Vincenzo Palma
University of Salerno, Department of Industrial Engineering, Faculty Member
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The forecasts in the industrial chemistry field evidenced the growing demand of propylene, and the necessity to develop effective processes able to sustain the market. Selective propane dehydrogenation is emerging as the most competitive... more
The forecasts in the industrial chemistry field evidenced the growing demand of propylene, and the necessity to develop effective processes able to sustain the market. Selective propane dehydrogenation is emerging as the most competitive technology for the production of propylene, on the other hand, the well-known drawback closely linked to the high temperature required to reach a sustainable propane conversion and the coke formation that suppress the catalytic stability still requires appropriate solutions. In this sense, the process intensification through the combination of hydrogen permselective membranes and the reduction of operating temperature could strike the targets of very high propylene selectivity and a quite high conversion value. Since the integration of membrane units in a process required a revision of the operating conditions, the effect of feed composition and temperature was investigated, in order to determine the optimal operating parameters window to operate th...
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Abstract: This chapter focuses on the study of hydrogen selective membranes from an economic perspective. The first section provides an overview of the classification of membranes for hydrogen separation, while the second section... more
Abstract: This chapter focuses on the study of hydrogen selective membranes from an economic perspective. The first section provides an overview of the classification of membranes for hydrogen separation, while the second section describes their preparation technology in detail. Pd-based membranes are also examined, and the correct manufacturing strategy identified, with the aim of improving their industrial competitiveness by lowering production costs. The last section deals with the analysis of the water gas shift (WGS) reaction as a case study, and in particular its application downstream to a reforming step plant in order to reduce the CO content in the exhaust stream. Two possibilities of coupling a membrane with a water gas shift reactor (WGSR) are investigated: either as an open architecture, where hydrogen separation modules are located before and/or after the WGSR, or as an integral WGSR membrane reactor (closed architecture), where reaction and separation occur in a single step. After a literature review focusing on the use of membranes for hydrogen separation in the WGS reaction, the next section discusses the mathematical modeling of a WGS membrane reactor, comparing the performances of the two proposed configurations. The last part of the chapter focuses on a preliminary techno-economic analysis, comparing conventional technology with membrane assisted WGSR developed around open architecture.
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Ammonia has been intensively studied as a clean, sustainable fuel source and an efficient energy storage medium due to its effectiveness as a hydrogen carrier molecule. However, the currently used Haber–Bosch process requires a large... more
Ammonia has been intensively studied as a clean, sustainable fuel source and an efficient energy storage medium due to its effectiveness as a hydrogen carrier molecule. However, the currently used Haber–Bosch process requires a large fossil fuel input, high temperatures and pressures, as well as a significant capital investment. These constraints prevent decentralized and small-scale ammonia production at the level of small farms and local communities. Non-thermal plasma (NTP) can promote ammonia synthesis in operating conditions in which, in a conventional process, a catalyst is generally not active. In this study, the production of NTP-assisted catalytic ammonia at milder temperatures and ambient pressure was investigated. Four different structured catalysts were prepared and tested using an experimental plant based on a dielectric barrier discharge (DBD) reactor. The effect of the gas hourly space velocity (GHSV) was investigated, as well as the effect of the N2/H2 ratio on catal...
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Nitrous oxide (N2O) is considered the primary source of NOx in the atmosphere, and among several abatement processes, catalytic decomposition is the most promising. The thermal energy necessary for this reaction is generally provided from... more
Nitrous oxide (N2O) is considered the primary source of NOx in the atmosphere, and among several abatement processes, catalytic decomposition is the most promising. The thermal energy necessary for this reaction is generally provided from the external side of the reactor by burning fossil fuels. In the present work, in order to overcome the limits related to greenhouse gas emissions, high heat transfer resistance, and energy losses, a microwave-assisted N2O decomposition was studied, taking advantages of the microwave’s (MW) properties of assuring direct and selective heating. To this end, two microwave-susceptible silicon carbide (SiC) monoliths were layered with different nickel–cobalt–aluminum mixed oxides. Based on the results of several characterization analyses (SEM/EDX, BET, ultrasound washcoat adherence tests, Hg penetration technique, and TPR), the sample showing the most suitable characteristics for this process was reproduced in the appropriate size to perform specific MW...
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Nitrous oxide (N2O), produced from several human activities, is considered a greenhouse gas with significant environmental impacts. The most promising abatement technology consists of the catalytic decomposition of N2O into nitrogen and... more
Nitrous oxide (N2O), produced from several human activities, is considered a greenhouse gas with significant environmental impacts. The most promising abatement technology consists of the catalytic decomposition of N2O into nitrogen and oxygen. Many recently published papers dealing with N2O catalytic decomposition over Ni-substituted Co3O4 are related to the treatment of N2O concentrations less than 2 vol% in the feed stream. The present work is focused on developing catalysts active in the presence of a gaseous stream richer in N2O, up to 20 vol%, both as powder and in structured configurations suitable for industrial application. With this aim, different nickel-cobalt mixed oxides (NixCo1−xCo2O4) were prepared, characterized, and tested. Subsequently, since alumina-based slurries assure successful deposition of the catalytic species on the structured carrier, a screening was performed on three nickel-cobalt-alumina mixed oxides. As the latter samples turned out to be excellent ca...
Research Interests: Catalysis, Catalysts, Decomposition, Cobalt, Nickel, and 2 moreNitrous Oxide and Cobalt Oxide(Nitrous Oxide and Cobalt Oxide)
(Nitrous Oxide and Cobalt Oxide)
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Abstract Microwave heating was studied as assisted regeneration technique of diesel particulate filters. An SiC foam was used for the good microwave-absorbing properties of silicon carbide with respect to other ceramic materials. The... more
Abstract Microwave heating was studied as assisted regeneration technique of diesel particulate filters. An SiC foam was used for the good microwave-absorbing properties of silicon carbide with respect to other ceramic materials. The influence of the soot-loading ...
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Systems based on Ce-Zr are used in catalytic converters for their oxygen storage ability. Recently, their application for soot abatement is under investigation. In this paper, preliminary results of the performance of Ce-Zr systems with... more
Systems based on Ce-Zr are used in catalytic converters for their oxygen storage ability. Recently, their application for soot abatement is under investigation. In this paper, preliminary results of the performance of Ce-Zr systems with the addition of K are reported by varying potassium content and calcination temperature. The powder catalysts were prepared by a variant of the citrates route developed at University of L’Aquila. Characterization of the catalysts after calcination was performed by different techniques: profile fitting of the XRD data, estimation of surface composition by XPS, evaluation of catalytic performance by temperature programmed oxidation tests of the soot-catalyst mixture and of redox properties by carbothermic reduction and subsequent oxidation in a high resolution thermobalance. The characterization by XRD showed that the system maintains the crystallographic structure Fm-3m and that the potassium is segregated on the grain boundaries. The catalytic activi...
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Abstract A kinetic model of propane dehydrogenation on a Pt,Sn/Mg(Al)O is presented, accounting for product distribution due to main and side reactions, for deactivation rates and for diffusion resistance. Parameters were estimated from... more
Abstract A kinetic model of propane dehydrogenation on a Pt,Sn/Mg(Al)O is presented, accounting for product distribution due to main and side reactions, for deactivation rates and for diffusion resistance. Parameters were estimated from steady state experiments at varying pressure and from temperature-programmed experiments, and are compared with previous models on similar catalysts and with published computed results. Steam was added to slow coke formation, leading to some steam reforming. The rate of deactivation was shown to correlate with carbon build up on the surface, which was determined from the selectivity to carbon. Application of the model to design a Pd-membrane reactor suggests that pressure should be kept below 5 bar and steam around 10% in feed, while pellet size affects mainly the selectivity while the effect on conversion is small. While the main reaction is fast, side reactions are not negligible, especially under conditions of a membrane reactor, but selectivity to propane can be maintained about 95%.
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Abstract In response to the escalating energy crisis and related pollution problems, we urgently need to adopt new energy supply technologies that utilize renewable energy sources in an efficient and environmentally friendly manner.... more
Abstract In response to the escalating energy crisis and related pollution problems, we urgently need to adopt new energy supply technologies that utilize renewable energy sources in an efficient and environmentally friendly manner. Today, approximately 65 million tons of hydrogen are produced annually worldwide. Steam reforming of natural gas is the prevalent hydrogen production technology. Large quantities of hydrogen are needed in the chemical and petrochemical industry, in particular for ammonia production, oil refining, and methanol synthesis. Moreover, hydrogen is increasingly discussed as a fuel for transport applications. Especially production from logistic fuels is considered a viable option to accelerate market introduction of hydrogen as an alternative energy carrier. Today, hydrogen is predominantly produced by steam reforming of natural gas in large-scale, central production plants. However, with an increasing share of fuel cell vehicles in the market, central hydrogen production will suffer from additional costs associated with the distribution of gaseous-phase hydrogen by trailer over long distances. In contrast, distributed hydrogen generation (DHG) at fueling stations offers the advantage of using readily available liquid fuels such as diesel and biodiesel with high energy densities and existing infrastructure. DHG is widely seen as a promising alternative in the transition phase toward a fully renewable hydrogen production economy. According to the most recent studies, conventional hydrogen generation processes up to 300 Nm3/h H2 are being increasingly substituted with advanced steam reforming technologies, in particular using biofuels as feedstocks. In this chapter the hydrogen production from the most important biofuels is described. The attention is focused on bioethanol, biogas, bio-oil, and biodiesel.
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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... more
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.
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Highly thermal conductive honeycomb structures were proposed as attractive catalyst supports in order to enhance heat and material transfer properties. This work is focused on experimental testing and preliminary numerical modeling of the... more
Highly thermal conductive honeycomb structures were proposed as attractive catalyst supports in order to enhance heat and material transfer properties. This work is focused on experimental testing and preliminary numerical modeling of the methane steam reforming reaction performed on Ni-loaded SiC monolith, packaged into an externally heated tube: in particular, Flow Through and Wall Flow configurations were investigated. A preliminary steady-state heterogeneous 3D model was developed: the model equations include momentum, mass and energy balances. The experimental tests and the numerical simulations indicate that the Wall Flow configuration may overcome the fixed-bed reactor problems, yielding a more uniform temperature distribution and a more effective mass transport
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Research Interests: Engineering, Chemical Engineering, Condensed Matter Physics, Chemistry, Hydrogen, and 13 moreCatalysis, Ceria, FUEL TECHNOLOGY, Hydrogen Energy, Ethanol, CHEMICAL SCIENCES, Oxidative phosphorylation, Carbon Deposition, Mesoporous Silica, Electrical And Electronic Engineering, Steam Reforming, Ethanol Reforming, and Mesoporous Material
Abstract The process intensification (PI) is a design approach offering concrete benefits in manufacturing and processing, shrinking equipment size, boosting plant efficiency, saving energy, reducing capital costs, increasing safety,... more
Abstract The process intensification (PI) is a design approach offering concrete benefits in manufacturing and processing, shrinking equipment size, boosting plant efficiency, saving energy, reducing capital costs, increasing safety, minimizing environmental impact, and maximizing the raw material exploitation. Membrane processes address the goals of PI because they have the potential to replace conventional energy-intensive techniques, to accomplish the selective and efficient transport of specific components, and to improve the performance of reactive processes. This chapter discusses how membrane engineering contributes to the realization of the principles of PI. First of all a general classification of the type of membranes and the catalyst configuration in the membrane reactors is proposed. The overview of current developments regarding the processes for H2 production by methane steam reforming, autothermal reforming, water-gas shift, and dehydrogenation reactions through these integrated systems is discussed.
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Abstract The synergic effects presented by membrane reactors (MRs), coupling reaction and separation processes in the equal unit comprise an interesting concept that has already exhibited many advantages (increased reaction rate,... more
Abstract The synergic effects presented by membrane reactors (MRs), coupling reaction and separation processes in the equal unit comprise an interesting concept that has already exhibited many advantages (increased reaction rate, selectivity and yield) for different reactions concerning hydrogen production. In this chapter, a summary description of the working notions of membrane reactors and general considerations related to the type and role of the membranes are reported. This is followed by an overview of the MRs’ configurations for hydrogen production via most common reactions such as steam reforming, dry reforming, partial oxidation of methane, and water gas shift (WGS). The most common configurations, such as the packed bed membrane reactor (PBMR), fluidized bed reactor (FBMR), micro-membrane reactor (MMR), and membrane bio-reactor (MBR), have been discussed. Finally, the properties and limitations of the membranes as well as the sealing with the rest of the reaction unit have been summarized for various applications.
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Publisher Summary This chapter studies the carbon–oxygen reaction in the presence of catalyst for different carbonaceous materials. In the study described in the chapter, catalytic and thermal combustion tests were performed with a flow... more
Publisher Summary This chapter studies the carbon–oxygen reaction in the presence of catalyst for different carbonaceous materials. In the study described in the chapter, catalytic and thermal combustion tests were performed with a flow microreactor loaded with the catalyst mixed to different amounts of carbonaceous materials or with the latter alone. The temperatures of carbon oxidation are strongly affected by the presence of the catalyst 137AA. As an example, thermogravimetric curves in air flow of CB330 and of crystalline graphite with and without catalyst are reported in this chapter. They show that the temperature ranges in which combustion occurs is lowered by more than 300°C by the catalyst. Similar effect has been observed for other carbonaceous materials. The uncatalyzed and the 137AA-catalyzed reactions showed different activation energies, Ea. The rate of reaction shows a first-order dependence with respect to oxygen concentration. Instead, an apparent order of 0.5 has been found with respect to the mass of the other reactant—that is, C.
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This chapter provides a brief introduction to the state of art in the use of bimetallic and alloy catalysts as well as bed reactors in alcohol and bio-alcohol reforming. Among hydrogen production systems, alcohol and bio-alcohol reforming... more
This chapter provides a brief introduction to the state of art in the use of bimetallic and alloy catalysts as well as bed reactors in alcohol and bio-alcohol reforming. Among hydrogen production systems, alcohol and bio-alcohol reforming is considered one of the most suitable routes, due to the high yields at low temperature, the non-toxic characteristics of the reactant and the renewable sources making the widespread diffusion in energy production processes possible. However, the efficiency of hydrogen production strongly depends on the control of the formation of unwanted by-products, that generally occur at low temperatures. Thus, a great deal of attention has been given over recent years to the preparation and study of properly designed catalysts for low temperature reforming processes. Naturally, the use of bimetallic and alloy catalysts makes it possible to design systems with unique characteristics, which monometallic catalysts cannot provide. Studies on the reforming of various alcohols have been published, with the majority on ethanol steam reforming. We therefore focus on this kind of process. In the second part of the chapter, we provide a brief introduction to the state of art of structured catalysts with particular attention to the structural stability in harsh environments that include vibrations, thermal cycling as well as continuous start up and shut down. The concrete transfer of catalytic knowledge on ethanol reforming from powders to structured catalysts results in a crucial breakthrough towards the industrial diffusion of hydrogen production from bio-alcohols