pH in the product stream decreases initially, it rises above pH 7 at longer operation times. This pH increase can be attributed to a combination of proton compensating effects. The use of ammonia-selective membranes for the transfer into the acid concentrate could provide a solution to generate an ammonium phosphate product at low pH and high recoveries.

scholarly journals Hydrodynamic and Mass Transfer in the Desorption Process of CO2 Gas in a Packed-Bed Stripper

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 46
Author(s):  
Pao Chi Chen ◽  
Ming-Wei Yang ◽  
Yan-Lin Lai
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Total Pressure ◽  
Mixed Solvent ◽  
Liquid Flow Rate ◽  
Packed Bed ◽  
Process Variables ◽  
Desorption Process ◽  
Co2 Gas ◽  
Transfer Data

A lab-scale packed-bed stripper containing Dixon rings was used to explore the effects of the process variables on the hydrodynamics and mass-transfer in a stripper using a mixed solvent loaded CO2. The variables are the liquid flow rate, reboiler temperature, and amine concentration, and the hydrodynamic and mass-transfer data can be determined using different models. In the case of hydrodynamics, the dimensionless pressure drop at the flooding point and the total pressure drop were explored first. In the case of mass-transfer, the correlation of the mass-transfer coefficient and the parameter importance were also observed. In addition, the number of plates per meter can be compared with the Dixon rings manufacturer. Finally, the performances of a mixed solvent and monoethanolamine (MEA) solvent were also discussed.

scholarly journals Designed porous milli-scale reactors with enhanced interfacial mass transfer in two-phase flows

2017 ◽  
Vol 2 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Aditi Potdar ◽  
Lidia N. Protasova ◽  
Leen Thomassen ◽  
Simon Kuhn
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Packed Bed ◽  
Transfer Performance ◽  
Two Phase Flows ◽  
Two Phase ◽  
Reduced Pressure ◽  
Packed Bed Reactors ◽  
Interfacial Mass Transfer

Designed porous milli-scale reactors with enhanced mass transfer performance and reduced pressure drop compared to conventional packed bed reactors.

scholarly journals Hydrodynamics and axial mixing in a packed gas-liquid column

2003 ◽  
pp. 33-48
Author(s):  
Branislava Barjaktarovic ◽  
Milan Sovilj ◽  
Svetlana Popovic
Keyword(s):  
Pressure Drop ◽  
Gas Phase ◽  
Liquid Flow ◽  
Packed Column ◽  
Packed Bed ◽  
Axial Dispersion ◽  
Gas Absorption ◽  
Phase System ◽  
Two Phase ◽  
Gas Phases

The objective of this study was to investigate the pilot-plant gas absorption packed column hydrodynamics, as well as axial mixing in the system air-water. The pressure drop and the gas phase holdup data were determined in dependence on the flow rates of gas and liquid phases. The influence of superficial velocities of liquid and gas phases on the liquid axial dispersion in a gas-liquid packed bed column (ID 15 cm) consisting of Raschig rings (15x15x2 mm) were investigated. The pressure drop was measured with a U-type manometer, connected to the bottom and the top of the working part of the column. The gas phase holdup data in the air-water two-phase system was calculated as a ratio of the gas phase volume to the total volume of the two-phase system. Axial dispersion in the water phase has been determined by examining of the distribution of residence times of a salt tracer (NaCl) in the packed bed. The tracer was injected in the liquid flow above the packed bed; samples of liquid were simultaneously taken from two sites at 1 m distance along the bed. Salt concentrations in the samples were determined by conductivity measurements. The mean residence time and the axial dispersion number were calculated by the moment method. The axial dispersion increases with an increase of liquid flow velocities and decrease of superficial air velocities.

Gas-phase mass transfer characteristics in a counter airflow shear rotating packed bed

2016 ◽  
Vol 94 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Youzhi Liu ◽  
Fangfang Zhang ◽  
Deyin Gu ◽  
Guisheng Qi ◽  
Weizhou Jiao ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Gas Phase ◽  
Packed Bed ◽  
Transfer Characteristics ◽  
Rotating Packed Bed

Performance calculation and configuration optimization of annular radiator by heat transfer unit simulation and a multi-objective genetic algorithm

2021 ◽  
pp. 095440892110017
Author(s):  
Zhe Xu ◽  
Yingqing Guo ◽  
Huarui Yang ◽  
Haotian Mao ◽  
Zongling Yu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Pressure Drop ◽  
Design Parameters ◽  
Configuration Optimization ◽  
Nsga Ii ◽  
Transfer Unit ◽  
Side Pressure ◽  
Heat Transfer Capacity ◽  
Performance Calculation

A performance calculation method based on heat transfer unit (HTU) simulation is proposed to calculate heat transfer capacity and air-side pressure drop of Annular radiator (AR), which can avoid the problem of a huge amount of grids, and at the same time, ensure the calculation accuracy. Calculation results are compared with experimental data, and the average errors of heat transfer capacity and air-side pressure drop are 11.5%, and 5.9%, respectively, which effectively validates the effectiveness and the reliability of this method. Besides, based on HTU simulation knowledge database, a configuration optimization method of AR using Non-dominated Sorted Genetic Algorithm-II (NSGA-II) is introduced. Number of fins in circumferential direction, number of fins in axial direction, and fin height are chosen as design parameters, and two conflicting optimization objectives include heat transfer capacity maximization and air-side pressure drop minimization. Three optimal structures of AR are obtained, and the optimal results indicate that the heat transfer capacity of the optimal configurations increases by 34.31% on average compared with the original one, while the air-side pressure drop decreases by 24.00% on average, which indicates that this method is feasible and valid and can provide significant guidance for structural design of AR.

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