An RNG upgrader that starts with raw biogas often removes 35 to 45 percent CO₂ before the methane can enter the pipeline.
That CO₂ stream is one of the most practical new sources of domestic supply in the market. It is already separated at the site. It is produced every day the facility runs. It is biogenic. It is regional. In a supply chain that still depends on a small number of large legacy sources, that matters.
But there is a gap between a useful CO₂ stream and a usable commercial product. Concentrated CO₂ from an RNG upgrader is not automatically beverage grade CO₂. It has to be purified, tested, documented, stored, and delivered in a way that food and beverage customers can trust.
Concentrated Is Not The Same As Clean
Raw biogas starts with organic material. Dairy manure, landfill gas, food waste, wastewater sludge, and other feedstocks all create different gas profiles. The upgrader removes CO₂ so the methane can meet pipeline quality, but the CO₂ side of the process can still carry trace contaminants from the original feedstock and the treatment system.
Those contaminants can include moisture, sulfur compounds, volatile organic compounds, siloxanes, residual methane, oxygen, nitrogen, and hydrocarbons. Some appear in small concentrations. That does not make them irrelevant. Beverage grade specifications are written around small concentrations because small concentrations can still affect taste, product stability, equipment performance, and food safety.
This is the difference between having CO₂ and having a product. A vent stream has potential value. A beverage grade product has verified market value.
The Market Cares About The Finished Spec
Food and beverage buyers do not buy a source story by itself. They buy an ingredient. The CO₂ touches the finished drink or food product, so the buyer needs confidence that each load meets the right specification and arrives with the right documentation.
That is why beverage grade is the key differentiator. Industrial grade CO₂ may have buyers in some applications, but it does not solve the highest trust part of the market. Beverage, food processing, and quality sensitive customers need CO₂ that meets strict limits on moisture, sulfur compounds, oxygen, hydrocarbons, benzene, acetaldehyde, odor, and other trace components.
The spec matters because reliability is not only about volume. A supplier can have plenty of gas available and still create risk if the product cannot pass the test, if documentation is inconsistent, or if delivery practices allow contamination after purification.
Why RNG Streams Need A Different Kind Of Attention
Older CO₂ sources were not all clean, but many were built around large centralized industrial processes with long operating histories. RNG is different. It is distributed across hundreds of sites, tied to local organic feedstocks, and built primarily to make renewable methane. CO₂ recovery is usually not the reason the facility was designed.
That creates a practical challenge. The same qualities that make RNG attractive as a CO₂ source also make purification discipline more important. The sites are local. The CO₂ is biogenic. The supply can be close to customers. But the raw stream reflects the biology and chemistry of the feedstock, which means the purification system has to be built for that reality.
A generic cleanup step is not enough. The system has to remove the contaminants that matter for the target market, protect the product through liquefaction and storage, and produce repeatable results load after load.
Where Cryogenic Purification Fits
Cryogenic purification is useful because it uses temperature, pressure, and phase behavior to separate CO₂ from contaminants in a controlled process. The goal is not simply to liquefy the gas. The goal is to turn a raw stream with variable trace impurities into a stable product that can meet beverage grade requirements.
At CleanCycleCarbon, our Lewiston, NC facility proves that this can be done commercially. We use a patent pending cryogenic purification process to produce FDA registered beverage grade CO₂ from challenging raw streams. The hard part is not saying the CO₂ is biogenic. The hard part is removing the contaminants that keep it from being accepted by the customers who need the highest quality product.
Hydrocarbons are a good example. They are a normal concern in RNG related streams, and they matter for beverage and food customers. A process built for this market has to handle them directly, not treat them as an afterthought.
New Supply Has To Fit The Existing Industry
The CO₂ market already has distributors, bulk tanks, tanker trailers, certificates of analysis, customer quality systems, and delivery expectations. New supply only helps if it can fit that system. A buyer should not have to rebuild its entire quality program to use a lower carbon or regional source.
This is why CCC works with the industry. The opportunity is not to route around distributors or pretend the existing supply chain does not matter. The opportunity is to add new domestic beverage grade supply that can move through channels buyers already trust.
For RNG operators, that means the CO₂ byproduct can be more than a vented stream, but only if it is upgraded into a product. For buyers, it means new regional supply can reduce exposure to outages, freight constraints, and legacy source concentration without lowering the quality bar.
The Practical Takeaway
RNG CO₂ is not valuable because it exists. It is valuable because it can become beverage grade supply when the right purification, testing, and delivery controls are in place.
That distinction matters for both sides of the market. RNG operators should treat the CO₂ stream as a potential commercial product, not just a compliance detail. CO₂ buyers should ask whether a new source can meet the same beverage grade expectations they apply to traditional supply.
The U.S. needs more CO₂ supply. It also needs supply that can be used by the customers who depend on purity, documentation, and reliability. RNG can help close that gap, but only when the CO₂ is purified all the way to the standard the market actually needs: beverage grade.
