Considering the cost of some essential oils exceeds $400 per oz. (30 ml) and most essential oils cost about $100 per oz. I thought it would be an interesting project to experiment with home made extraction.
The cost of a pre-built unit (that is only about 5 gallons) is about $1,000 however, I sat up an experiment using a 55 gallon drum - and other junk I found around the farm for $0.00. The following pictures describe the materials and process.
1. Here is the 55 gallon drum I used. Note that the drum needs the metal band that allows the lid to be removed then replaced. These are not as common as most 55 gallon drums but can be found.
ATTENTION: USE EXTREME CAUTION if you don't know what has been in a drum... or if it isn't THROUGHLY clean. A friend of mine from college was nearly killed when he cut into a drum with a cutting torch to remove the lid and make a trash barrel. His arm was broken in several places and his jaw was broken and he suffered a cuncusion from the explosion.
2. A cooling/condensation coil is needed to convert the steam back to water and separate the oil. Note that it's easier to make a coil of copper tubing by rolling it up on something like a 5 gallon bucket. That prevents the tube from kinking that would stop the flow.
3. It would take hours and hours and a LOT of fuel to bring 20 or 30 gallons of water to a boil and make steam. So the efficient thing to do is to add 2 to 4 gallons of water then boil it out and add some more. HOWEVER how would you get more water into the drum? I welded a faucet near the bottom where I could attach a water hose and add more water. USE EXTREME CAUTION before you weld. Most drums have contained explosive liquids.
4. The removable lid is not easy to get resealed perfectly so that steam doesn't escape. I put about 3 layers of duct tape on the realm of the drum before replacing the lid. This helps increase the pressure inside the drum and forces all the steam into the cooling coil.
5. A source of heat is needed and I didn't want to burn up all my firewood. I found an old gas heater that was thrown away and removed the heating element and attached a propane tank. This was perfect for boiling the water inside the 55 gallon drum.
6. I used a christmas tree for my source of oil to extract in my experiment. It is perfect since the leaves are thick and arranged on the limbs to allow the steam to pass through. If I used only the leaves I would have had to design and build some kind of rack to keep them out of the water and allow the steam to pass through.
7. I cut the bottom and top off the tree so it would fit in the drum.
8. I put it in the drum.
9. Then I trimmed the leaves that were sticking up and added the clippings into the drum.
10. I replaced the lid and whacked the band with a hammer while tightening the bolt so that it would not allow any steam to escape. Note that it's important to place the steam spout in the position you want it BEFORE you put on the band to hold the lid in place. If you put the drum in a small area you need access to the water inlet. You may not have room if the water supply is on the opposite side of the copper cooling tube.
11. Here is the basic setup.
12. I had washed out the drum and a small amount of water was still inside when I first applied the heat. Before I could connect the water supply and copper coil the steam was coming out.
13. This is the MOST essential part of the process. Since the oil FLOATS on the water ... IF your collection container overflows your oil will run out first, onto the floor, and be lost. For $4 I picked up a small watering container. As you can see the spout is LOWER than the top. This means you can add water all day long and it will never run over the top - it will run out the spout first. Fill the container half full of water BEFORE putting it under the cooling coil to catch the distilled water/oil from the drum. The oil will float and the water will sink to the bottom then run out the spout. You may note that the system for the oil collection is more complicated in the diagram on the page I listed. But this simple setup will work MUCH better. In their setup they have to continue to monitor the collection container and manually let out the water. My system allows you to set it up and forget about it.. until you have to add more water.
14. I checked my flame after the water started boiling and turned it down so that fuel wouldn't be wasted but the water would continue to boil.
15. The coils will eventually get so hot that steam will come out the end without condensing. The web page had a setup with the coils inside a container of water that kept the coils cool. I cooled the coils by applying a trickle of water from a hose.
16. The trickle of water does not cover much area on the coil or cool very effectively, but placing some old rags on the coils covers more of the surface area and cools the coils efficiently. If steam - not water was coming out of the cooling coils then the oils would be escaping.
17. Here is the entire setup in operation. Note: Do NOT put the tip of the cooling coil INSIDE the collection container!!! If you disturb the setup the coil will PROBABLY tip over your collection container and spill your oil. Keep the coil at least 3 or 4 inches ABOVE the container.
It's better to set up inside a shed. If it's outside the wind will cause more fuel to be needed to keep the water boiling. And someone may think you are making moonshine and call the law.
18. Speaking of fuel, that's the only expense in the process so it's the only way to reduce cost. If you have a 300 gallon propane tank your fuel cost will be MUCH lower than filling the 5 gallon tanks that come with grills, etc.
19. Here is about 3 ounces of christmas tree oil I extracted in about 10 hours. I probably extracted over 4 ounces but I tried to remove the oil from the top of the water and that didn't work very well.
20. The right way, and efficient way to separate the oil is to pour out the water, through the spout till it you get down to the oil level. Then dump the entire remaining water/oil solution into a glass container and take a turkey baster and suck the water from the bottom.
21. ...till only the oil remains.
Conclusion: For less than $5 in propane fuel I was able to extract about $150 worth of cedar oil. I have an abundance of pine trees to get needles and extract pure pine needle oil that would cost about $25 per oz. Also keep in mind that this is PURE oil. When you buy essential oils they are FREQUENTLY DILUTED with other solvents. I will look for other plants in my area that may contain more exotic oils.
