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Conceptual Study of Electrochemical based novel process using Lignosulfonates to produce bio-based monomers & polymers

Periodic Reporting for period 2 - SElectiveLi (Conceptual Study of Electrochemical based novel process using Lignosulfonates to produce bio-based monomers & polymers)

Berichtszeitraum: 2020-11-01 bis 2022-10-31

Bio-based industries make use of European biomass sources and sustainable European supply chains. As such, they lower dependency on imports and contribute to raw material security. With 90% of Europe’s chemical industry feedstocks for non-energy use coming from fossil fuel resources, access to alternatives is an important strategic issue.
Bio-based industries are important players in building the European circular economy, pioneering processes to produce value-added products from feedstocks. By replacing fossil-based products with bio-based products which tend to have a smaller footprint, bio-based industries can make a critical contribution to Europe’s climate goals.
To unlock their full potential, Europe’s bio-based industries need to make sustainable, resource-efficient, and largely waste-free use of renewable materials to play an essential role in spurring sustainable growth and boosting Europe’s competitiveness.
SElectiveLi provides a proof of concept on the laboratory scale to demonstrate the potential for converting low-cost lignosulfonate feedstocks as by-product from the paper and pulp industry into high-value bio-sustainable chemicals through the following:

1) Electrochemical synthesis of important bulk chemicals from bio-based feedstock.
2) Development of downstream separation and purification processes to extract the target products.
3) Modelling the process to ensure commercial viability, benefitting from surplus energy, and accommodating energy fluctuations.
4) Conducting a full life cycle analysis of all processes to establish that a future biorefinery process can reduce the environmental footprint of a value chain.
The SElectiveLi project started in May 2019 with a duration of 36 months. At the point of this report, the project end in month 42 has been reached, due to a cost-neutral extension of 6 months.
In WP1 ‘Lab-scale screening and optimization of electrolysis conditions’, feedstock materials were successfully analyzed, reaction conditions evaluated, and finally, electrochemical depolymerization proved to be as successful as envisaged. JGU elaborated an electrolysis protocol that allows to selective generate vanillin and low molecular weight aldehydes. One of the keys is electrolyte composition and the anode material. In WP2, ‘Downstream separation processes’, separation techniques delivered valuable insights on the nature of the LS feedstock.
The product of the electro-conversion undergoes a solid separation step for the protection of other technologies. After this, a closed nanofiltration with special membranes developed for caustic conditions will be used for sodium hydroxide recovery as well as a concentration step for the electro-conversion products. Also, the distribution of partly purified LS and compounds in the relevant feedstocks were analyzed. WP3 focused on reactor design and upscaling. Work primarily related to efficient design of biorefineries has been carried out and particular separation sequences improved the understanding of the process. WP4 confirmed that the SElectiveLi approach is highly beneficial in terms of efficiency. During the evaluated period several scripts and models have been developed to assess the coupling of the SElectiveLi process and renewable energies. Among all of them, the most relevant achievements are the sets of tools to download and manage data related to the use of the renewable surplus of national grids from official databases. That way, a flexible methodology, and tool was developed for the assessment and integration of RES in electrochemical processes. They can be extended to a wide range of processes and locations. The same is true for WP5, 'Life Cycle Analysis’ where life cycle assessment has been established and data for a full LCA was collected. The development and launch of the web-based data collection platform were performed. Also, the development of a project-specific LCA framework to be fed with data was done, this model was used to evaluate the environmental performance of the new value chain and compared it with existing systems providing the same function. WP6 ‘Validation and conversion of intermediates into polymers’ validated possible products and involved polymerization experiments based on the substrates produced in other WPs.
CHIMAR tested magnesium lignosulfonate samples as partial phenol substitutes in the synthesis of Phenol-Formaldehyde (PF) resins suitable for the production of plywood panels, with the aim to develop and prove the viability of bio-based phenol-formaldehyde adhesives. VITO is developing synthetic protocols taking into account the specific characteristics of lignosulfonate. The resulting fractions (after chemical modifications) display improved solubility in organic media and offer a platform for the design of various polymer systems, especially the focus on the synthesis of polyurethane bio-resins from epoxy-modified lignosulfonate. The obtained PU materials (films, foams) possess promising properties comparable to non-biobased polyurethanes. In the future, the developed protocols will be adapted in order to design a wide range of PU materials from the depolymerized lignosulfonate phenolic fractions.
These protocols can be extended in order to design a wide range of epoxy formulations and resins with tunable properties. WP7 ‘Exploitation, Dissemination and Communication’ accompanied the project as planned with communication, dissemination, and exploitation efforts and took care of the medial visualization of the project´s content. WP8 ‘Management’ managed all described tasks successfully. WP9 ‘Ethics requirements’ is already finalized and closed.
However, the project advances were heavily impacted by the Corona situation. This resulted in time schedule deviations due to the unprecedented situation and several timelines became obsolete. Nevertheless, due to the extension, the general effectiveness of the project was not diminished. In that sense, the impact of the Corona pandemic could be numbered as a delay of 6 months. An amendment to the GA has covered this time and allowed the consortium to reach all goals described in annex 1.
Electrolytic Products: The amount of vanillin at relatively mild conditions and the timely separation of both events – electrolysis and depolymerization are innovative.
Downstream separation: Solid separation coupled with forward osmosis has never been designed before for that kind of feedstock. Also, purification and analysis of this feedstock type are new.
Reactor Design: For the majority of biorefinery processes, separation costs are the single largest CAPEX ad OPEX part. Understanding how to develop newly integrated processes is vital for future process development.
Polymerization of electrolytic products: Although several lignin-based epoxy resins have been reported in the literature, most of the studies reported so far are focusing on Kraft lignin and not on lignosulfonates. We developed synthetic protocols taking into account the specific characteristics of lignosulfonate. These protocols can be extended in order to design a wide range of epoxy formulations and resins with tunable properties.
RES Integration: A flexible methodology and tools are being developed for the assessment and integration of RES in electrochemical processes. They can be extended to a wide range of processes and locations.