EXPERIMENT MODULE CHEMICAL ENGINEERING EDUCATION LABORATORY

Transcription

1 EXPERIMENT MODULE CHEMICAL ENGINEERING EDUCATION LABORATORY SIMPLE DISTILLATION CHEMICAL ENGINEERING DEPARTMENT FACULTY OF INDUSTRIAL TECHNOLOGY INSTITUT TEKNOLOGI BANDUNG 2018

2 Contributor: Dr. Danu Ariono, Dr. Dianika Lestari, Dr. Ardiyan Harimawan, Fardhila Rochman, Alexander Armyn, Dr. Pramujo Widiatmoko DIS 2016/PW i

3 TABLE OF CONTENT TABLE OF CONTENT... ii LIST OF FIGURES... iii LIST OF TABLE... iv CHAPTER I INTRODUCTION... 1 CHAPTER II PURPOSE AND TARGET OF EXPERIMENT... 2 CHAPTER III EXPERIMENTAL DESIGN... 3 III. 1. Experiments and Measurements... 3 III.2. Materials / Chemicals... 4 CHAPTER IV WORK PROCEDURE... 5 IV.1. Work Procedures... 5 IV.2. Experimental Flow Diagram... 7 BIBLIOGRAPHY... 8 APPENDIX... 9 A. Raw Data... 9 B. Examples of Data Processing B.1. Determination of ethanol density B.2. Determination of the volume of ethanol needed to make the feed solution B.3. Calibrate refractive index of ethanol solution with refractometer B.4. Determination of heating rate B.5. The relationship of distillate concentration to time B.6. The relationship of distillate volume to time B.7. Mass balance of distillation C. Specification and Literature Data Tablel C.1. Water density at various temperatures JOB SAFETY ANALYSIS CONTROL SHEET DIS 2016/PW ii

4 LIST OF FIGURES Figure IV.1. Experimental flow diagram... 7 Figure B.1. Refractometer calibration curve Figure B. 2. Relationship curve of distillate concentration to distillation time Figure B. 3. Distillate volume relation curve to distillation time Figure B. 4. Cumulative distalate volume relation curve to distillation time Figure C.1. T-x-y diagram of water ethanol mixture at 1 atm DIS 2016/PW iii

5 LIST OF TABLE Table A.1. Laboratory condition... 9 Table A.2. Thermometer calibration... 9 Table A.3. Determination of pure ethanol density... 9 Table A.4. Refractometer calibration... 9 Table A.5. Calibration heating rate Table A.6. Distillation Table B.1. Raw experimental data for ethanol density determination Table B.2. Physical data of ethanol used Table B.3. Refractometer calibration result data Table B.4. Measurement data of heating rate Table B.5. The measurement data of the refractive index of distillate Table B.6. Data of distillate volume measurement Table B.7. Data table for the calculation of the distillate mass balance Tablel C.1. Water density at various temperatures DIS 2016/PW iv

6 CHAPTER I INTRODUCTION Separation is one of the most important process especially in the downstream part of a chemical process. The principle of separation is to determine the nature difference between the components to be separated so as to determine the proper separation process to use. The properties of components can be physical or chemical. One of the physical properties of a component is its boiling point or temperature when it has the same vapor pressure as the environmental pressure. Simple distillation is one of the distillation methods that can be used to separate the mixture in the liquid form which one component with the other components has a much difference in boiling point. The mixture will be heated until the temperature exceeds the boiling point of the lower component but does not exceed the boiling point of the higher component. The mixture having a liquid phase, some of the more volatile components will be in the gas phase due to heating so that the two components are separated. In this experiment a simple distillation process will be carried out to separate the ethanolwater solution and review the aspects that affect this separation process. The purpose of the distillation is to obtain a distillate product with higher purity than the feed so that the aspect under consideration is the aspect affecting the concentration and the quantity of distillate. Some of the influencing aspects are the feed concentration and feed heating rate which then reviewed the results by looking at the distillate concentration over time. DIS 2016/PW 1

7 CHAPTER II PURPOSE AND TARGET OF EXPERIMENT The purpose of implementing this experimental module is to study the process of separating binary mixtures and acquiring skills in performing simple distillation experiments. After doing the experiment, practition expected: 1. Create a mass balance for ethanol-water distillation experiments. 2. Determine the relationship between the time distillate concentration and the variation of the ethanol concentration in the feed or the variation in the rate of heating the feed. 3. Compare the results and discuss the experiments with different variations. 4. Determine the relationship between distillate volume to distillation time. DIS 2016/PW 2

8 CHAPTER III EXPERIMENTAL DESIGN III. 1. Experiments and Measurements 1. A set of simple distillation apparatus consisting of: 1 piece of three-necks boiling flask 1 electric heater and heating mantle 1 condenser for counter-current distillation 1 piece adapter to connect three-necks flask with condenser 3 rubber plugs equipped with a hole in the middle (2 pieces fitted with a three-neck flask and 1 piece fitted with a condenser adapter) 2 pieces of thermometer to measure distillate and bottom 1 sampling device 2 water hoses 2 pairs of stative and clamps 1 piece of adapter to drain the condensed distillate 2. Refractometer 3. Pycnometer 4. Beaker 5. Erlenmeyer flask 6. Vial 7. Drop pipette 8. Filler 9. Stopwatch 10. Measuring cylinder 11. Digital balance 12. Label 13. Cotton 14. Gloves 15. Cloth 16. Aluminium foil 17. Boiling stone DIS 2016/PW 3

9 III.2. Materials / Chemicals 1. Ethanol 2. Aqua dm 3. Acetone 4. Vaselin or silica grease 5. Soap water 6. Ice cube DIS 2016/PW 4

10 CHAPTER IV WORK PROCEDURE IV.1. Work Procedures a. Checking Tools 1. A glassware removed from cabinet 2. The glassware is checked, if any is broken or cracked please return it. If something is not clean, clean it first. 3. If any equipment is incomplete, immediately equipped with a report to the officers and assistants. 4. Once the equipment is ascertained in perfect condition, the lab can proceed. b. Thermometer Calibration 1. Thermometer that has been confirmed in good condition is prepared. 2. Ice cube is melted in a beaker and then measured melting temperatures of ice cubes with both thermometers. Temperatures read by both thermometers are recorded after indicating a constant number. 3. Aqua dm is boiled in a beaker and then the temperature is measured with both thermometers. Temperatures read by both thermometers are recorded after indicating a constant number. c. Refractometer Calibration 1. The standard ethanol-water solution with 8 variations of concentration is made, the concentration variation include the range of the distillation feed concentration in order to avoid extrapolation. 2. The refractive index of each is measured using a refractometer 3. The refractive index of each standard solution is recorded. d. Measurement of Ethanol Density 1. An empty pycnometer mass is weighed and recorded. 2. The pycnometer is filled with aqua dm and its mass is weighed and recorded. 3. The pycnometer is emptied and then cleaned with acetone and dried. 4. The pycnometer is filled with ethanol and its mass is weighed and its measured results are recorded. DIS 2016/PW 5

11 e. Making feed solution 1. The feed solution was prepared by mixing the ethanol and aqua dm mixtures with a predetermined amount. 2. Cover the container with aluminum foil. f. Determination of Heating Rate 1. Water is put into three-necks boiling flask. 2. Flask is placed on top of heater with heating mantle. 3. The thermometer is inserted into one of the necks. 4. The heater is turned on. 5. When boiling, the temperature at each time is recorded. 6. Heating rate is calculated. g. Distillation 1. The feed solution is fed into the distillation flask together with the boiling stone. 2. Trial tools are strung together and ensured to keep all tools straight. 3. Water to the condenser is flowed. 4. The heater is turned on with a predetermined heating scale. 5. The tool set is checked so that no leakage by dripping the soapy water in the circuit junctions. 6. The first drop of distillate is awaited. After the first drops drip, the stopwatch is turned on. 7. Every 3 minutes, the distillate container is replaced with a new one until 8 distillates (24 minutes) are obtained. The volume of each distillate is recorded. 8. Bottom and steam temperatures of distillates formed, the thermometer read are recorded at each change of the distillate reservoir. 9. After the data is obtained, the heater is turned off and the equipment is kept to cool. 10. Mass of the distillation flask with the residue is measured. Next, the distillation flask is emptied and its mass is weighed. 11. All equipment is cleaned up. Steps 1 to 10 are repeated with varying concentrations or heating rates. DIS 2016/PW 6

12 IV.2. Experimental Flow Diagram Start checking and preparation of module tools feasible and complete Yes No completeness, replacement, and repair tool the actual T calibration equation against actual theoretical T Thermometer calibration determination of ethanol density using pycnometer Ethanol density the calibration curve of the refractive index against the ethanol fraction Refractometer calibration Set of distillation devices variation of feed concentration Yes No Variation of heating scale determination of heating rate repeat for 3 different scales Distillation Distillation repeat up to 3 variations repeat up to 3 variations Finish the distillate volume relationship with time Finish the relationship of distillate concentration to time Figure IV.1. Experimental flow diagram DIS 2016/PW 7

13 BIBLIOGRAPHY McCabe, W.L., Unit Operation of Chemical Engineering, 3 rd Edition, McGraw-Hill Book Co., New York, 1978, Chapter 19. Treybal, R.E., Mass Transfer Operations, McGraw-Hill, 1981 Chapter 9. Perry, R., Green, D.W., Maloney, J.O., Perry s Chemical Engineers Handbook, 6 th Edition, McGraw-Hill, Japan, Veazey, W.R., Hodgman, C.D., Handbook of Chemistry and Physics, 64 th Edition, CRC press, DIS 2016/PW 8

14 A. Raw Data APPENDIX Table A.1. Laboratory condition Time Pressure (mmhg) Temperature ( o C) ± 0,05. ± 0, ± 0,05. ± 0, ± 0,05. ± 0,5 Table A.2. Thermometer calibration T literature Thermometer 1 Thermometer 2 Water freezing point ( o C) Water boiling point ( o C) Table A.3. Determination of pure ethanol density Thermometer used (Thermometer 1/Thermometer 2) Aqua dm temperature ( o C) Empty pycnometer mass (g) Pycnometer mass contains aqua dm (g) Pycnometer mass contains ethanol (g) Table A.4. Refractometer calibration No. Composition of ethanol Ethanol volume aqua dm volume Refractive index 1 Refractive index 2 Average refractive index DIS 2016/PW 9

15 Table A.5. Calibration heating rate Heating scale : Time (s) Temperature ( o C) Heating scale : Time (s) Temperature ( o C) Heating scale : Time (s) Temperature ( o C) Table A.6. Distillation Feed compotition (%-mol etanol) / Heating scale Thermometer for distillate Thermometer for bottom Run to- 1 Feed compotition (%-mol etanol) / Heating scale Feed mass (g) Bottom mass (g) Ethanol volume (ml) Aqua dm volume (ml) Distillate mass (g) DIS 2016/PW 10

16 No. Time (menit) Distilate volume (ml) Cumulative volume (ml) Refractive index Bottom temperature ( o C) Distillate temperature ( o C) Run to- 2 Feed compotition (%-mol etanol) / Heating scale Feed mass (g) Bottom mass (g) Ethanol volume (ml) Aqua dm volume (ml) Distillate mass (g) No. Time (menit) Distilate volume (ml) Cumulative volume (ml) Refractive index Bottom temperature ( o C) Distillate temperature ( o C) DIS 2016/PW 11

17 Run to- 3 Feed compotition (%-mol etanol) / Heating scale Feed mass (g) Bottom mass (g) Ethanol volume (ml) Aqua dm volume (ml) Distillate mass (g) No. Time (menit) Distilate volume (ml) Cumulative volume (ml) Refractive index Bottom temperature ( o C) Distillate temperature ( o C) Distillation Bottom data Refractive index Refractive index No. Time (variaton 1) (variation 2) Bottom mass for variation 1 (g) Bottom mass for variation 2 (g) Bottom mass for variation 3 (g) Refractive index (variation 3) DIS 2016/PW 12

18 B. Examples of Data Processing B.1. Determination of ethanol density For example data obtained from experiment: Table B.1. Raw experimental data for ethanol density determination Temperature of aqua dm ( o C) 26 Empty pycometer mass (g) 8,907 Pycnometer mass contains aqua dm (g) 13,708 Pycnometer mass contains ethanol (g) 12,704 Ρ waater at aqua dm temperature (g/cm 3 ) 0,99678 The equation used to obtain pure ethanol density is The data obtained from the experiment is entered into the equation. So obtained pure ethanol density. B.2. Determination of the volume of ethanol needed to make the feed solution For example data bait solution to be made: Table B.2. Physical data of ethanol used Feed total volume (ml) 100 Ρ water at room temperature 26 o C (g/cm 3 ) 0,99678 ρ ethanol at room temperature 26 o C (g/cm 3 ) 33 Ethanol fraction(%-mole etanol) 10 Available ethanol concentrations (% -v / v) 95 Mr ethanol (g/mole) 46 Mr aqua dm (g/mole) 18 The equations used to calculate the volume of ethanol required to prepare the feed solution are: DIS 2016/PW 13

19 Entered data to make the feed solution. From the calculation, the required ethanol volume is obtained to obtain the aqua dm volume required to prepare the feed solution which is the difference between the total volume of the desired feed and the required ethanol volume. The above equation can also be used to calculate the volume of ethanol and aqua dm required to prepare ethanol solution at the refractometer calibration. B.3. Calibrate refractive index of ethanol solution with refractometer Example data obtained from the experiment: Table B.3. Refractometer calibration result data Each sample volume is 20 ml No. The composition of Ethanol Aqua dm Average ethanol (mol Refractive Refractive volume volume Refractive ethanol / mol aqua index 1 index 2 (ml) (ml) index dm) ,00 1,3326 1,3325 1, ,03 1,83 18,17 1,3363 1,3362 1, ,06 3,44 16,56 1,3405 1,3416 1, ,09 4,87 15,13 1,3458 1,3448 1, ,12 6,15 13,85 1,3480 1,3491 1, ,15 7,30 12,70 1,3522 1,3512 1,3517 DIS 2016/PW 14

20 Refractive index INSTRUCTIONAL LABORATORY 7. 0,18 8,34 11,66 1,3543 1,3544 1, ,21 9,30 10,70 1,3565 1,3559 1,3562 The measurement data of refractive index of ethanol solution with various concentrations using refractometer was plotted and linear regression was done so that it is become calibration curve. The calibration curve was used to determine the ethanol fraction for the distillate sample taken during the distillation experiment y = x Ethanol fraction(%-mol etanol) Figure B.1. Refractometer calibration curve From the calibration curve obtained equation or B.4. Determination of heating rate Suppose the data obtained from the experiment is Table B.4. Measurement data of heating rate DIS 2016/PW 15

21 Heating scale : 7 Time (s) Temperature ( o C) , , From the data in Table B.4 we can calculate the rate of heating by the equation With an average increase in temperature every 30 seconds ie 1,86 o C the rate of heating is obtained. For aqua dm as much as 300 ml, its mass is 299,1 gram and from literature obtained data of Cp aqua dm at 26 o C that is equal to 4,179 kj/kg.k. B.5. The relationship of distillate concentration to time Suppose the data obtained from the experiment is Table B.5. The measurement data of the refractive index of distillate Ethanol No. Time (minute) Refractive index fraction (% - mol ethanol) ,3617 9, ,3616 9, ,3609 8, ,3606 8, ,3605 8, ,3594 8, ,3583 8, ,3571 7,71 The mole fraction of ethanol in the sample was obtained from the previous calibration of refractometer so that the curve of the relationship between the distillate concentration and the distillation time was obtained. DIS 2016/PW 16

22 Ethanol fraction (%-mole) INSTRUCTIONAL LABORATORY Time (menit) Figure B. 2. Relationship curve of distillate concentration to distillation time B.6. The relationship of distillate volume to time Suppose the data obtained from the experiment is Table B.6. Data of distillate volume measurement No. Time (minute) Distillate volume (ml) Cumulative volume (ml) ,5 14, ,7 28, ,6 40, ,3 52, ,1 63, ,0 73, ,5 82, ,0 91,7 By diverting the distillate volume data to the distillation time, there is a relationship of volume at each time or cumulative volume to the distillation time and a graphic tendency can be seen. DIS 2016/PW 17

23 Volume (ml) Volume (ml) INSTRUCTIONAL LABORATORY Time (menit) Figure B. 3. Distillate volume relation curve to distillation time Time (minute) Figure B. 4. Cumulative distalate volume relation curve to distillation time B.7. Mass balance of distillation reaction then In accordance with the law of conservation of mass for system without For example experimental data for distillation with 10% feed solution -mol ethanol DIS 2016/PW 18

24 Table B.7. Data table for the calculation of the distillate mass balance Feed mass (g) 278,4 Final bottom mass (g) 180,6 Bottom sample mass (g) 19,6 The distillate mass (g) 77 gram Loss of mass as much as 1.2 gram can be explained when done by calculation of mass balance more detail by involving ethanol fraction of experiment analysis result so that can know whether mass loss of water or ethanol and can be analyzed why mass balance calculation is deviated as 0,43%. C. Specification and Literature Data Tablel C.1. Water density at various temperatures (Source : Handbook of Chemistry and Physics, CRC press, 64 th Ed.) DIS 2016/PW 19

25 (Source : Dortmund Data Bank) Figure C.1. T-x-y diagram of water ethanol mixture at 1 atm DIS 2016/PW 20

26 JOB SAFETY ANALYSIS CONTROL SHEET No. Material Material properties Repressive act - Colorless - No need special handling - No smell because it is not harmful to the - Non-toxic body. 1. Water - Boiling point: 100 o C - Avoid substances scattered near - Melting point: 0 o C the power source. - Stable - Delivers electricity 2. Ethanol 3. Acetone 4. Vaselin -Liquid -Colorless -Easy to evaporate -Flammable in both liquid and gas form -Smell light -Boiling point: 78 o C - Melting point: -114 o C - Soluble in water -Liquid -Colorless - Smells strongly fragrant - Soluble in water - Good solvent -Stable - Not corrosive - Boiling point: o C - Melting point: o C - Shaped white gel - Not reactive - Melting point: 48 o C-52 o C - Flash point: 190 o C -Make sure the substance container is closed when not in use. -Store in a place with good ventilation. -Avoid from the fire. -Avoid contact with eyes and mouth. - Make sure the substance container is closed when not in use. -Store in a place with good ventilation. - Avoid from the fire. Avoid contact with eyes and mouth. - Avoid contact with eyes and mouth. DIS 2016/PW 21

27 Accidents that may occur Equipment breaks and fractions exposed to body parts. The vapors of the substance are exposed to the eye resulting in irritation. Substances inhaled in large quantities. Substances ignite fire and cause fire. Shorting due to the entry of water to the power source. Safety equipment Repressive act - Put the broken equipment in a stable place so it is not easy to fall. - The hot glass equipment is not directly cooled with water. - When fractions exposed to body parts immediately contact the assistant to provide first aid. Rinse eyes with running water, seek medical help. Immediately move to the open, breathe fresh air, seek medical help. Substances ignite fire and cause Fire extinguisher with a damp cloth or fire extinguishers, keep the fire away from potentially flammable items, away from fire. - Keep water from a power source. - Clean and dry the stagnant water. - If electrocuted, a non-stuck practitioner should unplug an electrical connection with rubber gloves, contact the assistant and the clerk. Gloves Laboratory coat Goggle Safety Procedures Preparation of materials - Acetone and alcohol are always placed in a closed container so that the vapor is not harmful. - Keep acetone and alcohol from the fire. - Keep acetone from soluble ingredients. Post distillation - Turn off the heater before discharging the condenser water flow. - Be careful on equipment that is still hot. - Unplug the electricity and dry the work Tools preparation - Put the equipment tightly and neatly, attach the clamps in a prone area. - Apply vaseline on each tool joint. Distillation - Use boiling rocks during distillation for homogeneous heating. - Flow the condenser water before DIS 2016/PW 22

28 area. turning on the heater. - Observe the distillation feed, warm up to the exhausted feed can be harmful to the distillation flask. Assistant Advisor Lab TK Coordinator DIS 2016/PW 23