Hemp Processing

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. 

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. 

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.

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.

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.

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.

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.

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.

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.

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.