In order to reduce dependence on fossil resources and reduce the carbon footprint of production processes, renewable resources are transformed into chemicals in so called bio-refineries. Lignin, the second most abundant terrestrial polymer and the only large source for bio-based aromatics, is currently used in limited amounts. Conventional lignin extraction processes are often optimized towards the fractionation and purification of cellulose for pulp production, with lignin regarded as a by-product, resulting in a poor lignin quality i.e. an undefined structure and a low degree of functionalization. Usually, only its energy content is recovered by combustion.
Objectives: Development of processes for the production of new functionalized bio-aromatics from lignin
To render biorefineries sustainably and economically, the material use associated with the conversion of lignin into high-quality products is essential. The aim of the project is therefore the development of processes for the use of lignin-based aromatics. By lignin extraction processes, which preserve the structure and functionality of lignin in combination with innovative chemical and biotechnological conversion routes, this should enable the production of functionalized bioaromatics. New, hitherto not accessible structures including new functionalities and, thus, new performances, can be detected, which can be used in a variety of industrial applications. Aromatics represent a significant share of today’s chemical building blocks used for a wide variety of applications in the field of polymers, adhesives, coatings, resins, surfactants, anti-oxidants and cosmetics. Within the project, the use of phenolic resins for laminates as well as the production of natural vanillin for food and beverages are conceivable.
Project plan: Development of procedures and their scale-up for the use of aromatics from lignin
The ALIGN project focuses on upscaling of three extraction processes that lead to both a high-value lignin fraction and a pure cellulose/sugar fraction: The LX process (LXP), an Organosolv process combined with base-catalyzed depolymerization (BCD) and the lignin-first process (LFP). The lignin fractions derived from the three processes differ in their composition in regard to the degree of depolymerization and functionalization. Testing in different applications is a further subject within the project.
Starting with this broad range of different lignin derivatives combined with tailor-made downstream processing (DSP) strategies, a wide variety of bioaromatics with unique properties can be produced. The project aims at applying these bioaromatics as phenolic resins for the production of high-pressure-laminates as well as natural vanillin for food and beverages.
In addition, the processes can be adjusted in future projects for a wide variety of applications in the aromatics sector from fine chemicals to bulk products.