Chemical products on a renewable basis

Today, the chemical industry mainly uses fossil raw materials such as crude oil and natural gas. From these materials, so-called basic chemicals or platform chemicals serving as precursors for various industrial products such as plastics or substances for coatings, paints, and varnishes are manufactured. However, in view of today's limited resources, the climate change, and our quest for sustainable development, the interest in renewable raw materials that can replace crude oil increases. The platform chemical 5-(hydroxymethyl)furfural (5-HMF) plays a key role in the change from a crude-oil-based to biomass-based chemistry.

5-HMF is an organic compound that forms during thermal decomposition of carbohydrates and can thus be detected in many heat-treated foods such as milk, fruit juice, honey or coffee. Heating sugar in a pan, we can, for example, smell the compound as the sugar caramelizes. 5-HMF can be obtained from vegetable biomass and can serve in the future as a precursor for different innovative materials, in particular for polymers with specific properties. According to the U.S. Department of Energy, 5-HMF is one of the ten most important platform chemicals. It is, however, a challenge to manufacture the compound on an industrial scale. Karlsruhe Institute of Technology and the Swiss AVA Biochem BSL AG now achieved a significant scientific-technical breakthrough: In January this year, the facility "Biochem 1" operated by AVA Biochem in Muttenz near Basel started commercial operation for industrial manufacture of 5-HMF. The manufacturing method was developed by researchers from KIT.

Cooperation with AVA Biochem is part of comprehensive KIT activities for manufacture of chemical energy carriers as well as intermediates from biomass with emphasis on so-called hydrothermal methods i.e. reactions in water at increased temperatures. "The hydrothermal methods can be well integrated in different process chains for which biomass is used as raw material," explains Professor Jörg Sauer, head of KIT's Institute of Catalysis Research and Technology (IKFT). "On the one hand, biomass with a high water content which, for example, is a by-product of food production, serves as raw material. On the other hand, hydrothermal procedures can be combined very well with biotechnological methods.

Within 18 months, the researchers at KIT developed a 5-(hydroxymethyl)furfural laboratory production technique that can be implemented in the industry. Hydrothermal carbonization i.e., a method which at high temperatures and increased pressure converts biomass in a closed system in aqueous suspension into biochar, served as the basis. Unlike hydrothermal carbonization, the new method, however, prevents formation of a solid. The fragments from the biomass are converted into chemical components, for example for plastics manufacture.

"Within the short time of only 18 months, our team had to develop a solution to be scaled up from the laboratory to an industrial scale," says Professor Andrea Kruse from KIT. "Thanks to our more than twenty years' experience in hydrothermal methods, we have succeeded in mastering this great challenge." Together with engineers from AVA Biochem, the KIT researchers, parallel to the laboratory experiments, started at an early stage to work on upscaling to the production scale. Already since 2010, KIT and AVA-CO2, the holding company of AVA Biochem, had researched into hydrothermal carbonization and put it to industrial application. This was also to the benefit of the development of the new method. "The close cooperation between researchers and plant engineers has enabled a rapid industrialization. We are several years ahead of the market," sums up Jan Vyskocil, CEO at AVA Biochem.

In parallel to current production, the teams at KIT and AVA Biochem now optimize the method and prepare it for further applications. Both the spectrum of usable biomasses and the achievable yields have much development potential and open up additional opportunities. A joint patent was taken out on the developed method. There is lively interest now already in different branches of the industry. Orders have already been received.