Development of a bifunctional material incorporating carbon microspheres for the intensified hydrogen production by sorption-enhanced glycerol steam reforming

Abstract

Glycerol steam reforming is a green and sustainable alternative to hydrocarbon steam reforming for hydrogen production. Reaction intensification by in-situ CO2 removal using Ni/CaO-based bifunctional sorbent-catalyst materials was investigated in this paper to improve the hydrogen yield and purity significantly. Employing carbon microspheres as the foundation for sorbent synthesis resulted in the development of a hollow CaO sphere sorbent with higher and more stable sorption capacity over multiple adsorption/regeneration cycles compared to sorbents synthesized with conventional methods. The incorporation of different stabilizers improved further the capacity and stability of sorbents. The sorbent materials were tested under different sorption and regeneration temperatures in a dry and wet atmosphere. The intensified sorption-enhanced steam reforming process was evaluated under various reaction temperatures, weight hourly space velocities, and steam-to-carbon molar feed ratios. The bifunctional materials synthesized with carbon microspheres led to improved reaction performances, including a more extended pre-breakthrough period and a more stable behavior during reaction/regeneration cycles.