Biobased drop-in products: Same molecule, new rules
Karin Hjelmstedt and Paul François of Afyren discuss drop-in products, based on the concrete example of carboxylic acids *
For generations, industry focused on turning natural molecules into drop-in petrochemicals, not because nature did not produce these molecules, but because it could not deliver them at the scale, purity and costs required by industry.
Industry built entire global supply chains around fossil-based dropins, only to realise the world now needs biobased alternatives that are, ironically, drop-ins for the very molecules that once had to be synthesised. They have the same chemical structure, the same performance, but represent a radical shift in carbon origin, sustainability and supply chain resilience.
Same molecule, smooth transition
The greatest strength of a drop-in biobased carboxylic acid lies in its continuity. For speciality chemical users, continuity is everything, because reformulating, revalidating and winning customer acceptance are costly, time-consuming and risky.
A drop-in molecule massively eliminates these hurdles. It requires no or minimal adjustment to the chemistry and, often, no regulatory issues in the formulation logic. The structure, chemical properties and physical behaviour remain identical, ensuring performance stays consistent across applications.
This similarity makes adoption far easier than introducing novel molecules. Customers face lower technical risk, as proven processes and existing infrastructure can be leveraged without modification. There is no need to redesign production lines, retrain teams or navigate regulatory uncertainty. In an industry where speed to market and operational stability are critical, a drop-in biobased molecule offers a minimal-friction path to sustainability, without sacrificing performance or reliability.
Figure 2- Differences between drop-in biobased products & fossil-based products
Nothing changes... Molecular structure Functional properties Reactivity Existing derivatives Formulation logic Customer performance target
Biobased Mass balance Segregated
A product- material, intermediate, semi-finished or finished product- that is entirely or partially derived from biomass. It is characterised by its biobased carbon content( in Europe according to EN 16640 – expressed as the ratio of biobased carbon to total carbon) or by its biobased content( in Europe according to EN 16785- expressed in dry matter as the ratio of biobased fractions( C, H, O and N) to total product mass). These are derived from a segregated production process.
Figure 1- Defining the vocabulary
... but everything changes Carbon origin Feedstock base Product carbon footprint Supply-chain resilience Green-claims evidence Traceability and certification
Applied to bioeconomy, the mass balance approach provides a set of rules for allocating biobased raw materials to different end products. This method, based on the principle of conservation of mass, ensures the appropriate allocation of biobased content to end products via verifiable accounting. The mass balance method is a practical solution to meet customer expectations for the gradual substitution of fossil materials in supply chains.
Segregated products are made from a mixture of feedstocks that are mixed in the same production line. The claim of the final product reflects the approach and its exact physical content. When applied to bioeconomy, a segregated approach consists of fossil resources and renewable feedstocks are mixed in the same production system and flows are merged. The final product physically contains exactly what is claimed and what has been integrated at the beginning of the process.
Different origin, different value
The molecule itself does not change but its origin does and that changes everything. The real shift lies upstream, in how the molecule is produced. A carboxylic acid derived from biomass side streams, local feedstocks or fermentation unlocks a value proposition far beyond performance compared to its petrochemical counterpart.
Beyond sustainability facts, such as reduced dependence on fossil feedstocks, lower carbon footprints and the valorisation of agricultural by-products, biobased drop-ins transform supply chain strategy: local or regional sourcing strengthens resilience by supporting local or domestic production and reduces geopolitical risks.
In an era of industrial sovereignty and decarbonisation, the origin of a molecule is not just an environmental footnote; it is a strategic asset, enabling companies to align with regulatory pressures, stakeholder expectations and long-term resilience
84 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981