"Developing continuous microwave-assisted processes for clean hydrogen"

Microwave technology is reshaping how we convert waste into energy. At Université de Technologie de Compiègne, Prof. Dr. Christophe Len and the i-CLeHS team are pioneering new reactor designs to extract clean hydrogen from plastic waste.

Their work focuses on microwave-assisted processes—batch, semi-batch, and continuous flow—powered by catalytic systems made of ionic liquids and metal oxide nanoparticles.

1.What are the main responsibilities of i-CLeHS in this project?

The main responsibilities of i-CLeHS in the WASTE2H2 project are to develop batch, semi-batch, and continuous microwave-assisted processes for the efficient conversion of plastic waste into clean hydrogen and valuable carbon materials. This will be achieved using a catalytic system based on ionic liquids and metal oxide nanoparticles. A key objective is to understand the effect of microwave irradiation on the selective generation of the clean hydrogen and the carbon materials, which will allow the optimization of the process and ultimately lead to the scalability of a continuous-flow process.

2.What are the key advantages of using microwave (MW) irradiation instead of conventional heating?

The primary advantage of microwave irradiation in this project is the rapid heating of the catalytic system, which occurs directly through microwave absorption. Since plastic waste is transparent to microwaves, it is subsequently heated through conduction from the catalytic system to reach the target temperature. This synergistic heating approach enhances the reactivity of the system, improving the production of clean hydrogen and valuable carbon materials. At an industrial scale, especially in continuous reactors, MWs significantly reduces overall energy consumption, offering a cleaner and more energy-efficient solution.

3.What are the expected effects of MW irradiation on the catalytic performance of IL-based systems?

Microwave-assisted chemical transformations offer the distinct advantage of rapid and uniform heating throughout the reactor. The IL/MO-NPs (ionic liquid/metal oxide nanoparticles) catalytic system is highly responsive to high-frequency microwave energy, enabling a swift rise in reaction temperature—crucial for continuous processing. This leads to enhanced catalytic performance, facilitating the efficient production of clean hydrogen and valuable carbon materials while minimizing energy input.

4.What are the main challenges in designing the continuous-flow reactor at TRL4 for WASTE2H2 process validation?

The primary challenge in designing the TRL4 continuous-flow reactor lies in scaling up from batch to continuous operation while preserving key performance metrics such as yield, productivity, and selectivity. While achieving rapid temperature increases via microwave heating of ionic liquids is relatively straightforward, the critical hurdle is selecting an effective IL/MO-NPs catalytic system that enables the selective production of clean hydrogen and valuable carbon materials under microwave conditions. Another major challenge will be the efficient separation of the carbon material from the catalytic system post-reaction.

By unlocking the unique benefits of microwave heating, the i-CLeHS team is helping WASTE2H2 scale up clean hydrogen production. Their research brings us one step closer to efficient, low-energy solutions for a circular, sustainable future.