Showing papers by "Giuseppe Barbieri published in 2008"
TL;DR: In this paper, a model of hydrogen transport in Pd-based supported membranes was described by means of a model considering several elementary steps of the permeation process, improving what done by Ward and Dao [1999] for self-supported membranes.
116 citations
TL;DR: In this article, an innovative configuration for a membrane reactor (MR) was proposed: the membrane is located only in the second part of the catalytic bed, which allows a good exploitation of the whole membrane area for the permeation.
102 citations
TL;DR: In this paper, the authors proposed a novel Sieverts-Langmuir's model taking into account the mentioned adsorption, in order to take into account a fraction of the membrane surface not active for hydrogen permeation, which is the surface loading in the classical Sieverts' permeation equation.
77 citations
TL;DR: In this paper, a series of membranes with different permeation properties, prepared by secondary growth, Pt-loaded by ion exchange and reduced was used for the analysis of CO selective oxidation using catalytic zeolite (Pt/Na-Y) membranes.
37 citations
TL;DR: The H 2 flux profile allows the area of a Pd-based membrane to be evaluated in order to have the same permeate flow rate of H 2 when it is fed with CO or as a pure stream, and proves important in the design of a hydrogen purification unit.
37 citations
TL;DR: In this paper, an integrated system composed of a Pd-Ag membrane module and a polymeric electrolyte fuel cell (PEMFC) was studied, where a pure hydrogen permeate stream was fed directly to the PEMFC as an H 2 purification step with a mixture containing also CO and CO 2.
Abstract: In this work an integrated system composed of a Pd–Ag membrane module and a polymeric electrolyte fuel cell (PEMFC) was studied. The Pd–Ag membrane module, allowing a pure hydrogen permeate stream to be fed directly to the PEMFC, was used as an H 2 purification step with a mixture containing also CO and CO 2 . The CO poisoning effect on the Pd–Ag membrane and its consequences on the hydrogen permeation were analysed in a temperature range 300–450 °C in terms of permeance reduction conditioning also the H 2 recovery index (RI). A comparison between the experimental data obtained feeding the fuel cell (FC) with pure H 2 from a cylinder and from the purification step was also performed in order to evaluate the PEMFC performance stability. After the experimental study of each single step, particular attention was devoted to the analysis of the integrated system Pd–Ag membrane purification step—PEMFC, focusing on the influence of the Pd–Ag membrane module operating conditions on the electrical performance of the PEMFC. The PEMFC internal crossover was also considered and its effects on the electrical performance were taken into account by means of a PEMFC actual efficiency. Furthermore, integrated membrane plant chemical efficiency was defined considering the H 2 converted into electricity with respect to the total amount of H 2 contained in the mixture. The integrated Pd–Ag membrane purification with PEMFC shows very good results: the hydrogen is well purified and the PEMFC performance is very high near the nominal value.
26 citations
TL;DR: In this article, the reaction rate profiles of palladium membrane reactors for methane steam reforming were analyzed by means of mathematical modeling, and it was shown that reaction rate decreased from the inlet in zones I and II, it increased in zone III.
13 citations
TL;DR: This chapter discusses mathematical modeling of Pd–alloy membrane reactors, using simulations of MRs behavior to predict and analyze the effect of some parameters on the performance of a Pd-alloy MR.
Abstract: Publisher Summary This chapter discusses mathematical modeling of Pd–alloy membrane reactors In these systems, reaction and separation are performed in the same vessel A permselective membrane, dividing the reactor into a reaction volume (where the reaction happens) and a permeate side allows the selective removal of products from the reaction volume under the effect of a driving force that is a function of the species partial pressures on the reaction and permeate sides It can be created by means of an inert sweep gas in the permeate compartment (nitrogen, helium, and water), or with the application of a pressure difference between the retentate and the permeate compartments or by their combination The removal of a product from the reaction volume allows the thermodynamic equilibrium limit of a traditional reactor (TR) to be exceeded, obtaining higher conversion in analogous-operating conditions This allows the membrane reactors (MRs) to achieve—for endothermic reactions—the same conversion as that attained in a TR but at significantly lower temperatures The simulations of MRs behavior are useful to predict and analyze the effect of some parameters on the performance of a Pd–alloy MR
9 citations