Maria Anna Murmura

Purification of Hydrogen-Methane Mixtures Using PSA Technology

Mixtures of hydrogen-methane (hydromethane), composed of 20–30 %vol. hydrogen, are considerably interesting, especially in the field of sustainable mobility, because their energy content is higher than that of pure methane; moreover, the carbon dioxide emissions due to the combustion are reduced. The production of such mixture can be effectively carried out by means of steam reforming of natural gas (97 % methane and 3 % carbon dioxide) at 500–550 °C. However, the reformed gas must be purified in order to reduce the carbon dioxide concentration (lower than 3 %). The pressure swing adsorption technology, which uses activated carbon as adsorbent material, may be employed to remove carbon dioxide and to obtain a high recovery of hydrogen and methane. To improve the recovery of methane, a second pressure swing adsorption unit, which uses carbon molecular sieve as an adsorbent, can be introduced.

Modeling Fixed Bed Membrane Reactors for Hydrogen Production through Steam Reforming Reactions: A Critical Analysis

Membrane reactors for hydrogen production have been extensively studied in the past years due to the interest in developing systems that are adequate for the decentralized production of high-purity hydrogen. Research in this field has been both experimental and theoretical. The aim of this work is two-fold. On the one hand, modeling work on membrane reactors that has been carried out in the past is presented and discussed, along with the constitutive equations used to describe the different phenomena characterizing the behavior of the system. On the other hand, an attempt is made to shed some light on the meaning and usefulness of models developed with different degrees of complexity. The motivation has been that, given the different ways and degrees in which transport models can be simplified, the process is not always straightforward and, in some cases, leads to conceptual inconsistencies that are not easily identifiable or identified.

A Tunable Microfluidic Device to Investigate the Influence of Fluid-dynamics on Polymer Nanoprecipitation

A Tunable Microfluidic Device to Investigate the Influence of Fluid-Dynamics on Polymer Nanoprecipitation Stefano Cerbelli*, Alessia Borgogna, Maria Anna Murmura, Maria Cristina Annesini, Cleofe Palocci, Marco Bramosanti, Laura Chronopoulou Dip. di Ingegneria Chimica Materiali Ambiente, Sapienza Università di Roma, Via Eudossiana 18, 00184 Roma (Italy) Dip. di Chimica, Sapienza Università di Roma, Piazzale A. Moro 4, 00185 Roma (Italy) stefano.cerbelli@uniroma1.it