Transforming Biomass Waste for Sustainable Water Management: Advanced Pyrolysis Techniques for Biochar Production

Swiss partners

• HES-SO Valais-Wallis - Haute Ecole d'Ingéneurie: Mathieu Soutrenon (main applicant)

Partners in the MENA region

• Université Mohammed VI Polytechnique - Rabat, Morocco: Fouad Ghamouss (main applicant)

Presentation of the project

This project revolves around the utilization of two advanced pyrolysis techniques, photo-pyrolysis and laser pyrolysis, for the transformation of biomass and organic waste into porous biochar for water treatment. Pyrolysis is used to convert biomass into syngas, bio-oil, and solid carbon. Each of these end products has a commercial value and find applications in various fields, including energy storage, environmental remediation, and advanced materials synthesis. This project focuses on the solid product of pyrolysis: biochar to use it for water treatment and soil remediation. Water scarcity is a significant issue in Morocco, the arid conditions and desertification are exacerbated by the climate crisis. Morocco also faces significant water quality challenges, with surface and groundwater contamination from agricultural runoff, industrial discharge, and untreated municipal waste. This situation underscores the urgent need for strategies to safeguard water resources. Incorporating biochar into water filtration systems is a demonstrated and efficient approach for the removal of toxic compounds, leveraging its high surface area (up to 2000 m2/g) and adsorption capacity. Additionally, the hydrogen-rich gas produced during the pyrolysis can be used for fertilizers production, especially ammonia. It can also be an indirect way of extracting water from biomass through hydrogen.

Pyrolysis, a well-established method for biochar production, serves as foundation for our novel approaches. Photopyrolysis, pioneered at EPFL-Sion, involves exposing biomass or organic wastes to intense xenon flash lamp pulses, while laser pyrolysis, developed at MSN/UM6P, utilizes a CO2 laser. Both processes take seconds/minutes instead of hours for standard pyrolysis, and lead to a predominant formation of hydrogen-rich gas over bio-oil, and porous biochar. It should be noted that our works are centered on those innovative and sophisticated pyrolysis techniques. It is also important to note the low CO2 impact of these methods, since a large proportion of the carbon is recovered in solid form, and the energy to be supplied can be of renewable origin.

This project between MSN/UM6P and HES-SO Valais-Wallis aims to explore and enhance the capabilities of laser and photopyrolysis to produce highly porous biochar from arid zone vegetation and assessing its effectiveness for brackish water desalination, olive mill wastewater treatment and soil amendment.