Concetta Ruocco

Bimetallic Pt and Ni based foam catalysts for low-temperature ethanol steam reforming intensification

The increasing world power demand is driving scientific interest toward the research of alternative energy sources. As energy production from fossil fuels is limited by both reduced availability and pollutants emissions, H2 from renewable feed-stocks (i.e. bioethanol) appears a good clean chance, especially for fuel cells. In this paper, the performances of ceria and ceria-zirconia supported bimetallic powder and foam catalysts in the low temperature range (300-600 °C) Ethanol Steam Reforming reaction were investigated with the aim to highlight the improved heat transfer properties of the structured samples. Two different reactor configurations were employed: catalytic powders were tested in both an annular and a tubular reactor and the hollow one was also used for foam catalysts. SiC foam catalysts, by exploiting the high thermal conductivity of the support, could reduce heat transfer resistance, thus assuring very interesting results in terms of both activity and stability. Moreover, the role of catalytic support was studied and CeO2-ZrO2 based catalysts were found more suitable for the desired reaction.

State of the Art of Conventional Reactors for Methanol Production

Abstract Because it is involved in the production of a wide range of added-value chemicals, methanol is one of the most important compounds in the industrial chemistry field. The significant thermodynamic limitations related to methanol synthesis via syngas conversion has intensified interest in this process. Starting with the development of the BASF process at the beginning of the 20th century and the ICI process, introduced in the 1960s, many schemes have been proposed for the overall optimization of the process. This chapter aims to explore the methanol synthesis process and the most relevant technologies available in the methanol industry.

Catalysts for conversion of synthesis gas

Abstract A more comprehensive exploitation of biosources could be assured by the conversion of biofuels to valuable chemicals. The syngas, obtained by hydrocarbons reforming process, represents the most important reactants mixture for other processes devoted to the production of methanol, higher hydrocarbons (Fischer-Tropsch synthesis), and ammonia. The first two processes are very similar, since they involved main components of syngas in exothermic processes in which a more complex compound is achieved; they are promoted at high pressure and low temperature, for which anyway other side reactions occur (mainly methanation), and each reaction could be considered side-reaction for the other. Such observation remarks the relevance of the catalytic system that should enable desired reactions in the selected operating system. In particular, the Fischer-Tropsch synthesis is widely carried out on cobalt-based catalysts at low temperature, achieving long-chain hydrocarbons as main products; conversely, if low chain is preferred, iron-based catalyst could be employed. Methanol catalysts were effectively developed in the 1960s, in which Cu-ZnO-based formulations appeared very promising both in terms of activity and selectivity. Ammonia synthesis utilized hydrogen obtained by syngas purification (WGS, PROX, and PSA), reducing nitrogen to NH3: such process is thermodynamically promoted at low temperature and high pressure. Iron catalysts are currently used in industrial plants. For all these processes, the very high operating pressure was reflected in a limited catalyst lifetime, so nowadays, studies are focusing in the ability to enlarge catalyst lifetime, by doping active phases or supports. Globally, the exothermic nature of these processes suggests to investigate the effect of highly thermal conductive structured carrier, in order to have a better thermal management in the catalytic volume that could reduce hot spot risks and in turn assure a more stable behavior.

High Thermal Conductivity Structured Bimetallic Catalysts for Low Temperature Ethanol Steam Reforming

This study focuses on the development of bimetallic structured catalysts, supported on CeO2 and CeO2–ZrO2, active in Ethanol Steam Reforming (ESR) reaction at low-temperature (300–600 °C) and characterized by improved heat transfer properties. ESR reaction was carried out on ceramic foams and on powders catalysts. In particular, catalytic test were performed on two reactor configurations (annular and tubular), evidencing that the better thermal management of the foams, tested in the tubular reactor, results in very higher conversions mainly due to the overcoming heat transfer limitations. Moreover, the effect of catalytic support on system performances was investigated.