Plant Oil Extractor

Essential oils are all over the world and their popularity continues to grow. But how are they made? Well, the proper term would actually be “extracted” using equipment like a plant oil extractor to get the job done. There are plenty of extractors and methods of doing this, but certain methods prove to be safer and more effective than others. In this article, we will review plant oil extraction, the methods involved, and how an essential oil extractor operates.

Guide to a Plant Oil Extractor

There are a good number of varying plant oil extractor products(Check out our THC Extraction Machine guide) on the market that utilize a variety of methods and processes to complete the task. Many of these products use a few common methods to perform extraction: steam distillation,solvent extraction, or CO2 extraction. Let’s take a brief look at each of these plant oil extractor methods.

Steam Distillation

Likely the most popular method of essential oil extraction, steam distillation utilizes steam to vaporize the volatile compounds that are desired from a plant which are then condensed and collected before being further processed into a final product. This form of essential oil extractor is typically composed of a still that contains the plant material and where steam is added to strip the plant oils and other compounds. After this point, the vaporized product finds its way into a chilled condenser flask. The essential oil then falls into a separator where it is siphoned and refined to create popular essential oil products.

Solvent Extraction

This extraction method utilizes some kind of food grade solvent in order to extract the same desired plant compounds from the plant material. Common solvents used for this are often ethanol, or hexane. While this method is effective at stripping and collecting the compounds used in essential oil extractions, it is not always possible to remove those solvents from the final product leaving a slight smell of the remaining solvent leftover and altering the desired product.

CO2

A form of extraction that utilizes carbon dioxide (CO2) in order to strip volatile products from the plant material. This form of plant oil extractor is often most effective on a large scale making it highly efficient in industrial applications of plant or essential oil extract products. However, this form of extraction is perhaps the most technical in order to achieve desired results needed specific heat and pressure applications to reach a “supercritical” state to perform the extraction. But how is this done? Let’s explore supercritical CO2 extraction in more detail.

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What is CO2 oil extraction

One of the most common and efficient methods of extracting plant oils is supercritical CO2 extraction. This clean and green extraction is a safe and reliable method to create quality products that are less costly to produce than conventional solvent extraction methods. In fact, many using a CO2 essential oil extractor is far more profitable in the long term than other extraction systems. Let’s briefly look at the supercritical CO2 extraction process:

The Science Behind the Supercritical CO2 Plant oil Extractor

A supercritical CO2 plant oil extractor uses carbon dioxide (CO2) at an elevated temperature and pressure to extract soluble compounds from plants. CO2 becomes a supercritical fluid above the critical temperature (31ºC) and pressure (1071 psi), which has an increased capacity for diffusion of molecules and solubilizing non-polar compounds in a desired plant material. Raising the temperature and pressure of the liquid CO2 further provides highly efficient extractions of essential oils in a short period of time.

For these reasons, supercritical CO2 extraction has become the preferred method for extracting essential oils to serve markets with the most demanding standards for quality, safety, consistency and purity. It is also preferred by consumers for the same reasons, as natural, safe products have become increasingly more crucial to the plant and essential oil industries.

Diagram of Supercritical Co2 Extraction Process

Production Of Essential Oils

So, we’ve explored how supercritical CO2 works as a whole, now let’s take a look at how exactly essential oils are produced:

As the supercritical liquid CO2 passes through an extraction chamber filled with a particular plant material, it acts as a solvent capable of stripping off various plant materials and leaving behind the biomass itself. Some of those plant compounds are terpenes, flavonoids, chlorophyll, waxes, fats and others. Some of these are key in creating quality essential oil products, while others need to be remediated before a product is created:

Terpenes are responsible for the smell and flavor of a variety of plants, fruits and other natural products. For example, pinene is a common terpene that is found in pine needles and is responsible for that common pine smell. These terpenes are the key factor in creating desirable essential oil products for diffusion, topicals, and other products.

But, in order to derive products from terpenes, those other undesirable plant products need to be removed as they can cause a lesser quality product. In order to do this, a further process of filtration and distillation must be performed. Filtration is often performed through a process called winterization. This process uses a solvent like ethanol at incredibly cold temperatures mixed in with the extracted oil to solidify waxes, fats and chlorophyll before vacuum filtration. This leaves a solvent/terpene mixture that needs to be distilled.

Distillation involves removing the remaining solvents and other plant components to create a final, usable plant product. This is often performed using some form of thin film evaporation coupled with heat and vacuum pressure which allows the volatile solvent to evaporate from the oil at a lower temperature without damaging the terpenes needed for the final product. After this process, a high quality, usable essential oil is ready for product formulation.

calculator-ethanol-co2-comparison

CO2 Essential Oil Concentrate Products

Once final distillation processes are completed, the plant oils are ready for product formulation. Because of a natural, safe CO2 extraction process, essential oils can be used in a wide variety of products:

Topicals

Essential oils are often used in products like lotions, balms, chapstick and other skin products to provide a pleasant aroma. However, there are also benefits outside of simply making a topical product smell good. Many terpenes like linalool – found in lavender – are found to provide a relaxing effect when inhaled. Others like limonene have been regarded to have uplifting effects. So, adding these terpene derived essential oils are likely to provide numerous benefits when added to these products.

Distilled Oils

Essential oils themselves have become widely popular on their own. These oils are often used in diffusers, which vaporize the oils mixed with water to provide a pleasant aroma in the home, or can even be used to substitute come cooking products like peppermint extract. These are used frequently as homeopathic solutions for those who want a more natural approach to relieve certain ailments such as anxiety, immune deficiency and more.

Home Remedy Products

As mentioned before, essential oils are seeing a rise in use to deal with a number of medical or household issues. Some of these products are rather creative. Some may include aromatherapy products like terpene infused bug bite sticks, CBD creams, roll-on products, stress relief bath scrubs and more. Other terpenes like peppermint extract are useful for things like bug repellents and are often used to replace more harmful, chemical based products.

Industrial Hemp seed and oil

Why You Should Use a Plant Oil Extractor

According to some studies, the essential oils industry could potentially reach a staggering $27 billion by the year 2022 from an already impressive $17 billion market from 2017. If that wasn’t inspiration enough, the essential oil industry is a worldwide market that is stable and growing every year. This means it is the perfect time to dive into the extraction industry, and that means choosing the right plant oil extractor.

At extraktLAB, we specialize in creating the highest quality supercritical CO2 extractors for the botanical extraction industry. As we’ve discussed, CO2 extraction methods are the best option for quality, pure, safe products with a much lower long-term production cost. This is why we provide botanical extraction training with all of our extraction equipment.

If you are interested in stepping foot into the profitable botanical extraction industry, we’re here to make that venture a success. Reach out to us at 651-600-0036 to speak with an extraction expert today. We will discuss your intentions and goals no matter what they may be and find a solution that works best for you when choosing your essential oil extractor and starting your journey into the profitable world of botanical extraction.

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Get access to extraktLAB’s line of supercritical CO2 extractors which considered as the  highest in quality, efficiency and GMP compliance in the hemp and cannabis extraction industry.

Frequently Asked Questions

What is the solvent loss for ethanol extraction?

Hemp and cannabis biomass is an extremely absorbent material.  As a consequence, a large amount of solvent volume must be added to the biomass to first solvate the biomass and then fluidize it. For ethanol extraction, approximately one gallon of ethanol is required to extract 1 lb of hemp. Solvent loss comes from the incomplete recovery of that solvent from the hemp.

The following table details the estimated solvent loss from ethanol extraction as a function of volume of hemp processed:

Lbs processed per day Daily requirement of 

ethanol  (gallons)

Daily Loss of ethanol (gallons) at 90% recovery of ethanol Max Cost of Solvent Loss per day:

$16-30/gal food grade ethanol

$6-8/ gal denatured

Calculated at $30/gal

500 500-1500 50-150  $1,500-45,000
1000 1000-3000 100-300 $3,000-9,000
2000 2000-6000 200-600 $6000-18,000
10000 10000-30000 1000-3000 $30,000-90,000

 

 Another source of solvent loss is incomplete recovery of solvent from the CBD hemp oil. 

How many times can I recycle or reuse ethanol from an ethanol extractor?

In guidance published by the FDA in 2010,  plans for the reuse of solvents  must be accompanied by a  Declaration of the maximum number of times the solvent can be reused. 

 the FDA has recognized that contaminants buildup in the solvent over time as they are  recovered and reused  

As a consequence, the FDA guidelines recommend that the solvents be brought back to a suitable state before Reuse. A suitable reuse is defined by  the original specifications for the solvent that is being used.  

 In keeping with a risk-based approach to process validation, the key risk to address with solvent reuse is cross-contamination. Cross-contamination could happen when a  solvent dissolves a low level contaminant  from the biomass being extracted. As the solvent is removed, the contaminant can become magnified and concentrated in either the oil or the solvent during solvent recovery. Cross contamination then occurs when a contaminated solvent is used to extract a non contaminated batch.

Contaminants are typically identified during incoming inspection  but may show up  later during processing  as the oil becomes more refined. Hemp is typically sampled at receiving by quality assurance and a series of tests are conducted on the Hemp biomass in order to determine if the incoming material  is contaminated with pesticides, solvents, heavy metals or if it has significant microbial content. Contaminants that are identified in the quality inspection should be tested for build up in the extraction solvent during validation.

Other sources for contamination include carbon black or activated carbon that is typically used in ethanol extraction to remove chlorophyll from the ethanol. Combustion byproducts that are incorporated into the structure of carbon black can dissolve in the ethanol  and contaminate.

According to FDA guidelines, the number of times ethanol solvent can be reused must be validated according to a validation protocol. Once the method and process has been validated, the requirements for testing each reuse batch  may not be required depending on the risks identified during the validation study.

 As a general rule of thumb, a solvent may be reused successfully 20-50 times. Whatever your company’s current practice is, it is important to define the process, validate the process, establish specifications for reuse, and also set up a testing program to measure for contaminants. In all likelihood, a solvent changeover is probably in your future  and it’s cost should not be neglected in your overall operating cost model. It is easy to estimate the cost of solving change over as it is the same as the start-up cost:

Lbs processed per day Daily requirement of 

ethanol  (gallons)

Cost per gallon:

$16-30/gal food grade

$6-8/ gal denatured

Calculated at $30/gal

500 500-1500 $15,000-45,000
1000 1000-3000 $30,000-90,000
2000 2000-6000 $60,000-180,000
10000 10000-30000 $300,000-900,000

 

 The solvent changeover cost on a 60 day change over cycle can then be estimated on a per year basis according to the following table:

Lbs processed per day Change Over Frequency Cost of Changeover Max Annual Cost 
500 60 days $15,000-45,000 $270,000
1000 60 days $30,000-90,000 $540,000
2000 60 days $60,000-180,000 $1,080,000
10000 60 days $300,000-900,000 $5,400,000

 

By extension, the solvent testing costs will also be important to address:

Lbs processed per day Change Over Frequency Cost of Testing

(pesticides, solvents), 

Unknowns testing can be 5-10k USD per unknown.

Max Annual Cost 
500 60 days $200-400 $2400
1000 60 days $200-400 $2400
2000 60 days $200-400 $2400
10000 60 days $200-400 $2400

 

 It is important to insist that unknowns be flagged by your laboratory. 

What is supercritical CO2 extraction?

Supercritical CO2 extraction is used in hemp processing in hemp extraction for extracting CBD oil from hemp biomass. You can also be used to extract any Botanical oil from any plant material.

The co2 extraction typically takes place above the supercritical pressure and temperature for CO2. Is 1,070 PSI and 31 degrees Celsius.

Under supercritical conditions, the CO2 behaves much like hexane in terms of its solubility selectivity.

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.

How much hemp can be processed per day with CO2 extraction?

CO2 extraction facilities have been scaled to do hundreds of tons per day of biomass extractions. These facilities are very safe compared to the equivalent extraction facilities that use Flammable solvents.
In Terms of extraction facilities for processing hemp, we have built facilities that will process 5 tons of hemp biomass per day in a safe, low cost, low energy, small footprint operation.

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.

What is the highest yield you can expect from hemp extraction?

Industrial Hemp extraction typically has a CBD content of 5 to 15% by weight. The THC content of the Industrial Hemp is required by law to be less than 0.3% by weight in the flower that is sold.

Does raw hemp moisture affect yield?

Yes, moisture content will affect weight yield. For example, if 10% of the hemp To be extracted was water, and that water was removed during CO2 extraction, the denominator would be larger in the yield calculation, thereby giving a smaller yield number. By extension, if the same hemp was extracted but had zero water in the hemp, the overall weight percent yield of the extract would be a greater percent of the weight.

One thing to note is that in ethanol extraction, water that is in the hemp will dissolve into the ethanol. If the ethanol is removed from the CBD oil with a falling film evaporator, some of the water will be Co evaporated with the ethanol, thereby increasing the amount of water in the ethanol for each extraction cycle. Some of the water will stay in the extract and is typically removed in a secondary stirred reactor before wiped film evaporator and distillation.

Do you offer training on hemp processing and hemp extraction?

We Have taught hundreds of customers how to extract CBD oils from hemp and THC oils from cannabis. Our training package typically includes installation of the equipment, standard operating procedures, commissioning of the equipment in the facility, and training of operators on the procedures that are provided.

We also offer advanced training and quality management system implementation services for those companies who wish to achieve GMP certification.This training dresses all aspects of the quality management system, laboratory information management, batch record system, and Manufacturing execution.

What kind of employees do you need for hemp processing or hemp extraction?

There are basically four different employees that you need to have in order to run a hemp processing or hemp extraction facility. These are as follows:

  1. assurance
  2. Shift manager
  3. Operators
  4. Optionally analytical operators.

If your goal is to produce a quality product that complies with GMP requirements, you are going to need to have staff that can help you comply with those requirements.That typically means you need to have a quality assurance manager that is aware of the requirements And can Implement those requirements in your facility.

It is also necessary that you have a shift manager. This is someone who is organized and can schedule operators at each station and track the production output. This person will also ensure that operator training has occurred, ensure that yields are met, and also manage the workforce. They are also responsible for producing products that can form with the quality requirements of the end product.

Operators typically execute on the production plan by following standard operating procedures. They are typically trained on how to use the equipment and how to move materials in and out of the process. It is their job to record the data for the quality management system. The Operators typically will be successful if they are Hands-On and are able to follow instructions. It is also a big Advantage if the operator can conduct basic maintenance on the equipment. This requires someone who is Hands-On and has the physical strength to do simple maintenance tasks. This is important for the proper running in the efficiency of a hemp processing facility.

Last but not least, analytical operators or quality control technicians are important for providing yield and in-process testing to the manufacturing facility. They will work with quality assurance directly to ensure that incoming raw hemp biomass conforms to purchasing specifications and to Quality specifications. Quality control technicians are typically chemists and have a laboratory background.

Get in touch with our team to request a quote, learn more about our training or get help with your business plan

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