Isobutylene Extraction

I’m new to the site but very well versed in the arena. What is the hive mind’s opinion on using isobutylene for extraction? CLS system, obviously. I have been running saturation trials and the isobutylene selectively holds and strips 40% more oil over isobutane. The isobutylene is 99.98% pure extraction grade. I’m constantly evolving and have moved from R600, to 70/30, to pure isobutane, and finally to pure isobutylene. I am a BS chemist and don’t see any pitfalls. What are your thoughts?

You said selectively strips more oil. Usually things that strip more oils also pull more fats/wax. Any data on that?


I may have used selectively in the wrong context. The oil is 40% more selective to isobutylene over isobutane. You are correct, this also means more waxes are pulled. My anecdotal experience however, has been the additional waxes pulled are higher higher in molecular weight and tend to be heavier. I have yet to confirm this via GPC. On the bright side, this means that the extra waxes are easily mitigated via winterization.

Are the trials run under subzero temperatures?

1 Like

Yes, these trials have all been performed in an impinger at both cryo and room temperatures.

That’s good because ethylene and propylene are both prone to polymerization and I assume isobutylene is as well so the colder the better.

That is precisely my main area of interest, I’m glad you brought that up. I do know that heat + acidic catalyst site will generate polyisobutylene. Polyisobutylene would be harder to pull off, depending on the MW. Polyisobutylene is not hazardous as it is used in many beauty products, but I sure don’t want it in my end product. Any thoughts?

Polyisobutylene is a synthetic rubber so you would definitely want to make sure it doesnt end up in your extract. And you should not be using isobutylene with any adsorbents. But question, why not just buy propane fuel and use that? The local gas stations sell blue rhino brand propane fuel and it’s like 50/50 propane and propylene. It would probably be cheaper than buying isobutylene.

1 Like

I am weird when it comes to gas purity, and the 99.98% isobutylene comes from a respected Kosher source. Polymerization into polyisobutylene would be extremely hard and would require substantial heat inolut. Would also need a super strong acid catalyst to kick it off, HF etc.

1 Like

Good to know, it makes me wonder again about how useful that blue rhino fuel would be as an extraction solvent after distilling it thru a column of 13x sieve. I was under the impression I would need to remove the propylene due to the issue of polymerization.

Shit is cheap as fuck compared to this refrigeration grade shit we’re buying but I worry about the polarity of propylene as well. It’s got a dielectric constant of 11.9, although I wonder if it would even matter at cryogenic temperstures.

maybe residual odor

The odorants in propane fuel can be removed by 13x molecular sieve.