Looking beyond established feedstocks
The renewable fuels market is evolving. Alongside established feedstocks such as Used Cooking Oil (UCO) and animal fats, attention is increasingly turning to more complex residues from food production, agricultural processing, oil refining, and renewable fuel production itself.
These materials are often referred to as advanced feedstocks. But when it comes to determining their true potential, the material’s name is only the beginning.
Where does it come from? Which process generated it? What is its composition? Does it have alternative uses? And in which market will the final renewable fuel be supplied? Each of these factors can influence how a feedstock is classified, and ultimately whether and where it can be used.
At Connex, we believe this is where new opportunities emerge. By looking beyond the label and understanding the full story behind a material, we can determine what it is, where its potential lies and what it takes to create a responsible route to market.
Different streams, different considerations
Connex is currently exploring several feedstocks that could play a greater role in future renewable fuel supply chains. Each comes with its own opportunities and its own complexities.
Cashew Nut Shell Liquid (CNSL) is an oil obtained from the hard shell surrounding the cashew nut after the edible product has been removed. It offers an opportunity to create value from residues generated by cashew processing. However, extraction methods and processing conditions can influence the composition and consistency of the resulting material. Understanding exactly how and where CNSL is produced is therefore essential when assessing its quality, classification, and potential applications.
Spent Bleaching Earth Oil (SBEO) is recovered from the filtration material used during vegetable oil refining. Its potential lies in recovering residual oil that would otherwise remain trapped in the spent material. Here, accurately defining the product is crucial: spent bleaching earth is the solid filtration medium, whereas SBEO is the oil recovered from it. Recovery methods, impurities and inconsistent terminology can all influence how the stream should be assessed.
Residue of FAME end distillation is generated during the final processing stages used to bring biodiesel within the required specification. However, not every residue produced at a biodiesel facility automatically qualifies. The original feedstock, production process, physical characteristics and volumes generated all need to correspond with the recognised criteria. This makes traceability back to the original FAME production process particularly important.
Food waste can originate from food producers, retailers or consumers and may include expired products or materials removed from the market for health or safety reasons. Its diverse origins also make it a complex stream. Ingredients, collection systems, contamination risks and moisture levels can all affect quality and consistency. Crucially, it must be demonstrated that the material is unsuitable for both human and animal consumption. Surplus food, for example, does not automatically qualify as food waste.
Soapstock Acid Oil contaminated with Sulphur (SAO cont. S) can arise when soapstock from vegetable or animal oil refining is treated to recover fatty acids. Where contamination with sulphuric or phosphoric compounds makes the material unsuitable for other applications, an energy outlet may offer a potential route forward. Classification, however, is key. Eligibility depends on evidence of the production process and contamination, as well as the specific requirements of the market in which the final fuel is supplied. A material should therefore not be assumed to have the same status across every European market.
Turning complexity into opportunity
This is where Connex creates value.
Rather than taking a commercial product name at face value, we dig deeper. We look at where a material comes from, how it is produced, how it should be classified, and where it can find the right application.
For the Dutch market, this includes assessing individual streams against the applicable NEa requirements, including Annex 5 where relevant. By combining regulatory understanding with market knowledge and strong industry connections, we help explore responsible pathways for complex residues to enter renewable fuel supply chains.
Because the opportunity is not simply about finding more feedstocks. It is about understanding them. Knowing what sits behind the blend. And connecting the right material to the right market through transparent, responsible supply chains.
As renewable fuels continue to evolve, so will the feedstocks behind them. And that makes looking beyond the familiar increasingly important.