Episode 1

Published on:

22nd Dec 2020

S1 E01 - Cannabis Extraction And Post Processing Overview

Jason Showard walks listeners through an overview of the extraction, distillation, and crystallization processes used to take cannabis from cultivars to concentrates.

Episode Transcript:

Hello, and welcome to the modern extractor. I'm your host, Jason Showard. And I work professionally in the cannabis extraction field. After years of experimentation tens of thousands of dollars in lab tests to collect data from those experiments, and hundreds of thousands of pounds of biomass successfully extracted and distilled. I decided to spill my secrets to you with this podcast. The modern extractor will be focusing on the processes, equipment and science found inside a cannabis extraction laboratory. I've yet to find a curated collection of extraction knowledge, and that's exactly what I'm going to build here. I decided to produce this podcast because I kept looking for something like it to listen to, and it just didn't exist. In Season One, we'll be focusing on ethanol extraction and post processing and either distillate or isolate. The shows will be released in an order which follows the workflow of material through a lab. Each episode will dig deep into a particular stage in that workflow and discuss the various approaches with industry expert guests. In today's show, we'll be taking a bird's eye view of the entire ethanol extraction and post processing workflow. For the sake of simplicity, and getting through the whole process in one show, this will be a less technical overview of the full process. For this overview, I'll be following what I believe to be the best approach to ethanol extraction. in future episodes, we'll dig deeper into each of the stages and pick apart the different options and approaches a lot more technically, think of this as both a walk through the process and a syllabus for what lies ahead in season one.

So after this week's overview, next week, in Episode Two, we'll talk about sourcing biomass and prepping it for extraction. The first step in any extraction operation is getting your hands on good material to extract from. Obviously, the ideal situation is to get a sample of the material you're interested in buying, send it to a lab and have the seller agree to hold the material for you until the test results come back and tell you exactly how much of each cannabinoid is present before you buy it. But this is a fast moving field. And there may not always be time for a lab test. You don't want to miss out on a good opportunity. But you also don't want to get burned by buying bad material. We'll go over some tests that you can do to ensure you're buying high quality fresh material that hasn't already been processed. After you've sourced your biomass, it's time to prepare it for extraction. The first step in the preparation process is either milling, shredding or grinding your material. It's just not efficient to extract from biomass that hasn't been appropriately broken up. There's no magic spec when it comes to mill size and your decisions here should be based on variables specific to your extraction operation. And Episode Two, we'll go over how to determine your ideal mill size based on variables unique to you, such as your evaporation capacity, your cost of ethanol, because the biomass, your access to biomass, and the amount of demand there is for your finished goods. Once you determine what your mill size will be, there are a lot of options out there to mill grind or shred your material down to spec. After trying way too many options. I landed on Futurola shredders to do the job right. On next week's show we will have Bri Tolp from Futurola as a guest to discuss how Futurola shredders will get you to your desired mill size better than the competition. After your material has been milled down, it's time to bag it up for extraction. Most centrifuge manufacturers sell specially constructed nylon bags that zip shut and fit their centrifuges perfectly. Once filled, the bags of biomass should be held at your desired extraction temperature for about eight hours.

In episode 3 we'll get into the extraction process. It's time to decide what temperature we want to run our extraction. Room temperature extraction will ensure we extract the most from our biomass but along with maximizing the extraction of desirables we also extract far more undesirables than with a cold extraction. If done correctly, cold extraction will leave a very small percentage of desirables behind, but reject so many of the undesirables that it will allow us to skip cumbersome downstream processes like winterization and carbon filtration. Cold extraction requires pre shelling of both our ethanol and our biomass. I'm a big proponent of this method, but in Episode Three, we will break them both down and discuss why it may be correct to choose one over the other as well as ideal run temperatures and some low tech chiller hacks to save some money until you're ready to buy that chiller. The majority of ethanol extraction is done in centrifuges, only micro garage scale or huge high throughput CBD labs use other methods. While we may touch on some of the other methods out there, we'll be focusing primarily on centrifugal extraction. An extraction centrifuge is basically an explosion proof stainless steel washing machine that's optimized to agitate and extract cannabis. A typical centrifuge run will look something like this. Get your biomass to your extraction temperature for about eight hours, get the ethanol down to the extraction temperature. Put the bagged biomass into the centrifuge, push or pumped chilled ethanol into the centrifuge, run the agitate cycle, run the spin cycle and then drain the ethanol which now contains oil. Often, extractors will get the same batch of ethanol back down to extraction temperature and run it through a second, third, or even fourth bag of biomass. This is another decision that is directly dependent on your operation variables. We will get into picking all this apart with our guests Adam Chambers of Delta Separations. Delta is the creator of the first extraction centrifuge to hit the market and has become quite a beast in the industry. With his extraction experience and education in forensic biology. Adam is super knowledgeable on the entire process, and I'm excited to have him on the show.

Moving on to Episode Four, we'll tackle filtration. I can't stress the importance of filtration enough, trust me, having effective stage filtration processes makes life so much easier and reduces the wear on your equipment. So at this point in the process, we've run our ethanol through two or three bags of biomass. What we have now has many names, tincture, masella mother liquor, the list goes on. Technically, I think masella is the correct term. But you'll catch me saying tincture here and there as well. Old habits die hard. It's It's funny how the terminology you use in your first lab will stick with you forever, get me around my original crew and we have some ridiculous names for everything. You'll catch me peppering them in here and there. Anyway, back to filtration. Some particulate matter will always break free from the biomass during the extraction agitation. The majority should be retained in your nylon centrifuge bags with some amount always get through and be suspended in our solution. All of our downstream equipment is depending on us to get the particulate as well as any fats, waxes and lipids extracted from the plant out of solution. If we're running cold, we likely haven't extracted too many of the fats, waxes and lipids. But it is important to get our miscella filtered well it's still called as these components are more easily filtered out at the lower temperatures. medium scale operations typically put together or purchase a filters skid. In my experience. The best configuration here is a bag filter, sometimes two in series staged in mesh size, feeding into a one micron lenticular filter. We'll have Maria Peterson from Scott laboratories join us in Episode Four to discuss the ins and outs of the many different styles of filtration used in cannabis extraction. She's the most knowledgeable person I've ever spoken to about filtration and I'm really happy I get to share her with you guys. Let's catch back up with our work in progress. After running our ethanol through a few bags of biomass and filtering the miscella, it's now time to separate the oil from the ethanol.

Episode Five takes us into evaporation solvent recovery and reproofing. So far, we've extracted the oil from the plant, but it's currently dissolved in ethanol at a very low ratio. In order to continue processing the oil the ethanol has to be removed. This part of the process has certainly come a long way. In the beginning, people were boiling ethanol off of their extracted oil on a hot plate. This is definitely not efficient, definitely not scalable and just plain dangerous. From there, rotary evaporators became the standard tool to separate the oil from the ethanol. While they were a significant safety improvement from a hot plate, rotovaps just weren't fast enough and bottlenecked many an extraction operation. Then along came falling film evaporators! These completely changed the solvent recovery game, with one unit being able to replace about 10 rotovaps. Trusteel was one of the first if not the first company to design a falling film evaporator for extractors. Thanks to their AUTOVAP line, ethanol extraction became much more scalable. Falling film evaporators are now the industry standard solvent recovery device. In Episode Five, I'm very excited to have Ray Van Lenten, founder and CTO of Trusteel on the show to discuss how falling films work and why they're the best solution for solvent recovery. For the sake of today's overview, the important thing to know about the falling film is that its function is to separate the cannabis oil from the ethanol that it's dissolved in. There are typically two collection vessels, one for the oil that's had the majority of the ethanol removed from it now referred to as crude, and one for the ethanol that's been vaporized off, re-condensed and collected again for future use. Before we follow the crude on to the next stage, it's important to note that during the extraction process, the ethanol can pick up water, it picks it up from the plant material and even from exposure to the air in the room. The ethanol and water from azeotropes that are hard to break. The azeotropes have a boiling point close to that pure ethanol, so they can't be separated out with any of the equipment we've discussed so far. As the proof of the ethanol decreases with the addition of water, the extraction efficiency also decreases. Medium to large scale operations will usually reproof the ethanol, removing the water and azeotropes with the molecular sieve or a multi plate fractional distillation column. At small scale, it's just not worth investing in the extra equipment. But at any real scale it's critical to reproof your ethanol and ensure you're getting the maximum extraction efficiency.

So back to our work in progress. We have crude oil... now what? In episode six we'll get deep into decarb with our guests Greg Arias of Aftermath Laboratories. Greg's a chemical engineer who you can usually find working on formulations, various cannabis chemistry projects or consulting of some sort. He's also my first phone call when I realize I need to call on the big guns for problem solving or brainstorming. Decarboxylation is the only chemical reaction that occurs during the entire extraction, distillation and crystallization processes. In the Decarb step, we will break the bond attaching the carboxylic acid groups to the cannabinoids through a timed exposure to heat. The majority of the THC and CBD found in a cannabis plant are found in their acidic forms of thca and cbda. thca is not psychoactive and won't produce the desired effects unless you decarboxylate it and convert it into delta 9 THC, which is psychoactive. CBDA has gotten a little bit more attention lately, and neither CBD nor CBDA are psychoactive. So occasionally the CBDA heavy hemp crude will be collected pre-decarb, but more commonly the hemp crude gets decarbed, distilled, and then crystallized into CBD isolate. A typical Decarb setup is a sealed jacketed pressure vessel with a mixing motor and a cold trap. Heated fluid is circulated through the jacket for temperature control. The mixing motor mounts to the lid of the vessel and has a shaft that penetrates down through a bearing seal on the lid. There's a small propeller mounted at the bottom of the shaft to stir the crude inside the reactor. The cold trap will we condense any residual solvents that are vaporized at decarb temperatures and pressures. decarboxylation takes place when the oil is held at a certain temperature for a certain amount of time. In Episode Six, I'll give out my time and temperature SOPs which I've kept top secret for years. They're way faster and lower temperature than a lot of the information that's out there and they work great.

Episode Seven takes us to devolatilization, which is a mouthful, so we call it terp strip. We terp strip so that we can remove all the volatiles which have a lower boiling point than our sought after cannabinoids. We do this so that we can achieve a far deeper vacuum on the distillate run that follows the terp strip run. The deeper vacuum on the ensuing distillate run allows us to keep the temperatures on our equipment lower and results in less thermal degradation or cannabinoids. wiped film or rolled film distillation is by far the most efficient method for this stage. So while I will touch on short path, the majority of the SOPs discussed will be pertaining to wiped or rolled film distillation units. If decarb went correctly, there shouldn't be any residual solvents in our decarbed crude at this point. The remaining volatiles are mostly terpenes. And we'll remove them much the same way that we removed the ethanol from our miscella by vaporizing them from the crude and re condensing them elsewhere to separate, or strip, the terpenes from the terp-stripped crude. In this process, your decarbed crude oil is pumped from the wiped films heated feed tank into the top edge of the evaporator body. The evaporator body is heated to a specified temperature using a fluid filled jacket. A wiper unit containing multiple sets of flexible squeegee-like vertical wipers spins inside the evaporator body. The wipers make light contact with the heated inner wall of the evaporator body so that when your crude is pumped into the body, the spinning wipers squeegee it around the entirety of the inner wall. The thin film of oil created by the wipers is easily heated to the temperature of the hot wall, vaporizing any volatiles in the crude that will vaporize at or below the set temperature and pressure. The vapors created are condensed on a condenser that runs down the center of the evaporator body. The condenser has a separate temperature control bath that allows it to be set at a different temperature than the evaporator body temperature that allows the vaporize terpenes to re condense into a liquid and the distilled terpenes run down the condenser and into the distillate collection vessel. Gravity and small angled grooves on the wipers help the decarbed crude make its way down the hot evaporator body wall and into the residue collection vessel. along the way and the volatiles have been removed and it's now referred to as terp-stripped crude. Extensive cleaning and a slight reconfiguration of the machine are needed before the terp-stripped crude can be run again on our wiped film to create distillate. For the sake of both time and loss efficiency. it's advisable to build up enough decarbed crude to do a large terp strip run followed by a large distillate run. Cleaning between runs is time consuming, and more or less the same amount of loss occurs on every run, whether it's 5 liters or 500.

Episode 8 is what we've all been waiting for. By far the most gratifying part of the process. cannabinoid distillation. time to make some Goldie's. We will be using the same style wiped film distillation unit we used on the terp strip for the distillate run, this time by raising the temperatures on the evaporator body and main condenser as well as achieving a deeper vacuum than we had on the trip strip. We will vaporize, condense, and collect our cannabinoid distillate. Similar to the last run on this machine. The terp stripped crude is pumped from the wiped film unit's heated feed tank into the top edge of the evaporator body. The spinning wipers squeegee the oil around and down the inner wall of the evaporator body and the thin film that thin film of oil is quickly heated to the new set temperature and the cannabinoids were after vaporize, just like the distilled terpenes did on the last run the THC or CBD distillate quickly condenses on the main condenser and flows down into our distillate collection vessel. The crude remaining on the evaporator body wall is wiped around and down and flows into our residue collection vessel. This 'one-pass' crude can be run again later at higher temperatures with diminishing returns. This is the end of the line for THC, but CBD distillate can be crystallized into Isolate. Delta nine THC's natural state is a light golden colored oil. So if we want THC crystals, we would have had to go after the THCA, which is crystalline in nature, before the decarb step. It is worth noting here that if we are after the THCA crystals, hydrocarbon extraction is 100% the way to go. Our CBD distillate can now be crystallized into Isolate if we want to take purification to the next level. The crystallization process starts with dissolving CBD distillate into pentane in a jacketed reactor vessel. The dissolved the CBD/pentane mix is moved into a jacketed crystallization tank and incrementally dropped in temperature over time. Once crystallization is complete, the crystals can be filtered out and collected as isolate, or re dissolved and crystallized again for an even higher purity final product.

Alright, well that takes us through the full extraction, distillation and crystallization workflow. I plan to record some more episodes on other lab related topics as the season progresses. Stay tuned for additional episodes with topics like breaking down your vacuum system, discussing lab testing, and what to think about all the Chinese equipment that's coming onto the market. Also, if you want to hear something specific, let me know. Email me my emails Jason at modern extractor.com I'll be excited to hear from you. If you guys like the show, please subscribe, the more subscribers I get the better guests I can get on in the future. Well with that, a big heartfelt thanks to everyone for tuning in to the first ever episode of the modern extractor. New episodes will be out every Tuesday. I'm Jason Showard. Let's talk soon!

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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.