Episode 5

Published on:

19th Jan 2021

S1 E05 - Solvent Recovery In Cannabis Extraction

Learn the ins and outs of solvent recovery from Ray Van Lenten, founder and CTO of Trusteel. Trusteel's falling film evaporators completely revolutionized the solvent recovery game in 2018. Since then they've released an end to end suite of equipment to take you all the way through the extraction and distillation processes. Hear how Trusteel's gear can help break your lab's bottlenecks and streamline your operation. Ray gives us some awesome tips and tricks to speed you up on the falling film that definitely aren't in the owner's manual. Hear his SOPs for solvent recovery on the Autovap line, and his SOPs for decarboxylation in the DR-10. We've got times, temperatures, pressures, and feed rates on all the gear, and a special bonus at the end of the episode... METAL!


Jason Showard - 00:00:11 

Hello and welcome to episode five of The Modern Extractor. The podcast that 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 - 00:00:40 

Last week on The Modern Extractor, we had Maria Peterson on from Scott Laboratories to help us break down the intricacies of filtration. She's my go to filtration expert over at Scott. And with the help of her and Scott products, I've been able to get beautifully filtered extracts for years. Upon listening back to last week's show, it occurred to me that I really didn't mention Buechner filters and vacuum filtration. Probably because my brain somehow blocked it out as a defense mechanism. 


Jason Showard - 00:01:06 

But this is the way things were done for a long time. It's a very slow and miserable process where lots of things can go wrong. There's messes and broken filter papers and the list goes on. It's just not recommended for production scale. But for lab scale, it's not terrible to have one around for experiments. If you're using vacuum filtration or Buechner filters for production, Scott Labs' lenticular will absolutely change your life. Also, upon listening back, I realized that I didn't stress quite enough how important it is to filter while cold. 


Jason Showard - 00:01:35 

I've always tried to make sure that my miscella made its way through the filter before it had a chance to rise above -35 Celsius. Moving on to this week's show, let's catch back up with our material on its way through the lab. We've performed a cold ethanol extraction in a centrifuge, and cold filtered through a lenticular filter. This leaves us with a nicely filtered mix of cannabis oil dissolved in ethanol, which we refer to as tincture or miscella. 


Jason Showard - 00:01:59 

The next stage in the process is almost every extraction operations bottleneck, which is solvent recovery. One of our show's listeners, Tommy Ethanol, hit me up on Future4200 and said that I shouldn't skip over Rotary Evaporators and jump right into falling film evaporation. He's right. I shouldn't. I really wanted to, but I shouldn't. I think rotovaps for solvent recovery fall into a similar category in my mind, as the Buechner filtration I mentioned a few minutes ago. Something we'd all like to forget but are worth mentioning. 


Jason Showard - 00:02:26 

If anything, an understanding of the way things were for so long yesterday, makes us appreciate the way things are today a little bit more. It's worth noting here that it doesn't hurt to have a rotovap around the lab for other purposes. But a roto is definitely not where you want to be using for your primary means of solvent recovery. So let's break one down. A rotary evaporator or rotovap for short, is used to separate the cannabis oil from the solvent used to extract it. 


Jason Showard - 00:02:50 

The material that you'd like to separate is loaded into a glass round-bottom boiling or evaporation flask. The neck of that flask connects and seals to a motor assembly that will rotate it. The flask is held at about a 45 degree angle, with the liquid settling in the bottom side area of the round-bottom. The part of the machine that the flask is attached to, has the ability to be raised or lowered. Which allows for the bottom portion of the boiling flask to be lowered into a heated water bath. 


Jason Showard - 00:03:17 

The rotation causes the miscella inside to fully coat the interior of the flask, creating a thin film on all parts of the flask that aren't covered by the liquid. The liquid, thanks to gravity, constantly stays at the lowest point in the flask. Picture taking a stemless glass of wine, holding it at a 45 degree angle and rotating it. The bulk of the liquid always stays at the lowest point, but the rest of the glass is still coated in a thin layer and reapplied every time the glass passes under the liquid. 


Jason Showard - 00:03:44 

Vacuum is applied to the system. The motor is turned on to rotate the boiling flask and the spinning flask is lowered into the heated water bath. Under heat and vacuum, the ethanol is vaporized and the vapor's drawn towards the vacuum pump. Between the boiling flask and the vacuum pump, is a chilled condensing coil which re-condenses the vaporized ethanol back into a liquid state. The liquid runs down the condensing coil and drips into a collection flask ready to be used for future extraction. 


Jason Showard - 00:04:11 

As the ethanol is removed from the material in the boiling flask, the volume in the flask decreases and it becomes increasingly dark and viscous. The system vacuum can be utilized to suck more miscella into that boiling flask so the process can continue. This dance goes on until you find yourself with enough concentrated material in the boiling flask to warrant disassembling the machine and messily transferring the crude to another vessel. In addition to the slow recovery time, one other slight disadvantage to using rotovaps is the residence time your crude spends at temperature. 


Jason Showard - 00:04:42 

Since transferring out of the boiling flask is cumbersome, the concentrated crude keeps getting more miscella transferred in on top of it and remains at process temperature for extended periods. It isn't until you're done with a whole lot of evaporation, that you eventually dump out your freshly separated crude oil. The temperatures aren't high enough to do any real damage, but I think it's just generally good practice and procedure in the lab to expose your material to as little heat as possible while you're processing. 


Jason Showard - 00:05:07 

So there you have it, Tommy rotovaps not skipped. Hopefully now those of you that haven't had the pleasure of endlessly rotovaping have a better understanding of the solvent recovery landscape in 2018. Across the board, every extraction operation was hitting the same bottleneck of solvent recovery. Labs were just buying more and more rotovaps to have on the production floor. This resulted in more glassware to clean and possibly break. More operators to manage them all. It was a mess. 


Jason Showard - 00:05:33 

So today on the show, I'm very excited to speak to the man that solved the rotovap problem. He drastically changed the solvent recovery game. He's the first person to release a falling film evaporator to the cannabis market. He's the founder and CTO of TruSteel, Ray Van Lenten. Ray, welcome to The Modern Extractor. 


Ray Van Lenten - 00:05:50 

Thank you, Jason. How's it going? 


Jason Showard - 00:05:52 

Pretty good, man. Where are you calling in from today? 


Jason Showard - 00:05:54 

I'm calling in from my home recording studio here in Nevada City, California. 


Jason Showard - 00:05:59 

All right. I'm a little bit further south from you. Down in the Los Angeles area, trying to hunker down a bit and wait this thing out. So tell me a little bit about your humble beginnings. What did the path to starting TruSteel look like for you? 


Ray Van Lenten - 00:06:13 

About 2014-2013, is when I started my extraction journey. And I always found that the thing that I like to do more than actually processing, is scaling things up and finding new ways to do processes. So my chase towards perfecting the equipment and perfecting the process and trying to automate everything is kind of what ultimately led me to starting TruSteel. I'd been doing a lot of [inaudible 00:06:39] work and needed to build a falling film just out of necessity. And once I did build the first prototype, I realized that I really had something and maybe I should change my path in life and start TruSteel. And I'm really glad that I did. 


Jason Showard - 00:06:54 

Right on. What was it that brought you to decide you wanted to go the falling film route to recover your solvents? 


Ray Van Lenten - 00:07:02 

Well, I was running a rotovap. Do I need to say anything else? 


Jason Showard - 00:07:05 

Not to me, not at all. But as far as the listeners go, I mean, I'm sure plenty of people out there are familiar with the old taxing rotovap and it just crushes your time. But other than that, I mean, like, what was it that gave you the idea to decide, you know, "Hey, I'm going to build a falling film evaporator." Just looking at industry or what? 


Ray Van Lenten - 00:07:27 

Yeah. So obviously, you know, the bottleneck of the rotovap is what made me look at scaling it up. And really, I just got on Google and started looking up, you know, how do they recover solvent on a large scale. And first thing that popped up is a falling film evaporator. And I started looking at it as like, OK, you know, I think I could build one of these and put it together. So I had already had a decent supplier for a bunch of equipment that I already had custom made for my facility. 


Ray Van Lenten - 00:07:55 

And as anybody who's played with a tri clamp knows, it's fairly modular. So over time, I had ordered all the bits and pieces that I needed, and just kind of amassed them. Put it all together. And the first one just worked right out of the gate. I think it was like ten gallons an hour out of the very first prototype. 


Jason Showard - 00:08:14 

All right. Ready to throw your rotovaps out the window right there. 


Ray Van Lenten - 00:08:17 



Jason Showard - 00:08:19 

Right on. So that's how it all began. Give us a current bird's eye view of TruSteel as a company. Where are you now? 


Ray Van Lenten - 00:08:25 

Yeah, so the first thing that we did is we scaled up our AutoVap line up. So we brought the AutoVap 30, which has full automation on it. Has a touch screen controller. And really, you set your parameters on it and all the operator needs to do is start and stop it. And then there's obviously a cleaning cycle once you're done. 


Ray Van Lenten - 00:08:44 

So our lineup now has an AV 15, a 30, 100 and a 300, and those numbers correspond to gallons per hour of ethanol recovery. So on top of our AutoVap lineup, there's obviously a bunch of other different pieces that you need to complete your lab. 


Ray Van Lenten - 00:09:04 

And one of our core values is having modular systems for processing, so that you can plug different devices in to create your ideal extraction chain. So, for example, we have a new product called the InstaCool. And its function is to cool down solvent completely inline. So instead of having a large vat that has a coil inside that you're hooking a chiller up to, and you're waiting hours for your solvent to come down. It has a series of heat exchangers on the inside in a pump, control screen, thermocouples, and a flow meter on the inside of it that essentially allow it to pump out of a storage tank, through the heat exchangers and cool down your solvent inline. 


Ray Van Lenten - 00:09:53 

And the idea is with the HMI and the PLC that we've put on the system, they can all talk to each other. And I'll use another example here, our Evo system, which is our wiped film evaporator. On the Evo, for example, your stage one, if you're having issues with vacuum, there's likely too much solvent, from your solvent recovery step. So the Evo can communicate with the AutoVap and tell it to slow down, so that it can strip out more solvent from your residue streams. So the idea is that all these little bits and pieces can kind of talk to each other and modulate to control your lab. 


Jason Showard - 00:10:33 

Wow, that's fantastic. You're going to put consultants out of a job, man. 


Ray Van Lenten - 00:10:38 

Yeah. And, you know, the idea is to have to different programmable recipes, and just kind of remove a lot of the human input. Just because humans make mistakes. And the nice thing is being able to data log, you know, and kind of have a receipt for whatever batch you have. 


Jason Showard - 00:10:53 

All right. So if that's what you guys got going on right now, what's the future look like for TruSteel? What do you see in the next year or two? 


Ray Van Lenten - 00:11:00 

We're hoping to put out a lot of full plants. So we've focused a lot of time on creating kind of all of the individual modules that you need. So now I think the focus this year is just putting it all together and making it all work as one giant facility. 


Jason Showard - 00:11:18 

With everything as crazy as it is right now with this whole pandemic or anything. Are you guys experiencing any kind of supply chain issues or anything like that? 


Ray Van Lenten - 00:11:28 

Previous to COVID, we've actually done a lot of work to bring a lot of our manufacturing sources back to the domestic market. So starting with our AV 30 and a majority of our lineup, at least 80 percent of our stuff is domestically sourced. And we were really lucky to do that in time before COVID because we're seeing a lot of shipping delays from China and some of these overseas companies. So that's done a really good thing for us. 


Ray Van Lenten - 00:11:57 

And another one of the things that COVID has kind of helped us bolster, is we weren't able to travel to the customer to install equipment. So we had to do a lot of documentation. And just kind of a lot of work to help guide some of our customers through the installs because we couldn't touch base. So it actually really strengthened our install team, and our project management teams' communications with the customers. And we were actually able to install two AV 30s in Colombia during the pandemic. 


Ray Van Lenten - 00:12:30 

And actually something really cool is our programmers speak Spanish as well. So our equipment is actually bilingual. So we were able to install equipment halfway across the world even during the pandemic. 


Jason Showard - 00:12:42 

That's fantastic. 


Ray Van Lenten - 00:12:43 

Yeah, I'm really proud of the team for doing that and just being able to handle it during this. So it's really made us stronger, if anything. 


Jason Showard - 00:12:52 

Yeah, so the AV 15 was basically the first falling film to market, it's really what put you guys on the map, or at least the first falling film into the extraction industry. Put you guys on the map. Shortly after that, you released the AV 30. 


Jason Showard - 00:13:07 

And just like, those machines completely changed the game for solvent recovery. I can speak to that myself after moving away from a rotovap into one of your AV 15s and it changed my world. So in previous episodes, we've talked about how you would use a falling film to separate the oil that you're after from the ethanol that you want to recollect. But let's get a little deeper into it. Give us a rundown of how your machines actually do that, like how do they work? 


Ray Van Lenten - 00:13:33 

So the entire machine is controlled by an Allen Bradley PLC system that's mounted outside of the hazardous zone. And the touch screen essentially takes all of the IO on the systems. So all the thermocouples and all the different inputs. Takes that and converts it to ethernet and allows it to talk to the PLC in a different room. So you can have all of your controls on the front of the system. But the actual PLC doesn't take up a lot of the room that you might see on some of these other systems, you know, that has a large panel mounted to the side of it. 


Ray Van Lenten - 00:14:04 

So it's nice to kind of be conscious about the space that you're taking up in your lab, for starters. But as far as the actual, the functionality of the system, you know, everything's controlled through the PLC. And the system has three pumps on it, there's a feed pump and then there's a residue and a distillate pump. I also like to use concentrate and condensate as distillate might be a little bit of a confusing term. Most people just think of THC distillate when in reality distillate is anything that you're distilling off. So it would be your condensate. 


Jason Showard - 00:14:37 

In this case, it would be your ethanol. 


Ray Van Lenten -...

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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.