(424a) Using Mining Waste As a Catalyst for Green Hydrogen Production through a Non-Thermal Plasma-Assisted Dry Methane Reforming System.

Dry methane reforming (DMR) is emerging as a pivotal technology for valorizing industrial waste, particularly in sectors where magnesium is extensively used for its lightweight properties, such as in automotive manufacturing. A notable example is Tergeo, a magnesium producer in Quebec, which annually produces approximately 1,100 metric tons of flammable and hazardous residues. These by-products, resulting from electrolysis and foundry processes (BPEFs), pose significant environmental challenges due to their complex chemical composition and the release of hazardous gases such as hydrogen (H₂) and ammonia (NH₃). These residues are currently stockpiled in Val-des-Sources, contributing to environmental degradation.

Our research addresses this issue by transforming these BPEFs into valuable catalysts for converting methane into hydrogen, thereby reducing the environmental impact and promoting circular economy practices. The initial phase of the work involved extensive characterization of the residues using various analytical techniques such as XRD, ICP-MS, ion chromatography, elemental analysis, TGA-MS, and SEM. This comprehensive analysis revealed the precise chemical composition, accounting for up to 95.09% w/w of the total mass and provided detailed structural insights.

Following the characterization, the research progressed to the decontamination and deactivation stages, produced hydrogen and generated a secondary residue rich in magnesium hydroxide (Mg(OH)₂) and magnesium oxide (MgO). MgO was subsequently used as a substrate for developing an innovative catalyst enhanced with 5% nickel concentrations through the wet impregnation method. This catalyst was then tested in a non-thermal plasma-assisted DMR system under atmospheric conditions. Operational parameters for power settings were varied among 800W, 1000W, and 1500W. The gas flows were set with argon fixed at 10 slpm, and CO₂:CH₄ ratios were adjusted to 3:3, 6:4, and 7:3 slpm. The performance of the catalyst was assessed after the reaction using characterization techniques such as XRD, BET surface area analysis, TEM, and TGA.

The different results demonstrated high hydrocarbon conversion rates and hydrogen yield, with H₂/CO ratios nearing unity in the output stream, indicative of efficient catalyst activity. The results underscore the potential of this approach in mitigating the environmental issues associated with industrial waste but also in advancing sustainable waste management practices in the industry.