Kinetics Model Development and Experimental Scale-up of Cargen® Technology from Milligram Scale to Multi-Kilogram Scale

Dry reforming of methane (DRM) offers an avenue for converting carbon-dioxide (CO₂) and methane (CH₄), the two major greenhouse-gases, into syngas— a vital chemical precursor. However, DRM is constrained by high energy-demands, catalyst-deactivation, and an unfavorable H₂/CO ratio. Previously, a unique dual-reactor system that produces multi-walled carbon nanotubes (MWCNTs) and syngas as products was proposed that offers at least 65% CO₂ conversion at 50% the energy demands of DRM. The present study experimentally proves and scales the concept from milligram scale to multi-gram scale and finally to multi-kilogram scale of MWCNT production. This study also introduces and experimentally validates a lumped Langmuir-Hinshelwood-Haugen-Watson (LHHW) kinetics model capturing a network of nine-primary-reactions involving CO, O₂, H₂, CH₄, CO₂, H₂O, and solid carbon. At milligram scale, the model performs within 5% error-margin for carbon-formation rate at 550°C. At multi-gram scale, the model is validated at 500, 550, and 600°C to capture temperature effect. At this scale, the CH₄-conversion and CO2-conversion predictability is within 8% and 30% error-margin respectively. At multi-kilogram scale, the model predicts carbon-formation rate within 21% error-margin at 550°C. Finally, characterization of the MWCNTs using Raman, SEM, TEM, STEM, and TGA-DTA confirms MWCNT quality consistency at all the scales.

In this presentation, we will highlight the unique journey of the scale-up of the CARGEN® process from milligram-scale to multi-kilogram scale demonstrating its readiness for commercial implementation for the large-scale decarbonization and bulk MWCNT production.