che 334: separation processes
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بسم الله الرحمن الرحيم. Text Book : Separation Process Principles by J. D. Seader , Ernest J. Henley , Second Edition, 2006. CHE 334: SEPARATION PROCESSES. Dr. Saad Al-Shahrani. - PowerPoint PPT PresentationTRANSCRIPT
Text BookText Book: : Separation Process Principles by J. D. Seader , Ernest J. Separation Process Principles by J. D. Seader , Ernest J.
Henley Henley , Second Edition, 2006, Second Edition, 2006
CHE 334: SEPARATION PROCESSESCHE 334: SEPARATION PROCESSES
Dr. Saad Al-ShahraniDr. Saad Al-Shahrani
بسم الله الرحمن الرحيم
References:
1.Separation Processes by King, C.J., 2nd ed. Mc Graw Hill (1980).
2.http://www.separationprocesses.com/Mainmenu.htm.
Dr Saad Al-ShahraniChE 334: Separation Processes
What are separation processes?
The main goal of separation process is to purify solution,
Introduction to Separation processes
Dr Saad Al-ShahraniChE 334: Separation Processes
To do this we must cause different transport of species or convection of species so that the purer mixture can be collected.Most separation processes involve differential transport.
Separation processes are defined as those operations which transform a mixture of substances into two or more products which differ from each other in composition.
Dr Saad Al-Shahrani
Introduction to Separation processes
mixed separated
ChE 334: Separation Processes
Dr Saad Al-Shahrani
Introduction to Separation processes
ChE 334: Separation Processes
Dr Saad Al-Shahrani
Introduction to Separation processes
ChE 334: Separation Processes
Crude oil
Dr Saad Al-Shahrani
Introduction to Separation processes
Examples of Separation processes:
1. Separation of blood.
2. Purification of drugs.
3. Purification of Au, Ag, Ti.
4. Refining of crude oil.
5. DNA testing.
6. Purification of organic material.
7. Purification of water.
8. Separation of water and waste product of metabolism from blood Kidney
ChE 334: Separation Processes
Dr Saad Al-Shahrani
Distillation: Which separates various chemical component according to volatility.
Alkylation: to react small hydrocarbon molecules to create larger hydrocarbon molecules.
Catalytic reforming: which is used to modify the structure of medium sized hydrocarbons.
Fluid catalytic cracking: to break apart very large hydrocarbon molecules.
Hydrocracking: to break apart very large hydrocarbon molecules.
The separation technology involved in crude oil reforming include:
ChE 334: Separation Processes
Introduction to Separation processes
Why Separation?
There are many reasons for wanting pure substances. Some of these reasons include:
Dr Saad Al-Shahrani
Need for pure material in engineering applications.
Preparation of raw materials into their component.
Need for pure material for materials processing.
Need to remove toxins or inactive components from solution (drugs)
Need for ultra-pure samples for testing.
Need for analysis of the components of mixture (DNA testing)
ChE 334: Separation Processes
Introduction to Separation processes
Dr Saad Al-Shahrani
Analytical Separation
• Small scale
• To determine composition of complex mixture quantitative.
Example:
Chromatography
preparative Separation
• Small scale
• To recover and purify chemicals
Example:
Centrifugation
industrial Separation
• large scale
• To manufacture chemicals using separation methods
Example:
Distillation
ChE 334: Separation Processes
Introduction to Separation processes
Based on these motivation for separations, we can divide separations up into three main areas:
Dr Saad Al-Shahrani
The list of different existing separations methods is
limitless. Therefore we will emphasize the fundamentals of
separations.
Note: 50 to 90 percent of capital investment in chemical
plant is for separation equipments.
ChE 334: Separation Processes
Introduction to Separation processes
Basic Description of operations
Dr Saad Al-Shahrani
Separation processes can be run in various modes of operation:
Batchwise: no flows
Continuous: continuous flows in and out of separations
Semicontinuous: pauses in flows.
Operations are classified as key operations and auxiliary operations:
Key Operation: involves a change in chemical composition such as:
• Chemical reaction
• Separation of mixtures of chemicals.
Examples: leaching, distillation, and gas absorption
ChE 334: Separation Processes
Dr Saad Al-Shahrani
Auxiliary Operation: which is required to carry out the key operations
Examples: pumps, heaters, and compressors.
Basic Description of operations
ChE 334: Separation Processes
Dr Saad Al-Shahrani
Block Flow Diagrams indicate:
F
S1 P1
S2P2
Key operation by rectangles.
Flows and Streams by lines.
Distillation
Basic Description of operations
ChE 334: Separation Processes
Dr Saad Al-Shahrani
1
2
N
Feed
Stripping section stages
Feed stage
Boilup
Partial reboiler
bottoms
Total condenser
Reflux Distillate
Reflux drumOverhead vapor
Distillation
Process Flow Diagrams indicates processes by:
Realistic symbols of process equipment.
Including auxiliary operations.
Basic Description of operations
ChE 334: Separation Processes
Mechanism of separation:
The mixing of chemicals to form a mixture is a spontaneous, natural process that is accompanied by an increase in entropy or randomness (∆S)
Dr Saad Al-Shahrani
The inverse process (the separation of the mixture into its constituent
chemical species) is not spontaneous process, it requires an
expenditure of energy.
A mixture to be separated usually originates as a single homogenous phase (solid, liquid, or gas)
ChE 334: Separation Processes
Basic Description of operations
Dr Saad Al-Shahrani
If it exists as two or more immiscible phases, it must be first separate
the phases by some mechanical means based on gravity, centrifugal
force, pressure reduction, or electric or magnetic field. Then
appropriate separation techniques are applied to each phase.
A schematic diagram of general separation process
Separation process
Product 1
Product 2
Product N-1
Product N
Feed mixture to be separated
(S, L, V, Ci)
ChE 334: Separation Processes
Basic Description of operations
Dr Saad Al-Shahrani
The feed mixture may be vapor, liquid or solid, while the two or more
products may differ in composition from each other and the feed may
differ in phase state from each other and / or from the feed
Feed
liq.
50% Bz
50% Tol
Distillation
Top product
(vapor phase)
Bottom product(liquid phase)
97.6% Bz
3.4% Tol
98.6% Tol
1.4% Bz
ChE 334: Separation Processes
Basic Description of operations