floral extractor using R-134a

[mbingham]

HI EVERYONE me an my wife are in the aroma therapy industry and are getting into extracting our own essential oils. I recently found out that R-134a is a approved food grade solvent for extracting food grade safe oils which leads me here as i am in the middle of planning to build a extractor using refrigeration technology & knowledge as it is very well established an safe. yes this is not a refrigerator but it is new tech that uses refrigeration technology and it is new uses for R-134A please dont delete me i need help lol. anyway the extraction process is simple get R-134a into a liquid phase pass it or pump it through a chamber full of powered plant material and a filter then spray it into collection container while evaporating it in mid air thus the spraying action then all u need to do is condense it back to a liquid and pump it back through. there are some special issues though first everything in contact with the solvent(R-134a) has to be stainless steel or other inert material like glass, two nothing can have residue of lubrication oils so the solvent must be pure this may affect pumping issues, three the extraction chamber is filled with powdered plant material that gets very much compressed an turns solid and needs to be opened and closed very often in such a way that lets the solid plant brick material out easily so like open the top an bottoms like a pressure cooker not sure how to seal that but cant use rubber seals maybe metal to metal, four the collection container has the same issues so maybe quick connects and hoses, five what pressure to use or build for, was thinking 500 psi for safety but only need the gas to stay liquid but it gets real hot here so wanted to plan things for 150*F ambeint temp to insure no blow outs due to summer heat and possible sunlight heating the metal, and six we are going to use this like nonstop so there is some cooling issues to be looked at i would hate to have hot/cold swings to make fractures in the metal, and again both the extraction and the collection chambers are opened emptied filled then closed so loss of solvent and the introduction of air into the system are issues to look at.

there will probably be a lot more issues but these are the ones at hand still dont know if i can do this with out getting a pump or vacuum but if not i can buy one either way, any and all ideas are very much helpful if u have any knowledge or ideas about this please respond as i still have no clue what thickness all this stainless steel has to be and i have looked for relating sites they only tell me that its being used industrially not how they are made or where to buy one

[The Viking]

Good luck with your interesting project.

Personally I been in the refrigeration industry for more than 25 years and I don't think I have the skill set to pull of a project like yours, or at least not making it financially viable or even within current legislation here in UK/EU (pass on what laws you got on your side of the pond).

First of all you will need a compressor to pump your refrigerant around and condense it in to a liquid, to aid in this you will also need a condenser (Heat exchanger) and an expansion/metering device.
Then you will need to be able to section off the parts of the system you need access to and pump the refrigerant in to some sort of receiver.
And each time you opened the system (your chambers) to the atmosphere you will need to take the sections exposed to the atmosphere down to a deep vacuum.
Add to this filtration to prevent your plant material from getting to the compressor.

All in you will need a lot of $, a lot of time and access to a vast R&D organisation to pull this off. Nothing I would do in my shed and certainly nothing I would expect to be able to make money out of in the first 5-10 years...

To quote a TV show popular over here: "Sorry, I'm out".

:cool:

[mbingham]

well i was expecting a price tag around 10K for a large unit but it some how seems so simple given the pics i've seen 1109511094

[mbingham]

i mean like a receiver dryer is pretty much a separator for batch operation till it gets full. i have no clue how to do a extract flow from the bottom but that a side it seems all u do is add a chamber or tube full of plant material before where the receiver dryer would normally be and use some sort of pump with out the normal oil lubrication mixed in with the r-134a but i dont know about oil less systems and i heard that the motor oil from the pump can find its way into the clean R-134a too any help there i can design the material thickness for a super critical state as i do know physics from uc davis but would really like to use common industry stuff rather than reinvent the wheel

[monkey spanners]

How are other people doing this? Or are you the first to try doing this this way?

Could you use another refrigerant such as R718? I think this is what is used commonly for essential oil extraction.

[Doug30293]

It looks to me like you are trying to do low temperature fractional distillation. I have designed and built various pilot plants and prototype machines over the years. What you describe sounds closer to $100K than $10K, and that is if you do most of the design yourself.

The safety and environmental issues alone could eat up a year's research. Stainless pressure vessels are not something you want made in a local fab shop. 316L stainless runs $4 to $20 a pound in small quantities. Machine shops capable of machining and welding it typically charge $80 to $100 an hour.

You seem to understand the chemistry and thermal science behind the process. That's good. I suspect the fabrication part is going to be overwhelming.

Doug

EDIT: If you are going to do this on a very small scale you can probably purchase laboratory equipment for the purpose. There is a research paper in the Journal of Food Engineering titled "Effects of parameters on yield for sub-critical R134a extraction of palm oil" that describes a typical lab apparatus.

Some creepy background information: The recreational drug community has been extracting lipids for years, first with acetone, now with R134a. Their methodologies reflect blatant disregard the environment as the solvents are always vented, sometimes snorted, and occasionally used to blow themselves up.

If you do not wish to incur the significant cost of recovering your solvent I suggest ethylene or propylene instead of R134a. You can expend these to the atmosphere by combustion without ethical concerns.