Converting lignin into high-value products is still a challenge, but essential to render biorefineries profitable. Therefore, one of the most relevant topics in the BIG-Cluster initiative was named to be how to produce Aromatics from LIGNin.
The ALIGN consortium has covered stakeholders from the whole value chain starting from lignin extraction (Fraunhofer CBP, LXP Group, KU Leuven) via DSP (VITO) to application (Phytowelt, Axxence) under the coordination of CLIB. Moreover, several associated partners have joint the project (UPM, Henkel, and TU Braunschweig). In the last 4 years, the consortium has successfully scaled up three different extraction processes for lignocellulose to generate high-value lignin fractions that differ in their degree of depolymerisation and functionalisation. Fraunhofer CBP was able to successfully scale up the lignin-first process established by KU Leuven to pilot scale. In this process, high-quality phenols and pure cellulose/sugar fractions were obtained from beech wood chips. In addition, the LXP group was able to commission a demonstration plant with a biomass (dry matter) capacity of 500 t/a which substitutes 1500 t/a corn silage at the beginning of 2020. The LXP plant is able to produce about 10 t lignin per year. In the ALIGN project, with the different lignin fractions combined with tailor-made downstream processing strategies, a wide variety of applications in the aromatics sector from fine chemicals to bulk products can be foreseen. The classification of aromatic compounds as natural for their use in the food industry is particularly critical. To ensure this, an enzymatic depolymerisation of lignin as a biotechnological process can be applied. The TU Braunschweig has already achieved initial success in establishing a corresponding enzyme cascade. In addition to the original goal of producing natural vanillin, the use of lignin as a resin substitute for phenol and as a base for adhesives was also investigated and first results were successfully achieved.