Are you looking to compete in the cannabis industry on a shoe string budget? The secret is, you don’t have to have expensive technology to produce premium cannabis products. Instead of following the latest trends, think outside the box and keep the money in your pocket. Running a successful cannabis business is about getting a return on investment, and the faster this happens the better. In this series we will look at several tips on how to compete successfully in cannabis with as little investment as possible. In our first two blogs we looked at how to prep material and how to winterize. Now we will look at ethanol evaporation.
This article is meant to be a guide for beginners to point them in the right direction. It is also meant to show there are efficient methods to get the job done and produce quality without spending money. So lets get into it!
Tip #3 – How to evaporate and recover your ethanol without expensive equipment
Now that you have extracted all the oil, your left with gallons of alcohol solution. How do you separate it and reclaim your alcohol without breaking the bank? Lets start with the basics
Step 1 Evaporate the ethanol
Why do we need to evaporate it? Evaporating the ethanol removes it from the oil
How does alcohol evaporate? It needs to be heated until the point that it boils and turns into a gas. What does that do to the oil? Without getting deep into chemistry, your alcohol and oil solution will only get as hot as the boiling point of the lowest temperature constituent. In this case that is the alcohol so your oil will remain in liquid form until the alcohol is mostly gone. I say mostly because there will be residual alcohol trapped in the oil. The benefit of using pure ethanol vs Isopropyl or other solvents is that it is safe for human consumption. That doesn’t mean you will necessarily want to leave it though so Stay tuned for another blog on how to remove residual solvent. Moving on… So how hot do you need to get to boil the alcohol? Under atmospheric conditions which means you have not applied additional pressure or vacuum, the ethanol will boil at approximately 173F For example if you boiled ethanol in a pot on the stove it would be 173F There are variables such as purity and elevation so don’t be surprised if your boiling ethanol at 175F or even a little higher.
Step 2 Reclaim the ethanol
Why do we need to reclaim it? Two reasons a) to save money by reusing, and b) safety. Ethanol vapor is dangerous so it should be contained
How do we reclaim it? We reclaim the Alcohol by condensing the vapors. Since Alcohol boils under higher temperatures we need to cool it in order to return it back to liquid. In theory if your boiling at 173F and you reduce the temperature to 172F it will condense. While this may stop a boiling pot it will not necessarily turn vapors back into a liquid at least not in a timely fashion. We need to think about the three primary factors in cooling the alcohol vapors
In an effort to keep things simple I will try an analogy. Think about turning water into ice. Water freezes at 32F. If you have a pool and it is 32F outside, most likely that pool won’t be frozen unless the temperature remains 32F for several days, weeks or possibly months. If you drain that pool on the ground and it and goes from 4ft deep to 1/16 of an inch spread all over the ground the molecules become spread out and no longer insulated by each other and will freeze quickly. Spreading the water out created more exposed surface area. Lets try another option. The temperature outside is 32F but you also have bags of ices you drop into the pool. By doing this you have in essence accomplished the same thing by exposing those insulated molecules to the cold temperature speeding up the freeze. Initially only the top of the water was exposed to the cold temperature. When you added the ice you created more surface contact with the cold temperature of the ice. Not only was the top of the water exposed but all throughout the water became exposed. Similar to spreading it on the ground, just with a different method. Which method is faster and which is cheaper? It depends on which of the three primary factors Time, Temperature (something like ice) or Surface area you have available. The more you have of each, the faster it will condense. There is a sweet spot where you combine all three to achieve the results you need at the lowest cost.
In most instances, Temperature or low temperature to be precise, is typically the hardest and most expensive to come by. A chiller which provides a cold medium similar to introducing the ice example, is the method of choice for most to reduce temperature quickly. This is expensive however. Expensive in equipment and expensive in energy consumption. So what is the alternative for someone on a budget?
Ambient Air and water. Both are usually readily available for nearly free. The question now is surface area, and time. Because water is more dense than air it will absorb the heat much faster. How do you get air to work as fast as the water? Create more surface area! This is where condensing coils come in. To cool with water you need much less surface area than air. The air will require more surface area to achieve the same results which means more coils. Since air is not as dense as water you will also need to move the air over the coils. We will talk about building air cooled condensers in another article though.
Now we are still missing one thing! The volume of ethanol you are trying to cool. While there are formulas for calculating all of this, my goal is to give you the basics and get you going as soon as possible. To do this we will use the CRCfilters EV-2.5 evaporation vessel as our volume set point. This is 2.5 gallons with a 20+ cubic inch evaporation surface area.
So how do you build a low cost water condenser?
WARNING: Always be sure your materials are compatible with the solvent, heat and pressures your are using. Never use copper with pure alcohol and high temperatures or acetone can develop. Do not use brass, carbon steel or other non compatible metals either. Try to always use stainless steel for metal parts. Tubing material is also important. Many standard brew hose and tubing’s will not tolerate the combination of heat and pure ethanol and will leach poison into your product. Do your own research when making products for human consumption. Below are my recommendations and source links.
Materials needed with recommended source links:
- 55 gallon drum or garbage can – Uline.com
- 3/8” x 25’ stainless steel condensing coil commonly sold as Wort chiller – Amazon
- 3/8 ID PTFE (Teflon) tubing – usplastic.com
- 3/8” PTFE (Teflon) or similar check valve – Industrialspec.com
- Pinch clamps – Oetiker.com
- Stainless steel ½” Female camlock connection – Bargainfittings.com
- Stainless steel 3/8” hose barb to ½” Male NPT –Titanfittings.com
Check out the video below for a look at the completed condenser and if you have questions email me at ArthurPaulTips@gmail.com.
Check below for other videos and blogs in this series and get any information you may have missed.
Stay tuned for more money saving tips for beginners and start-ups
Written by Arthur Paul – 4/2021