Study : Methods of extracting essential oil & scent

Since I 've decided to do the chemistry way. I've got to study up on what are the science way of extracting and collecting scent. Therefore I went on with finding out the ways to extract smell and along the way I bumped into brilliant and interesting ideas.

I also studied graphs and drawings of distillation set ups so as to understand it better because the last time I've studied chemistry was a few years back. Besides, my memory has always not been brilliant and hey it's chemistry we are talking about.

Distillation:

The vast majority of true essential oils are produced by distillation. There are different processes used, however. In all of them, water is heated to produce steam, which carries the most volatile chemicals of the aromatic material with it. The steam is then chilled (in a condenser) and the resulting distillate is collected. The Essential Oil will normally float on top of the Hydrosol (the distilled water component) and may be separated off.

Steam Distillation

True Steam distillation uses an outside source of steam which pipes the steam into the distillation unit, sometimes at high pressure. The steam passes through the aromatic material, and exits into the condenser.

Hydrodistillation

The botanicals are fully submerged in water, producing a "soup", the steam of which contains the aromatic plant molecules. This is the most ancient method of distillation and the most versatile. It's the method most often used in primitive countries. The risk, of course, is that the still can run dry, or be overheated, burning the aromatics and resulting in an EO with a burnt smell. Hydrodistillation seems to work best for powders (ie, spice powders, ground wood, etc.) and very tough materials like roots, wood, or nuts.

Water & steam distillation

A water and steam distillation arrangement can be compared to a kitchen steamer basket, with the botanicals supported in a "basket" over boiling water, thus exposing the plant material only to the rising steam vapors. This is the best method for distilling leafy materials, but doesn't work well for woods, roots, seeds, etc.


Carbon Dioxide Extraction

When CO2 (carbon dioxide) is subjected to high pressure, the gas turns into liquid. This liquid CO2 can be used as a very inert, safe, "liquid solvent." which will extract the aromatic molecules in a process similar to that used to extract absolutes (above.) The advantage, of course, is that no solvent residue remains, since at normal pressure and temperature, the CO2 simply reverts to a gas and evaporates.
CO2 extraction has given us essences of some aromatics that don't yield essential oils, Rose Hip Seed, and Calendula, for examples. In my experience (or opinion!) if the same essential oil is available both as a steam distilled EO and a CO2 extracted essence, the CO2 seems to have a richer, more intense scent, since more of the aromatic chemicals are released through this process. 

Cold Pressing

We are all familiar with the spray of orange essential oil that can be released by scoring or zesting the skin of the fruit. The cold pressed citrus oils are commercial produced just this way, by machines which score the rind and capture the resulting oil. Although many citrus oils are also produced by steam distillation, they seem to lack the vibrancy of the cold pressed oils.

http://www.naturesgift.com/extraction.htm


My main aim is actually to find out ways to collect scent using the fractional distillation idea. However I found out that there are a few ways of distillation and the same method is being used not only for collecting scent but also to collect alcohol, which is not the direction I am going for. But I believe a study on these methods will help me understand better and maybe I can adopt the method and infuse into the design of my outcome.

I also found traditional chemistry way of distillation and alternatives that are diy and can be done at home. They would help me understand better and simplify the process.

I also found out another method of extracting scent, that uses water as the main element.

In theory, the process of steam distillation is simple enough: Generate steam, direct it through the biomatter to be extracted, condense it, and collect it. In practice though, steam distillation is a subtle art, and the details of equipment and technique are very important. 

The laboratory steam distillation setup as a reference 

The catnip extraction

The catnip and water goes in the bottom of a big pot, with a cup placed on top. The lid is really the key component here; by simply turning the lid of the pot upside down, the vapors will condense and drip down from the center, collecting in the cup below. By filling the top of the lid with ice water, the vapors are condensed very efficiently.

An idea of how to Build a Still Vodka Distiller

A very basic idea of how to get distilled water out of a DIY method

After studying all of the extraction ways, I noticed that they require a heat source and for the laboratory set ups, most of them use fire to heat up. Heating up is a must for distillation which is one of the obstacles I am currently facing. Because the usage of fire for my outcome would not only look raw but also not very convenient for users as my outcome is supposed to be interactive. 

Cracking up my brains.