Electrocatalytic Production of liquid Organic hydrogen carrier and CHemicals from lignin

Project Information

EPOCH

Grant agreement ID: 101070976

DOI

10.3030/101070976

EC signature date 27 June 2022

Start date 1 October 2022

End date 30 September 2026

Funded under

• The European Innovation Council (EIC)

Total cost

€ 3 502 967,49

EU contribution

€ 3 502 967,49

Coordinated by

LULEA TEKNISKA UNIVERSITET
Sweden

Periodic Reporting for period 2 - EPOCH (Electrocatalytic Production of liquid Organic hydrogen carrier and CHemicals from lignin)

Reporting period: 2023-10-01 to 2025-03-31

Summary of the context and overall objectives of the project

EPOCH proposes to develop a novel approach in linking green hydrogen production with the direct loading of liquid organic hydrogen carriers (LOHC) enabling a transformative logistic of green hydrogen distribution and storage. Lignin derivatives are used to be selectively oxidized. Compared to water electrolysis, EPOCH will advance the field by (1) using the nascent hydrogen at the cathode directly to load LOHCs allowing economic H2 storage and transport, and (2) converting at the anode waste lignin derivatives via selective oxidation. EPOCH is beyond the state-of-the-art solutions, as it does not form molecular H2 at the cathode nor generates oxygen at the anode. By modifying both cathodic and anodic reactions, EPOCH reduces the energy intensity.

EPOCH will enable better cell performance and enhanced added-value device operations by (i) improving energy efficiency, (ii) allowing cost reductions, and (iii) intensifying the process. The EPOCH device will be designed for flexible integration with biorefineries and pulp & paper industries, to valorize their lignin waste streams, thus, linking these industrial sectors and H2 economy. EPOCH will allow the production of green H2 in areas where renewable energy production (in the energy mix) is higher. Therefore, EPOCH will offer a new path to effectively decrease the carbon footprint of energy-intensive industries.

Development of the novel EPOCH electrocatalytic device requires (a) advanced components (electrocatalysts, electrodes, electrolytes and ionic liquid promoters, membranes) and (b) validation of the full module cell operation at laboratory scale. Thus, our project integrates multidisciplinary top-experts in areas such as electrocatalysis, lignin chemistry, and materials synthesis, with a large engineering company and a spin-off company on energy transition as well as an SME world-leading the LOHC technology development and logistic.

The overall objectives of the EPOCH project are:
1) To develop and validate an innovative technology of direct green H2-carrier (LOHC) production, based on renewable energy, without use of fossil fuels, and combined with the coproduction of carbon-neutral bio-derived chemicals.
2) To exploit waste materials and abundant natural lignin resources and to minimize the use of critical raw materials (CRMs) for cell development.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Within this period, the research covers two parts: component development and system development. From the aspect of component development, suitable anodes, cathodes, membranes, and electrolyte promoters (ionic liquids) have been developed and identified to perform the anodic and cathodic reactions determined in the first period. Additionally, the enzymatic hydrolysis lignin was also directly used as the reactant of the anodic reaction. The investigation shows that: (1) P@OMC is the most promising anode for the selective conversion of phenol to benzoquinone. It is possible to perform lignin electro-oxidation, but it is unsuitable for the EPOCH project. (2) Ni-based cathode shows acceptable results for the first time for the hydrogenation of phenol. (3) Nafion membrane is the best option, and a high degree of toluene/benzyl toluene hydrogenation is achieved in a zero-gap system. (4) Based on the theoretical screening, the developed IL-promoted electrolytes evidence the improved conversion rate experimentally for both electro-hydrogenation and oxidation. The research achievement has been summarized and published in 10 journal articles and presented 26 times.

At the system level, the “one device” with two configurations (zero/non-zero gap) is designed, and the performance of the developed components is tested in the one device for optimization by the partners of Unime, TU Delft, and Aalto. System evaluation is ongoing, where the boundary is extended, starting from lignin and ending with a pure biochemical as a final product on the anode side, and LOHC de-loading on the site 1000 km from the production site is included.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

1. A metal-free electrocatalyst/anode was developed, achieving high raw material conversion and product selectivity. In a microflow cell, it showed 68% phenol conversion and 55% benzoquinone selectivity when paired with Rh/C and Pt/C cathodes, also producing cyclohexanol and cyclohexanone.

2. Ni-based electrocatalyst/cathode has been developed with acceptable conversion performance for the first time.
3. Nafion proved to be the best commercial PEM, enabling single-pass hydrogenation of toluene and benzyl toluene in a zero-gap electrolyzer, with hydrogenated products observed.

4. Theoretical models accurately predicted viscosity and self-diffusion in IL-based systems, which also showed promise in electrocatalytic hydrogenation, oxidation, and lignin dissolution.

5. IL toxicity was examined but remains inconclusive; structural tuning may reduce toxicity.

6. A corrosion-resistant, heated flow reactor with full electrolysis setup was built and is operational. Optimal pH conditions were identified for simultaneous selective oxidation and hydrogenation, achieving 50% benzoquinone and 25.5% cyclohexanol yields in preliminary tests.

7. For system assessment, lignin depolymerization and product separation were reviewed, initial “basic design package” activities began, a TEA setup methodology was defined, and an LCA was conducted.