WWW.07MET.TK
Theory In mixtures some chemicals are valuable while others may be worthless. The trick is to separate the good from the bad without spending too much money along the way. While there are quite a few separation techniques in a chemical engineer's bag of tricks, distillation is the workhorse of the chemical industry. It is fairly inexpensive and can produce very high purity products. Because of this the petroleum industry has adopted it as their separation method of choice. The towers pointing skyward at oil refineries are in fact distillation columns, and their vast numbers reveal just how frequently this unit operation is used. Gasoline is a derived from petrolium consisting primarily of hydrocarbonsand enhanced with benzene or iso-octane to increase octane ratings, used as fuel in internal combustion engines. Gasoline is produced in oil refineries. Material that is separated from crude oil via distillation, called natural gasoline, does not meet the required specifications for modern engines, but will form part of the blend.Gasoline consists of hydrocarbons with between 5 and 12 carbon atoms per molecule.
Distillation Method separation substances
of of
WWW.07MET.TK based on differences in their volatilities. It is a chemical unit operation There are two types of distillation. ď ś Batch distillation process ď ś Continuous distillation process Distillation was developed into its modern form with the invention of the alembic (word often used to refer entire distillation apparatus) by Islamic alchemist Jabir ibn Hayyan in 800 AD. He is also credited with the invention of numerous other chemical apparatus and processes that are still in use today.It is theoretically impossible to completely purify a mixture of components by distillation because that would require each component in the mixture to have a zero partial pressure. If ultra-pure products are the goal, then further chemical separation must be applied.
Apparatus *25 ml conical flask *Condenser *Cooling bath *Flask support *Graduated cylinder *Gas burners *Thermometer
Procedure I took 100 ml of sample in the flask, tight the flask with the cork and fit the thermometer and condenser. Apply heat immediately at a uniform rate so regulated that the first drop falls from the end of the condenser is not less than two minutes nor more than five minutes i.e. its should be within 2-5 minutes. When the first drop falls from the end of condenser then it should touch the side of cylinder. Then regulate the heat such that the first 10 ml distillate should be recovered is not less than 3 minutes or more than four minutes. Here after maintain the rate of distillation it should not less then 4 ml/min nor more then 5 ml per min. record
WWW.07MET.TK the reading of the distillation thermometer when the level of the distillate reaches each 5 ml mark on the cylinder when the liquid residue in the distillation flask is approx. 5 ml there may be increased because of the presence of ends which have relatively high boiling point, however don’t apply any further increase of heat after this adjustment. Continue the heating until mercury reaches a maximum and start to fall consistently.
Precautions First drop falls from the end of condenser then it should touch the side of cylinder The heat provided should be kept constant. Reading should be taken carefully.
Observations & Calculations 1st drop falls at 45°C 10 ml of receiving cylinde 56°C 20 ml of receiving cylinder 62°C 30 ml of receiving cylinder 70°C 40 ml of receiving cylinder 78°C 50 ml of receiving cylinder 86°C 60 ml of receiving cylinder 94°C 70 ml of receiving cylinder 102°C 80 ml of receiving cylinder 132°C 85 ml of receiving cylinder 136°C 90 ml of receiving cylinder 138°C
Results 5 ml gasoline (undistilled) Graphical Representation
WWW.07MET.TK distillation of gasoline 160 140
tem perature
120 100 80 60 40 20 0 1st drop
10ml
20ml
30ml
40ml
50ml
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70ml
am ount (di stil led gasoli ne)
80ml
85ml
90ml