Green Mill Supercritical

By Eric Peterson | Jan 21, 2021

Company Details


Pittsburgh, Pennsylvania



Ownership Type





Botanical extraction systems

CEO Wes Reynolds sees a path to growth with the "holy grail" trifecta of CO2 extraction: perfect control of pressure, temperature, and flow rate.

Photos courtesy Green Mill Supercritical

Green Mill Supercritical is looking to go where no manufacturer of cannabis extraction systems has gone before. "We're on a mission to push CO2 beyond its known limits," says Reynolds.

Co-founder Jeremy Diehl has a mechanical engineering background with an emphasis on carbon dioxide. "He [Diehl] worked with Thar, one of the early pioneers with CO2," says Reynolds. "He had some very specific ideas about how to make CO2 extraction more elegant than anybody was doing at the time and started experimenting with that. One thing led to another."

Following two years of R&D, Green Mill went to market with its first supercritical CO2 extractor. in 2017. "A proprietary liquid displacement pump is the heart of the system," says Reynolds, calling Green Mill's equipment the "most precise, most efficient, most versatile, most dependable extraction system on the market today."

"You're evening the flow through a four-piston pump instead of a traditional two-piston pump," he continues. "People will badmouth liquid displacement, but actually liquid displacement is a huge advantage with cannabis, because you can control the pump and the pump is not affected by all the external forces that come from a non-liquid displacement pump. And it doesn't break down. We have systems that have now been out working daily in the market for a couple years, and they're going strong. We have virtually no downtime."

Proprietary software, along with extremely precise componentry and controls, drastically reduces variation in temperature, flow rate, and pressure, says Reynolds. "The more precise we can be with those variables, the more we can do with the system," he explains, noting that competing systems often have a 300 PSI variation in pressure, whereas Green Mill's extraction system sees swings of only five PSI.

The end result? "It's more about getting what you expected or wanted out of the product," says Reynolds. "Let's talk about the finished product you want to make. Our system allows you all the flexibility in the world to make it perfect."

Green Mill's SFE extraction systems start around $150,000 for a 7.5-liter model, with a flexible modular design that allows for plug-and-play expansion. Starting at $350,000, the Parallel Pro system "dramatically increases throughput while not increasing footprint at all," says Reynolds.

Reynolds, an early investor in Green Mill and 20-year Coca-Cola "brand guy," joined the company in late 2018. "I was running a seed-to-shelf cannabis company in Florida," he says. "I was drawn to this space primarily for primarily economic growth reasons."

The company is based in a historic factory for Westinghouse Electric that's been reinvented as 7800 Susquehanna. "We have a manufacturing area in that building along with several other companies," says Reynolds. "It's wonderful -- 20-foot ceilings, bright, natural light, just a really cool space for manufacturing."

Each system contains more than 1,000 components; many (including the pump) are manufactured in-house but Green Mill also works with a number of contract manufacturers and other vendors for machined stainless steel, fasteners, and other components.

"One of our engineers had the idea to create this heat exchanger that uses a chevron tubing pattern that's not possible to machine," says Reynolds. "So it's 3D-printed stainless steel, and it's really cool. We get that through a third party, but our guys did all the design work and [prototyping]."

Green Mill's certifications include UL, CSA, and ASME. "GMP is something we are working toward," says Reynolds.

After two years of headwinds in the form of the vape crisis, cannabis' capital crunch, and COVID-19, Reynolds says Green Mill is poised for growth. "This really put a chill on capital investment," he says, "but we're seeing a lot of that come back very strongly and we're also a really good pipeline of interested and expected customers for our business."

"We're just getting started with innovation," touts Reynolds. "Our core value is willingness to try, and you see it all the time. Everybody in the company is constantly trying new stuff and figuring out how to make it a work in a way nobody thought it would work."

Challenges: "Our biggest challenge is managing the return to growth," says Reynolds.

The other challenge relates to public awareness, he adds. "There's so much misinformation about what people expect and what they're being sold. That's a challenge for us to set a realistic expectation with our customers. . . We're seeing people buy a lot of stuff where they're promised one and they get something entirely different."

Opportunities: Continued cannabis legalization across the U.S. and in other countries will be the main driver for Green Mill's growth. "We're seeing more and more legalization and more and more consolidation in the industry," says Reynolds. "It's not like we need to build out our manufacturing capacity as we grow. We're ready."

While the hemp/cannabis industry is the primary market, Green Mill also counts hops extractors and lavender extractors among its customers.

The U.S. is the top market, and Green Mill has also found customers in Canada, Australia, Latin America, and Europe. Reynolds forecasts exports will grow. "International is a really interesting story to keep watching," he says.

Needs: Capital. "You never actually have enough money," says Reynolds. "I didn't appreciate that until I started running startup businesses."

He also highlights needs for "more data and transparency" and more CO2 "zealots" to engage with Green Mill.

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