High-Purity Hydrogen Production by Sorption-Enhanced Steam Reforming of Ethanol: A Cyclic Operation Simulation Study

A four-step pressure swing operation process in one column with two subsections for sorption-enhanced steam reforming of ethanol (SE-SRE) was developed by simulation for high purity hydrogen production. Within the two subsections, two different volumetric ratios (1:2 and 1:4) between the Ni impregnated hydrotalcite catalyst and K-promoted hydrotalcite sorbent were employed. Various reaction conditions and operating parameters were tested to improve the hydrogen production performance. The product gas with hydrogen purity above 99 mol % and carbon monoxide content of 30 ppm, which can be directly used in fuel cell applications, was continuously produced at 773 K and a swing pressure from 101.3 to 304 kPa. The yield of hydrogen in SE-SRE (78.5%) was found to be much higher than in SRE (38.3%) at the same reaction conditions. Besides, pure carbon dioxide can also be obtained as a byproduct with a yield of 75% during the regeneration step.