Why Hydrocarbon Extraction is superior compared to Ethanol and CO2.
Propane HEMP Oil (PHO) :
PHO vs “The Rest” – Why choose PHO? PHO (Propane Hash Oil) is the choice for Cannabis Connoisseurs on the “Marijuana” side of the industry (Cannabis with greater than .3% THC by weight). They choose PHO typically, for several palpable reasons: potency, color, smell & taste. These reasons are not just for indulgence, those four reasons are why Propane produces the perfect crude oil extract for refining, isolating and infusing. Therefore, using Propane (C3H8/Propyl Hydride) for extracting essential oils from Cannabis Sativa-L provides only the most potent and desirable concentrates.
Since propane (C3H8) is affirmed Generally Recognized as Safe (GRAS) with a very low toxicity rate (considered “nontoxic”) and its inherent properties make it perfect for cannabinoid extraction. Therefore we consider propane to be the best option available today for efficiently extracting and preserving the true plant essence.
Propane is Non-Polar : Using non-polar solvents (Hydrocarbons) to extract cannabinoids and terpenes which are all non-polar compounds as well and which are all hydrocarbon based2, is the most effective approach we have found. Putting it simply, the non-polar solvent acts as the “key” to “unlocking” the oils from the plant material without unlocking the undesirable, polar compounds within the plant. Non-polar compounds can only bind with other non-polar substances. For example, oils and other fuels are made from a mixture of hydrocarbons. They will not mix with a polar substance such as water. In general, polar solvents dissolve polar solutes, and non-polar solvents dissolve nonpolar solutes (“like dissolves like”).
Supercritical CO2 : (carbon dioxide) is non-polar naturally. However, C02 Supercritical Fluid Extraction(SFE) is cycled at extremely high pressures to keep CO2 in its’ supercritical state. This required phase change allows the operator to pass liquid CO2 though the material, necessary for extraction. This also adjusts/changes the polarity of the solvent and sometimes looked at as positive quality in certain industries where polar compounds are being extracted. For cannabinoid and terpene extraction, CO2 is less viable, due to this shift in polarity. This method has potential for cannabinoid degradation and terpene loss at these pressures. While the polarity shift makes it impossible to extract Live (wet) plant material.
Propane : is our Hydrocarbon of choice because of the -42c boiling point, which is not the lowest of thehydrocarbons. For example, Ethane (-89c) or Methane (-161.5c) have much lower boiling points but wouldboth require a great deal of energy and expensive equipment to migrate the phases and extract thecannabinoids properly. The fact that propane remains non-polar during these phase changes, is why weprefer it over CO2.
CO2 has quite a low boiling temp, as stated above however, for CO2 to extract cannabinoids it must betaken to the supercritical fluid state. Supercritical fluid state is achieved by greatly pressurizing the CO2(hundreds to thousands of psi) which causes the CO2 to change polarity to a non-polar solvent. These high pressures cause undesirables to be extracted from the plant and makes extracting live plant material impossible.
Ethanol is a very polar molecule due to its hydroxyl (OH) group, the ethyl (C2H5) group in ethanol is non-polar. Thus, ethanol can dissolve both polar and non-polar substances. This is an amazing trait of ethanol and why ethanol is one of the best solvents in the world. However, this is also why it makes poor quality cannabis extract with more undesirables and lower potency.
Ethanol, Butanol & Hexane, all having higher boiling points, take a great deal of heat and/or time toevaporate. Due to the lack of efficiency and considering the poor-quality concentrates created by these solvents, it is concluded that these solvents are best used in industries other than cannabis extraction.
Low-boiling Point CO2 (-78.5 °C), Propane (-42c), Butane (-1c), Hexane (68c) vs Ethanol (78.37c), Butanol (117.7)This is very important for preserving terpenes and mitigating cannabinoid degradation. The lower the boiling point the easier it is to remove solvent from the concentrate. A lower boiling point like propane’s -42c, allows for solvent recovery at temperatures/pressures that will not harm the concentrate. Additionally, this low boiling point allows solvent recovery without co-distillation of terpenes. There is however, more to it then just picking the lowest boiling point. When selecting a solvent, it is important to consider all its properties together before selecting.
Generally Recognized as Safe (GRAS) Propane is affirmed Generally Recognized as Safe (GRAS)4. This GRAS affirmation rule notes that the ingredient is used in food without limitations other than those outlined regarding good manufacturing practices. The FDA considers propane to be “GRAS” when used as a solvent5 for extracting cannabinoids and terpenes. Ethanol, CO2 and Butanol also have a GRAS recognition by the FDA. Contact with skin and eyes is non-irritating unless it is evaporating liquid which is why it is not classified as causing skin or respiratory sensitization. Further, repeated exposure to propane does not have any known effects on organs, and is not a carcinogen, mutagen or a reproductive toxin.
Extraction Method Comparisons
- Amber, red, or gold color
- Ran properly, it will pull very little undesirables out of the plant material
- Being non-polar, propane has trouble extracting polar solutes like chlorophyll which is an undesirable
- Sub-critical cycles, allow
operators to leave most of the fats/waxes in the plant rather than remediating later.
- Black/dark green in
- Chlorophyll A/B is the cause of this and is a direct result of the ethanol’s polarity
- Remediating these
undesirables is very expensive and requires a great deal of materials, time and labor
- Expensive remediation
processes do to ethanol crude, reflects on consumer products.
- This varies greatly among different equipment, operators and procedures.
- Most are black/dark brown
- Gold colors are possible,
hard to produce, and from
extremely expensive and
slow processes, which
usually requires the
separation of compounds and subsequent reintroduction of
the desirable compounds
only – very time consuming.
Potency & Yield
- 65% - 90% potency on crude oil, depending on input material
- Leaves most undesirables in
the plant rather than
remediating later. This results in a higher potency extract of a lesser volume (the decreased volume is due to the absence of undesirable compounds).
- 30% - 70% potency on crude oil, depending on input material and process
- Ethanol dissolves both non-polar and polar salutes, pulling
all desirables and
undesirables, resulting in the need for a long, multi-step refinement process
- Cryo-ethanol helps ethanol to extract less undesirables but still results in length, expensive steps throughout the process.
- 50% - 70% potency on
crude oil, depending on input material and process.
- Operators must adjust the temperature and pressures during phase changes which changes the polarity.
- This results in a multiple
step to the crude extraction process, usually requiring remediation of undesirables.
Smell / Taste
- Vibrant smells and flavors, PHO can extract the lightest and sweetest terpenes
- Live-plant material extracts are possible when using propane, this means less cannabinoid degradation and reduction of terpene loss.
- The higher quality extraction equipment such as typically have solvent recovery and dewaxing capabilities built in, reducing post extraction
- Like the color, typical ethanol extracts are un appealing to consumers, as well as consumer product companies.
- Usually earthy, spicy and/or very hay-like smell.
- Running cryo-ethanol helps mitigate this as well. However, the best of the terpenes are lost when distilling the ethanol
for recovery purposes – many terpenes co-distill with ethanol and are very difficult to separate.
- Like the color, this varies
greatly depending on
processes and equipment
- Most are odorless, dingy or funky. The sweetest smelling, and most volatile terpenes are typically lost – some can be captured but in less quantities than ethanol and far less quantities than propane
- CO2 equipment requires
less than 8% moisture
content; live-plant extractions
are not possible.
- Generally Recognized as
Safe per FDA GRAS
- Considered non-toxic and non-caustic
- Minor inhalation risk without long-term health effects or damage.
- Propane liquid and vapor are environmentally safe and friendly in their unused states.
- Not considered greenhouse gas and will not create an environmental hazard if
released as a liquid or vapor into water, soil, or air.
- Used widely and daily in
many consumer products
including; PAM Cooking Spray, other cooking sprays and AXE Body Spray and many other
- Generally Recognized as
Safe per FDA GRAS
- Considered non-toxic/low
- Flammable liquid, with an
inhalation risk (especially at higher proofs needed for extraction) can cause long-term damages to the brain and lungs.
-If inhaled, can cause instant inebriation and possible coma
- The high boiling point makes it difficult to remove all residual solvent – If all ethanol is not removed, it could result in dangerous vape products and would be undesirable for topical products.
- This solvent being liquid, yet still volatile makes it extremely dangerous.8
- Used widely and daily in
many consumer products.
- Generally Recognized as
Safe per FDA GRAS
- Considered non-toxic
- Inert non-flammable gas
- Carbon dioxide does not
only cause asphyxiation by hypoxia but also acts as a toxicant.9
- At high concentrations, it
has been showed to cause
instantaneously and respiratory arrest very quickly
- SFE requires extremely high pressures to keep CO2 in
- Emissions into the
atmosphere could have an
environmental risk according to the EPA11
- Most safety concerns have to do with the actual
extraction process and
- $3.25/lb. cost for the solvent
- 95% + solvent recovery rate
- Propane’s purity changes so little during extraction
(unmeasurable amounts), that it never needs to be replaced
- The quickest extraction
process, which means higher capacity/throughput.
- Will extract very few
undesirables, producing a
consumer ready extract.
Cutting out expensive
- Equipment is inexpensive
and easy to operate
- Live-Resin Extraction!
Propane is by far the most
efficient solvent for live-resin extraction
- $12.72/gal (3.36/l) cost for the solvent.
- 70% - 85% recovery - may be able to recover an additional 5% from the saturated spent material via expensive presses.
- Ethanol’s proof drops each run, losing effectiveness each
run after proof drops below 180 it must be replaced, resulting in the use of tons of solvent
- Extremely long extraction and refinement processes.
- Requires the most post-
extraction processing when compared to propane and CO2
- No Live-Resin Extraction –
some claim live-resin
capabilities with ethanol,
however, the fact that terpenes co-distill with ethanol, makes it impossible to achieve an
extract that is truly reflective of the “live” plant defeating the purpose while increasing costs
- $2.63/lb. cost for the solvent
- 95% + recovery rate, this
depends greatly on
equipment and processes
- Use of high pressure and
temperature. (large number of compounds extracted)
- High setup cost; technical knowledge of SFE properties required
- The high pressures can
cause terpene loss12
- Material must be dried to
<8% moisture content; No
chance of Live-Resin