(319c) Exploring Production Aspects of Blue Hydrogen and Valuable CNTs from Natural Gas in a Fluidized Bed Reactor

The need for clean, sustainable energy sources is increasing due to environmental fouling from fossil fuel emissions. Hydrogen is one of the best clean fuels with high energy density and no adverse environmental effects. The most common hydrogen production method, i.e., Steam Methane Reforming (SMR), emits a high amount of CO₂ (1300 times more than the product). Hydrogen produced in this way is called grey hydrogen. Exploring blue hydrogen and green hydrogen is essential considering current environmental concerns. Thermo-Catalytic Decomposition of methane (TCD) is an attractive approach for producing blue hydrogen. The energy requirement of the TCD process is quite similar to commercial SMR (37.8 kJ/mol H₂ vs. 41.3 kJ/mol H₂). Furthermore, the TCD process avoids energy-intensive units, i.e., pressure swing adsorption for CO₂ separation, because it produces CO_x-free H₂ and solid carbon. Different forms of carbon (i.e., CNTs, graphene) can be made by optimizing the shape and size of the metal crystals of the catalyst.

In this context, methane decomposition in a fluidized bed reactor was investigated. A transition metal-based alumina-supported catalysts were prepared and tested for methane decomposition in the fluidized bed reactor. These catalysts obtained high methane conversion (>80%) and multi-walled bamboo-shaped carbon nanotubes. Prepared catalysts and CNTs were characterized by TPR, BET, FE-SEM, HR-TEM, Raman spectroscopy, TGA, etc. Hydrodynamic aspects of the fluidized bed reactor were also taken into consideration.

References:

1. K. R. Parmar, K. K. Pant, S.Roy, Energy Convers Manag 2021, 232, 113893.
2. S. K. Saraswat, K. K. Pant, Int. J. Hydrogen Energy 2011, 36, 13352.