Wiped Film Parameters

thin-film
wfe

#102

We have a CDU and we want it to go faster. Obviously the input feed rate is going to be a big factor. Aside from that we want to make the distillation as effective as possible. For polish run (second pass), we run at 300-400 rpm on the wiper, 170c evaporator face, 130c residual, 70c on the distillate and condenser, and 70c feed input. Feed input is highest 350rpm, we notice worse color any faster. Any ideas would be appreciated. We have experience elsewhere other than wipers. Metering pumps on feed, residue, and distillate output all 300-350. Vac at 7.5 x 10⁻⁴ torr.


#103

“70C feed input” I would turn up the feed temp a bit. I like my feed to preheat to at least 110C- 135C. (Lower range if you can only heat the whole feed flask, 135C if you can heat smaller amounts right before entering still. Notice any vac depth issues at higher feed rate?


#104

Meant rpm


#105

Hello all,

I am running a 6’’ Chinese WFE and have questions about rpm, residence time, etc…

So when running our WFE, i calculate the approximate boiling point of CBD based on our vacuum ( we have it at around 30-50mt). But I’m noticing inconsistencies in our distillate, and I’m guessing it had to do with RPMs and resonance time.

Question being: How does RPM/resonance time affect seperation? I’m guessing that the higher the RPM, the lower the oil bath has to be (to a certain extent), since material is constantly being wiped.

Is there a way to know how fast/slow the rpm should be, and how does it affect the temperature/ evaporation rate?


#106

Usually the blades are designed to force the solution down. That means the faster the RPM the less residence time on the heated portion usually equating into more heat needed. Dial one variable in a time to avoid confusion/frustration in your process.


#107

The less time your material spends on the evaporation surface (usually referred to as “residence time”, although it does go by other names), the hotter the evaporation surface will need to be, or the thinner the film will need to be, or the lower the vacuum will need to be, to achieve evaporation.

so as @710ST suggests, only twiddle one knob at a time :wink:


#108

Hello Brethren,

This is my first time posting, although I’ve been reading for months. I pretty much learned everything (the little) I know so far by reading the threads here. Big ups to Future and the rest of you folks who are sharing so much knowledge and experience.

So after months of reading, I finally set up my spot. I am buying crude to winterize and distill. I am running a 6" chinese WFE. I am degassing in a reactor under vacuum. Below are the settings I am using. Just want to be transparent and share with the others. Not that this is a brilliant setup, or even close.

Winterize:
10:1 alcohol. Freeze for 48 hours. Filter twice through 25 micron then 2.5 micron. Recover in 50L rotovap. My chiller can’t seem to keep up but I can recover about 20L of ethanol every 4 hours.

Degass/decarb:
30L jacketed reactor with Busch MV 0040 pulling vac. Heating jacket with Julabo SE-12. I ramp up temp to 125C over 3 hours then let it sit for two hours at that temp. Agitating with Fusion Fluid lab agitator. The shit that comes out of the pump is GNARLY. I took a whiff and was traumatized for the rest of the night…

Distill:
Given that I am using a chines setup and have not made enough money to update components yet, my vac levels leave a little to be desired. Not sure if I am doing anything wrong, or if its just the price to pay for Chinese equipment, but, at best, vac levels usually hover around 150 mtorr. During my first run I experimented with the evap temp starting at 155C (buddy’s recommendation) going up 5C with each successive pass until I felt that enough of the THC was evaporating. I ended up at 180C on main body (big thanks to Bucky for posting the very thorough SOP above, which has been a major reference point). Using a IR thermometer, I can see that there is a tremendous gradient in heat on the main body, ranging from 179 or so to 157 (that with heater set to 180C). I hope that when I can upgrade to the Julabo on my main rig I will get more consistent temps given the much better circulations speed. The chinese heaters heat well enough, but circulate a snails pace so temperature gradient is very real.
Feed tank set to 90C
THC condenser set to 80C
Terp trap -25C
Cold trap (polyscience IP 100) set to -81
rotation speed between 300-500 rpm. (any advice?)
Feed speed 1L/hr. Supposedly this rig can do 2+L/hr, but I found too much ended up in retentate side, so I slowed it down, perhaps I actually need to slow down my rotors. I thought the faster the speed the better the evap, but after reading above I see that it may in fact push the material down too quickly.
First full run using the protocol I settled on had pretty good results (from visual inspection), no swirls, golden color. Havn’t tested it yet, with the wait times of 2-3 weeks, my sense is that we’ll sell what we have before we get results back. Perhaps naive.

Still not getting the yields I would like. In a 8L run, I ended up with about 4L of distillate (I will definitely rerun to squeeze out every last drop of THC, but looking to speed up the process a little bit) My starting material was good: shatter that didn’t quite make the cut.

A few questions for the generous souls on here:
I started with a little over 20kg of crude/shatter.
-How much should I expect to yield in distillate?
-Should I run evap a bit hotter to get more separation?
-Should I run condenser hotter? Colder?
-How essential is it to get vac levels super low? (After reading bucky’s SOP’s I’m a bit confused, because he said he’s getting super high purity with the vac levels at about 500 mtorr)
-Should I keep feed tank hotter? Originally I had water circulating, but replaced with silicone oil, but I’m scared to heat more than 100C because I’m worried residual water will boil and pressurize jacket, and perhaps blow feed tank. Is that plausible? Or will any vapor go out the tubes with the fluids?
-Any other insights in how to tweak my procedure to get better yields/color/potency? I realize that improving one of those metrics may well decrease the others. Ultimately my goal would be to produce the highest yields possible at or above 85% THC, preferably with one pass through WFE. Possible/plausible?

Also, I would be happy to pay for some consultation time with any of the OG’s on here. Message me if you think it would be a good fit. At present my setup is at my house, so just looking for a phone consultation.

Again, much thanks to everyone sharing their questions and/or knowledge on here. This is the only place I’ve found with legit crowdsourced info. I real gem!

-Tao


#109

Have you had experience on re-running distillate through a WFE? What temps on your evap column and condenser helped?


#110

135/98 evap/cond 50-100mt

Low and slow…


#111

135? thatd be low for even diff pump vac levels.


#112

Hey has anyone given these parameters a shot?

I’ve noticed most people with WF stills seem to be running lower condenser temps (80-90C) and I have been curious as to whether or not a “hot condenser” methodology similar to what @BreakingDabs uses could be applied to a WF still with noticeable results. The idea seems like it would apply in the same way it does in a pot still setup by doing a sort of rectification or second distillation on the material.


#113

hot condenser seems to be most “effective” when used on a counter-current flow system, like Pope Hybrid. especially with preheating feed right before it enters still body to a few degrees from jacket temp. Heat tape above jacket and/or on overhead vapor duct helps keeps overhead vapors from condensing above jacketed area causing em to return back down evap column. This op-tek isnt the only way to run, and its utility is dependent on end products desired, tools/time available. I’ve noticed less resolution with a co-current setups…


#114

I’m confused on what you mean when you say “counter-current flow system” and I’m not sure what a Pope hybrid is.

I have heard the term “counter-current flow” used in the context of wiped film evaporators when referencing vapor flow in units with an external main condenser. It is used in the same sense as in falling film evaporators: the vapor can flow downward, co-currently with the residue and out to the condenser at the bottom (common setup in our industry) or upward and counter-current to the flow of residue.

In a short path wiped film still, the vapor flow goes directly inwards to the condenser and doesn’t follow the residue in either direction, hence my confusion at your statement.

My thought on the hot condenser technique as applied to short-path wiped films is that usually due to recommendations from manufacturers and/or limitations of the supplied heater circulators people are usually running their internal condensers under 100C.

If the boiling point of THC is around 155C at .05 torr, it would make sense to run the internal condenser up around that level or a few degrees below, as @ColumboLabs suggested, in order to condense the THC but reject any latent heads fraction that may be co-distilling with main body.


#115

I do not run any sort of condensor but my oil temp, also my head temp is generally best set at 126°C to 135°C. without an uptake path for any unwanted gas to collect onto there is no need to devise what I term a high bypass mode of fractionating. In fact a high bypass design is by definition short circuiting the rejection rate of a traditional spd and from that point of view the device shares a common thread with one that also uses zero fractionating power of a glass or packed uptake colums.

The difference tech wise in this concept that turns a chiller into a heating element, is the attempt to fractionate past the confines of the device while it is distilling compound whereas in my sublimator I remove the terpene fraction and other volitiles too before attempting to employ a device with nearly zero rejection rate between fractions. These ideas, mine and others, are radical insofar as they are not typically practiced for various reasons. Some who try each method have complained that they do not work while others see a great deal of success. The other difference is cost. My sublimator cost under $600 and no chiller, forline trap, or inline vapor trap is needed so long as the right maintenance parameters are met. I have not seen third pass counter current wiped film disty or had a chance to sample. Of course with my own I sampled all of it. On third pass IF the goal is water gel clarity then a rig like a sublimator will work to isolate D9 THC into very high potency but at the exoense of going slow. Go slow and it is like a fine Rolls Royce in terms of quality but ramp up the speed into ultra high bypass distillation operations and the quality cannot match the sublimator quality but then again it is fast enough to go commercial.

One confusion of the term is Counter Current Distribution (CCD) which is based on Liquid to Liquid Extraction and has been done by me to R&D ratios of solvent systems and reveals the numbers you need as a percent to run versus attempting to guess beforehand. I used it almost like a gradient in the mobile phase to see exactly which tube revealled greatest rejection rate for my dewaxing process. I discovered a unique cross over in my lab that led me to successfully dewax the compound at a later stage because I knew what each stage wood reject.

A counter current separation is done traditionally by two immiscible phases that each can solvate the compound. I add water as part of the alcholol stage in a process known as louching to force cannabinoids out of the methanol layer and into the hexane. In traditional CCE then the top phase of now mixed solution will be transfererred to the next fresh tube in line to fill it up. So then you have a tube that is good at holding onto compound and one not so much. As each tube is fractioned into the next tube the top layer is replenished with acnew mobile phase, one tube at a time and you end up with most tubes being highly concentrated as you go along the train of tubes.

CCD is an old technique and is not a distillation technique per se as I have described it but I too have seen the term counter current separation and was initially confused why a dustillation run could be termed this way. However lots of things in terms of names and chemistry soemtimes seem odd. Every tiny clamp or tube used gets names for who came up with it. In honesty I wish somebody had an explanation how a wiped falling film exploits CCD to achieve its success.


#116

Thats around the setting the VTA runs at 2nd pass. Same setting i was hitting 99.9% on


#117

Do 72 degrees internal condenser, 146 external at 46-52 mtorr on second pass and let it run. You will see results going up to 96-99 total cannabinoids.


#118

@MagisterChemist what do you think of these parameters?


#119

I wish I had an answer for you but the condenser chillers i’ve used couldn’t go that high. If you try this be mindful of the cold trap – distillate bypassing into that section would be miserable.


#120

I will be reaching out to you coming very soon.


#121

How do you get 180C on the jacket on the VTA? Mine only goes up to 175C.