Projects / Programmes
Process development for lignin valorisation to aromatic building blocks and further production of bio-based polymers
| Code |
Science |
Field |
Subfield |
| 2.02.04 |
Engineering sciences and technologies |
Chemical engineering |
Catalysis and reaction engineering |
| Code |
Science |
Field |
| 2.04 |
Engineering and Technology |
Chemical engineering
|
Biomass, lignin, fractionation, catalytic hydrotreatment, bio-based building blocks, polymerisation, NMR, lumped kinetic model, ;
Researchers (16)
Organisations (2)
Abstract
The proposed project covers the topic of lignin valorisation to aromatic building blocks and the further production of bio-based polymers. Lignin is a complex branched polymer of p-coumaryl, coniferyl and sinapyl alcohols. Its diverse building blocks and random connectivity make lignin by far the most complex LC biopolymer, but is still the only renewable source of an important and high-volume class of compounds – the aromatics. The complexity of the structure of lignin is one of the main reasons it is being valorised into value-added chemicals on a small or demonstrational scale. The production of targeted chemicals from lignin, especially with high selectivity, is a very demanding task alongside further complex isolation and purification procedures. Therefore, this project will not aim at the conversion of lignin into a particular drop-in chemical, but rather demonstrate the suitability of selected raw materials and tailored lignin isolation, and the eventual fractionation and depolymerisation, to yield a blend of bio-aromatics with well-defined chemical properties (i.e. molecular weight distribution, concentration of free OH groups). Subsequently, these bio-aromatics will be tested in final phenol-formaldehyde and epoxy resins formulations. Lignin fractions in this case will serve as functional substitutes for phenol or bisphenol A. A comprehensive, well-structured, systematic and integrative experimental and in-silico supported study, will cover the whole value chain starting from the isolation of different lignin types and finishing with the testing of new chemicals in final polymer formulations. This will provide essential information for the understanding, optimization, and production of new bio-based chemicals as well as the establishment of feedstock structure-product quality correlation. For this reason, lignin will be isolated from different sources (hardwood, softwood, straw, algae) bearing different structural features and functionalities. An organosolv process will be applied to isolate lignin given that it is recognised as an effective isolation method, is industrially applicable, and yields close-to-native lignin structure. Isolated lignin will be separated into fractions with different molecular weight (Mw) distributions, which will be submitted to catalytic depolymerisation. Depolymerisation will likely yield different monomer/oligomer mixtures with different selectivity depending on different reaction parameters. Selected depolymerisation products as well as light (low Mw) lignin fractions will be tested in various polymer formulations. Suitability of the lignin-derived substitutes will be defined by comparing mechanical and thermoanalytical properties of the bio-based and conventionally prepared polymers. Finally, every step in the production of aromatic functional analogues from lignin will be mathematically described with a lumped kinetic model and statistical correlations which will allow optimization of the operation conditions and lignin type selection to achieve targeted product/formulation quality.
