packed column distillation process

UNIVERSITI KUALA LUMPUR MALAYSIAN INSTITUTE OF CHEMICAL BIOENGINEERING TECHNOLOGY

LABORATORY REPORT

SUBMISSION FORM

To: (Lecturer) Code Subject: CKD 20103 Separation Technology From: (Student Name) Student ID No. 1) 1) 2) 2) 3) 3)

4) 4) Section: No. of Group:

Title of Experiment: Date of Experiment:

Packed Column Distillation Process Received by: Date of Submission:

Note: If late with good reason, medical note must be submitted to the lecturer, otherwise the mark will be reduced by 5% of the total.

*To be filled by the marker*

CONTENT NOTE SUBMARKS MARKS COMMENTS BY MARKER

Result/Data Tables of results, graph and calculation 10

Discussion Graphical explanation or discussion 6

Conclusions and recommendation Principal Outcomes 4

TOTAL 20

Office Slip Date Submitted: Student Name: Student ID:

Lecturer’s Name: Chop

Student Slip Received

Date Submitted: Student Name: Student ID: Experiment title:

Separation Technology/CKD 20103/Jan 2011

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Vapour-Liquid Separation (Distillation)

Packed Column Distillation Process

1. Objective: The students should be able to: Operate Vapour – Liquid Separation Experiment using a Packed Column Distillation Process Unit. Analyze the sample for the Top and Bottom Product by Refractometer to obtain the Refractive Index in

order to determine their respective composition. To obtain the time when the Vapour – Liquid Separation is nearly finish. 2. Introduction: Distillation is one of the important unit operations in many chemical industries and has been used from the inception of chemical and process industry. Distillation is used for the separation of components in a liquid mixture of volatile constituents. The Distillation Column is usually a vertical column where the liquid and vapour phases of the mixture are made to mix and approach equilibrium. Packed Bed Distillation Columns are sometimes used to carry out the Distillation in the industry.

Distillation is a process of separating the components of a solution by the application of heat when the vapour produced by boiling the solution has a different composition to that of the solution. If the vapour formed is condensed and subsequently reboiled it will produce, yet again, a vapour of different composition. Repeated boiling of condensed vapours will ultimately produce a product of desired quality rich in concentration of one of the components of the original solution.

Distillation takes place in a Distillation Column which, in essence, comprises a Boiler, a Column and a Vapour Condensed. The Boiler provides the heat for vapour generation; within the column rising vapours continually mix with liquid flowing down the column, condense and are reboiled until vapour of required composition leaves the column and condenses in the Vapour Condenser to be removed as Liquid Product. A certain proportion of this condensate is returned to the column, called Reflux, the proportion being a major influence on the quality of the product achieved.

Since this experiment use Batch Distillation plant, therefore, it can be said that this is a process whereby a specific quantity of a liquid mixture is separated into its components. The technique is used extensively in laboratories and small scale production plants where the equipment is often used for separating several different mixtures of where if only one mixture is separated, the mixture is not produced continuously. The relatively high capital cost of Continuous Distillation Plants with their sophisticated control systems, often results in smaller companies operating Batch Distillation plants. Batch Distillation is particularly useful for separating liquid mixtures contaminated with solids which would otherwise foul a continuous plant.

This unit comprises of a Reboiler operating on the Thermosyphon principle heated by either steam or electrically. Process vapours enter at the base of the column which contains a Packed Column containing 10 mm Raschig Rings, ( the vapour temperatures entering and leaving the column are measured by temperature indicators TI 3 and TI1 respectively as shown in the Process Flow Diagram of this unit. ) and are condensed at the top of the column in a Condenser. The Distillate is separated into Reflux, which is passed back to the column and Product, which passes through a Product Cooler and then through a Graduated Pipe Section. The Product may then be collected or returned back to the Reboiler. Vapours leaving at the top of the column are totally condensed to Liquid Distillation in the Overhead Condenser and pass to the Reflux Control Flow Meters RI 1A and RI 1B. RI 1A indicates the quantity of Distillate returned to the column via the three-way valve while RI 1B indicates the quantity of Distillate removed as Product. A Process Flow Diagram for Packed Column Distillation Process Unit is as shown in the next page.


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3. Chemicals and Ancillary Equipments Required:

a) Chemicals required:

Ethanol industrial grade Water

b) Ancillary Equipments required:

Two 2000ml beakers and two 250ml beakers Refractometer for measurement of sample concentrations Calibration Curve for the Refractive Index Vs Concentration of Ethanol Water mixtures

4. Operating Instructions: 4.1 Safety Considerations

You must familiarize yourself with each item such as the Reboiler, Condenser, Distillation Unit and the flow paths and apparatus before conducting of the experiment. This distillation operation usually deals with very hot and highly flammable materials. Extreme care must be taken when handling the apparatus, in taking readings and collecting samples.

The Flow Meters should be operated smoothly in order to avoid pressure surges within the equipment.

Inspect the equipment visually for any damaged components or glass breakage. If any such defects are noticed, please report them to your instructor / technician.

Goggles must be worn at all times in the laboratory. Appropriate rubber gloves must be worn when Organic Solvents are handled. Avoid wearing clothes which can easily catch fire.


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The flow rates of liquids should not exceed the maximum of the rates shown in the flow meter. Do not allow the water pressure to exceed 2.0 bar maximum as indicated by PI.2. Always maintain

V8 in the open position during atmospheric operation (avoid system pressurizing). Don’t isolate cooling water until the heating has been shut down (at least 10 minutes). Don’t switch on the immersion heater with the level in the reboiler below the heater elements or

when the reboiler is empty. Don’t return the product distillate collected to the reboiler vessel when the equipment is in

operation. Do not allow the liquid level to rise much above the top graduation on the tube before the stop

valves V2 and V3 are opened. Don’t drain the liquid in reboiler vessel until is cold. Do not touch the hot components of the unit.

4.2 General Start-up Procedures Materials needed:

a. Ethanol industrial grade b. Water

Prepare between 30 to 40 litres of 10 % to 20 % mixture of Ethanol in Water by mixing appropriate

quantities of the Industrial Grade of Ethanol in Distilled Water. Refer to the diagram of the equipment in the lab for better / accurate view. Ensure that the concentration of feed in the reboiler vessel is correct and that the liquid level is at the

vessel equator. Ensure valves V1, RCV1, V3, V4, V5, V6, V7, V9 and FCV2 are closed. Ensure valves V2, V8 and V10

are open. Start fill in Ethanol / Water mixture up to the desired level (Ask Lecturer / Technician). Slowly open the cooling water to the condenser (max 2.0 bar). Make sure water is indeed flowing

through it. Check water flows to the drain from the Cooling Water outlets. Do not start the experiment until the Cooling Water flow is visible in the outlets to the drain. Ensure that the Bottom Product sampling valve V5 and Top Product sampling valve V4 is closed. Ensure that the Reboiler Vessel is already charged with the Ethanol – Water mixture through the Charge

Port (Refer to the diagram). Otherwise top up with the Ethanol – Water mixture through the Charge Port (Refer to instructor /

technician). Ensure that the concentration of feed in the Reboiler vessel is correct and that the liquid level is at the

Vessel Equator (Refer to Lecturer / Technician). The Reboiler Vessel should never be filled with liquid above the maximum level indicated. The level should never recede below the minimum level while on operation. Close the Reflux Adjustment Valve RCV 1 and valve below Product Cooler V2. Obtain a sample of Ethanol – Water mixture from the Reboiler through the Sampling Port and test its

composition using Refractometer and given graph of Refractive Index Vs Mole Fraction of Ethanol in Liquid.

Turn on the main power control switch. Turn on the power switch of the heater. Switch on electrical supply (green ‘heater on’ button). Set heater controller HC.4 to maximum setting (About 30A / 230 V). When distillate liquid is seen to flow through RI.A1, reduce the heat input and set HC.4 (About 20 A). Allow a period of 15 minutes for the equipment to maintain thermal equilibrium with surroundings. During this period observe HC.4. The unit is now ready to be used for an experiment. 4.3 Experiment: Operation under Partial Reflux Conditions Procedure: Ensure that the valve for Reflux Ratio adjustment RCV 1 is opened. Adjust both valve for Reflux Ratio RCV 1 and valve below Product Cooler V2 so that both readings on

R1 and R2 provide a Reflux Ratio of 1.0 for the operation. Wait for about 15 minutes until the flow rate shown by R1 and the temperature readings at the top and

bottom of the columns are steady ( Refer to instructor / technician ). Collect samples from the Reboiler and the overhead from the Sampling Port for every 5 minutes. Observe Temperature of the Reboiler TI 4. If the temperature is already 90ºC, reduce the current of the

Reboiler to between 10 A to 15 A.


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Observe the flow rate at R1. Adjust the valve for Reflux Ratio adjustment to ensure that the Reflux Ratio is maintained at 1.0.

The concentration of the samples drawn is measured using the Refractive Index method. Record the reading of temperatures for every 5 minutes. Readings are recorded in the provided table of results. 4.4 General Shut – Down Procedures Adjust heater controller HC.4 to minimum setting. Switch off electrical supply (red ‘heater off’ button). Turn off the power switch of the reboiler. Turn off the main power control switch. Do not drain the hot liquid from the Reboiler. If necessary, the liquid within the system could be drained

only when the liquid is already cooled. Allow the Cooling Water to run for some time (Ask Lecturer / Technician).


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5. Result: Complete the following data of results:

Time Temperature Readings ( º C ) RI RI (Min) TI 1 TI 2 TI 3 TI 4 TI 5 TI 6 Top Bottom

Product Product 0 5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85


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Discussion


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Conclusion

packed column distillation process

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