Robust autothermal microchannel reactors

• The behavior of autothermal microchannel reactors under real operating conditions is explored.
• An ensemble of solutions for improving steady-state and dynamic robustness is discussed.
• Theoretical concepts are extensively validated using rigorous simulations.

Autothermal microchannel reactors are intensified process units that bring significant energy efficiency benefits over their conventional counterparts. Efficiency gains are obtained, however, at the cost of operational challenges. These stem from the loss of control handles that is inherent to combining several unit operations in a single physical device. In this paper, we investigate the impact of two recently proposed reactor design concepts (a segmented catalyst macromorphology and an embedded layer of phase change material) aimed at improving the steady state energy distribution and, respectively, preventing the advent of hotspots during transient operation, on reactor dynamics and control. Using an autothermal microchannel reactor coupling steam methane reforming with methane catalytic combustion as a prototype system, we demonstrate through rigorous simulations that these design innovations have a synergistic effect, resulting in superior steady-state performance and excellent disturbance rejection ability.