What about less heat transfer loss under vacuum?
That’s got to have a little affect on how much energy it takes to atleast reach the decarb temp
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Now we are back to Gigs Of Data 
And I don’t need to start any religious wars…
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I’ll toss my experiences on the pile, why not …
While working at a licensed testing lab, I had the opportunity to do a buncha R&D on decarbing, results were measured by HPLC method with verified standards from k-prime, the goal was to achieve 99% decarbed material with under 1% THC-a or CBD-a (I like to see that we were not burning it).
We decarbed biomass in sealed canning jars, 125c for 26-28mins allowed for good heat within the jars and got us to our best numbers consistently, sealing the jars and letting them cool to RT before opening them really helped retain terps but this is moot if going to distillate… Capping terps from decarb always resulted in a degraded terp profile in the GC analysis.
With oil based decarbing, we found best results in a stainless reactor while under mild positive pressure to a slightly higher temp of 140c, agitation allowed for a shorter time in our trials (5-8mins less). because of the psi, higher temp and agitation we no longer had to watch for muffin bumping into a vac line and the trade off of the higher temp did not hurt the cannabinoid profile.
These tests did not yield the same results with hash and kief because of their density.
Overall I would say the easiest & safest method of decarbing on the cheap is course milled biomass in sealed mason jars at 125c for 26-28mins but for scale decarbing oil is much more efficient
2¢,
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-Vac = Good for pulling volatiles
-Vac does not accelerate decarb time (I’ve done side-by-side testing)
-Rotovap works ok, but there are better ways
-Instead of a chilled condenser, there’s other glassware that’ll improve terpene removal from the material. It employs a fluid effect (rhymes with penturi) that’ll help the escaping CO2 entrain the volatiles.
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How do you suggest this should be done?
In the cold trap rf.
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@Kingofthekush420 & @cyclopath & @Myrrdin… all excellent points that tie together into a cohesive theory from a hypothesis I’ve kicked around for a while to answer my obsequious question, “Wtf do they mean by pseudo-first order rxn?” Hypothesis: The effects of product concentration and pressure (which steer 2nd order rxn mechanisms) on the rxn rate are present, but fairly limited.
Here is how your results coalesce the theory of “pseudo-1st-order” for me, along with my and many others’ observations that almost ALL decarboxylation seems to actually occur at the interfaces of the fluid… most especially right where the liquid resin contacts the heated solid surface.
In the herb, this is practically impossible to observe, but each resin gland also has a lot of interface with air, which IS the heated surface in a baked sample. This would explain why we see that herb generally decarboxylates faster than larger volume aliquots of resin (as @Myrrdin observes here), and why even old school heads know that spreading the honey out thin in a pan works to decarb much faster than deep resin in a pot or jar.
Also, nanoscale materials science and common sense tells us that interfaces have greater energy than the bulk beneath them. Nucleation of bubbles in boiling and crystals in precipitation are both phenomena of the interface. A pointed needle penetrates a given surface (interface) with less force than a flat-end rod of equal mass… in many ways this surface area phenomenon is about the difference in energy of the interfaces.
Pressure does affect the rate of the decarb rxn, and it’s backward from what one might expect from CO2 being a gas and the product. This speaks to @Kingofthekush420’s point regarding energy removal by the escaping gas… similar to that seen in simple evaporative cooling. Instead of pressure slowing down the rxn (as might be the case in any 2nd order rxn involving 1 solid reactant breaking into 2 products), pressure speeds it up a little (as would be the case in a 2nd order rxn involving 2 gaseous reactants condensing to 1 solid product). Why? Well, if we treat the heat energy AS a reactant, this backward and limited effect of pressure may become clearer…
A. Pressure traps the heat by keeping the gas from expanding and leaving with its heat, AND
B. It keeps the bubbles smaller and therefore more numerous as they are unable to expand and coalesce, which increases the heated surface area in the immediate vicinity, allowing more molecules to react, BUT
This is naturally limited by the fact that
C. The majority of the molecules in that area have already reacted to create the gas bubbles in the first place, AND
D. Heat energy also dissipates by convection through a medium, (which is minimized as pressure increases, keeping new molecules from entering the more stationary hot zone) and by radiation through space, spreading over a larger area, which attenuates the exposure strength by the inverse square law… so at even one nanometer distance, the energy available to any molecule in the field along the expanded radiant area has been cut significantly.
Incidentally, such power attenuation at distance is probably why ONLY molecules right at the heated interface (where direct heat conduction occurs) will react in the first place… there’s just not enough energy left as the heat spreads outward with distance from its point (molecule) of origin! Although there might be faster convection with lower pressure as @cyclopath may have been guessing, IF it weren’t that the product is a gas able to expand and cool!
So the decarboxylation rxn really is just a 1st order (thermodynamically mediated) reaction, but because of the nature of its products (in this case, the molten dilatant fluid of generally amorphous solid: cannabinoids, and a highly linear non-polar molecular gas: CO2), it also has limited capacity to be driven apparently backwardly, but not reversed (which would be 2nd order) by pressure!
No wonder chemists just summarize that obvious but overtly complicated explanation as “pseudo”! 
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Does your oil smell like burnt toast when decarbing prior to extraction? I get higher yields when decarbing first but haven’t figured out the best parameters for running CBD-A.
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Agitation and application of vacuum are very different. While applying vacuum may result in mild agitation, if you’re decarbing in a roto then the difference won’t matter.
Edit: refer to @Photon_noir’s post
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Pay me!
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@Krative has some niffty way s and has spend a lot of time in finetunning these sop well worth the $$$
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Haha thanks buddy. It’s true!
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I’m keen on this, when the time is right I’ll be in contact
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I look forward to helping you upgrade!
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If you are performing decarboxylation prior to extraction it will speed up your run times at the cost of terpene loss… There are a couple of ways to offset this with CO2 extraction.
First would be to run your terpenes first, remove boimass, decarb, then reload. while it’s not the most efficient scenario it can help you to have higher yields of your terpene fractions. I talk to people about performing this in a batch process, taking a day of the week to run terpene pulls only, then the remainder of the week can be spent performing the deeper cannabinoid pulls on the same batch(es) of material.
If you only want to run the material once through the extractor I’d recommend looking to add a cold trap to your decarb oven. Scientific 710’s Odie can be utilized to recover terpenes.
You can also look into using a vacuum oven to decarb biomass, although it’s not the “best” solution it can get the job done. Cascade’s CVO-10 Package has their mechanical cold trap that can be used to pull them out prior to extraction.
Last option is going to be decarbing post-extraction. This extends your run times – as much as twice as long as decarbed biomass – but gives you the ability to fraction off your terpenes first, then pull the crude, and finally decarb through various methods depending on scale. Options for this route can be rotovap, decarb reactor, or using that vacuum oven with the cold trap listed above.
With the knowledge that decarboxylation is basically a function of time and heat, decarbing via rotovap can put a bottleneck in your production line depending on volumes/times needed to decarb. If you’re going the rotovap route you’d probably want to use oil in the bath instead of water, unless someone is there to babysit the bath and continue to top it off as the water evaporates.
No matter which way you decide recover your terpenes, if done correctly you should have more than you can utilize in end products if you pull terps from every pound you process. Diversify your product offerings by selling bulk terpenes, and get every penny you can out of your feedstock.
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whats a good cheap big oven to decarb material in? that big cascade is spendy
had a pair of these once upon a time. not sure why.
decarb ovens was the only use I could come up with.
never used them
won’t do your terps any favors.
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Place some kegs inside
Drill some holes treu the oven sidewall
And you have vacuum or inert sparge
Stainless or ptfe or viton hose all can Handel 220 C yust under vacuum only stainless is usefull
Anybody ever use a grain dryer like these:
I feel like it’s time to start looking to other industries and how they solve similar problems in a more efficient and cost-effective manner.
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Unless you fractionally extract them first!
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