(771c) Oxidative Steam Reforming of Iso-Butanol Over Promoted Nickel Xerogel Catalysts

Rapid development of alternative energy resources is the main challenge to meet the growing energy demand in the reality of depleting fossil fuels. Hydrogen energy is one of the clean alternatives.  However main drawbacks involved in this process are direct distribution and storage; hence onsite production from various feed stocks is one of the choices. In this process, current route for H₂ production is the catalytic reforming of hydrocarbons and alcohols. Presently, there is a growing interest in the use of C2-C4 alcohols as the raw materials for reforming, since these compounds can be produced from biomass feedstock. However, formation of coke and other undesired by-products is the main obstacle in the process of steam reforming of these alcohols. Hence development of new catalysts for higher hydrogen production and less or no coke formation are of great interest.  The oxidative steam reforming of alcohols is one of the best options to achieve these goals. It is a combination of steam reforming and partial oxidation. The addition of oxygen into the reaction prevents coke formation and results in a comparatively high hydrogen yield; it, also, requires less energy compared to the conventional steam reforming process. But thermal sintering of active and support materials make this process more challenging.

The present experimental study has been undertaken to investigate the effect of the operation variables on the oxidative steam reforming of isobutanol.  In this present study, we have prepared Ni-based catalysts by the sol-gel method, which results in the retention of hydroxyl-rich surfaces, which exhibit unique textural and chemical properties compared with those prepared by other conventional methods, like the impregnation method. Alumina is used as the support material, Ni is the main active metal, and Ce-ZrO₂ and Ru are chosen as promoters. Catalysts were characterized by XRD, TPR, TPD of H₂, BET surface area and porosity measurements. The oxidative steam reforming of isobutanol was performed in a microreactor setup at different reaction temperatures, space velocity, oxygen/carbon ratio and steam/carbon ratio. The Ru-Ni-Ce-Zr-Al₂O₃ catalyst showed high catalytic activity, low carbon deposition, good resistance to sintering and prolonged stability compared to the other catalysts prepared in the project.  The results from these experiments will be discussed during the presentation in terms of the effect of operation variables on the hydrogen yield and product gas composition.

Acknowledgement

            The authors acknowledge financial support from ARO grant (W911NF-10-1-0514).