Sorption-enhanced steam reforming of ethanol for continuous high-purity hydrogen production: 2D adsorptive reactor dynamics and process design

Abstract

Sorption enhanced steam reforming of ethanol process for high-purity hydrogen production has been investigated in this work. A two-dimensional mathematical model has been developed to describe the coupled mass and heat transport phenomena within both the axial and radial directions of the adsorptive reactor for sorption enhanced reaction process. The product distribution from the numerical simulation matches well with experimental data obtained from a laboratory-scale fixed-bed adsorptive reactor. In addition, the performance of sorption enhanced reaction is found to be sensitive to the temperature gradient in the radial direction in a scale-up reactor. Afterwards, four reactors with a seven steps cycle operation scheme have been employed in a continuous hydrogen production process. It is found that a hydrogen stream (dry basis) with purity higher than 99 mol %, carbon monoxide content 25 ppm and 0.95 mol kg(-1) h(-1) productivity of hydrogen can be produced under cyclic steady state operation. The ratio between energy output and input is around 1.7, and the estimated cost of energy is 0.71US$ per kilogram of hydrogen produced. Besides, high purity carbon dioxide (dry basis) can also be captured as a by-product during the sorbent regeneration step in this process.