PROMOTION OF COBALT-CONTAINING HYDROTALCITE MATERIALS WITH POTASSIUM, CERIA, AND ZIRCONIA FOR CO2 SORPTION-ASSISTED REFORMING OF BUTANOL TO H2

Abstract

Sorption-enhanced steam butanol reforming (SESBR) is capable of producing pure hydrogen (H2). In CO2 sorption-enhanced (or sorption-assisted) reaction processes, the application of hybrid bifunctional materials consisting of a reforming catalyst and CO2 sorbent is encouraging. In this work, a novel material (CoMgHTlc, here denoted by HM1) containing cobalt catalyst and Mg-based hydrotalcite was synthesized using the coprecipitation method. HM1 was then promoted with K, Zr, or Ce using incipient wet impregnation to yield K-HM1, Zr-HM1, and Ce-HM1, respectively. SESBR was investigated in a fixed-bed reactor between 723 and 923 K. Gas hourly space velocity (GHSV) was changed between 3000 and 6000 mL/g h. Butanol concentration in the feed was varied to provide steam-to-carbon ratios (S/C) ranging from 3 to 7.5 mol/mol. All materials were stable and exhibited a high pre-breakthrough period. At 873 K, H2 concentration of the product stream was 97.3 mol % over Ce-HM1; the CO2-sorption capacity was 1.43 mol CO2/kg sorbent.