Module 4 Lab: Distillation:
Thank you to everyone that added to this work 
, feel free to add the photos in the distilling process as I can not figure that out 
(a) distillation: how and why it works.
Distillation is a method used to purify liquids that boil without decomposition and have non-volatile impurities. Impure liquid is boiled and the resulting vapors are condensed to get the pure liquid. The process of distilling water is called as distillation process. The output of this process is distilled water.
There are a number of distillation apparatus and distilling equipment used for this process. Distillation involves the conversion of a liquid into its vapors upon heating and then cooling the vapors back into the liquid. Depending on the difference in boiling points of liquids, distillation is of two types:
• Simple Distillation
• Fractional Distillation
Distillation is a water purification process that uses a heat source to vaporize water and separate it from contaminants and other undesirable elements commonly found in ground and surface water. Distillation heats raw (untreated) water until the water reaches its boiling point and begins to vaporize. The heat is then kept at a constant temperature to maintain water vaporization while prohibiting other undesirable elements from vaporizing. Water has a lower boiling point than salt and other mineral sediments. This process also separates the water molecules from microscopic, disease-causing organisms. Once all of the water has vaporized, the vapor is led into a condenser, where, upon cooling, the water reverts to the liquid form and runs into a receiving container. The remaining elements, whose boiling point was too high to permit vaporization, remain in the original container and constitute the sediment. Because the distillation process can never ensure a complete separation between water and other materials, it is often repeated one or more times with the treated water. Many alcoholic beverages, like brandy, gin, and whiskey, are distilled, using an apparatus similar in constitution to the water distillation apparatus.
In a simple distillation, a flask is heated until the contents start boiling. The vapors evaporate, then are condensed, and become what are called overheads. In a simple distillation one overhead product is collected. During distillation, vapors are formed in the heated distillation flask. The condenser cools these vapors condensing them back to liquid droplets that flow down the condenser into the receiver flask. A completely filled condenser provides maximum cooling therefore allowing for maximum recovery of the purified liquid during distillation.
(c) some tips for a successful distillation experiment.
These are the process of distillation of water used for making distilled water.
Types of distillations:
There are different types of distillation as follows. They are,
• Simple Distillation
• Fractional Distillation
• Vacuum Distillation
• Steam Distillation
Simple Distillation
There are a number of water distillation equipment used in this process. It is used for separating liquids having boiling points differing by 10-20 degrees. The liquid having the lower boiling point distills over first, and the other liquid component is left behind. In this process, vaporization and condensation occur side by side.
Simple Distillation Process
The impure liquid or a mixture of two liquids is taken in a distillation flask fitted with a thermometer and a condenser. The flask is heated on a sand bath, on a wire gauze or in a water bath. The more volatile liquid, i.e. the one having a lower boiling point, boils first and the vapors distill over from the outlet near the top. These vapors pass through the condenser and get condensed into the liquid. This condensed liquid collected in a receiver is called the distillate. The less volatile liquid, i.e. the one having a higher boiling point, gets left behind in the distillation flask. To avoid bumping of liquid, a few glass beads or porcelain pieces are placed in the distillation flask.
Fractional Distillation
It is used for separating two liquids in any mixture, which have boiling points within a narrow range of temperatures. In such cases, simple distillation does not give complete separation and a modified version called fractional distillation is employed.
Fractional Distillation Process
Due to the small difference in the boiling points, both liquids form vapors simultaneously. Vapors of the boiling liquid mixture are made to pass through a glass fractionating column. The fractionating column is a simple packed column, packed with glass beads, or it is a specially designed column called the bubble plate column. The vapors of the low volatile liquid (the liquid having a higher boiling point) get condensed in this column and return to the distillation flask.
The condensate consisting of the pure, more-volatile component (the compound having lower boiling point) leaves the column from the exit near the top and enters the condenser and gets collected in the receiver.
A typical example of this technique on a commercial scale is the refining of crude petroleum by fractional distillation to get different fractions such as petrol, kerosene, oil, grease etc.
Two typical fractionating columns Experimental setup for fractional distillation
Vacuum Distillation
Vacuum Distillation is also called as Distillation under reduced pressure. This technique is used for purifying or separating thermally unstable liquid compounds that decompose at their normal boiling points.
Vacuum Distillation Principle
The lowering of pressure on the surface of a liquid lowers its boiling point. As a result of this, a liquid can be boiled and distilled, without any decomposition, at temperature much below its normal boiling point.
Vacuum Distillation Process
Distillation under reduced pressure or vacuum is carried out in a specially designed glass apparatus. A two necked 'Claisen's flask' is used, the main neck of which is fitted with a long capillary tube and the side neck being fitted with a thermometer. The side tube is connected to a condenser carrying a receiver at the other end. The receiver is attached to a vacuum pump to reduce the pressure. The pressure is measured with the help of a manometer.
Vacuum Distillation Advantages
The advantages of distillation under reduced pressure are:
• The compounds that decompose on heating to their boiling points can be purified by distillation under reduced pressure. This is because at the reduced pressure, a liquid would boil at a temperature much below its normal boiling point.
• Distillation under reduced pressure is more fuel-economical as it makes the liquid boil at temperatures well below the normal boiling point.
Steam Distillation
This technique is used for separating/purifying liquids, which are immiscible with water, volatile in steam, and have high vapor pressure at the boiling temperature of water.
Steam Distillation Principle
This method is based on the fact that:
• Total vapor pressure above a mixture of two immiscible liquids is equal to the sum of the vapor pressures of the individual liquids i.e.,
Ptotal = P1 + P2
Hence, P2 = Ptotal - P1
• A liquid boils at the temperature when its vapor pressure becomes equal to the atmospheric pressure.
Steam is continuously passed over the impure organic liquid. The steam heats the liquid and gets condensed into water itself. The resulting mixture of liquid and water begins to boil when the vapor pressure above the mixture becomes equal to the atmospheric pressure. Hence the mixture of the two immiscible liquids will boil at a temperature lower than the normal boiling points of both the liquids. The mixture will continue to boil at the same temperature until one of the liquids is completely distilled out. The distillate, which contains water and the liquid, separates out into two layers as both are immiscible with each other. The two layers can be separated using a separating funnel.
Steam Distillation Process
The impure compound and water are placed in a distillation flask kept at a slight slant position and heated on a sand bath. Steam is then bubbled through this mixture. The vapors of the compound, along with steam, leave the flask from the outlet and get condensed in the water condenser. The condensate collected in the receiver is transferred to a separating funnel. The liquid compound being immiscible with water forms a separate layer and can be separated. There are a number of steam distillation equipments and apparatus.
(c) If you have the time, you could distil the distilled content twice, this accounts for a purer distillation. Have a continuous flow of water through the condenser is necessary; however, the lower the flow rate, the lower the pressure and the lower the chance of having the tubing pop off (resulting in you spraying yourself or others). If you are using a mercury thermometer, the mercury bulb of the thermometer should be positioned so that vapors condense readily on it. The tip of the bulb should be in line with the lowest part of the connecting tube of the stillhead. Always have the water go in from the BOTTOM of the condenser. So, when connecting the water tubing to your condenser, remember that water enters from the bottom of the condenser and exits from the top. Add boiling stones to your distillation flask BEFORE you start heating.
Remember that distillation is complete when:
a) no more liquid collects in the receiving vessel,
b) when the temperature of the thermometer starts to drop or
c) when the distillation flask is empty.
Also in your report, discuss a specific example of something you interact with everyday that is a result of or has come about because of the distillation process. If you cannot think of anything, at least give a specific example (not alcohol!) of a liquid that could be separated into its components through the process of distillation.
In the refractory distillation of crude oil, crude oil is separated into petrol, gas, diesel, oil and various other components. Crude oil distillation is used to separate the hydrocarbons in crude oil into fractions based on their boiling points. The separation is done in a large tower that is operated at atmospheric pressure. The tower contains a number of trays where hydrocarbon gases and liquids interact. The liquids flow down the tower and the gases up. The lighter materials such as butane and naphtha are removed in the upper section of the tower and the heavier materials such as distillate and residual fuel oil are withdrawn from the lower section. I know you said that alcohol cannot be used, but it is a good example nonetheless. Distillation is used to make alcoholic drinks of a higher v/v than 12% v/v, i.e. wine is distilled to make brandy.
Definition of the following terms:
(a) bumping
Liquids often boil in an uneven fashion, or "bump" as it's called in chemistry. Bumping occurs frequently when you are distilling solvents or mixtures and there aren't any scratches or irregularities on the walls of the boiling pot that would help boiling bubbles to form. If this happens, a thing called superheating occurs- because the walls of your boiling pot are smooth and bubbles of vaporized liquid cannot easily form, the temperature of the liquid can actually rise above it's boiling point without boiling- the solution is now a superheated liquid. This can be dangerous because bubbles eventually will form, and when finally do, they usually erupt violently because so much of the liquid is just itching to boil but hasn't been able to, that it all goes bloooop and releases all of it's superheated boiling energy at once.
Bumping is easily prevented by adding boiling chips to the liquid.
(b) distillation
Distillation is the process of heating a liquid until it boils, capturing and cooling the resultant hot vapors, and collecting the condensed vapors. Mankind has applied the principles of distillation for thousands of years. Distillation was probably first used by ancient Arab chemists to isolate perfumes. Vessels with a trough on the rim to collect distillate, called diqarus, date back to 3500 BC. In the modern organic chemistry laboratory, distillation is a powerful tool, both for the identification and the purification of organic compounds. The boiling point of a compound—determined by distillation—is well-defined and thus is one of the physical properties of a compound by which it is identified. Distillation is used to purify a compound by separating it from a non-volatile or less-volatile material. When different compounds in a mixture have different boiling points, they separate into individual components when the mixture is carefully distilled.
(c) fractional distillation:
Fractional distillation is the separation of a mixture into its component parts, or fractions, such as in separating chemical compounds by their boiling point by heating them to a temperature at which several fractions of the compound will evaporate. It is a special type of distillation. Generally the component parts boil at less than 25 °C from each other under a pressure of one atmosphere. If the difference in boiling points is greater than 25 °C, a simple distillation is used.
(d) heating mantle
A heating mantle is a laboratory device designed to heat boiling flasks.
(e) reflux
Reflux is a distillation technique involving the condensation of the distilled product vapors and the return of a portion of the condensate to the distillation system from which it originated. Reflux is widely used in large-scale, industrial continuous distillation columns as well as in laboratory distillation apparatus setups. It is also used in laboratories to supply heat to reactions over a long period of time.
(f) simple distillation
The impure liquid or a mixture of two liquids is taken in a distillation flask fitted with a thermometer and a condenser. The flask is heated on a sand bath, on a wire gauze or in a water bath. The more volatile liquid, i.e. the one having a lower boiling point, boils first and the vapors distill over from the outlet near the top. These vapors pass through the condenser and get condensed into the liquid. This condensed liquid collected in a receiver is called the distillate. The less volatile liquid, i.e. the one having a higher boiling point, gets left behind in the distillation flask. To avoid bumping of liquid, a few glass beads or porcelain pieces are placed in the distillation flask.
Generally the component parts boil at less than 25 °C from each other under a pressure of one atmosphere. If the difference in boiling points is greater than 25 °C, a simple distillation is used.
(g) theoretical plates
A theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. Such equilibrium stages may also be referred to as an equilibrium stage, ideal stage or a theoretical tray. The performance of many separation processes depends on having a series of equilibrium stages and is enhanced by providing more such stages.
Having more theoretical plates increases the efficacy of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process. The concept of theoretical plates and trays or equilibrium stages is used in the design of many different types of separation.
References:
http://www.tutorvista.com/content/chemistry/chemistry http://journeytoforever.org/biofuel_library/ethanol_manual/manual11.html http://www.docbrown.info/page01/ElCpdMix/EleCmdMix2.htm http://www.erowid.org/archive/rhodium/chemistry/equipment/distillation4dummies.html http://www.erowid.org/archive/rhodium/chemistry/index.html http://misterguch.brinkster.net/chemfiestanew.html And from some people on this site
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