With the help of green chemistry and a high level of innovation, the Symrise fragrance experts have been restructuring the portfolio for years to include biodegradable fragrance ingredients that come from natural products. The fragrance ingredient dihydromyrcenol is a good example of what’s ­needed for this to work.

INNOVATION AND DEVELOPMENT

“The task is as clear as it is challenging,” explains ­Johannes Panten, an innovation scout who has worked for the Group for 30 years. “All of us – Symrise, the consumers, and our customers who produce perfumes, shampoos or cleaning products – want to have bio­degradable fragrance ingredients.” “And they should come from natural raw material sources. This also means we face a huge transformation because many ingredients are currently produced using fossil resources.”

Originally, from the beginning of ancient perfumery until well into the Middle Ages, almost all fragrances came from nature – for example, by treating flowers with different processes. “During the 20th century it became clear that the natural resources couldn’t keep up with the rapidly increasing demand,” continues Panten. There were many reasons for this – one of which was the introduction of modern laundry technology. In the middle of the last century, the washing machine began its triumphal march in the USA. The demand for the base material and thus also fragrances for washing powder grew exponentially. Another reason is the perfume industry’s much sought-­after musk scent, which can be found in nearly every perfume. It used to be sourced from a stomach gland of the wild musk deer, but the animal had to be killed in order to get to it. To improve animal ­welfare and also to save costs, the industry transitioned to using synthetic ingredients.

When is something biodegradable?

A material is biodegradable when it does not accumulate in nature after it has been used – instead, after a certain period of time, it can be transformed into CO2. Plants absorb carbon dioxide and then turn it back into organic material. The OECD has specific requirements for this process, all of which Symrise fulfills. One definition says, for instance, that the ingredients in perfumes, household cleaners and shampoos must be bio­degraded by up to 60 % in wastewater from sewage sludge within 28 days.

We apply the principles of green chemistry by avoiding waste and adding value to byproducts.Johannes Panten, Innovation scout at Symrise

New approach: Green chemistry

Turning the dial back to natural materials isn’t quite so easy, however. “For some ingredients, we’re looking for alternatives to synthetic products in raw materials from nature,” explains Panten. For years, Symrise has also used the residual materials from production processes involving natural raw materials. “We apply the principles of green chemistry by avoiding waste and adding value to byproducts.”

One example of this is dihydromyrcenol. Thousands of tons of it are needed on the global market, making it one of the most important fragrance ingredients. With its citrusy and herbal scent, it is used in perfumes, shampoos and cleaning products. The material comes from a byproduct of paper production. ­Johannes Panten grabs a marker and sketches out the process on a flip chart. A highly simplified process, of course, because the chemical reality is naturally a lot more complex. “It all begins in the pine forests of North America, where the wood is grown sustainably. It is then processed into pulp for paper production using the Kraft process. This process creates the byproduct raw sulfate turpentine oil,” explains Panten. The Symrise plant in Jacksonville, Florida, uses this byproduct and removes the sulfur, which has been added earlier in the process in the form of a solvent. Finally, the company breaks the material down into ­alpha- and beta-pinene – volatile liquids with a turpentine scent –and uses hydrogenation or pyrolysis to transform them into biodegradable fragrance and flavor ingredients: linalool, citronellol, geraniol and, of course, dihydromyrcenol.

The bridge-builder

The US company Renessenz, which has been part of Symrise since 2016, created the process, and Symrise has further developed it over the years. To continue this development, Panten recently conducted a survey to find not only the latest process technology but also the best-suited external partners who could work together with the internal researchers to carry out the optimization. One of the main tasks in his job is to get in contact with startups, universities, research centers and suppliers as a “bridge-builder,” as he calls himself, in order to find the best solutions.

The Dutch process developer InnoSyn proved to be the right partner for the production of dihydromyrcenol. At the Brunswick site on Colonels Island in Georgia, Symrise chemical engineer Thomas Mikulencak and his team then introduced, tested and scaled a new process. “We work with a flow chemistry process. The unique thing about it is that there is a continuous inflow of raw materials and an equally continuous outflow of reaction products,” says Mikulencak. “It’s extremely efficient, there are hardly any waste products because we are processing all of the base material that we are putting in. And it works in a very selective way, meaning we get exactly the result we want in the reactions.” The new process also increased the potential capacities for dihydromyrcenol production, so Symrise can continue to grow with the plant.

At the Brunswick site on Colonels Island in Georgia, chemical engineer Thomas Mikulencak and his team have further developed and introduced a flow chemistry process.

“We work with a flow chemistry process. The unique thing about it is that there is a continuous inflow of raw materials and an equally continuous outflow of reaction products.”

Thomas Mikulencak,
Chemical engineer at Symrise

Optimizing the process wasn’t an easy task though, because production had to continue running at the same time. “That’s why it was so important to have a strong partner like InnoSyn on our side, who had developed the process with us in the lab to such an extent that we could implement it 1:1,” continues Mikulencak. In chemical engineering, a process must be very well thought-out and tested to get the optimal result. “Flow chemistry is particularly well suited here because we can control the reaction parameters, such as the temperatures, very precisely.” The process, the expert makes very clear, is specially ­designed for dihydromyrcenol. “The small improvements really pay off, especially when it comes to large production volumes,” says Mikulencak. “And we learn more with every new or optimized facility, so that we will be able to set up and expand sustainable processes in the future.”