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 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

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.

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.

The effect of two-phase flow regime on hydrodynamics and mass transfer in a horizontal-tube gas-liquid reactor

1985 ◽  
Vol 50 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Andreas Zahn ◽  
Lothar Ebner ◽  
Kurt Winkler ◽  
Jan Kratochvíl ◽  
Jindřich Zahradník
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Flow Regime ◽  
Liquid Flow ◽  
Horizontal Tube ◽  
Liquid Holdup ◽  
Two Phase ◽  
Flow Rates ◽  
Type Relation ◽  
Good Agreement

The effect of two-phase flow regime on decisive hydrodynamic and mass transfer characteristics of horizontal-tube gas-liquid reactors (pressure drop, liquid holdup, kLaL) was determined in a cocurrent-flow experimental unit of the length 4.15 m and diameter 0.05 m with air-water system. An adjustable-height weir was installed in the separation chamber at the reactor outlet to simulate the effect of internal baffles on reactor hydrodynamics. Flow regime maps were developed in the whole range of experimental gas and liquid flow rates both for the weirless arrangement and for the weir height 0.05 m, the former being in good agreement with flow-pattern boundaries presented by Mandhane. In the whole range of experi-mental conditions pressure drop data could be well correlated as a function of gas and liquid flow rates by an empirical exponential-type relation with specific sets of coefficients obtained for individual flow regimes from experimental data. Good agreement was observed between values of pressure drop obtained for weirless arrangement and data calculated from the Lockhart-Martinelli correlation while the contribution of weir to the overall pressure drop was well described by a relation proposed for the pressure loss in closed-end tubes. In the region of negligible weir influence values of liquid holdup were again succesfully correlated by the Lockhart-Martinelli relation while the dependence of liquid holdup data on gas and liquid flow rates obtained under conditions of significant weir effect (i.e. at low flow rates of both phases) could be well described by an empirical exponential-type relation. Results of preliminary kLaL measurements confirmed the decisive effect of the rate of energy dissipation on the intensity of interfacial mass transfer in gas-liquid dispersions.

Enhancement of Inter-Phase Transport in Mini/Micro-Scale Applications Using Passive Mixing

2011 ◽  
Author(s):  
Adam A. Donaldson ◽  
Patrick Plouffe ◽  
Arturo Macchi
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Scale Up ◽  
Interfacial Area ◽  
Flow Patterns ◽  
High Mass ◽  
Two Phase ◽  
Initial Flow ◽  
Micro Scale ◽  
Passive Mixing

Structured mini/micro-scale reactors continue to receive attention from both industry and academia due to their low pressure drop, high mass transfer rates and ease of scale-up when compared to conventional reactor technology. Commonly considered for heat and mass transfer limited reactions such as hydrogenations, hydrodesulphurization, oxidations and Fischer-Tropsch synthesis, the performance of these systems is highly dependent on mixing and the interfacial area between phases. While existing literature describes the initial flow patterns generated by a broad range of two-phase contactors, few studies explore the dynamic impacts of downstream passive mixing elements. Experimental and computational methodologies for characterizing two-phase flow pattern transitions, pressure drop, mixing and mass transfer are discussed, with relevant examples for serpentine and venturi-based passive mixing designs. The efficacy of these two configurations are explored in the context of pressure drop, conditions leading to significant interface renewal, and design considerations for optimizing mass transfer. Challenges associate with the characterization of multiphase flow through these systems are highlighted, and strategies suggested for both experimental and computational analysis of dynamic flow patterns and fluid-fluid interactions.

Modelling the Hydrodynamics of Gas-Liquid Packed Beds via Slit Models: A Review

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Ion Iliuta ◽  
Faical Larachi
Keyword(s):  
Mass Transfer ◽  
Multiphase Flow ◽  
Complex Geometry ◽  
Packed Bed ◽  
Packed Beds ◽  
Reactor Performance ◽  
Two Phase ◽  
Flow Equations ◽  
Considerable Impact ◽  
Transfer Thermodynamics

Packed bed columns are intensively used as multiphase contactors and reactors in chemical, biochemical, and petrochemical industries. Due to two-phase through the packed beds, the performance of multiphase contactors depends on the complex interaction of the interphase mass transfer, thermodynamics and hydrodynamics. Under reaction conditions, the intraparticle mass transfer and reaction kinetics have additional considerable impact on the reactor performance. The inherent complexity of multiphase systems leaves many issues unresolved and leads to many inconsistencies and questionable approximations, especially in the modelling of multiphase flow. Multiphase flow modelling in packed beds is a complicated task because of the difficulty incorporating the complex geometry into the flow equations, and the difficulty in accounting for the gas-liquid interactions in the presence of complex fluid-particle (e.g., partial wetting) contacting. This review focuses on recent advances made in the modelling of the hydrodynamics of two-phase downflow and counter-current flow in packed beds via two-fluid models coupled with slit and double slit phenomenological approximations relating the mutual three phase hydrodynamic interactions.

Contamination Prevention of the Sulfur Dioxide Using Structured Packing

2002 ◽  
Author(s):  
Rosa H. Cha´vez ◽  
Javier de J. Guadarrama
Keyword(s):  
Mass Transfer ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Energy Content ◽  
Primary Source ◽  
Pollution Effects ◽  
Absorption Column ◽  
Atmospheric Contamination ◽  
Structured Packing ◽  
National Production

The atmospheric contamination is a significant problem for the population of the big cities. This problem has its origin in the burning of heavy oil, that is carried out to liberate its energy content. Its use as a primary source of energy has high pollution effects in its process due to the formation and expulsion of gases and particles as a consequence of its combustion that contaminate the atmosphere. Although it has had enough relative elements of legal type relative to the contamination, specially atmospheric contamination, there is a lack of solutions adapted to the characteristics of the problem for each country. The present work quantifies the improvements in mass transfer, using absorption column with structured packing of high efficiency for the recovery of the SO2, through the process of removal of SO2 in the form of CaSO3. For such study, the hydrodynamic and mass transfer models are used to design the column, as well as to prove different packings (national production, denominated ININ in Mexico, SulzerBX, Mellapak and Raschig) to evaluate the separation efficiency. It is discussed that the ININ packing was one of the best of those tested because it has the highest separation efficiency.

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.

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