Evonik invests in rhamnolipid biosurfactants

The specialty chemical maker Evonik Industries will spend what it describes as “a three-digit million-euro sum” to build a rhamnolipids plant at its site in Slovakia. Evonik says the plant will be the world’s first commercial-scale facility for the biosurfactant.

Rhamnolipids are biodegradable surfactants made via fermentation and feature rhamnose sugar groups with fatty-acid tails. In addition to strong environmental bona fides, rhamnolipids are effective cleaners at lower concentrations than conventional surfactants while being gentler on skin and hair.

Evonik already has customers in mind for the new capacity. “Our initial focus is on applications in personal and home care based on foaming, sensory, and mildness benefits as well as a pressing need to improve the sustainability profile of surfactants in these markets,” the firm says.

The investment builds on a partnership between Evonik and the consumer product giant Unilever, which launched a dish soap using Evonik’s rhamnolipids in Chile in 2019. Unilever says rhamnolipids are an important part of its push to remove all fossil-derived ingredients from its cleaning products by 2030. Evonik also launched an industrial cleaning ingredient based on rhamnolipids in 2021.

Evonik makes its rhamnolipids by fermenting sugar using a genetically modified Pseudomonas putida bacteria. Dan Derr, a bioprocessing consultant who developed a P. aeruginosa–based rhamnolipid process now owned by the surfactant maker Stepan, says a plant in the price range Evonik announced would have a capacity of thousands or tens of thousands of metric tons (t) per year.

In February 2021, Stepan bought an idle 20,000 t plant in Louisiana where it plans to make rhamnolipids. The specialty chemical fermenter Jeneil Biotech says it already manufactures rhamnolipids in industrial-sized equipment.

“At those scales, prices are going to come down dramatically, and rhamnolipids will be able to compete with other specialty surfactants,” Derr says. “Investments these companies are making—Stepan and Evonik in particular—are going to get them to a scale where you will be able to put [rhamnolipids] into higher-end consumer products.”

The appeal of rhamnolipids extends beyond cleaning, foaming, and emulsifying. Recent research suggests rhamnolipids can kill some bacteria as well as viruses including SARs-CoV-2. Though Evonik and Stepan are not currently making disinfectant claims in the cleaning products market, Stepan and Jeneil jointly market a rhamnolipid fungicide for farmers.

In the US, Derr says, disinfectant claims for cleaning products are regulated by the Environmental Protection Agency, and the companies are unlikely to tout that benefit until they gather the data the agency requires. Although being able to claim both surfactant and disinfectant action would make rhamnolipids even more valuable, Derr says their sustainability, potency as a surfactant, and established agricultural fungicidal action create plenty of incentive to boost production.