How can we make the most of decarbonated hydrogen?

This spring, the Student Scientific Convention of engineering students and scientists submitted 28 recommendations to the French government on the priority uses of carbon-free hydrogen. Sebastian Vallejo Jimenez, ENSTA Paris 2022 graduate and doctoral student at the interdisciplinary Energy4Climate center, was part of the group of experts supporting the young scientists.

Inspired by the Citizens' Climate Convention, the Student Scientific Convention, organized by the Young Graduates Committee of IESF -Ingénieurs et Scientifiques de France, aimed to get talented young people from all over France to think about whether hydrogen could contribute to the decarbonization of our societies.

A graduate of ENSTA Paris 2022, Sebastian Vallejo Jimenez's task was to contribute his expertise to the debates, a mission in which he invested a great deal of time and effort. "I saw it as a real responsibility, because it's up to our generation of young engineers to get involved and implement the right decisions around the energy transition. In 15 years' time, it will be too late."

Sebastian Vallejo Jimenez
Sebastian Vallejo Jimenez, ENSTA Paris 2022

Sebastian Vallejo Jimenez, who had completed his final year project at ENSTA Paris on modeling the hydrogen value chain, was able to demystify some of the illusions surrounding the use of this technology.

"The expert groups were divided into different themes, and I chose to take part in the transport one. During the debates, I could see that some students imagined using hydrogen for individual mobility. As the discussions progressed, I was able to help them realize for themselves that, due to thermodynamic and low energy density issues, hydrogen posed such technological problems, particularly in terms of storage, that it was not appropriate to use it for individual mobility and that other uses should be prioritized."
 

Originally from Colombia, Sebastian Vallejo Jimenez came to ENSTA Paris under a double degree agreement with the Antioquia School of Engineering (Universidad EIA), but nothing predestined him to become a researcher.

 

thumbnail Testimonio de un graduado internacional: Sebastian Vallejo Jimenez

"Initially, I simply wanted to gain international experience with this double degree. But during my second-year research internship, which is a compulsory part of the ENSTA Paris engineering program, I had the chance to do it at the École Polytechnique's Molecular Chemistry Laboratory, and the subject fascinated me. Two years later, Cédric Tard, director of the Laboratory, suggested I continue with my thesis , as the subject was still very topical. In addition to the interest of the subject, the recognition of the doctorate at international level was an additional motivation for me to go down this path. I'm now working on a thesis on the recovery of hydrogen and carbon dioxide from the aquatic environment as part of the E4C interdisciplinary center, with co-supervisors Cédric Tard and Didier Dalmazzone, Deputy Director of the Chemistry and Processes Unit at ENSTA Paris."

In the end, Sebastian Vallejo Jimenez is very pleased to have contributed to the emergence of what he considers to be the most important of the 28 recommendations put forward by the Student Scientific Convention: to prioritize industrial applications for the use of decarbonated hydrogen, particularly in the fields of chemistry and metal processing, sectors with enormous potential for reducing CO2 emissions.

thumbnail Plateforme pilote hydrogène ENSTA Paris : production, stockage, utilisation