Construction Of Packed Distillation Column
The construction of a packed distillation column involves assembling a vertical vessel with structured or random packing materials designed to enhance mass transfer efficiency during the separation of liquid mixtures through fractional distillation. Packed columns consist of trays or plates that facilitate vapor-liquid contact, allowing components to condense and vaporize as they move up or down the column. The design and selection of packing materials, such as ceramic, metal, or plastic, depend on factors like the desired separation efficiency, pressure drop considerations, and corrosion resistance. Additionally, the column construction integrates components such as distributors, redistributors, and liquid collectors to optimize flow distribution and enhance separation performance. Effective construction methodologies prioritize factors like column diameter, packing density, and material compatibility to ensure operational effectiveness and longevity of the distillation process.
This is an abstract on the construction of a packed distillation column. A packed distillation column is used in the separating process distillation that is the separation of two miscible liquids.
It was constructed by marking out the dimension of the column, condenser, pot, using steel rule scriber, oxyacetylene flame was used for cutting after which the work piece were center punched and drilled using the drilling machine. At last they were folded, shaped, welded tested, finished and painted.
This construction was done with the following specifications, 650, 220, 188 for height, external and internal diameter of column respectively.
For condenser, 650, 120, 114 for height, external and internal diameter respectively. For boiler pot, 450, 240, 236 for height, external and internal diameter respectively all in mm dimension.
It was generally required that stainless steel be used totally for the construction as the standardized Material but due to tits cost, galvanized metal was used. Using the constructed packed distillation column, a fermented palm wine can be distilled to collect gin as the distillate. In comparing the standardized distillation column with the Oni constructed it was rated 80% due to cost of materials (galvanized of construction used. But the standard material of construction that was supposed to be used is stainless steel.
At the end of the construction the cost was (N9, 000). Nine thousand Naira from the direct labour condenser etc. the cost is as a result of economy situation in Nigeria.
Title page
Letter of Transmittal
Dedication
Acknowledgement
Abstract
Table of content
CHAPTER ONE
1.0 Introduction
1.1 Historical development
1.2 Definition
CHAPTER TWO
2.0 Literature review
2.1 Theory of distillation
2.2 Types of distillation
2.2.1 Binary distillation
2.2.2 Multi-component distillation
2.2.3 Differential distillation
2.2.4 Rectification distillation
2.2.5 Flash distillation
2.3.0 Distillation column
2.3.1 Types of distillation column
2.4.0 Packing
2.4.1 Random packing
2.4.2 Regular packing
2.4.3 Tower shell
2.4.4 Packing support
2.4.5 Packing restrainer
2.4.6 Entrainment eliminators
2.5.0 Countercurrent flow of liquid and gas through packing
2.5.1 Flooding and loading
2.5.2 Pressure drop for two phase flow
2.5.3 Mass transfer coefficient for packed tower
2.5.4 Liquid hold up
2.6.0 Material of construction
2.7.0 Properties of material construction
2.7.1 Physical property of material construction
2.7.2 Chemical property of material construction
2.7.3 Mechanical property of material construction
2.8 Factors to be considered when selecting a material of construction
2.8.1 Definition of terms in the factors
CHAPTER THREE
3.0 Methodology/Fabrication Procedure
3.1 The column
3.2 The condenser
3.3 The packing
3.4 The boiler pot
3.5 Steam travel pipe
3.6 The stand
CHAPTER FOUR
4.0 Discussion
CHAPTER FIVE
5.0 Conclusion
5.1 Recommendation
References
Appendix I
Appendix II
INTRODUCTION
The aim of this project is to construct a packed distillation column. The separation of liquid mixtures into their several components is one of the major operations in the chemical and petroleum industries, and distillation, the most widely used method of achieving this end, is the key operation of the oil refinery. Throughout the chemical industry the demand for puner products, coupled with a relentless pursuit of greater efficiency, has necessitated continued research into the techniques of distillation. The operation is restricted to situations when components distribute themselves between liquid and vapour phases. The vapour phase is generated by the addition of heat and separation is enhanced by the differences in the vapour pressure of the components, hence their boiling points.
Packed columns are generally used for distillation, gas-absorption and liquid-liquid extraction. They ensure continuous contact of liquid and gas in both counter-current and concurrent flows and are essentially, vertical columns which have been filled with packings or devices of larger surface. The liquid is distributed over and trickles down through the packed-bed, exposing a large surface to contact the gas, while the gas or vapor moves upwards counter-currently. In some gas-absorption columns, concurrent flow is used.
The packings for the tower should offer the following characteristics: –
1. Provide for larger interfacial surface between liquid and gas.
2. Posses desirable fluid characteristics.
3. Be chemically inert to fluids being processed.
4. Have structural strength to permit easy handling and installation.
5. Represent low cost
6. Should be light in weight.
There are two major types of packings arrangements:
a. Random and
b. Regular packings.
The performance of a packed column is dependent on the maintenance of a good liquid and gas distribution throughout the packed-bed and this is an important consideration in packed column design.
A packed distillation column is similar to a plate column with the plates replaced. Be packed sections but in process industries they are considered more economically than plate columns for the following reasons: –
a. For columns less than 0.6m (2.0 ft) diameter, packings are usually cheaper than plates unless alloy-metal packings are required.
b. Acids and many other corrosive materials can be handled in packed columns because construction can be of ceramic, carbon, or other resistant materials.
c. Packings often exhibit desirable efficiency drop characteristics for critical vacuum distillations.
d. Liquids ending to form may be handled more readily in packed columns because of the relatively low degree of liquid agitation by the gas.
e. Holdup of liquid can be quite low in packed columns, an advantage when the liquid is thermally sensitive.
Conditions unfavourable to packed columns are:
a. If solids are present in the liquid or gas plate columns can be designed to permit easier cleaning.
b. Some packing materials are subject to easy breakage during insertion into the column or resulting from thermal expansion and contraction.
c. High liquid rates can often be handled more economically in plate columns than packed columns.
d. Cooling coils can be incorporated more readily into plate devices.
e. Low liquid rates lead in complete welting of column packings, thus decreasing contacting efficiency.
f. Packed columns exhibit narrower operating ranges than cross-flow plate columns.
However, the packed tower is a cylindrically vertical column operating with top and bottom flow allowances. Provisions are made for packing support, packing restrainers, packing entrainment eliminators liquid distributor etc. the cost and choice of materials of construction are also important considerations in this project as they go along way to influence the safety and efficiency of the equipment and also dictate its service-life for distillation in packed towers,
It is normally a practice to increase the calculated height of packing by 40 per cent to allow for liquid maldistribution and wetting problems.
Construction Of Packed Distillation Column:
Constructing a packed distillation column involves assembling the column’s components, including the column shell, internals, and packing material, to facilitate the separation of liquid mixtures into their individual components through distillation. Packed columns are commonly used in chemical processes for separation, purification, and fractionation of liquids. Below are the steps involved in constructing a packed distillation column:
Design and Planning:
Begin by designing the distillation column based on your specific separation requirements, such as the type of feedstock, desired products, operating conditions, and capacity.
Determine the column’s dimensions, including diameter, height, and the number of theoretical trays or packing sections required for efficient separation.
Column Shell:
Fabricate or procure the column shell. The material and thickness of the shell should be suitable for the process conditions, including temperature and pressure.
Install necessary access points, such as manholes, nozzles, and sight glasses, according to the design specifications.
Column Internals:
Depending on your design, install various column internals. For a packed column, this typically includes:
Liquid distributor at the top of the column to evenly distribute the feed across the packing.
Liquid collector at the bottom to collect the separated products.
Support trays or packing support plates to hold the packing material in place.
If applicable, tray support beams or ring spacers for structured packing.
Packing Material Installation:
Select the appropriate packing material based on your separation requirements. Common choices include random packing (e.g., Raschig rings or Pall rings) or structured packing.
Begin by installing the bottom layer of packing material and securing it in place using a support plate or grid.
Continue adding packing layers while ensuring a consistent and even distribution of the material.
It’s essential to maintain proper spacing and ensure that the packing is not overly compressed, as this can affect the column’s performance.
Instrumentation and Controls:
Install necessary instrumentation and control systems to monitor and regulate the distillation process. This may include temperature sensors, pressure gauges, flow meters, and control valves.
Connect these instruments to a control system that can adjust process parameters as needed to achieve the desired separation.
Insulation and Heat Sources:
Depending on the process temperature requirements, insulate the column to minimize heat loss or gain.
Provide the necessary heat sources, such as reboilers at the bottom and condensers at the top of the column, to maintain the required temperature gradient.
Safety Measures:
Implement safety measures, including relief valves, emergency shutdown systems, and fire protection, to ensure safe operation.
Testing and Commissioning:
Before putting the column into service, conduct thorough testing and commissioning to ensure that all components are functioning correctly and that the separation performance meets the desired specifications.
Regular Maintenance:
Establish a routine maintenance program to inspect, clean, and replace packing material or internals as needed to maintain optimal column performance.
Operation and Optimization:
Once the packed distillation column is operational, continuously monitor and optimize the process to achieve the desired separation efficiency and product purity.
It’s important to note that the specific steps and requirements for constructing a packed distillation column can vary depending on the process conditions and the particular industry in which it is used. Always follow industry standards and safety guidelines throughout the construction process.