Episode 7

Published on:

2nd Feb 2021

S1 E07 - Wiped Film Evaporators For Cannabis Oil Distillation

Learn how a wiped film evaporator works from the man that makes 'em best. John Hart, founder of Chemtech Services, joins us to discuss how his rolled film distillation machines are the best in the biz for the distillation of cannabis oil. John and Jason discuss the latest equipment offerings and innovations Chemtech is bringing to market, as well as the advantages to using multi-stage distillation units.


Jason Showard - 00:00:10 

Hello and welcome to Episode Seven of The Modern Extractor. This podcast focuses on the processes, equipment and science found inside a cannabis extraction laboratory. I'm your host Jason Showard, and I work professionally in the cannabis extraction field. Here in season one, we're focusing on ethanol extraction and post processing. With each episode digging deep into a particular stage in that process. The shows are released in an order that follows the workflow through a lab, as material makes its way from cultivar to concentrate. 


Jason Showard - 00:00:39 

Last week we had Greg Arias of Concentrated Science and Aftermath Labs on the show. He helped us demystify decarboxylation on a molecular level. We talked a bit about the differences between decarbing THC versus CBD. And I talked through my decarb SOPs. Moving on to this week's show, let's catch back up with our material on its way through the lab. So far we've performed a cold ethanol extraction in a centrifuge. We cold filtered the resulting miscella through an insecure filter. 


Jason Showard - 00:01:06 

We ran that miscella through a falling film evaporator to separate the oil and the ethanol. And we decarboxylated the crude oil we separated, converting the acidic forms of the cannabinoids into THC or CBD. This week we make our way to the most complicated machine in the lab, the wiped film evaporator. Technically, we'll be talking about a rolled film evaporator today, which is the best style of wiped film for use in the cannabis sector. Joining us today to discuss rolled film distillation is John Hart, founder of Chemtech Services. 


Jason Showard - 00:01:35 

John and his team currently have a ton of equipment out there in the field. You'll find their machines installed at the premier cannabis processing laboratories throughout the country and all over the world. They're always working on developing new equipment for our industry and interesting R&D projects. But I'll let John tell you all about that. Without any further ado, John Hart, welcome to The Modern Extractor. 


John Hart - 00:01:54 

Oh, thank you very much, Jason. Happy to be participating. 


Jason Showard - 00:01:57 

Absolutely glad to have you on today. Where are you calling in from? 


John Hart - 00:02:01 

Calling in from our headquarters in Lockport, Illinois. Lockport's a suburb of Chicago. 


Jason Showard - 00:02:09 

Right on. All right. What's the weather like out there right now? 


John Hart - 00:02:12 

We have an amazingly sunny day here. Unfortunately, it's really cold. It's about 20 degrees Fahrenheit. 


Jason Showard - 00:02:20 

All right. I'm in Los Angeles now. It's got a little rain recently, but we could use it. All right. Anyway, what was your path like to starting Chemtech? 


John Hart - 00:02:32 

OK, so I'd spent most of my career working for a couple of major chemical companies, and I did a lot of things. I mean, I did mergers and acquisitions. I was an engineer on the technical side. So I was also building or let's say managing the construction of chemical plants in addition to chemical plants around the world. And I, you know, in the early part of my career, I spent about 60% of my time outside of the United States. 


John Hart - 00:03:00 

And the nature of my job was such that I actually earned some pretty significant dollars for the companies I was working for. So at some point in my career, I decided, gee, maybe I should just strike out on my own and see if I can earn a little more money myself than I was getting paid a salary. 


Jason Showard - 00:03:21 

At what point did you decide it was time to, you know, just go ahead and jump for it? 


John Hart - 00:03:26 

You know, I think I was about 50 years old. Maybe 51 or 52. But that's about the point in time I did that. And Chemtech has been around for 15 years, so that gives you a little bit of a time perspective. 


Jason Showard - 00:03:45 

So were you already in distillation when you were traveling around doing your other jobs? 


John Hart - 00:03:51 

You know, the chemical industry is such that the technologies I was working with did utilize distillation methods. And I mean, actually, my first major job at Ashland Chemical, Ashland was a subsidiary of Ashland Oil. So you can imagine distillation is a big part of processing oil. 


Jason Showard - 00:04:13 

Yeah, certainly is. So if that's how it all began, give us a little bit of a bird's eye view of what Chemtech is today. 


John Hart - 00:04:22 

OK, so I typically regard Chemtech as being two divisions. One division is the design and fabrication of our core technology, which is distillation systems. But we also do other technology, especially pilot plants for chemical companies, as may be required. The other division is our toll processing of chemicals division. And we have a lot of really major clients. I mean, I would say pretty much Fortune 200 companies. We distill some really sophisticated stuff. 


Jason Showard - 00:05:00 

OK, so what industries do you typically serve? 


John Hart - 00:05:04 

You know, historically we were very petroleum, petrochemical, specialty chemical oriented. In more recent years, obviously, the hemp and cannabis folks discovered that our high vacuum distillation equipment could be really useful for separating the cannabinoids from the other riff-raff molecules in the extracted oils. 


Jason Showard - 00:05:30 

I can certainly attest to that. I've used your machines and I absolutely love them. I'll get into what you offer in a moment here, but you've kind of brought up a great segway into the cannabis field. Tell me about the moment that you realized that your equipment was being used to distill cannabis oil. What was your initial reaction to that? 


John Hart - 00:05:50 

You know, it kind of started when a client out in California actually asked us if we could separate the CBD from a hemp oil that they were importing from Europe. And, you know, our reaction was, "Well, it's just another essential oil to us." And so we asked them to send us the sample. They sent us the sample. We processed it and sent the results back to them, the distillate residue fractions. And they were pretty happy because we had definitely separated and concentrated up the CBD. 


John Hart - 00:06:30 

So I think probably within about six months of that exercise, they bought a two-stage KD10 system from us, which they continue to operate out in the California area. Roughly about that same time, though, another California organization had called us and was asking for quotations on some of our smaller laboratory units. And we came to find out that they were distilling THC, and they ended up buying a lot of our lab scale units because they had multiple locations. Also about that time, we hooked up with an outfit called Helderpad, and Helderpad had a processing license in the state of Washington and they ultimately became our agent. 


John Hart - 00:07:21 

They were operating one of our units. They liked it and became our agent. They've done a really good job selling our equipment and they continue to distill out in their facilities in Seattle. 


Jason Showard - 00:07:33 

That's great. So a lot of the players in this space are making equipment specifically targeted at the cannabis market. Well, others kind of fall into the "fell into it" category because you already had something you made that was a good fit. From what you've explained to us so far, it seems like you are already in the game and then your equipment was just the right option for what the folks in the cannabis industry needed. With that said, what are you doing to keep the people that are targeting the cannabis field off your heels? Are you doing anything specific to stay relevant and hold your position? 


John Hart - 00:08:10 

Yeah, I mean, we actively have about six different R&D projects that actually are associated with more novel methods of processing cannabinoid molecules. But in the meantime, we've obviously embellished our existing offering to accommodate the industry. I mean, for example, we introduced some decarboxylation units into the industry a few years ago. We've also introduced specialty ethanol distillation units. Our two-stage distillation systems that will allow the user to get his ethanol content in the final oil down below a tenth of a percent. 


John Hart - 00:09:00 

And those obviously are peer reviewed. So they can pass the scrutiny of the regulators in the West Coast states. But like I said, we're continuing to work on things. I think one of the bigger novelties we brought to the industry also was the introduction of the turbo molecular pump into, not only cannabis processing, but short path distillation processing. Historically, the turbo molecular pump had been regarded as a little bit too fragile for distillation operations. But our primary supplier of vacuum equipment, Leybold Vacuum, came to us and said, "Hey, we have a new design. We'd like you guys to test it because we think it's robust enough to use in distillation." 


John Hart - 00:09:49 

So we actually engaged in a testing program that took longer than a year, and worked very closely with Leybold to develop the proper setup for the use of that turbo molecular pump in distillation. And I mean, just to give you an example, some of our early work was done with distilling epoxy resins, which are notoriously hard on the vacuum pumps. 


John Hart - 00:10:22 

But it turned out the pump ended up being pretty robust. And we introduced that into the industry. And absolutely, we're the first company to introduce the turbo molecular pump. And I think in general, the folks in the cannabis and hemp sectors like the turbo molecular pump. Like anything, any piece of vacuum equipment, it's got its pros and cons. But we're big fans of the turbo pump. 


Jason Showard - 00:10:48 

Yeah, I can certainly personally attest to the fact that you guys killed it on, you know, R&Ding that turbo. I had a counterpart I used to work with that we would be constantly doing battle about how hard to run things because I wanted to go easy on that turbo, and then I would leave for a couple of days and come back. And I know that it got tortured. So we actually went so far as to take the system apart and look in there, and you could see distillate built up on the blades of the turbo, which was killing me. But the thing just kept working. So well done on your R&D. 


John Hart - 00:11:23 

Yeah, no, it ended up being robust enough. I mean, we've also tried to get more focused on low temperature chillers and cold trap technologies to try and preclude the contaminants condensing into the turbo pump. 


Jason Showard - 00:11:42 

Yeah, that would be ideal. 


John Hart - 00:11:44 

Yeah. No, it is a constant battle. I mean the nature of the terpenoids in particular, they're good carrier molecules for some of the heavier or higher molecular weight molecules in oil extract. And these terpenoids are really tough to condense in the cold trap. You have to get to extremely low temperatures to achieve that. Maybe even as low as -100 degrees Celsius. But I mean, we went into it with knowledge that the folks who are using liquid nitrogen cold traps were tremendously successful in keeping their vacuum systems clean. 


John Hart - 00:12:26 

So we know if you get down to about -120 C, you're going to be running clean vacuuming equipment. 


Jason Showard - 00:12:35 

All right. That's good info. We'll jump into that in a little bit here when we get to the technical section. But you piqued my interest on a couple of things that you mentioned. Specifically your ethanol recovery and your decarb units that you've released for the ethanol recovery. Is that a system to recover all of the ethanol used in extraction, or is that specifically to get the residual ethanol out of your crude oil? 


John Hart - 00:13:00 

No, that's to recover the ethanol that's being used for ethanol extraction. 


Jason Showard - 00:13:07 

Okay, so all of it. 


John Hart - 00:13:08 

Yeah, all of it. All of it. And unlike many of our competitors, we are using a really, a fairly powerful vacuum pump on the system. You know, having said that, we typically like to see our clients run that system, maybe around 200 millimeters of mercury. Whereas that vacuum pump will easily take them down to one millimeters of mercury. 


John Hart - 00:13:31 

But at 200 millimeters, it operates pretty well. And when we designed the initial system, our target was 50 liters per our processing rate. And when we tested in our own facility, we saw that the system had so many features that were overkill that we were able to run the system at 200 liters per hour. So it's a robust system. 


Jason Showard - 00:13:58 

Wow, that is fantastic. If somebody wants to look that up on your website, what do you call that one? 


John Hart - 00:14:02 

It's a falling film/rolled film system, but it's probably indicated on the website under ethanol distillation. But it's a nifty little unit. I mean, "a little unit", it's being a two-stage unit, it's shall I say, bigger than most of the falling film and rising film units that you see out there. But like I said, the intent was to get that ethanol content to a low enough level that we could process the oil in our short path units. 


Jason Showard - 00:14:33 

So now from that stage, you mentioned decarb units. Do your units, is it a modular setup where you can put your decarb unit after this ethanol recovery unit? 


John Hart - 00:14:44 

Yeah, the decarb unit itself is a pretty independent unit with its own control enclosure. The only thing that I would caution anybody about, that's dealing with both ethanol, and let's say the de-ethylated oil, is ethanol, handling ethanol has to be done in a class one, division two electrical environment. Which, you know, is essentially an explosion proof environment. So the decarb unit itself is not really made in an explosion proof fashion. We can, but, you know, again, it's better to put your decarb unit and your short path unit outside of your classified zone. 


John Hart - 00:15:30 

And, you know, again, it's just a function of the equipment you use. For example, the turbo molecular pump, they don't make a class one, division two version of the turbo molecular pump. 


Jason Showard - 00:15:42 

Gotcha. Yeah. And it costs more money to build those C1D2 zones anyway. So if you can keep that as small as possible, you're going to end up building your lab in a more efficient manner. 


John Hart - 00:15:51 

Yeah, exactly. And if you've got open space, and you've got one space in that open space designated C1D2, then I think the, if I remember National Electric Code, if you get 15 feet beyond the classified zone, then you're outside the classified zone. So, you know, again, distance always helps when it comes to potential of flammable or explosive vapors. 


Jason Showard - 00:16:17 

All right. Interesting. What's the best selling item that you sell into the cannabis market specifically out of your offerings? 


John Hart - 00:16:25 

OK, so we sell a pretty broad spectrum of units. But if I had to pick any one unit, that seems to be a favorite, that would be the KD10 unit. Either in the single-stage or two-stage version. But the single-stage is a real workhorse. It's very easy to use. It's you know, everything is pretty much fully integrated into the skid, and we find our customers really like that unit. 


Jason Showard - 00:16:55 

All right. Yeah, I can agree with that one. I've seen them in use and had a chance to play with them. My original unit that I got from you guys was a Mini 5, that by the time we got done strapping extras on to it, it was almost KD6. And then I've had a chance to play with a friendly labs, KD10 for a little while. And that thing's a fantastic unit. It's beautiful. I love it. 


John Hart - 00:17:20 

Yeah. I mean, even our, the company that does most of our installs out in California, they look at the KD10 and they've told me it's a pleasure to install those units because they're so functional. 


Jason Showard - 00:17:35 

Getting a little bit more into the technical side of things here. I like to listen to podcasts kind of when my hands are full or I'm driving or riding a bike or just doing something where I can't watch video or look at pictures. And I think it's pretty common amongst most podcast listeners. So I try to cater to that audience. What's going on inside your machines is certainly not easy to describe without the visual aids. But can you do your best to describe a KD10 and what's happening inside that machine while it's distilling? 


John Hart - 00:18:04 

Yeah, sure. I mean, I frequently will describe the operation inside the evaporator itself as a very, very low-density fog or cloud. So you've got this heating surface that's boiling off these molecules, you know, pretty rapidly. And then you've got a cooling surface, you know, basically about an inch away from that heating surface. And that intermittent space is kind of a nebulae. It's consisting of this fog of molecules. And the condensing element will be condensing the vapor into the liquid state. 


John Hart - 00:18:44 

And that's creating a pressure drop that's encouraging all those molecules to flow towards the condenser and then ultimately down into the evaporator. So, you know, you can just kind of picture yourself in a fog and seeing that fog move in one direction, and get into a clear zone when the molecules condense. 


Jason Showard - 00:19:09 

All right, you mentioned something on that, that I found kind of interesting, which is the low pressure being created when those molecules re-condense. Now, with my experience, when you have things evaporating that's going to raise your vacuum level or create pressure. And then when they are being re-condensed, that's going to lower it back down again. Now, one of the big reasons that we do the terpene strips on these machines is to make sure that our vacuum can get to a low enough level, to where we don't have to expose too much heat moving forward to distill the cannabinoids. So that said, when you're creating this pressure and then reducing that pressure by re-condensing, is it a zero-sum game there where you have reduced it by exactly the same amount that you have created? Or if there's stuff that doesn't get re-condensed, have you effectively raised your pressure levels inside your machine? 


John Hart - 00:20:14 

For sure, if you aren't going to a low enough temperature to condense the materials, then you are going to create more pressure than you would like. And that's a phenomena that you see more in relation to a terpenoid strip, for example. And it's a little challenging because if you look at the lighter terpenoids, for example, beta-myrcene is an example I often use. Beta-myrcene is a wonderful odor terpene. It's got a boiling point of roughly 150 degrees Celsius. 


John Hart - 00:20:57 

But if you're trying to run your evaporator at a, let's say, a level of .005 millimeters of mercury, which would be short path level. At that vacuum or absolute pressure, the boiling point of the beta-myrcene falls from 150 down to -50. OK? So if your cold trap isn't operating somewhere below -50, you're going to have a hard time condensing that beta-myrcene. And the thing people also have to recognize is, boiling point is just a reference on a curve. 


John Hart - 00:21:42 

So there's an equation called the Antoine equation, which is used to develop what's called a partial pressure curve. And if you look at this partial pressure curve of let's say beta-myrcene. Or, you know, for that example, let's shift gears and think about the partial pressure curve of water. Because this is a good illustration to recognize. Boiling point is just a reference point. So, you know, water boils at 212 Fahrenheit. Right? 


John Hart - 00:22:13 

Or let's say 202 if you're in Denver, Colorado. OK? So, but the point is in Los Angeles, on a nice sunny day when the temperature may be 70 degrees Fahrenheit. A puddle of water will still evaporate. And that's because the partial pressure of water is such that some molecules will attain a high enough energy to jump into the vapor state. So that's why I say if the boiling point of beta-myrcene at .005 millimeters of mercury is -50, you really need to be down to a level of about -100 degrees Celsius, to truly get down to the point where the partial pressure curve has no implication on things. In other words, you're condensing effectively, virtually all of your vapor. 


Jason Showard - 00:23:10 

Okay along the lines of condensing effectively. I spend a lot of time reading on a lot of the forums. There's been a lot of stuff posted that, you know, some of these folks are chemists. Some of these folks have just put the work in, and know how to make things work right for them. So there's a lot of information out there. Not all of it is correct. And sometimes by design, with all the secrecy in the industry. 


Jason Showard - 00:23:42 

So what I've been kind of interested in lately is your Delta T between your evaporator body wall and your condenser. So talk to me a little bit about what your ideal delta is there, to get things to condense the way you want. To be able to sure that you are condensing everything that you're evaporating, and to make sure that, you know, you're maintaining the pressures you're looking for inside of your machine. 


John Hart - 00:24:10 

OK, so the challenge here is there's really no fixed value for a Delta T. I mean, it's really a function of what's the composition of the material you're trying to distill. OK, so if you're dealing with an oil that's predominantly cannabinoid based oil, i.e. You've removed virtually all of your terpenoids OK. So let's say you might be running your evaporator 160 degrees Celsius. Generally speaking, you're going to be running your condenser at somewhere in this gap between 80C and 100C. And that would be let's say at a vacuum level of again five microns, .005 millimeters of mercury. 


John Hart - 00:24:55 

So you've got, I'm saying 80 degrees might constitute the low point because you've got to stay above the melting point of the cannabinoids. And so if you get below, let's say, 80 degrees C, the viscosity associated with, you know, the cannabinoids on the condensing elements starts to become an issue. So you generally want to stay above that melt point condition. The melt point's going to be somewhere around 50 to 60 degrees Celsius, the theoretical melt point. 


John Hart - 00:25:29 

So staying above 80 is pretty important. Likewise, you don't want to go above 100 C, because if you're running your condenser hotter than 100 C and you know, you might be able to marginally get it hotter than 100 C, but the problem will become you aren't going to capture all your cannabinoids. You've got to get those condensed. So you have to stay in a good zone to achieve the proper level. A lot of our customers actually like to run at 100 C because they feel that gives them the best cannabinoid for the marketplace. 


Jason Showard - 00:26:09 

Yeah, I'm certainly a fan of the 100 C. A little tip of the hat here to Breaking Dabs and his hot condenser tech, which really changed the game quite a bit. He's one of the fellows that contributes on the Future 4200 forum. And really did help everybody out a lot in the beginning. Because originally people were running their condenser a lot lower, and that was condensing. But then a lot of these, you know viscous cannabinoids were getting stuck on this condenser, and remaining in the hot evaporator body for way too long. 


Jason Showard - 00:26:44 

So that increased temperature helps them evacuate the condenser, which I think is a big one. And then also allows you to really condense the best quality cannabinoids with very little of anything that you don't want getting condensed on there. 


John Hart - 00:27:04 

Yeah, I always try and encourage our customers to plan their campaigns. And, you know, the best way to plan a campaign is to know your starting point, the composition of your starting material. You know, unfortunately, I would say most of our customers don't have the GC or HPLC equipment to define their feed material. And they're kind of flying by instruments. But yeah, I mean, 100 degrees is, these days, I would say that's probably about the most common condenser temperature operating point. 


Jason Showard - 00:27:40 

I will say if I've done an ineffective terp strip or if something possibly went a little bit awry in terp strip or I find myself with more remaining in my product than I would like at that stage. Sometimes I'll kick my condenser up to 105 or 110 just to make sure that I'm blowing everything into the cold traps and not condensing any of the stuff that I don't want there. If I find myself with a source material that is not where I wanted it to be originally. 


John Hart - 00:28:13 

Yeah, no, that's a reasonable approach. And like I said, planning a campaign based on as much information you have available to start it with is really important. Because the melt points, you need to know those. And you also need to keep track of where the boiling point is of these various compounds throughout the distillation process. And, you know, again, recognizing boiling point is a variable. It's a function of temperature and pressure conditions. 


John Hart - 00:28:49 

So you've definitely got to keep track of these issues. And I mean, just something as simple as setting the evaporator 160 degrees Celsius. You know, the boiling point of CBD is actually 438 degrees Celsius. So it's the fact that you've got that high vacuum condition that's bringing that boiling point way, way down to actually the boiling point ends up being about 134 degrees Celsius, if you're running a vacuum level of .005 millimeters mercury in conjunction with 160 degree evaporator. 


Jason Showard - 00:29:30 

Yeah, I can't stress enough the importance of keeping your vacuum system healthy. There's a lot of folks out there that really punish their vacuum system in order to get more throughput, and run faster and run harder and harder, because you can crank out more final product like that. But jeopardizing your vacuum system in the long run is going to end up making you have a higher vacuum, and making you have to run hotter, and expose your future material to more temperature and thermal degradation and eventually going to slow you down anyway. So it's, you know, it's really important to keep that vacuum system healthy. 


John Hart - 00:30:11 

Yeah. I mean, for sure, of all of the components on the distillation unit, I would say probably the vacuum system requires more maintenance than the other elements. Regular things like regular oil changes are really, really helpful to your vacuum pump. 


Jason Showard - 00:30:30 

Absolutely. Yeah. Every time I terp strip, I will do a flush. So basically a double oil change. A flush and then a new oil in there just to make sure that it is as healthy as possible and gets all those terpenes that made their way by the condensers and the cold traps out of there. 


John Hart - 00:30:47 

That's a good practice. 


Jason Showard - 00:30:49 

Let's say your goal is to get absolutely everything out of the vapor stream before it goes into your vacuum system and you're not trying to use one of your two cold traps as a theoretical plate, but you just want to remove the maximum amount. Is your best bet there then to just get both cold traps as absolutely as low as you can get them? Or is there anything to be said for having staged temperatures to be able to more effectively remove more things from the vapor stream? 


John Hart - 00:31:17 

Well, to some extent that depends on, you know, what you're distilling. But if you're doing purely a terpenoid strip, and let's say you're trying to do that strip at an atmospheric equivalent temperature, let's say below 300 degrees Celsius. Then I would say run your cold traps, both of them as cold as possible. But we have to remember that some of these high molecular weight terpenoids, they will be solids at cold temperatures. So off the top of my head, I can't remember the name of some of the high molecular weight terpenoids, but you could conceivably plug up your condensing element on the first cold trap. If you're getting some of these high molecular weight terpenoids that will condense and they'll solidify. 


Jason Showard - 00:32:20 

OK, so that makes sense why you see a lot of staged temperatures on these machines with the double trap. 


John Hart - 00:32:28 

Yeah, I think a number of clients have, I think the terpenoid they've encountered is phytol. If my memory serves me correctly. And again, as I recall, phytol has a very, very high boiling point as a terpenoid. It's above 300 degrees Celsius. And so conceivably a phytol molecule, I would expect to condense on a cold trap. Even under high vacuum conditions. 


Jason Showard - 00:32:57 

Gotcha. Yeah, with the gear that I was working with, I had the capabilities of getting trap number one down to -40 and trap number two down to -60. I would have liked to get it colder and possibly gone to the liquid nitrogen or something to that effect. But really, -40, -60 was doing the trick for me. And then, you know, you're still going to end up having some blow by into your vacuum pump. But, you know, that's why you change the oil. It may not be a bad idea to mention here, if you're doing your terpene strip, making sure that your turbo is not between your vacuum pump and your system during that terpene strip, really helps to not contaminate the turbo. 


John Hart - 00:33:39 

Absolutely. And on virtually all of our systems for the cannabis and hemp sector, we build in bypass valves so you can bypass the turbo pump simply by adjusting your valves. 


Jason Showard - 00:33:58 

All right. That's a great feature to have. I used to have to disassemble the thing and put it back together each time. And that's never any fun. As far as moving on from there. Let's talk about wipers versus rollers. I know a lot of your machines use rollers and some of the competitors that are out there use wipers. Talk to me about the difference between that and why you've chosen to go that route for your stuff. 


John Hart - 00:34:23 

Yeah, I mean, a lot of our technology was kind of inherited technology and the predecessor, well Chemtech, acquired the distillation business from UIC Inc, another Joliet corporation. But UIC Inc had actually acquired the business and technology from Leybold Vacuum. 


John Hart - 00:34:46 

OK, so we tend to follow the direction of the Leybold folks, and they had actually had a patent on wiper rollers. As I recall, I think that patent was occurring like in the 1960s era. And they had done really, really significant testing in their facility to determine that the rollers seemed to be a more effective methodology of creating the thin film. And they liked the rollers because very, very easy maintenance. The rotational speed of the wiper basket controlled the centrifugal force of the rollers against the evaporator wall, thereby controlling the film thickness, which again is something you want to do. And the other aspect that people tend to forget about is the fact that the rollers will kind of take on the same temperature as the evaporator or very close therein. And so they operate as an extended evaporator surface, as well as creating some agitation within the evaporator. 


John Hart - 00:36:05 

So rollers, we feel, are going to accommodate about 90% of the applications that we typically look at. And, you know, certainly I haven't seen anything in the cannabis field that a roller wouldn't perform better than a blade. 


Jason Showard - 00:36:22 

Yeah, I didn't even consider that extended surface area. That's huge. That's a big deal. 


John Hart - 00:36:28 

Yeah, no, absolutely. And like I said, I mean there, it's very easy to change rollers. And they're really robust, particularly in the cannabis field. I mean, if you're distilling epoxy resins, they aren't. You have to pay a little more attention. But definitely, other than fixed blade type of wiper systems, the other wiper systems that have hinged blades, they're kind of high maintenance items. And you never know if the hinge is really doing the job it's supposed to. 


Jason Showard - 00:37:01 

Yeah, I worked with a wiper for a couple of years and it was not fun. You actually have to get in there, take the whole evaporator body apart, take those wipers out because they'll break. I believe is it PTFE that they're typically made of? Or some type of a plastic. And these things will break. They will recede. If you accidentally don't filter your material well enough and you're wiping some, you know, some filtration media or anything that could be in your oil due to a lack of filtration, wiping that around in there, you can actually grind off a little bit of these wipers. And then your thin film gets a little bit thicker as they recede. And I love the idea of the rollers because that centrifugal force will always bring them right out to the wall. 


John Hart - 00:37:55 

Yeah, I mean, I'm a firm believer in the rollers. Like I said, they'll accommodate the vast majority of the distillation circumstances. But, you know, again, we've used wipers, fixed wipers. Well, actually adjustable wipers on some really, really nasty crude products where we've built pilot plants for, you know, for our petroleum clients for the sole purpose of distilling stuff you wouldn't think you'd distill. And in that case, the viscosity is so high that you simply have to use a wiper blade to move the material. 


Jason Showard - 00:38:39 

Okay. That makes sense. So you heard it here, folks. Cannabis applications, it's all about that roller. 


John Hart - 00:38:47 

There you go. 


Jason Showard - 00:38:48 

Moving on from there. We mentioned turbos earlier today. The turbo molecular pump from Leybold prior to that. And still with a lot of the Chinese equipment that's out there, you're finding a lot of diffusion pumps. I'd like to pick apart a little bit what the difference is and how these different tools work and why you may use one over the other. 


John Hart - 00:39:10 

Yeah, sure. And again, I mean, we kind of crossed that bridge five or six years ago because the units that we were selling, some of the initial units in the cannabis sector actually had oil diffusion pumps. Because we hadn't yet approved the use of the turbo pump. And the oil diffused pump, it can be a very reliable pump, but you have to remember that's a wet pump as opposed to the turbo molecular pump is a dry pump. 


John Hart - 00:39:40 

So being a wet pump, it uses a fluid. And if the fluid becomes contaminated, then just like your rotary vein pump, you've got to change the fluid. And so we typically found that the clients using the oil diffusion pump, you know, they'd have to frequently change the oil as it becomes contaminated. One interesting aspect of the oil diffusion pump is it has no moving parts. So that's a good thing. And the way it works is, there's a heater at the bottom of the oil diffusion pump that heats the oil above the boiling point of the oil. 


John Hart - 00:40:33 

And so the oil is kind of going up, you know, you might think of it like a volcano. It's going up this tube where it hits some deflectors that create a very uniform conical molecular stream. And the molecules are, they're coming out of this conical area at a supersonic speed. So, you know, it's a little bit like an umbrella with rainfall and so heavy, it's creating a curtain all around the outside of the umbrella. 


John Hart - 00:41:08 

But if the elements that create this curtain, if they get a little bit plugged up from contaminants, then the effectiveness of that curtain will diminish. And also, you have to remember that the outside of the oil diffusion pump does have to be cooled. And the smaller oil diffusion pumps are air cooled. But the larger oil diffusion pumps generally have a cooling coils around the outside, which re-condenses these hot vapors, so that they can undergo that cycle once again. 


John Hart - 00:41:43 

The thing that I think most of our customers appreciate the turbo molecular pump for, is the fact that it spools up so fast. If you're using an oil diffusion pump on a distillation unit, it may take between 15 and 60 minutes before you get to the low vacuum level that you want to get to. I mean, remember, you've got to get this oil heated up to a very, very hot state. It's going to do some degassing during that period. And then when it finally kicks on, you will start to see the temperature go down. 


John Hart - 00:42:20 

But like I said, that's probably going to take at least 15 minutes and it may take as long as 60 Minutes to achieve the vacuum you want. Whereas with a turbo molecular pump, you're going to spool that puppy up within, usually it's within two minutes. 


Jason Showard - 00:42:34 

So both of those can have their issues. One with the turbo pump, you can have issues with too high of a vacuum, and too many molecules hitting that pump. And then with the diffusion pumps there can be issues with not having your vacuum low enough when you fire those up as well. Can you break those down for us? 


John Hart - 00:42:55 

Yeah. I mean, both of these pumps, you want to have a fairly low vacuum, but certainly the oil diffusion pump is a little bit more sensitive to achieving that low vacuum. Let me kind of go back a moment to your comments on the turbo pump. That's the very reason that we built the bypass system into the turbo, is to make it really easy for the customers to protect that turbo. So if they're experiencing a scenario where there's potential for molecules contaminating the turbo pump, that's when they want to close the valve to the turbo, open the valve to the backing pump so that they protect that pump. 


Jason Showard - 00:43:43 

So what happens inside that turbo? Let's say that you don't have the correct conditions, the correct vacuum conditions, and you fire that turbo up when there is not a deep enough vacuum in your system. What actually happens? Why doesn't that work well, with the turbo? 


John Hart - 00:44:01 

You know, it's just not going to be able to increase the vacuum level that you want to increase it to. But I will say that the turbo is actually a really robust pump, and it's going to be very forgiving. Whereas the oil diffusion pump isn't nearly as forgiving. 


John Hart - 00:44:16 

So if you turn on your turbo pump at, let's say, a less than optimal vacuum. I mean, I'm trying to think they do have an interlock there in the turbo pump that may not allow it to come on. But, you know, turbo pumps in industry in general are sometimes used, you know, like a let's say, a GC mass spec uses a turbo pump. And, you know, some of the smaller GC mass specs, as I recall, don't actually have backing pumps for the turbo pump. 


John Hart - 00:44:53 

The larger ones certainly do. Our laboratory model has a backing pump, but it also has a turbo molecular pump. So turbos are capable of a lot of things. And you might seen, picture the inside of that turbo pump as being a little bit like a jet engine with all of these rotor and stator blades that are used to increase that pressure drop between the front of the turbo pump and the discharge of the turbo pump. But they're really robust pumps. 


Jason Showard - 00:45:25 

Yeah, I can't agree more. Definitely in my mind, turbo hands down over a diff pump if you have the choice out there. Moving along from vacuum and into system design here for some of your machines. So far we've touched on the idea of multi-stage machines, but we've been primarily talking about single-stage machines. So that said, why would one use a multi-stage machine? Can you give us the rundown of how you would approach distilling cannabis with a multi-stage? 


John Hart - 00:46:03 

Yeah, I would if I were doing it, I would always choose a multiple stage machine. Because we tend to think of distilling these extracted oils, you're kind of dealing with three groups of molecules. You've got your terpenoids, you've got your cannabinoids. And you've also got the triglycerides and waxes. OK, so the first stage of that machine would be dedicated to separating the terpenoids. Or, you know, if you're using a single-stage machine, you're going to do three passes. 


John Hart - 00:46:37 

But with a three-stage machine, you do one pass. You keep your products in the liquid state throughout the process. And what you're collecting off of the distillate on the third stage, is probably going to be the product you're taking to market. So we're talking about removing terpenoids on the first stage or first pass. The second stage would be dedicated to separating the cannabinoids from the triglycerides and waxes so your distillate would be a cannabinoid rich distillate. 


John Hart - 00:47:13 

And that third stage is kind of a polishing stage where you're trying to further concentrate your cannabinoids up to, you know, in the folks with dealing with THC, typically are reaching 95% plus in terms of the purity of their concentrated distillate. But I'd always, like at Chemtech, we have three distillation units and they're all three-stage units, because that's going to be the most versatile. And the amount of handling you're going to do in a single-stage is considerable. Especially if the, let's say the cannabinoids are solidifying in a container that has to be remelted and recharged back into a single stage. 


Jason Showard - 00:48:03 

Oh, yeah, I can attest to that. That's how I got my start and it is a headache. And there's plenty of waste, and it is less than fun. But, you know, that's the nature of the game when you have a one stage machine, and it's a heck of a lot better than having a little desktop short path machine. So, you know, count your blessings, right? 


John Hart - 00:48:24 

Yeah. And if you're in a GMP environment, you know, a multiple stage system is definitely the way to go. 


Jason Showard - 00:48:31 

Absolutely. You've piqued a bunch of interesting questions for me while you were describing that. I guess one we'll start with the configuration of what feeds into what stage. So what you just described was terpenoid strip happening on the first stage. And then moving on to that, you're separating your distillate from your waxes and triglycerides. Now, from that point, if you go over into the third stage, and let's say that you don't want to repolish your distillate, but instead you want that third stage to rerun your residual from stage two, can you easily configure it to have it do that? 


John Hart - 00:49:20 

Yeah, most of the systems that we're building right now that are multiple stage systems, on the downstream of the first stage and downstream of the second stage, we have them piped. So there are valves in the system. So what do I mean by that? I mean that on the first stage downstream of the pumps for residue and distillate, you have three-way valves that will allow you to send either the distillate or the residue to the second stage. And the third, the same would apply on the second to third stage. 


John Hart - 00:49:56 

You can set your valves so that you can send either the residue or distillate to the third stage. But we've also found that different customers of ours have different philosophies. I mean, we had one client that was very, very effective in the industry. They were doing THC, and he wanted to pull a light distillate on both the second and the third stage. So he was doing exactly what you indicated. 


John Hart - 00:50:29 

The residue from the second stage went over to the third stage, and he was distillate off both the second and third stages. That was a THC rich distillate. And he felt that gave him the highest concentration that he could get to market with as quick as possible. 


Jason Showard - 00:50:46 

Yeah, absolutely. Because a lot of times people will rerun their residue. And I've always found that I spent more time rerunning my residue than I would spend rerunning my distillate. I feel like if you do everything up into that point correctly, you can get away with a one pass on your distillate pretty regularly. And I was hitting, you know, 99% total cannabinoids very regularly just, without a polish pass. So that's why I'm more interested in putting that residue back through on that third stage? 


John Hart - 00:51:17 

Yeah, I think that's certainly the case with the THC, where the feed materials are, you know, very, very rich in THC in the oil. Maybe a little more problematic with CBD, where the CBD concentration in the oil isn't quite as high as it is on the THC side. But like I said, we try and build that selectivity into the equipment. So it's as easy as possible for the customer to switch back and forth as he may feel necessary. 


Jason Showard - 00:51:52 

Great. I love it. The more options better. The next question that kind of popped up when you were describing that three-stage machine, was on the first pass of the terpenoid removal. Oftentimes you're going to be, as we discussed earlier in the interview, sometimes you're going to be creating more pressure by evaporating those, or vaporizing those terpenoids, than you can take out by re-condensing those terpenoids. Especially if they're blown through all the way to your cold traps. 


Jason Showard - 00:52:25 

That said, do you ever run into problems with this affecting your vacuum and the rest of the system, or do you have your own very specific vacuum systems for each stage? 


John Hart - 00:52:42 

Yeah, that's a good question, because if you're doing a terpenoid strip on the first stage, to avoid damaging your vacuum system, and incidentally, typically we don't include a molecular pump on the first stage. Because we realize that first stage is going to see a lot of light molecules. And we'd prefer to just use a rotary vein pump on that first stage. But I would also kind of comment that ideally, if you're doing a terpenoid strip, you want to stay in this range one to ten millimeters of mercury. 


John Hart - 00:53:18 

And again, it's got to do with your ability to condense those molecules. Because if you're running higher vacuums, as I kind of alluded to earlier, you're going to have to be running your condenser in cold trap at a lot lower temperature. So if you control that vacuum in between this one to ten millimeters or, you know, sometimes even higher, you're going to make sure that you protect your vacuum equipment, and you're able to condense your terpenoids. 


John Hart - 00:53:49 

And this system comes equipped with bleed valves so you can bleed air into your vacuum system. And actually, purposely destroy vacuum. So that you get to a good vacuum level for terpenoid strips. And terpenoids are relatively easy to distill. And we don't worry too much about the pressure drop other than the fact that we don't want to achieve too high a vacuum if we're doing that terpenoid strip. 


Jason Showard - 00:54:22 

OK, the other question I had regarding the various stages is, again, specific to that first stage. On your machines, is there still the internal condenser that runs right up the center of the evaporator body in addition to the external condenser? Or is the external condenser the only one used to collect the distilled product? 


John Hart - 00:54:48 

OK, let me make a few general comments here. We manufacture systems that have conventional wiped film evaporators with external condensers and cold traps. As well as systems that contain short path evaporators on the first stage, which has the internal condenser. But what we found out in the cannabis sector is that having a wiped film with an external condenser, i.e. No internal condenser was a little bit risky. And I say risky because you couldn't assure that the high molecular boiling point terpenoids would be removed like phytol. And so the only way to absolutely ensure that you could remove these high boiling point terpenoids was to put a short path evaporator on the first stage. 


John Hart - 00:55:50 

Again, I'm saying you still want to control very carefully the pressure you operate the first stage at. And if we knew, you know, if your client knew that he didn't have any of the heavier molecular weight terpenoids, then I would say, yeah, he'd be an ideal candidate for the wiped film with the external condenser. Because the advantage they're in is that the condenser surface area in that case is typically going to be five times greater than the surface area of an internal condenser. 


John Hart - 00:56:26 

So you get a lot more condensing surface area and your likelihood of condensing your terpenoids, and of protecting your vacuum system is much greater. But, you know, again, I mean, it's just a function of building a general purpose machine that can accommodate the worst conditions. Those conditions are being able to knock down or distill on the first stage molecules like the phytol, which does have a very, very high molecular weight and boiling point. 


Jason Showard - 00:56:58 

OK, thank you for breaking that one down for us. Just, you know, to wrap things up a little bit here, what are you personally most excited about in regard to the future of the industry and your equipment being used in it? 


John Hart - 00:57:13 

Yeah, that's an interesting question, because we've got a number of different research projects. Some I can talk about, some I can't talk about because we're hoping to get some patents. But we are working on some patented products that we think will significantly reduce the entry level capital for the industry if we're successful in these projects. So we're right on the cusp of applying for one particular patent. But we're also looking at industry sensitive things like, you know, the CBD guys have a real problem with residual THC levels in concentrated CBD. 


John Hart - 00:57:59 

So we're looking at a couple of different methods in relation to derivatizing that THC to convert it to CBN or maybe some other biproduct. And in that regard, we're using a couple of different techniques, you know, including a fixed bed, tubular reactors that would be continuous reacting products. So there's a lot of interesting things that we're looking at there. And, you know, essentially we've got a couple of engineers that are almost fully dedicated to these R&D projects. 


John Hart - 00:58:41 

So we're hoping to see some interesting stuff. But, you know, also trying to work on some of the more conventional methodology that the industry already has. I mean, for example, the freezing methodology used to make CBD isolates. We're trying to see if we can improve that process and make it a more continuous process. But, you know, all these things, it takes time and equipment. 


John Hart - 00:59:14 

And, you know, fortunately, we're pretty good at designing equipment, and we have good, you know, our own chemical laboratory. We're equipped to measure terpenoids and cannabinoids in our GC mass spec and HPLC equipment. 


Jason Showard - 00:59:30 

That's great. Yeah. You find plenty of these people that are in a similar situation to you guys, where you already had equipment that worked well for the industry. This industry started buying it. There's plenty of people that were in that scenario that just cashed in on it and said, "Great, we've got more customers." So I always love hearing, like when you guys embrace it and start innovating for it. That I mean, that makes my heart happy. 


John Hart - 00:59:56 

Yeah, I mean, because a lot of the work that we've historically done has been the design of, especially pilot plants, that may or may not have included the distillation elements. It gives us perhaps a little bit broader overview of the chemical process side of things. And, you know, again, that's where most of our R&D efforts are geared right now, into utilizing our process design competence. 


Jason Showard - 01:00:29 

That's fantastic. If people want to get a hold of you to purchase some equipment or see if your equipment will work well for their scenario. What's the best way they can reach out? 


John Hart - 01:00:41 

Either by email, and the website has, Chemtech Services website, which is www.chemtechservicesinc.com, has an area where they can reach out. But I'm usually pretty good at email and I also take a lot of telephone calls. I mean, it's not unusual for me to be the last one to leave the office. So I get, and you know, California time is a little different from Chicago time. So I get a lot of the late calls where somebody has a problem. And I put on my tech service hat. 


Jason Showard - 01:01:16 

Well, that's the story of any good founder. 


John Hart - 01:01:18 

Right. Right. 


Jason Showard - 01:01:19 

John Hart, thank you so much for coming on the show. It was great to have you and pick your brain on all this fun technical stuff. 


John Hart - 01:01:25 

Yeah, a lot of fun. I enjoyed it. And hopefully your listening clientele will enjoy hearing some of the podcast. Maybe I got a little bit boring on some aspects. But anyway, that's the problem - 


Jason Showard - 01:01:42 

That's what this show's designed for. This show is designed for people that actually want to hear all of this weird, dry, boring stuff. 


John Hart - 01:01:48 

There you go. There you go. 


Jason Showard - 01:01:52 

All right. Well, thank you, sir. We'll talk to you soon I hope. 


John Hart - 01:01:55 

OK, great. Thanks, Jason. 


Jason Showard - 01:01:57 

All right. Thanks again to John for joining us today. He certainly knows his way around designing some fantastic processing and distillation equipment. If you want to get a hold of John or the rest of the team over at Chemtech to see which of their machines is best suited for your operation, you can reach out via email info@chemtechservicesinc.com. That's info@chemtechservicesinc.com or get hold of them by telephone 815 838 4800. There's always someone full of knowledge and a willingness to help you out on the other end of the line. 


Jason Showard - 01:02:31 

As always, if you want to hear about something specific on this show, let me know. Email me jason@modernextractor.com. Make sure to follow the show on Instagram at the_modern_extractor. If you guys like the show, please subscribe and give us a rating. The more subscribers and better ratings we get, the better guests I can book for you here in the future. Stay tuned for next week. It's the episode we've all been waiting for. All the hard work that went into getting us this far in the process, will finally pay off and we'll be able to make some saleable product. Time to crank out some nice goldies with our guest, Jay Horton. 


Jason Showard - 01:03:04 

Jay is the founder of Genovations and also the man that gave me my first push down this distillation rabbit hole. Jay can often be found flying around the world, installing and training on Chemtech systems, as well as consulting for almost anything you can want to do in a cannabis lab. He's an absolute veteran to the industry, and we'll get deep into the SOPs of cannabinoid distillation, including the different approaches to distilling CBD versus THC. I've really been waiting for this one. 


Jason Showard - 01:03:29 

A big thanks goes out to Yzaura Vanegas for handling business on the show's Social Media. Thanks again to everybody for tuning in to The Modern Extractor. New episodes are out every Tuesday. I'm Jason Showard. Let's talk soon. 


Show artwork for The Modern Extractor

About the Podcast

The Modern Extractor
Professional extractors talk extraction!
The Modern Extractor is a podcast about the processes, equipment, and science found inside a cannabis extraction laboratory. Season one focuses on the process of ethanol extraction and post processing into either distillate or isolate. Season two focuses on hydrocarbon extraction and the craft concentrates that it can produce. Each episode digs deep into a particular stage in the extraction and finishing processes, and we discuss the various approaches with industry expert guests. Episodes are released in an order which follows the work flow through a lab, following material closely through the process from cultivar to concentrate.