Adolfo Iulianelli
CNR-ITM, Italy
Title: Pd-alloy supported membranes: hydrogen separation/purification and membrane reactor applications
Biography
Biography: Adolfo Iulianelli
Abstract
The main industrial process for producing hydrogen is represented by the natural gas reforming, which consists of a multi-step process in which the steam methane reforming takes place in harsh conditions (800-1000 °C and 15-20 bar), followed by two water gas shift reactors and other separation/purification stages for producing high purity hydrogen. However, the natural gas composition of the feeding stream can vary widely from source to source, but each of them contains some traces of H2S. This can damage dramatically the permeation characteristics of the Pd-based membranes and, consequently, affect the overall performance of the membrane reactor. In the last years, many authors studied the preparation of composite membrane based on Pd alloyed with other metals, such as Au, Ag, Pt or Cu, responsible of higher resistance to sulfur contamination. In this study, a composite membrane constituted of a thin layer of Pd-Au supported on porous supports has been fabricated for their utilization in hydrogen separation field. For comparison, a supported pure Pd-membrane has been also studied in order to compare the performance under long-time operation of the different membranes and for evaluating the H2S effects on both systems. They have been also used in membrane reactors to carry out steam methane reforming reaction, by comparing the experimental results with an equivalent conventional reactor.