Industrial Scale Extraction: Energy Consumption Analysis

In cannabis extraction, from an operational perspective, we have one goal: convert the largest possible fraction of cannabinoids from the plant into usable ingredients for finished products, while incurring the lowest total amount of cost.

As such we have worked to develop a proprietary extraction system with the specific goal of maintaining extraction efficiency while minimizing cost, and maximizing the throughput of the system.

We believe that it isn’t currently possible for anyone to develop a system that extracts cannabinoids in a more cost-efficient manner than EnCann.

Highlights of the EnCann extraction system:

  • Substantially decreased operational cost vs traditional processes
  • >75% reduction in evaporative process volumes
  • Can handle wet or dry material
  • No additional solvents introduced from extraction to isolation
  • Similar capex to equivalent ethanol systems

For those who don’t want to dig too far into the calculations, the below image is a snapshot of the results of the comparison between a traditional ethanol system and the EnCann system.

Industrial scale extraction energy consumption analysis

Extraction Fundamentals

Before we dive into how we’ve achieved the efficiencies we have, we need to start by outlining the basic steps of extraction:

  1. Add solvent to your biomass
  2. Separate the solvent from the biomass
  3. Remove the desired compounds out of the solvent
  4. Produce finished product

Each of these steps can be performed in many different ways. Ask 100 extractors what the best way to do any given thing is and you’ll probably get 115 different answers. For example, the solvents used are generally liquids, but they can also be gasses or novel states of matter like supercritical CO2. The solvent picks up pretty much everything that is soluble in that solvent at the temperature and pressure you’re applying the solvent at.

Let’s take a closer look at number three because that’s where most extractors find that they run into significant operational bottlenecks. That step is where we get the desired compounds out of the solvent, prior to using them to create finished products.

Sometimes this can first require removing compounds that were co-extracted in the extraction step – this is what extractors are doing when they precipitate or “winterize” material to remove fats and waxes, or when a water or brine wash is performed on crude oil to remove water-soluble compounds.

If you talk to extractors who work with volumes in the tons per hour or day range, many of them will use ethanol, isopropyl, or other alcohol-based extractions. Frequently, these extractions are performed at cold enough temperatures that fats and waxes are only sparingly soluble in the solvent, so the winterization step is able to be skipped. If you have to winterize, it adds a lot more time into the process – as a rule of thumb, it’s frequently better to not extract something than to remediate it later.

Another rule of thumb you hear a lot is “one gallon per pound” in reference to how much liquid solvent is required per unit mass of biomass to be extracted. This ratio tends to result in nearly complete extraction of the cannabinoids in the biomass, and also results in a pumpable slurry for extractors moving material around in that manner.

The solvent is then generally recovered using evaporative methods, with Falling Film Evaporators being one common example.

Distillation also falls into this category – lighter compounds such as terpenes boil before the cannabinoids, so can be removed. Compounds heavier than cannabinoids are left behind in the boiling flask.

There are many reasons for this overall process design, but most of them boil down to “at this scale, in many cases, it’s the best and most efficient compromise available with the present technology that is commonly available and well-understood.”

The EnCann Way

Extraction is an imperfect science, but in that imperfection lies an opportunity to be more effective. That’s where EnCann sets itself apart.

Two of the founders of EnCann are engineers, and so we see things a little differently. We want to reduce the total amount of resources we have to expend to get any given job done.

To put it plainly, we’re efficiency nuts. In this case, less is more – and more is better.

Other extractors deal with a litany of challenges that increase energy costs and decrease efficiency – primarily temperature swings and phase changes. Whenever you’re dealing with heating or cooling something, and sometimes heating or cooling to the point of a phase change – liquid to solid (freezing) or liquid to gas (evaporation), for example – the energy required is massive. It takes approximately 4 times as much energy to boil one litre of ethanol as it does to raise the temperature of that ethanol by 100 degrees. Increased energy consumption increases operational costs because it requires resources to generate that energy and make it available for use. In technical and economic terms, phase changes are expensive.

So instead of taking the traditional route, we’ve leveraged bleeding edge technology to remove as many temperature swings and phase changes from our system as possible.

From a pure chemistry and thermodynamics perspective, there are no major process bottlenecks in this system – no places we can make massive improvements in efficiency or throughput – other than secondary solvent/terpene recovery. But we’ve got some tricks up our sleeve for that one as well.

Oh, and did we mention that we can process material that is wet from the field instead of requiring that it be dried prior to processing?

These process changes result in a massive reduction of required energy, which means that our process has an incredibly low operational cost. We believe that it isn’t currently possible for anyone to develop a system that extracts cannabinoids in a more cost-efficient manner than EnCann. That’s why we filed for a patent on this process – in the production of commodities, being the lowest cost producer is an incredible advantage.

“When it comes to evaluating extraction system IP it’s easier than most, everything comes down to cost (time and scale are also factors, but cost is the major differentiator) […] Instead of blocking people from extracting, IP is used to defend methods of cheaply extracting compounds from cannabis. […] Assuming the profit margins and yields are similar, the company that offers you the cheapest price to produce CBD isolate arguably has the most valuable extraction IP. If a new company comes along and is able to extract for cheaper, while maintaining margins, they’d devalue the IP of every other extraction company.”

-Graham Jones (CytochromeP4)
thecannalysts.ca

(This quote was retrieved from TheCannalysts independent analysis of the cannabis industry and is used with the author’s permission. It is not to be considered an endorsement by the author of EnCann or EnCann’s patent-pending extraction technology.)

In addition to the operational cost savings, until we have access to true zero-carbon energy sources, reducing our energy consumption is also something that has positive effects on the environment and society as a whole. We can operate in a way that has a lower impact on the planet and make more money? That seems like the right combination to us.

And have you seen how much time and capital it takes to get your local power company to set up to feed you 6 megawatts of power if you don’t already have it?

Energy Consumption Analysis

Engineers tend to like spreadsheets, and we are no outlier in that. So we put together a spreadsheet to help explain the impact of the changes we’ve made in our system.

But before we link that, a brief explanation is in order:

This is an energy use comparison between a traditional ethanol-based extractor and the patent-pending EnCann extraction system. Both extractors are extracting 1000 kg per hour of dried input biomass, with a 10% CBD content, and converting it into CBD isolate.

To be clear, this is only comparing the basic energy requirements of these various processes. It doesn’t account for labour, solvent consumption, or other overhead costs. It also doesn’t account for the energy required to perform steps that are the same for both extractors – such as running centrifuges or screw presses for the solid/liquid separation stages or pumping liquids from one process to another.

The ethanol extractor is assumed to use one gallon per pound of biomass and extracts at -20°C so as to completely mitigate the requirement for a winterization step. They then perform two stages of evaporative solvent recovery methods to remove all traces of the ethanol – this would generally be a falling film evaporator followed by a rotary evaporator. The resulting crude oil is then decarboxylated and distilled. It is then dissolved into pentane and isolated.

Now it is time to let the numbers speak for themselves. Click here to open the page with the calculations in a new window.

Here are the editable parameters if you would like to adjust the calculations to match your situation:

  • CBD%
  • Kilograms biomass per hour
  • L solvent per kg biomass
  • Voltage
  • Chiller efficiency
  • L of solvent per L of CBD (isolation)
  • Ambient Temperature
  • Energy cost in $/kWh
  • Temperature change required by the Ethanol extractor for:
    • Solvent chilling
    • Primary and secondary solvent recovery
    • Decarboxylation
    • Distillation
    • Isolation
  • Solvent selection can be changed by editing the top “Input” line on the Competitor Energy Budget” tab
  • Thermophysical properties of solvents and be edited with the table on the Summary tab
  • If a solvent that isn’t listed is desired, edit the “Custom” column in the thermophysical properties table, and change the solvent in the “Input” line on the “Competitor Energy Budget” tab

You may have reached the end of this article and thought to yourself, “wait just a second – you never really told me what you actually do for your process,” and you’d be correct.

We don’t want to make things too overly easy for our competitors, and our lawyers tell us there is only so much that we are able to put into the public realm without an NDA in place.

If you’d like to learn more, please don’t hesitate to contact us using the form below.