Ethanol Extraction CBD

Though ethanol is commonly used in the hemp extraction industry, ethanol extraction CBD has potential to be detrimental to the health of the user over the long-term that is often not talked about.

While the FDA considers ethanol “Generally Regarded As Safe” (GRAS, studies show that denatured ethanol products used for extraction purposes could have potential denaturant contamination. Some may argue that the levels are not high enough to cause concerns, research may show that continual use of ethanol extraction CBD in products such as CBD oil may have adverse effects.

In this article, we discuss the potential issues of ethanol extraction CBD and why CO2 is a far healthier alternative.

oil

The Road in Extracting CBD

The road of botanical extraction goes back quite a long way and includes a variety of extraction solvents that are still prevalently used today. Among the common three that will be discussed briefly are hydrocarbons, ethanol, and CO2:

Hydrocarbon: Hydrocarbons like propane and butane are often used in the extraction industry due to their overall efficiency. While these particular solvents are volatile in nature and not safe to consume, they are easily purged from a final extract making them relatively safe – though more studies are necessary to determine any long-term effects.

CO2: Is often considered to be the safest extraction solvent in terms of purity. As an organic solvent, CO2 is often called the “clean and green” extraction solvent as it is environmentally friendly as well as safe for the end user. While some extractors may try to argue that it is not an efficient method, proper equipment and operations lend evidence to the contrary making it a highly selective, powerful and safe extraction solvent.

Ethanol: Ethanol has been used in various extraction industries for many years, but there are some disparities in the safety of this particular extraction solvent. While food grade ethanol is considered to be safe, denatured ethanol can be a very risky alternative that could potentially cause long-term detrimental effects to the user. Let’s get into more detail about denatured ethanol and why ethanol extraction CBD can be risky.

Why Denatured Ethanol Extraction?

What is most concerning about ethanol extraction CBD products is not necessarily that it was extracted with ethanol, but what kind of ethanol is used. In order to use ethanol as a cleaning or industrial product, chemicals called denaturants are added in order to prevent human consumption. In doing this, federal beverage taxes do not apply to denatured ethanol making it much cheaper than food grade ethanol. Unfortunately, this reduced cost is all too appealing for a majority of ethanol extractors in the hemp industry making denatured ethanol the most common ethanol used in the industry. So, if it’s not safe for human consumption, what makes it safe for extracting CBD products for human consumption?

What Are The Most Common Denaturants in Ethanol?

Denatured recipes are published by the TTB that is administered by the National Bureau of Alcohol Tobacco and Firearms. There are many different recipes. One of the most common denaturants used in ethanol extraction is heptane. However there are other substances that may be used including acetone, isopropyl alcohol, methanol and other longer chain alcohols.

There is very limited data on the safety of heptane over the long term exposure. In fact the limit that the FDA has placed on the amount of heptane in a tincture for example was established in the 1990s on the basis of a single study published in 1981. That studies the effect of heptane on Sprague Dawley rats. That is why there are many disclaimers and the general guidance from the FDA is to limit the amount of solvent in any drug that is consumed.

Ethanol can also become contaminated during ethanol extraction. It is important that you address the contamination with testing and reuse protocols. Guidance for solvent reviews have been published by the FDA in 2010.

Are Cannabinoids Extracted by Ethanol Easier to Purify Than When They Are Extracted with CO2?

Cannabinoids extracted with ethanol are not necessarily easier to purify compared with CO2 extracted cannabinoids. There really is no difference.

An ethanol producer might suggest that they are skipping the winterization process that would be required for example with a CO2 extraction. However, it is important to note that they are not necessarily skipping it but they are making it a part of the process.

There are several disadvantages to a completely integrated process. Specifically, the facts and waxes that you get out of the winterization process are valuable for many different products. Second, when the process is completely integrated, from extraction to winterized oil,  the terpene profile is greatly altered and sometimes unrecoverable.

Is it possible to make a solventless extract with CO2

It is absolutely possible to make a solventless extract with CO2. solventless extracts are typically made with subcritical CO2 extraction methods.

man with extraction machines and equipment

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Ethanol Extraction CBD Products

So, we have discussed the three most common extraction methods in the industry including their benefits and detriments, but what is the best option for making these products? Leaving hydrocarbons out of the equation, let’s take a look at CBD ethanol extraction products compared to CO2 extraction products to see what method is preferable to create them.

What Extraction Method is Best For Making Products?

  1. In ethanol extraction, removal of the ethanol is a process that requires a significant amount of heat over a long period of time. This heat exposure will degrade the terpenes significantly. Many of the terpenes during this process are co-distilled or are destroyed in the process. The oil from this process is typically dark black and does not taste very good. The aroma profile is also not very desirable due to the breakdown of the terpene profile. The use of a crude extract for the tincture it’s not desirable because it doesn’t taste very good, doesn’t smell very good, and it also may contain too much psychoactive material.
  2. Once the ethanol has been removed from the ethanol extract, the oil typically is introduced to a distillation process which removes the remaining terpenes. If your intent is to use distillate for your tincture, then you will have to find a way to add some terpenes to that tincture. The only resort is to purchase synthetic terpenes. you will also need to figure out how to reduce the amount of psychoactive cannabinoids.
  3. One other thing that needs to be considered is that if you do not distill the ethanol extract, it is very likely that you will have a significant amount of chemical contaminants in your extract. This is especially true if you are using denatured ethanol for your extraction process.
  4. Process of distillation does not necessarily remove all of the denaturing from the extract. It may remove the vast majority of the solvent contaminant but there are always trace residuals remaining in the distillate.
  5. It is always desirable to start with organic hemp biomass so there is little risk of those contaminants making their way into the tincture.

In contrast, CO2 extraction is far superior in terms of terpene profile preservation

  1. Supercritical CO2 extraction is highly selective, making it ideal to create products that are high in quality and preserve valuable plant compounds like terpenes, or extract with the intention of isolated CBD compounds instead. 
  2. The CO2 extraction also avoids the issues related to chemical contaminants that come from the use of denatured ethanol.
  3. CO2 extraction is much less expensive to produce a kilogram of oil compared to ethanol extraction. For example, CO2 is 4 cents a pound compared to ethanol which is greater than $4 per pound. Solvent losses with ethanol extraction are a key cost contributor and drive a major increase in operating cost compared to CO2 extraction. For more information read our blog.

In summary, both CO2 extraction and ethanol extraction can produce desirable products. However, CO2 extraction has an edge over ethanol extraction due to preservation of the terpene profiles and the avoidance of risk related to chemical contaminants. Finally, CO2 extraction is much less expensive than ethanol extraction. For those reasons CO2 is a better extraction method for safe and quality products.

Final Thoughts

So, it is clearly important for consumers to understand that ethanol extraction CBD can be detrimental to one’s health over a long term consumption rate. While studies are still necessary to validate these concerns, the amount of residual chemical denaturants left in extracted products, even at lower levels, can add up when taken daily for a number of years. 

This is why extraktLAB chooses to extract with supercritical CO2. Not only is it the most long-term cost efficient extraction option for production, it is, without question, the safest option for hemp extracts intended for human consumption. 

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We have the perfect machine for small, medium and large producers. Our model line makes it easy for you to scale your operations while keeping your operating costs at a minimum.

Frequently Asked Questions

Why should I choose extraktLAB equipment?

extraktLAB’s supercritical CO2 extractors are highly efficient and increase overall extraction yield. They are also capable of decreasing your yearly operating costs and leave scale up opportunities.

Does hemp biomass need to cure before extraction?

No, the material does not need to cure. Our methods complete the final drying step in a vacuum oven to bring the water content down from 10% to the 1% – 1.5% range for efficient CO2 extraction.

Can the drying process be accelerated using higher temps/lower humidity?

There are several drying methods used by growers to accelerate drying, but this is outside our scope of solutions. We recommend researching the agricultural methods to find what works best for you.

What are the typical conditions to dry hemp for extraction?

Harvest drying methods are outside the scope of our solutions; however, you want to dry the biomass to roughly 10% water content for quality storage to prevent mold or mildew.

When producing CBD from hemp, which part of the plant is typically used?

Typically flowers and leaves – no stems or stalks. Some producers will sort out the flowers and process them separately, but most processing includes the leaves and flowers.

Can ethanol become contaminated during ethanol extraction?

Yes, ethanol can become contaminated during ethanol extraction. It is important that you address the contamination with testing and reuse protocols. guidance for solvent reviews have been published by the FDA in 2010. Please refer to the many articles in this blog for more information on cross-contamination with extraction.

What is the electrical cost of ethanol extraction vs. CO2 extraction?

Processing a ton of hemp per day into extracts  can be an energy-intensive process depending on how the hemp is extracted. The following table compares the energy expense for ethanol extraction versus the energy expense for CO2 extraction:

Energy cost for Ethanol Extraction for 1 ton per day at 1 gallon ethanol per 1 lb of hemp
18711 litres to cool from 25 to -20
16840 litres to heat and evaporate after ethanol loss
454 kwhr to Cool from 25 to -20
481 kwhr to heat to boiling point
3105 kwhr to evaporate
4040 kwhr total @ 100% Efficiency
75% Efficiency
5387 kwhr Total
$           0.09 per kwhr
$          506.36 per day

 

Energy cost for CO2 Extraction at 1 ton per day including winterization
636 litres to cool from 25 to -20
636 litres to heat and evaporate after ethanol loss
15 kwhr to Cool from 25 to -20
18 kwhr to heat to boiling point
117 kwhr to evaporate
151 kwhr total @ 100% Efficiency
75% Efficiency
201 kwhr Total
$           0.09 per kwhr
$        18.92 per day for winterization
43.20 Kwhr per day for CO2 extractors
$         3.88 Per day for CO2 extractors

Would you recommend ethanol extracted oils for Vape products?

Due to the risk of chemical contaminants that are found in 25 to 30% of  ethanol extracted oils, we recommend that CO2 oils be used for Vapor Products.

Is it possible to make a solventless extract with CO2?

It is absolutely possible to make a solventless extract with CO2. Solventless extracts are typically made with subcritical CO2 extraction methods.

Does ethanol extraction have a greater throughput than CO2 extraction?

Hemp processing equipment can be scaled for 1 to 5 tons of extracted hemp per day. It’s generally not a fair comparison to compare the throughput on an instrument from two different companies. What is fair is to specify the throughput At the tonnage process per day and then look at the operating cost for that process. You can also look at the equipment and Facilities cost to accommodate that level of Production. after you have all of your costs accounted for including the hidden costs, then you can calculate the net present value for each investment.

What are the most common denaturants in ethanol?

Denatured ethanol is a mixture of denaturants and pure ethanol. Chemical companies add the denaturant to Pure ethanol so that they will not be consumed as a food.
Denatured recipes are published by the ttb that is administered by the National Bureau of Alcohol Tobacco and Firearms. There are many different recipes. one of the most common denaturants used in ethanol extraction is heptane. However there are other substances that may be used including acetone, isopropyl alcohol, methanol and other longer chain alcohols.
Is very limited data on the safety of heptane over the long term exposure. In fact the limit that the FDA has placed on the amount of heptane in a tincture for example was established in the 1990s on the basis of a single study published in 1981. That study the effect of heptane on Sprague dawley rats. That is why there are many disclaimers and the general guidance from the FDA is to limit the amount of solvent in any drug that is consumed.

Doesn’t ethanol extraction equipment remove all the ethanol from the biomass after extraction?

No. Approximately 5 to 10% of the ethanol is left in the biomass and is counted as a solvent loss. These solvent losses add up to operating costs. This is especially true if organic ethanol is used or food grade ethanol is utilized as the extraction solvent.

If you had an ethanol extraction facility, would you ever use CO2 just for stripping terpenes?

Ethanol extraction typically destroys the terpenes when the ethanol is removed from the extract or is distilled from the winterized oil. Many ethanol extractors are seeking a way to preserve the terpene profile of the plant in the output oil. To this end people have tried techniques such as Steam distillation, CO2 stripping, and vacuum distillation.
Certainly, CO2 can be used to strip terpenes from Hemp biomass Prior to ethanol extraction. However, vacuum distillation is by far the most gentle and effective way to harvest the terpene profile prior to ethanol extraction.

How do I model and compare the financial return of ethanol extraction vs CO2 extraction?

There are many inputs that need to be defined when creating a financial model comparing two different extraction methods. The first decision to be made is to decide what the financial metric will be used to make a decision on the superiority of one method over the other. 

In this case, we recommend the use of the Net Present Value as the way to model the return of each extraction technique because it accounts for the cash flow associated with the operation. Many ethanol extraction companies try to make the argument that ethanol extraction is lower cost because the equipment cost is less. However, the equipment cost will have very little impact on the overall profitability of the operation at the same throughput.

The best way to compare the two techniques is to fix the throughput so that an apples-to-apples comparison can be made. Comparisons such are payback time and return on investment can mislead someone into making a bad investment decision. 

So if we fix the throughput at one ton per day the cost of the hemp is equal between the techniques and operating cost variance is the only contributing factor.     

Here are the twelve key questions that need to be defined in order to do a comparison:

  1. What is the direct labor to process?
  2. What is the energy to process?
  3. What are the solvent losses? 
  4. What are the direct material startup costs including solvent startup costs?
  5. What are the cannabinoid recovery rates?
  6. How much solvent do I use, reuse, and when do I need to replace the solvent with fresh solvent?  and at what interval?
  7. What is the insurance cost for each option?
  8. What is the cost of hazardous waste disposal?
  9. What is the cost of solvent removal?
  10.  What is the cost of reuse of the solvent?
  11.  What is the cost of HAP emissions?
  12. What is the depreciation for each option including building costs for H2 vs F2 occupancy?

Once these questions are answered you will be able to build a pro forma income statement. 

Revenue

  • Standard labor
  • Standard materials
  • Overhead

Gross margin

  • SGA
  • R&D

Net Margin

You can then hold SG&A and R&D constant for both techniques and account for the difference in depreciation to get to a net margin number.  

A cash flow statement can then be generated from net margin. One thing to note is that depreciation must be added back to net margin as it is a non-cash expense on the income statement.  

Cash flows are then added up for 5 consecutive periods (years) including the initial outlay of cash for startup working capital.  Those cash flows are then discounted at a discount rate (Weighted average cost of capital estimate at 13-17%).  

If you do this analysis, you will find that CO2 extraction will absolutely crush ethanol extraction in terms of net present value.  

Does it cost less to process hemp with Co2 compared with Ethanol?

Yes.
In fact the operating cost for CO2 extraction is dramatically less than the operating costs associated with ethanol.

Extraction with Ethanol is a process that is typically run at low temperatures. First the ethanol is cooled to below -20oC before it is introduced to the hemp. Cooling the ethanol reduces the amount of extracted chlorophyll and waxes. If you account for the energy required to chill the ethanol down to those low temperatures and then also evaporate after use, the energy bill for extracting ethanol is approximately 3-6x the cost of extracting with CO2. However, the energy cost is really not the key driver in the overall operating costs.
Ethanol extraction requires a significant amount of ethanol to be used per pound of hemp. In fact, about 1 to 1.5 gallons of ethanol must be used per pound of dry hemp in order to extract. Hemp is a very absorbent biomass material and the ethanol must fully saturate the hemp plant before any extraction can take place. For this reason a large volume of ethanol is needed to extract cbd from hemp.
The key cost driver or ethanol extraction is recovery of that solvent from the biomass. Even though many ethanol extraction equipment companies provide centrifuges and or presses to eliminate the amount of ethanol left over in the biomass, The best equipment will provide only a 90 to 95% recovery of the ethanol. This 5 to 10% loss in ethanol is a huge cost driver for extracting ethanol.
For example, suppose you wanted to process 1000 lb of hemp. You would need 1000 gallons of ethanol to start out at a cost of $16-33 per gallon for food grade ethanol for a total cost of $16,000 to $33,000. If you recovered 90% of the ethanol the ethanol loss would be $1,600 – $3,300 per 1000 lbs. Furthermore if you process 1000 pounds per day, this would be your daily loss.
In contrast, you will lose the equivalent of about $70 per day for CO2 extractions for the exact same process.
Besides energy and solvent usage, there are many other hidden costs related to extraction with ethanol including solvent reuse costs, insurance cost, increased facilities cost, and testing costs.

Is CO2 cheaper than ethanol?

Yes.
A pound of food grade ethanol when purchased in bulk is $4.71/lb at current price.
A pound of food grade CO2 when purchased in bulk is about $0.04/lb at current price.

What’s the purity of the CO2 used in CO2 extraction?

There are many grades of CO2 including industrial and food grade and medical grade. We typically use food grade but medical grade is also highly desirable. the specifications for each of these grades are published by the Compressed Gas Association or by your gas supplier.

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