Primary Refining

Development of a Purification Cascade for Industrial Wood Hydrolysates
(DBFZ gGmbH, Germany)

Hemicellulose-rich side streams are a valuable source of C5 sugars and hemicellulose polymers, making them suitable for fermentation or direct chemical modification. However, the presence of inhibitors released during lignocellulosic biomass processing, added chemicals, and high water content can impede their direct application in biorefinery processes. To overcome these challenges, a purification cascade will be developed. This process utilizes various separation technologies, including membrane processes, adsorption, and evaporation, to achieve the following objectives:

Purification of C5 sugars for fermentation and
Concentration and purification of hemicellulose oligomers for formulations with bio-based macromolecules.

The cascade is optimized for large-scale applicability, prioritizing low energy requirements, minimal use of additional chemicals, and high product purity.

Secondary Refining I

Fermentation of Monomeric C5 Sugars to Itaconic Acid in a Fed-Batch Process
(Extraction Department, Celabor S.R.L., Belgium)

Using commercial xylose residues in a series of lab-scale experiments in flasks are conducted as a multiple-parameter analysis including moisture content, temperature, pH, and additional nitrogen nutrients on fungal growth using xylose residues.

The optimized conditions are investigated in fermentation tests utilizing the industrial effluent of various monomer/oligomer levels from the Hemicoat purification cascade. Primary tests utilize the total hemicellulose effluent including sugar monomers and oligomers opting to optimize key fermentation criteria such as residual carbohydrates, mycelium concentration, and itaconic acid productivity. A set of optimized conditions is scaled-up to 2-L bioreactors for further analysis such as soluble sugars and acid production.

Final optimization leads to conditions being applied in a 10-L bioreactor in batch, fed-batch, and continuous modes, which focuses on itaconic acid productivity considering scale-up parameters like air flow rate, stirring, mycelium concentration/age, pH control, and nutrient addition. In parallel, alternative carbohydrate sources from the Organosolv pretreatment of other lignocellulosic biowastes are tested for itaconic acid fermentation.

Secondary Refining II

Production of Adhesives and Coatings using Hemicellulose Oligomers
(Material Department, Celabor S.R.L., Belgium)

The feasibility of using hemicellulose oligomers from the Hemicoat process flow to produce adhesives and coatings is tested, leveraging the strong bonding performance of hemicellulose with wood components.

Performance loss due to molecular weight is negated through water-based formulations with bio-based macromolecules such as Chitin or Chitosan and adhesive properties are evaluated using tensile tests on wood specimens.

Secondary Refining III

Chemical Modification of Itaconic Acid to Biobased Surfactants
(Materia Nova ASBL, Belgium)

Raw itaconic acid as fermentation product in an aqueous fermentation broth is purified concerning cost-efficiency and scalability. Materia Nova’s expertise in numerous downstream process steps, e.g., crystallization, filtration, or membrane separation, is applied to ensure a highly efficient purification and concentration process from the fermentation. Purification efficiency is evaluated using Materia Nova’s analytical platform, including infrared spectroscopy, nuclear magnetic resonance, and other techniques.

The purified itaconic acid is chemically functionalized to meet the physicochemical properties required for various applications. Herein, mechanical, surfactant, barrier, and antibacterial properties as well as flame retardancy are emphasized. Initial protocols are established with commercially available itaconic acid. In a later stage of the project, these results are compared to the ones gained from the itaconic acid obtained in the Hemicoat process. Chemical modifications focus on synthesizing novel low molecular-weight itaconic acid derivatives through esterification and functionalization. In parallel, high molecular weight itaconic acid derivatives such as oligomers and polymers are synthesized and evaluated for coating applications. Comparing the performance of these itaconic-acid-based chemicals obtained from different hemicellulose purification cascades of the Hemicoat project will allow tailoring the purification process to a target application, e.g. a coating offering specific properties.

This work helps to (re)evaluate the potential of itaconic acid as a biobased substitute to petrol-based building blocks and chemicals such as acrylic and methacrylic acid or maleic anhydride. Comparing functional properties, reaction kinetics, and efficiency the potential of fermented and purified itaconic acid from different woody hemicellulose side products is assessed as an alternative to commercial products.

Supporting research I

Evaluation of Industrial Biomass Potential and Full-Scale Process Simulation
(DBFZ gGmbH, Germany)

Hemicellulose-rich hydrolysates, a by-product of cellulose pulp and lignin production in processes such as sulfite-process, organosolv-process, and bioethanol production from lignocellulosic biomass, represent an underutilized resource.

To assess the potential of a biorefinery process based on these hydrolysates, it is necessary to determine their local production volume within the EU. This involves mapping and interviewing relevant industries to gather data on production processes, valorization potential, hydrolysate prices, and other factors.

The collected data is integrated into a database and used to establish an industrial-scale process. Leveraging biomass potential and process data from the HemiCoat project, we will simulate an industrial-scale process to evaluate its economic and ecological feasibility.

Supporting research II

Ecologic and Economic Evaluation of the Value Chain
(DECHEMA e.V., Germany)

A multistep life cycle assessment (LCA) is conducted to evaluate the ecological impact of the HemiCoat process flows from wood-born hemicellulose by-products to bio-chemically produced coating and painting materials.

In the first LCA, the upstream part of the process chain is investigated. Herein, xylose is purified from woody hemicellulose gained from different extraction methods and transformed into Itaconic acid by fermentation.
In a second LCA, the impact of chemical modification of this versatile building block to synthesize coatings and paintings is evaluated.
To maximize resource efficiency of the hemicellulose fractions another approach is developed utilizing hemicellulose oligomers-born wood adhesives through chemical grafting with bio-based macromolecules such as chitin or chitosan. The environmental impact of this approach is evaluated in a third LCA.

Combining all three LCAs the ecological footprint of the HemiCoat process chains from hemicellulose to coatings is evaluated from “Cradle-to-Gate”.

A market analysis is conducted for Itaconic acid as a key intermediate of the HemiCoat process and a value-added chemical from biomass with expected economic growth, particularly for agricultural applications and bio-based plastics.

An economic evaluation of the HemiCoat process chains is completed through market analyses of the final coating and painting products, which is of particular interest to small and medium-sized companies (SMEs) as the main end-users of the project.