Steam distillation used to separate rosemary oil. This project focused on building steam distillation apparatus and how to extract oil and improve the quantity.
In the experimental part we design and install pilot plant steam distillation unit, and the capacity of steam distillation unit is determined to be 71 liter .
The steam distillation unit of 71 L capacity having proper condenser. The oil yield is 18g oil per 1 kg of dry rose marry.
The modification on reservoir is very important and contributed to increase of the yield.
Steam distillation is a special type of distillation or a separation process for temperature sensitive materials like oils, resins, hydrocarbons, etc. which are insoluble in water and may decompose at their boiling point. The fundamental nature of steam distillation is that it enables a compound or mixture of compounds to be distilled at a temperature substantially below that of the boiling point of the individual constituent. Essential oils contain substances with boiling points up to 200°C or higher temperatures. In the presence of steam or boiling water, however, these substances are volatilized at a temperature close to 100°C, at atmospheric pressure.
Advantages of using Steam Distillation:
The advantage of Steam Distillation is that it is a relatively cheap process to operate at a basic level, and the properties of oils produced by this method are not altered. As steam reduces the boiling point of a particular component of the oil, it never decomposes in this method. This method apart from being economical, it is also relatively faster than other methods.
Water and steam Distillation :
Water and steam distillation involves the storing of the plant material above a water bath Situated in the bottom of the charge vessel and heating the water either through direct fire Steam jacket or closed or open steam coil. Water and steam distillation produces saturated wet steam at the prevailing vessel pressure, which is usually atmospheric pressure. Within this configuration, unlike water distillation, only steam comes in contact with the plant material.
Steam Distillation :
Steam distillation employs an external steam generation system, external to the charge vessel. This configuration provides much more control (depending upon the boiler capacity) than water and steam distillation. This is because in steam distillation the wetness fraction, temperature and pressure can be manipulated according to needs and conditions
The Condenser System :
A condenser in an essential oil distillation system is a heat exchange or dissipating device. The condenser must not only cool the condensate vapour into a liquid , but also cool the condensate to the temperature range where the oil will separate spontaneously from the water.
Design process :
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Design and install pilot plant steam distillation .
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The capacity of steam distillation unit is determined to be 71 liter.
This due to following reasons:
It was more easy to design with stainless steel cooker with this volume that purchase from Ansar company at AL-Bira Ramallah
The entering hot steam is caused the evaporation of the essential oil, so the condensed oil/water mixture enter the reservoir at the place where oil collected this causes to its evaporation and loosing.
Some modification on reservoir is occurred for changing the feed (condense water oil)entrance point to reservoir.
The feed will not face the oil layer at all, it goes to the system where it separated into oil and water.
The amount of oil obtained from the first experiment is about 9.5ml of oil from 1000g of dry rosemary while after modification we have got 13.5 ml of oil from the same amount of rosemary.
After changing completely the apparatus with proper condenser the amount of oil obtained is 18 ml. As shown in table 3
The result
|
Exp. 1 |
Exp.2 |
Exp.3 |
Dry rosemary |
1000 |
1000 |
1000 |
oil |
9.5 |
13.5 |
18 |
Steam D.unit |
20 L |
20 L |
71 L |