Absorption Process
Autor: Siddyag • October 29, 2017 • Lab Report • 6,078 Words (25 Pages) • 679 Views
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Contents
1. Introduction 2
2. Background theory 2
2.1 Absorption 2
2.2 Absorption Equipment 3
2.3 Tower packing 3
2.4 Tower fluid mechanics 4
3. Design Considerations 4
4. Chemical Engineering Design 5
4.1 Mass balance 5
4.2 Packed Column Diameter 7
4.3 Operating Line 8
4.4 Packed Column Height 8
4.5 Mass transfer 10
5. Mechanical design 12
5.1 Absorption column 12
5.2 Support plates 13
5.3 Hold down Plates 14
5.4 Liquid Distributors and Redistributors 15
6. Process Control 16
7. Safety Considerations 18
Introduction
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As proposed in part one of the report ethanol and carbon dioxide coming out from the fermenter is going to the absorption column for the maximum recovery of ethanol. They both are in the vapour phase and a homogenous separation is needed to be carried out. For the recovery of ethanol a packed tower absorption column is installed which will absorb the carbon dioxide introduced from the bottom of the column with the help of the solvent water introduced from the top (counter current). A compressor is also needed which compress the carbon dioxide coming from the column so that it can be sold to the chemical industries.
Background theory
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In this section some brief background theory is described about the packed column absorption and how it works.
2.1 Absorption
Absorption is a process by which a gas mixture is contacted with a liquid solvent that preferentially dissolves one or more components of the gas. It is generally used for separating low molecular weight materials and often requires an extraneous material (liquid solvent).
Absorption is based on Henry’s law:
Pi= Hi xi
Where, pi = partial pressure of component i Hi = Henry’s law constant (determined experimentally) xi= mole fraction of component i in the liquid phase
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