XyloSolv – Sequential extraction process for the production of high-value intermediates from beech wood

Our project partner HV-Polysaccharides GmbH & Co.KG has developed a hydrothermal aqueous extraction process of beechwood which produces the polysaccharide xylan in a higher quality than ever before thanks to special process control. Thus xylan is suitable for use as a raw material in the manufacture of active pharmaceutical ingredients.

From the gram to the kilogram

To ensure full utilization of the beechwood material, in the XyloSolv project the aqueous xylan extraction was combined with the Organosolv process, an ethanolic pulping of lignocellulose producing high-quality lignin and pulp.

We implemented the sequential extraction at the pilot plants of Fraunhofer CBP for the first time. Individual process steps were optimized to enable the high-yield production of products without any variations in quality. The extraction processes, which have been developed and optimized jointly by all the partners involved, are resource-efficient and environmentally friendly. According to analyses, both the xylan and the organosolv lignin are of high-purity, making them suitable for pharmaceutical, cosmetic or food applications.

From the kilogram to the metric ton

The technical feasibility of the overall combined process was evaluated by our project partner Glatt Ingenieurtechnik GmbH. This evaluation was then used as a basis for drawing up a production plant concept. The subsequent techno-economic assessment revealed that the xylan production costs lie within the range of the current market prices for pharmaceutical xylan.

However, the costs of producing Organosolv lignin are relatively high due to the planned production scale of a few metric tons only, thereby ruling out its use in material applications. Alternatively, Organosolv lignin might be utilized in high-end pharmaceutical or cosmetic products, where the high purity would justify the high price. Given that lignin has never been used in large quantities in pharmaceutical or cosmetic applications, future projects are to be undertaken to investigate this option in collaboration with our partners from science and industry.

Irrespective of this, HV-Polysaccharides GmbH & Co. KG is striving to implement the key results of the collaboration with Fraunhofer CBP in a commercial xylan production plant, which is scheduled to go into operation in 2025.