Supercritical CO₂ extraction is a way to recover fat-soluble fractions from hemp seed without heat and without organic solvents. The method rests on a single physical phenomenon: at a certain pressure and temperature, carbon dioxide enters a supercritical state and begins to behave as a liquid and a gas at once. Below we look at what happens then, how extraction differs from cold pressing, and why no trace of solvent remains in the finished product.
What the supercritical state of CO₂ is
Every substance has a critical point — a combination of pressure and temperature above which the boundary between liquid and gas disappears. For carbon dioxide it lies at about 31 °C and roughly 74 bar (≈73.8 bar). Above this point CO₂ becomes a supercritical fluid: it takes on a density close to that of a liquid, and with it the dissolving power of a liquid, while keeping the diffusivity of a gas.
It is this combination that makes supercritical CO₂ a working solvent. Its density lets it dissolve the target compounds, while gas-like diffusion lets it penetrate the milled raw material and wash those compounds out of the cellular structure. CO₂ is a non-polar solvent, so it works well with the lipophilic (fat-soluble) components of the seed.
Tunable selectivity: pressure and temperature
The key property of supercritical CO₂ is that its dissolving power is tunable. By changing pressure and temperature, the operator changes the density of the fluid, and with it which fractions it dissolves. This makes selective extraction possible: matching the regime to the target fraction rather than extracting everything at once.
The process runs at mild temperatures. At the plant, extraction is carried out at no more than 40 °C, and this matters: thermolabile lipophilic components — fatty acids, tocopherols and others — are sensitive to heat and break down at high temperatures. The low-temperature regime keeps them in the recovered fraction.
A clean product with no residual solvent
Once extraction is complete, the pressure in the system is released. Under ordinary conditions CO₂ returns to a gaseous state and evaporates from the product completely. No solvent remains in the extract — this is what a label calls a «clean label».
Here the method differs fundamentally from extraction with organic solvents such as hexane. There the solvent has to be separately removed from the product, and part of it can remain as residual traces. CO₂ extraction has neither that stage nor that risk: the gas leaves on its own.
- CO₂ is non-toxic and non-flammable;
- the gas can be recycled within the process and reused;
- CO₂ is food-grade (GRAS status);
- no residual solvent remains in the finished extract.
CO₂ extraction and cold pressing are different methods
It is important not to confuse the two processes. Cold pressing mechanically squeezes oil from the seed under press pressure — this is how green cold-pressed oil (INCI Cannabis Sativa Seed Oil) is produced. CO₂ extraction works differently: it dissolves and selectively recovers lipophilic fractions, and the result is CO₂ extracts — concentrated fat-soluble fractions and microemulsions.
The two methods do not replace each other; they are complementary. The green oil is a product of pressing, not of extraction; CO₂ extracts are a separate line obtained by the supercritical method. Keeping them distinct matters both in substance and in documentation: each has its own product and its own use.
Where this applies to hemp seed
For hemp seed, supercritical extraction yields lipophilic fractions and extracts without thermal damage and without solvents. That makes the method suitable for two directions: cosmetics, where CO₂ extracts are in demand, and premium food ingredients, where both the integrity of the components and the purity of the composition matter.
The mild temperature regime and the absence of residual solvent are the two properties that define the value of an extract as an ingredient. They make it possible to work with heat-sensitive compounds and to offer a composition without a chemical load.
Processing without chemical reagents
CO₂ extraction fits naturally into the approach of «processing without chemical reagents». The solvent here is a food-grade gas that leaves the product entirely — which means the extract retains neither organic solvents nor the by-products of their removal. This is reflected in patent No. 2764298 for deep processing without chemical reagents.
OOO «MAKOSH» is the first full-cycle deep-processing plant for industrial hemp seed in Russia; its process chain combines impact dehulling, cold pressing and CO₂ extraction at no more than 40 °C. Delivery terms and prices are available on request.
This is what we make
Our own full-cycle plant in the Uzlovaya SEZ. Wholesale, EAEU documents, 0% THC.
Hulled hemp hearts (separated)
Protein over 30% · omega-3/6
Cold-pressed green hemp seed oil
Omega-6 : omega-3 = 3.5 : 1
Hemp protein flour
Protein 40–45 g/100 g
We’ll match a product to your production need and send samples with documents.