Moving Beyond Hydrocarbons

by | Feb 24, 2021

Written by Deborah Agboola

Extracting cannabinoids is a complex and often challenging process. Depending on the intended use, factors like the purity level, safety, and cost-efficiency are integral to selecting an extraction process.

With the world turning towards a green revolution, industries are becoming more focused on exploring more natural methods. Sourcing for higher purity compounds and practicing eco-savvy techniques are top of the list for most. 

Now, of the many commercial extraction methods out there, some have certainly stood out for their high efficiency. However, these techniques are laden with a few drawbacks, not to mention they do not align with today's eco-friendly trends.

Alternatives to Hydrocarbon Extractions Processes

Unarguably, this process has produced the best-quality cannabinoid. As expected, the solvent-based extraction process has evolved dramatically over time, with successive tweaks aimed at improving efficiencies, safety, and costs.

Below are some of these modifications, their comparative benefits, and their demerits to hydrocarbon extraction. Let’s review the hydrocarbon process. 

The use of hydrocarbons in cannabinoid extraction is certainly not the most environmental-friendly. However, its high efficiency convinces many manufacturing industries to ignore the hazards. Unfortunately, producers often focus more on yield quantity than its carbon footprint or impact on public health safety.

It’s a fact; the food manufacturing industry also favors hydrocarbons for extracting and producing flavorings. However, the method comes with a significant risk of high-level toxic materials, particularly when misused. So, what are some of the alternatives to hydrocarbons? 

Supercritical CO2 Extraction

This method is ultimately the best cannabinoid extraction method known to date. It falls under the category ‘Supercritical fluid extraction (SFE)’—a technology widely used in extracting essential food and bioactive compounds. 

As the cannabis extract market grows, CO2 extraction has seen a rise in popularity. Could this be due to its minuscule carbon footprint? Let’s find out. 

Merits: Unlike most inorganic solvents, carbon dioxide is inexpensive, easily attainable, and comes with no toxicity risk. Its process is easily scalable, offers high selectivity, and due to the chemically inert and non-flammable nature of the solvent used, the procedure has a low hazard risk. 

The chemically inert compound also makes the preservation of the final analyte’s molecular composition possible. Since CO2 is gaseous at room temperature, the solvent is an excellent extractant and leaves relatively minimal residual matter after extraction. Considering environmental safety, CO2, as a freely circulated compound in nature, is recyclable and has a low carbon footprint. 

Demerits: The primary disadvantage of this procedure is its high investment cost for equipment acquisition and operation. Also, as a nonpolar solvent with a quadrupole moment, it can only dissolve some polar compounds at elevated process parameters—a risk to thermal labile compounds. However, this is minimized with co-solvents, as they increase the polarity and elusive strength of the supercritical fluid. 

In comparison to Hydrocarbons:

The supercritical CO2 method is more efficient, as well as health and environment-safe. However, CO2 extraction requires the most expensive machines than most hydrocarbon systems. But in terms of overall cost, CO2 is more cost-efficient, needing fewer safety precautions and equipment than its flammable counterpart.

Pressurized Hot Water Extraction (PHWE) 

It is imperative to note that steam distillation is very different from PHWE. Although they are both used in extracting essential oils and are relatively health-safe, they are functionally dissimilar. Comparatively, steam distillation is not as efficient in extraction and preservation as pressurized hot water extraction.

Pressurized hot water extraction is an eco-friendly, non-toxic method of obtaining cannabis extracts with high efficiency using only water. This process uses superheated water to separate the cannabinoid from the biomass. PHWE also offers its operator dual options based on the desired extract quality and budget, including static and dynamic pressure hot water extraction systems.

Merits: As “a gift from nature,” water is the most inexpensive extractant and is also readily available. Due to the solvent type, the overall procedure is environmentally safe, relatively hazard-free, and the final analyte is usually of high purity.

The PHWE process is an easily scalable one—a beneficial feature to growing businesses. And the increased temperature levels allow for both polar and nonpolar compounds. 

Demerits: Although this process is easily scalable, its high-temperature needs pose a thermal degradation risk to the phytocannabinoids. The temperature factor of this method also decreases the selectivity of this process: solubilization of non-target materials.

In comparison to hydrocarbons

PHWE offers two options based on the operator budget and target quality. The method is comparatively more eco-friendly and results in extracts of lower toxicity levels than the hydrocarbon extraction method. PHWE is also non-flammable and has relatively fewer operating protocols.

Rosin Press Technique

Unlike the already discussed, Rosin press extraction is a solventless process, which relies on heat and pressure to obtain the compound from the stock. Over the years, this method has blossomed in popularity for its simplicity and relatively inexpensive procedure.

In considering rosin presses, there are two types available based on their modus operandi: hydraulic and pneumatic cylinders. The hydraulic press uses compressed fluids to create pressure, while the pneumatic uses air. There is so much more to this technique, but that’s a discussion for another time.

Now, what makes this technique different from the rest? Are there any merits associated with using primarily heat and pressure? And what demerits have been associated with this procedure? 

Merits: As earlier noted, the Rosin press extraction is a solventless process; hence, there is minimal risk of producing final analytes with contaminants or residual solvents. The technique is also simple to carry out and requires no heavy machinery. Concerning extraction time, this method is rapid and occurs almost instantaneously. 

Demerits: Too much heat can degrade the composition of the final analyte. So, pristine care must be taken while running the process to avoid obtaining inefficient results. Moreover, using a standard rosin press machine that combines the right amount of pressure with the lowest possible heat can be employed to this end. 

In comparison to hydrocarbons

Unlike hydrocarbon extraction, a solvent-based process, the rosin press has a lower toxicity risk and offers more concentrated extracts. Due to the flammability of the solvent, the hydrocarbon extraction procedure is more hazardous than rosin press’. As a result, it requires more technical know-how and safety precautions. By eco-safety standards, the rosin press method is safer than hydrocarbons.

The numbers of eco-alternatives for effectively extracting cannabinoids are not limited to these few. Which then begs the question, “why do we keep going for chemicals when we have healthier means?” The answer? Many of the demerits of these alternatives overshadow their health benefits. 

Though in need of high-quality yield, manufacturing industries also desire high-quantity yields. After all, why produce if you cannot make a profit? So, I would say, while we wait for better alternatives, why not develop these eco-friendly methods?

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