Gas absorption is a process used to separate gases by contacting a gas mixture with a liquid solvent. The key principles are the solubility of the absorbed gas and the rate of mass transfer as the gas dissolves into the liquid. Absorption is usually carried out counter-currently in vertical columns. The solvent is fed at the top while the gas enters at the bottom, allowing the absorbed substances to be washed out in the downward flowing liquid. Proper selection of solvent considers factors like gas solubility, volatility, cost, and viscosity. Rate of absorption is determined by volumetric mass transfer coefficients, which can be calculated from operating line and equilibrium curve diagrams.
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Distillation
Subject: 0.2 Introduction to distillation.
The processing technique employing a suspension or fluidization of small solid particles in a vertically rising stream of fluid usually gas so that fluid and solid come into intimate contact. This is a tool with many applications in the petroleum and chemical process industries. Suspensions of solid particles by vertically rising liquid streams are of lesser interest in modern processing, but have been shown to be of use, particularly in liquid contacting of ion-exchange resins. However, they come in this same classification and their use involves techniques of liquid settling, both free and hindered (sedimentation), classification, and density flotation.
Difference between batch,mixed flow & plug-flow reactorUsman Shah
This slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Distillation
Subject: 0.2 Introduction to distillation.
The processing technique employing a suspension or fluidization of small solid particles in a vertically rising stream of fluid usually gas so that fluid and solid come into intimate contact. This is a tool with many applications in the petroleum and chemical process industries. Suspensions of solid particles by vertically rising liquid streams are of lesser interest in modern processing, but have been shown to be of use, particularly in liquid contacting of ion-exchange resins. However, they come in this same classification and their use involves techniques of liquid settling, both free and hindered (sedimentation), classification, and density flotation.
Difference between batch,mixed flow & plug-flow reactorUsman Shah
This slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
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CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 3.2 Equipment
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 2.4 Interphase mass transfer
Absorption & indusrial absorber,Gas Absorption,Equipments,Absorption in chemical Reaction,Absorption in Packed Tower,Absorption for counter current,Choice of Solvent,Continuous Contact Equipment,Height Equivalent to Theoretical Plate,HETP
In this topic we have discussed working principle of a Batch Reactor. We've also discussed its kinetics like its Rate equation, Material and Energy balance. Its Design steps also have been discussed.
A common apparatus used in gas absorption, distillation and liq-liq extraction. Design and construction of packed towers, types of tower, packing materials, liquid distributers, types of packing...
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
Please show the love! LIKE, SHARE and SUBSCRIBE!
More likes, sharings, suscribers: MORE VIDEOS!
-----
CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Subject: 2.4 Plate efficiencies.
it is a mass transfer operation use in chemical industries
it is a simple diffusion of solid to liquid phase and foam a new concentrate liquid solution
it is base on simple diffusion how to work in industries this operation
it is use for pharma, seeds and oil industries.
Presentation on Azeotropic and Extractive Distillation. Introduction about distillation, azeotropic and extractive distillation and the difference between them.
I found no good source for extractive distillation on the internet.So i decided to make one myself.This ppt discusses about the technology,its working and benefits.It compares extractive distillation side by side to azeotropic distillation and counts the advantages.
This presentation is about the basics of Urea Formaldehyde. In This presentation you will find the basic method of preparing urea formaldehyde, applications of urea formaldehyde, general properties of urea formaldehyde and some latest research on urea formaldehyde.
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
Please show the love! LIKE, SHARE and SUBSCRIBE!
More likes, sharings, suscribers: MORE VIDEOS!
-----
CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 3.2 Equipment
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 2.4 Interphase mass transfer
Absorption & indusrial absorber,Gas Absorption,Equipments,Absorption in chemical Reaction,Absorption in Packed Tower,Absorption for counter current,Choice of Solvent,Continuous Contact Equipment,Height Equivalent to Theoretical Plate,HETP
In this topic we have discussed working principle of a Batch Reactor. We've also discussed its kinetics like its Rate equation, Material and Energy balance. Its Design steps also have been discussed.
A common apparatus used in gas absorption, distillation and liq-liq extraction. Design and construction of packed towers, types of tower, packing materials, liquid distributers, types of packing...
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
Please show the love! LIKE, SHARE and SUBSCRIBE!
More likes, sharings, suscribers: MORE VIDEOS!
-----
CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Subject: 2.4 Plate efficiencies.
it is a mass transfer operation use in chemical industries
it is a simple diffusion of solid to liquid phase and foam a new concentrate liquid solution
it is base on simple diffusion how to work in industries this operation
it is use for pharma, seeds and oil industries.
Presentation on Azeotropic and Extractive Distillation. Introduction about distillation, azeotropic and extractive distillation and the difference between them.
I found no good source for extractive distillation on the internet.So i decided to make one myself.This ppt discusses about the technology,its working and benefits.It compares extractive distillation side by side to azeotropic distillation and counts the advantages.
This presentation is about the basics of Urea Formaldehyde. In This presentation you will find the basic method of preparing urea formaldehyde, applications of urea formaldehyde, general properties of urea formaldehyde and some latest research on urea formaldehyde.
This presentation includes effective knowledge about Gasoline Engine.
The best thing about the presentation is this it includes many pictures for better understanding.
This is very helpful for students.
Me Majid.
Contact : +923005524644
+923455242696
An overview of distillation column design concepts and major design considerations. Explains distillation column design concepts, what you would provide to a professional distillation column designer, and what you can expect back from a distillation system design firm. To speak with an engineer about your distillation column project, call EPIC at 314-207-4250.
various types of flow meter
1. rotameter
2. venturimeter
3. electromagnetic flow meter
4. positive displacement flow meter
with their working advantage and disadvantages
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
2. WHAT IS GAS ABSORPTION????
Absorption, or gas absorption, is a unit operation used in the chemical
industry to separate gases by washing or scrubbing a gas mixture with a
suitable liquid .
The fundamental physical principles underlying the process of gas
absorption are the solubility of the absorbed gas and the rate of mass
transfer. One or more of the constituents of the gas mixture dissolves or
is absorbed in the liquid and can thus be removed from the mixture. In
some systems, this gaseous constituent forms a physical solution with the
liquid or the solvent, and in other cases , it reacts with the liquid
chemically.
3. The purpose of such scrubbing operations may be any of the
following :
Gas purification (eg , removal of air pollutants from exhausts
gases or contaminants from gases that will be further processed) ,
Product Recovery , or production of solutions of gases for various
purposes.
The absorber may be a packed column , plate column , spray
column , venturi scrubbers , bubble column , falling films , wet
scrubbers ,stirred tanks
4. Gas absorption is usually carried out in vertical
counter current columns.
The solvent is fed at the top of the absorber ,
whereas the gas mixture enters from the bottom
.The absorbed substence is washed out by the
solvent and leaves the absorber at the bottom as
a liquid solution .
The solvent is often recovered in a subsequent
stripping or desorption operation . This second
step is essentially the reverse of absorption and
involves counter current contacting of the liquid
loaded with solute using and inert gas or water
vapor .
5. Choice Of Solvent for Absorption
If the principal purpose of the absorption operation is to
produce a specific solution, as in the manufacture of
hydrochloric acid, for example, the solvent is specified by
the nature of the product, i.e. water is to be the solvent. If
the principal purpose is to remove some components (e.g.
impurities) from the gas, some choice is frequently possible.
The factors to be considered are:
6. GAS SOLUBILITY :
The gas solubility should be high, thus increasing the rate of
absorption and decreasing the quantity of solvent required.
Solvent with a chemical nature similar to the solute to be
absorbed will provide good solubility.
VOLATALITY :
The solvent should have a low vapour pressure to reduce loss
of solvent in the gas leaving an absorption column.
CORROSIVENESS :
The materials of construction required for the equipment
should not be unusual or expensive
7. COST :
The materials of construction required for the
equipment should not be unusual or expensive.
VISCOSITY :
Low viscosity is preferred for reasons of rapid
absorption rates, improved flooding characteristics in packed
column, low pressure drops on pumping, and good heat
transfer characteristics.
The solvent should be non-toxic, non-flammable and
chemically stable.
9. COUNTERCURRENT FLOW
• Countercurrent tower which may be either a packed
or spray tower, filled with bubble cape trays or of
any internal construction to bring about liquid gas
contact.
• Mole ratio may be define as
Y = y/(1-y)
X = x/(1-x)
• Here y for gas stream and x for liquid stream.
10. Material balance
Gs = G(1-y) = G/(1+Y)
Ls = L(1-x) = L/(1+X)
NOW
Gs(Y1 - Y) = Ls(Xs - X)
AND
Gs(y1/(1-y1) – y/(1-y)) = Gs(p1/(1-p1) – p/(1-p)) = Gs(x1/(1-x1) –
x/(1-yx))
11. MINIMUM LIQUID-GAS RATIO
• In the design of absorbers, the quantity of gas to be treated G or Gs,
the terminal concentrations Y1 and Y2,and the composition of the
entering liquid X2 are ordinarily fixed by process requirements.
• The operating line must be pass through point D and must end at the
ordinate Y.
• Liquid gas ratio is define by
L/G
• Graph of minimum liquid-gas ratio can be shown as behind slide.
12.
13. CO-CURRENT FLOW
• When gas and liquid flow cocurrently, the operating line
has a negative slope.
-L/G
• There is no limit of this ratio, but an infinitely tall tower
would produce an exit liquid and gas in equilibrium
• In cocurrent fow requirred height of tower should be
higher then in counter current flow.
14. Counter-current multi-stage absorption
(Tray absorber):
In tray absorption tower, multi-stage contact between gas and liquid takes
place.
In each tray, the liquid is brought into intimate contact of gas and
equilibrium is reached thus making an ideal stage.
In ideal stage, average composition of liquid leaving the tray is in
equilibrium with liquid leaving that tray.
The most important step in design of tray absorber is the
determination of number of trays.
The schematic of tray tower is presented in figure.
The liquid enters from top of the column whereas gas is added from
the bottom.
15. The efficiency of the stages can be calculated as:
𝑆𝑡𝑎𝑔𝑒 𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑑𝑒𝑎𝑙 𝑠𝑡𝑎
𝑔𝑒𝑠/𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑒𝑎𝑙 𝑠𝑡𝑎𝑔𝑒𝑠
…..Eq.(1)
Gs,Y1
Gs, YN+1
Liquid out
Ls, XN
Gas in
Gas outGs, Y1
Liquid in
Ls, X0
Ls, X1
Gs,YN
Ls, X1
N
N-1
1
2
16. The following parameters should be known for the
determination of “number of stages”:
(1) Gas feed rate
(2) Concentration of gas at inlet and outlet of
the tower
(3) Minimum liquid rate; actual liquid rate is
1.2 to 2 times the minimum liquid rate.
(4) Equilibrium data for construction of
equilibrium curve
Now, the number of theoretic stages can be obtained
graphically:
17. (A) Graphical Method for the Determination of Number of Ideal
Stages:
Overall material balance on tray tower:
Gs(YN+1 -Y1) = Ls(XN -X0)
This is the operating line for tray tower
If the stage (plate) is ideal, (Xn, Yn) must lie on the equilibrium line, Y*=f(X).
Top plate is located at P(X0, Y1) and bottom plate is marked as Q(XN,
YN+1) in X-Y plane.
A vertical line is drawn from Q point to D point in equilibrium line at (XN, YN).
From point D in equilibrium line, a horizontal line is extended up to operating
line at E (XN-1, YN).
18. The region QDE stands for N-th plate. We may get fraction of plates.
In that situation, the next whole number will be the actual number of ideal
plates.
If the overall stage efficiency is known, the number of real plates can be
obtained from Equation A.
0.0 0.2 0.4 0.6 0.8 1.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
E ( X
N-1
,Y
N
)
X
P ( X
0
,Y
1
)
Q ( X
N
,Y
N+1
)
Equilibrium line
Operating line
N
N-1
N-2
D ( X
N
,Y
N
)
19. Example:
It is desired to absorb 95% of acetone by water from a mixture of
acetone and nitrogen containing 1.5% of the component in a
countercurrent tray tower. Total gas input is 30 kmol/hr and water enters
the tower at a rate of 90 kmol/hr. The tower operates at 27ºC and 1 atm.
The equilibrium relation is Y=2.53X. Determine the number of ideal
stages necessary for the separation using graphical method.
21. 𝑌1 = 0.0225/29.55 = 7.61 × 10^−4
𝑌(𝑁+1)= 0.015
Equation.. 𝐺𝑠𝑌(𝑁+1)− 𝑌1= 𝐿𝑠(𝑋𝑁− 𝑋0)
29.55 × 0.015 − 7.61 × 10^−4= 90(𝑋𝑁− 0)
XN=4.68×10^-3
Solution by graphical method,Construction of operating line PQ:
P(X0,Y1)=P(0, 7.61×10^-4)
Q(XN, YN+1)=Q(4.68×10^-3, 0.015)
Construction of equilibrium line (Y=2.53X):
X 0 0.001 0.002 0.003 0.004 0.005
Y 0 0.00253 0.00506 0.00759 0.01012 0.01265
From graphical construction in Figure , the number of triangles obtained is
more than 7. Hence number of ideal stages is 8.
22.
23. 23
Rate of absorption
•Volumetric mass transfer coefficients (Kya, etc.) are used for most
calculations, because it is more difficult to determine the coefficients per
unit area and because the purpose of the design calculation is generally to
determine the total absorber volume.
•Kya=overall volumetric mass-transfer coefficient, kmol/(m3·h·unit mole
fraction).
•a=effective area of interface per unit packed volume, m2/m3
24. 24
•Simplicity Treatment
•The following treatment applies to lean gases (up to 10% solute):
•(a) Correction factors for one-way diffusion are omitted for simplicity.
•(b) Changes in gas and liquid flow rates (V and L) are neglected.
•(c) kxa, kya, Kya, Kxa can be considered as constants.
25. 25
•the rate of mass transfer:
r=NA [kgmol/(m2·h·unit mole fraction)]
)()(
)(
AAixAiAyA xxkyykN
r
)(
)(
AAyA yyKN
r
)(
)(
AAxA xxKN
r
26. 26
•Let r =rate of absorption per unit volume, kgmol/(m3·h)
)(
)(
)(
)(
xxaKr
yyaKr
xxakr
yyakr
x
y
ix
iy
•It is hard to measure or to predict a, but in most cases it is not necessary
to know its actual value since design calculations can be based on the
volumetric coefficients.
27. 27
•Determining the interface composition (yi, xi)
•(yi, xi) is also hard to measure, but it can be obtained from the
operating-line diagram
ak
ak
xx
yy
y
x
i
i
)(
)(
•Thus a line drawn from the operating line with a slope –kxa/kya will
intersect the equilibrium line at (yi, xi).
29. 29
xyy
AAAiAi
AAixAiAyy
k
m
kK
mxymxy
xxkyykK
11
,,
)()(
•Determining the overall coefficients: Using the local slope of the
equilibrium curve m, we have
Therefore,
ak
m
akaK
mxymxy
xxk
yy
yyk
yy
K
xyy
AAAiAi
AAix
AAi
AiAy
AiA
y
11
,,
)56.17(
)()(
1
amkakaK
mxymxy
xxk
yy
yyk
yy
K
yxx
AAAiAi
AAix
AAi
AiAy
AiA
y
111
,,
)()(
1
Similarly,
30. 30
=overall resistance to mass transfer
= resistance to mass transfer in the gas film
=resistance to mass transfer in the liquid film
ak
m
ak
aK
x
y
y
1
1
ak
m
ak
aK
x
y
y
1
1
ak
m
ak
aK
x
y
y
1
1
ak
m
akaK
mxymxy
xyy
AAAiAi
11
,,
31. 31
•Gas film “controls” and Liquid film “controls”
When ""
11
,
1
controlsfilmGas
akaKak
m
ak yyxy
ak
m
akaK
mxymxy
xyy
AAAiAi
AAixAiAyy
11
,,
•Or, When the coefficients kya and kxa are of the same order of
magnitude, and m is very much greater than 1.0, the liquid film
resistance is said to be controlling. That is,
""
1
,
1
controlsfilmLiquid
ak
m
aKak
m
ak xyxy
32. 32
•Liquid film controlling means that any change in kxa has a nearly
proportional effect on both Kxa and Kya and on the rate of absorption,
whereas a change in kya has little effect.
•Examples of Liquid film controls: Absorption of CO2, H2,O2,Cl2 in
water;
•When the solubility of the gas is very high, m is very small and the gas-
film resistance controls the rate of absorption.
•Examples of gas-film controls: Absorption of HCl, NH3 in water; NH3
in acid solution; SO2, H2S in basic solvent.
33. 33
•With gases of intermediate solubility both resistances are important,
but the term controlling resistance is sometimes used for the larger
resistance.
•The absorption of NH3 in water is often cited as an example of gas-film
control, since the gas film has about 80 to 90 percent of the total
resistance.
35. 35
•Number of transfer units
b
a
y
yy
T
yy
dy
aK
SV
Z
)(
/
•The equation for column height can be written as follows:
b
a
y
y
oy
yy
dy
N
)(
=overall number of transfer units [NTU],
based on gas phase.
aK
SV
H
y
oy
/
=overall height of a transfer unit [HTU], based
on gas phase.
36. 36
oyoyT NHZ
(1)If the operating line and equilibrium line are
straight and parallel,
Equilibrium
line
Operating line
a
a
b
x
x
yy
y
y
y
1
2
3
b
a
a
b
xx
x
x
x
yy
y
y
y
3
2
1
1
2
3
a
a
b
x
yy
y
y
y
1
2
3
a
a
b
x
x
x
yy
y
y
y
1
1
2
3
a
b
x
yy
y
y
y
1
2
3
b
a
b
b
xx
x
x
x
yy
y
y
y
3
2
1
1
2
3
bb
ab
oy
aa
ab
oy
ab
oy
y
y
oy
yy
yy
N
yy
yy
N
yy
yy
N
yy
dy
N
b
a
.18(
)(
bb
ab
oy
aa
ab
oy
ab
oy
y
y
oy
yy
yy
N
yy
yy
N
yy
yy
N
yy
dy
N
b
a
1(
)(
bb
ab
oy
aa
ab
oy
ab
oy
y
y
oy
yy
yy
N
yy
yy
N
yy
yy
N
yy
dy
N
b
a
)(
37. 37
bb
ab
oy
aa
ab
oy
ab
oy
y
y
oy
yy
yy
N
yy
yy
N
NTP
yy
yy
N
yy
dy
N
b
a
)(
•If the operating line and equilibrium line are straight and parallel,
NTP=Number of theoretical plates
ab
oy
L
ab
oy
y
y
oy
yy
N
y
yy
N
yy
dy
N
b
a
)(
•(2) For straight operating and equilibrium line (not parallel),
aa
bb
aabb
L
yy
yy
yyyy
y
ln
)()(
Similarly,
bb
ab
oy
aa
ab
oy
ab
ox
y
y
oy
yy
yy
N
yy
yy
N
NTP
xx
xx
N
yy
dy
N
b
a
)(
bb
ab
oy
aa
ab
oy
oyox
y
y
oy
yy
yy
N
yy
yy
N
NTPNN
yy
dy
N
b
a
)(
38. 38
•(3) When the operating line is straight but steeper than the
equilibrium line,
bb
ab
oy
aa
ab
oy
oy
y
y
oy
yy
yy
N
yy
yy
N
NTPN
yy
dy
N
b
a
)(
NTP=Number of theoretical plates
NTP
y
yy
NTUN
yyy
yyyyyy
yy
y
x
y
L
ab
oy
Lab
aabbab
ba
a
b
b
1
Equilibrium
line
Operating line
yyyyyy
yy
y
x
y
aabbab
ba
a
b
b
yy
y
x
y
ba
a
b
b
x
y
b
b
y
x
y
a
b
b
x
y
a
b
39. 39
•Similarly, for straight operating and equilibrium line (not parallel),
bb
ab
oy
aa
ab
oy
L
ab
ox
y
y
oy
yy
xx
N
yy
yy
N
x
xx
N
yy
dy
N
b
a
)(
aa
bb
aabb
L
xx
xx
xxxx
x
ln
)()(
oxoxT NHZ
x
ox
y
y
oy
m
aK
SL
H
yy
dy
N
b
a
][
/
)(
40. 40
•Common equations for calculations of height of packed section:
height of packed section=height of a transfer unit number of transfer
units
•There are four kinds of transfer units:
•The overall height of a transfer unit [Hoy OR Hox] can be defined as
the height of a packed section required to accomplish a change in
concentration equal to the average driving force in that section.
bb
ab
oy
aa
ab
oy
oyTmab
y
y
oy
yy
yy
N
yy
yy
N
HZyyyy
yy
dy
N
b
a
)(
)(
41. 41
•Four kinds of transfer units:
Gas film:
Liquid film:
Overall gas:
Overall liquid:
b
a
b
a
b
a
b
a
x
x
ox
y
ox
y
y
oy
y
oy
x
x i
x
x
x
y
y i
y
y
y
oxoxoyoyxxyyT
xx
dx
N
aK
SL
H
yy
dy
N
aK
SV
H
xx
dx
N
ak
SL
H
yy
dy
N
ak
SV
H
NHNHNHNHZ
/
/
/
/
42. 42
• Alternate forms of transfer coefficients
The gas-film coefficients reported in the literature are often based on a
partial –pressure driving force instead of a mole-fraction difference and
are written as kga or Kga.
•Similarly liquid-film coefficients may be given as kLa or KLa, where the
driving force is a volumetric concentration difference. [kL=kc defined by
Eq.(17.36)]
)20.17()(
,
0
AAi
T
v
AA
y
g
y
g
y
y
AMv
B
A
A
MvAA
cc
B
D
JN
P
aK
aK
P
ak
ak
dyDdbN
db
dy
DNJ
A
Ai
T
44. 44
•The terms HG, HL, NG AND NL often appear in the literature instead of
Hy, Hx, Ny AND Nx, as well as the corresponding terms for overall values,
but here the different subscripts do not signify any difference in either
units or magnitude.
•Relationships among different kinds of height of a transfer unit:
ak
m
akaK
mxymxy
xxk
yy
yyk
yy
K
xyy
AAAiAi
AAix
AAi
AiAy
AiA
y
11
,,
)()(
1
M
M
x
M
y
M
y
M
AAAiAi
AAix
AAi
AiAy
AiA
y
L
L
ak
mG
ak
G
aK
G
mxymxy
xxk
yy
yyk
yy
K
,,
)()(
1