The chemical industry currently runs on aromatic compounds, or aromatics, that are almost exclusively obtained from fossil fuels. Given the scarcity of these fossil fuels, like crude oil, scientists are looking for alternatives, which would also help to reduce the impact of climate change, reduce CO2 and so on. Two projects that finished at the end of 2019 – ARBOREF (VLAIO-CATALISTI) and BIO-HArT (Interreg Vlaanderen – Nederland) – saw VITO working with universities, research institutions and industrial partners to investigate the potential of lignin as an alternative to fossil fuels, with initial results that are promising and worth further investigation. Having a pilot installation available is essential for further development of the technology and its uses, so the LignoValue Pilot EFRO project is focused on designing and building one to produce bioaromatics from lignin and wood.

The European chemical industry needs new, innovative and sustainable products and processes to replace fossil-based and/or toxic products with biobased, high-performance and safer alternatives, reducing our dependency on crude oil and lowering CO2 emissions. By using waste streams as a raw material, VITO (including as part of the Biorizon community) is helping to move towards a circular economy and offering the chemical industry and its supply companies the prospect of a future that is both profitable and sustainable. Lignin is under the spotlight as part of this process as, along with cellulose, it is the most common organic material on earth. According to estimates, between 60 and 70 million metric tonnes of lignin are available from wood pulp and the paper industry, with around 95 % of that currently being burned. Lignin has huge potential: it can be used as a filler or as a renewable resource to produce biofuels, but also as a raw material for bioaromatics for all kinds of chemicals and materials, including resins and polymer blends.

The processes for using lignin to create a bioaromatic mix ("lignin soup") are wide-ranging and highly complex, but most of them are still at laboratory level; in other words, the technology readiness level is low. Several studies in recent years have focused on the search for technologies to depolymerise lignin into biobased aromatics, and two of them are now complete: Interreg Vlaanderen – Nederland BIO-HArT and the Flemish (VLAIO-CATALISTI) ARBOREF project.

The Flemish (VLAIO-CATALISTI) project ARBOREF and the interregional BIO-HArT project saw scientists focus on lignin as an alternative feedstock for fossil-based aromatics. These projects commissioned VITO to use its expertise to assess how membrane separation technology can be used to process the lignin soup further. This involved testing existing membranes and developing new ones tailored to the lignin soup. The research showed that, while membrane technology is necessary, it may be inadequate depending on the intended uses for the bioaromatics. The need for additional purification steps – for example, using distillation – will be investigated further. What these bioaromatics can be used for is just as important, so VITO has also established a biopolymer team to investigate potential uses for each lignin component, from coatings to glues and insulation material.

Big goals mean thinking big as well. Practising on a few grams of lignin is necessary and useful, but this effort is insufficient if it doesn't lead to more extensive testing. The goal is therefore to set up a demo business to produce lignin components on a larger scale. The first step is for the LignoValue Pilot facility to produce the required bioaromatic fractions in large quantities so they can progress development of business-oriented applications and product development. The creation of the pilot installation in the LignoValue Pilot project is co-financed by The European Regional Development Fund (ERDF), the province of Antwerp and the Flemish Government. This 4.3 million-euro project is tasked with creating a functional pilot line to produce bioaromatics from lignin/wood in Flanders by the first quarter of 2021. Several companies have already shown an interest in the innovative molecules and are ready to carry out application testing.

The Catalisti project entitled 'BioAromatics Feedstock and Technology Assessment (BAFTA)' is part of the LignoValue Pilot project. This involved VITO and KU Leuven carrying out a thorough landscape analysis of the technologies available worldwide for the immediate conversion of wood and the depolymerisation of lignin into biobased aromatics and applies several clearly defined criteria (e.g. TRL, sustainability level, yield etc.) to give  insight into the preferred depolymerisation technologies.  

So, what is the ultimate goal? In an ideal world, we would have biomass cracking units which specialise in 'cracking' lignin or wood in the port at Antwerp, like the chemical plant in the port at the moment, where businesses are focused around the naphtha cracking units. These biomass cracking units would create the foundation for a completely new chemical development to extract components from lignin instead of crude oil.

And finding a solution to replace fossil fuels with more sustainable raw materials is just the start. We also need to explore the important issue of how recyclable and toxic the new products are, as well as their economic profitability. These issues are already part of the development process but will need further investigation in the future. 


About the completed projects

ARBOREF (VLAIO-CATALISTI) grew out of the ambition to produce both new and existing aromatics in a new, fully integrated 'lignin first' biorefinery, based on technology that converts all the lignocellulose biomass into a soluble phenolic fraction and a solid pulp rich in carbohydrates. Fermentative and chemical synthesis pathways are being investigated for both fractions to convert them to aromatic molecules in a way that is atomically efficient.

The 'Biorizon Innovation and Upscaling of Renewable Aromatics Technology' project (BIO-HArT) links into the transition to a biobased economy. The project is part of Shared Research Center Biorizon, an initiative from TNO and VITO that is located on the Green Chemistry Campus, a Centre for Open Chemical Innovation in Bergen op Zoom. Some process set-ups will also be based in Ghent, Antwerp and Geleen, with the complementary locations focusing on their individual expertise.