Time filter

Source Type

Argenti F.,University of Pisa | Guerrini L.,University of Padua | Rossi F.,Consorzio Polo Tecnologico Magona | Landucci G.,University of Pisa
Chemical Engineering Transactions | Year: 2014

Fires may affect process and storage equipment causing severe damages and potential accident escalation. Passive protections, based on the application of fireproofing coatings, are usually implemented in order to prevent or mitigate such events. The design and testing of this type of barriers is a critical task due to the extreme heat exposure conditions. For this purpose, several standard tests, based on the use of large scale furnaces and experimental facilities, are adopted. In the present study, a methodology for the assessment of fireproofing materials performance was presented. The methodology was aimed at reducing the costs of fire tests by the combined use of small scale experiments and modeling activities. A novel inorganic formulation based on basalt fibers and silica aerogel was tested and compared with commercial fireproofing materials. A specific Key Performance Indicator (KPI) was evaluated in order to support the effective design of passive fire protections. © Copyright 2014, AIDIC Servizi S.r.l.

Bientinesi M.,Consorzio Polo Tecnologico Magona | Petarca L.,University of Pisa | Cerutti A.,IDS Ingegneria Dei Sistemi | Bandinelli M.,IDS Ingegneria Dei Sistemi | And 3 more authors.
Chemical Engineering Transactions | Year: 2013

Due to the depletion and the increasingly high cost of conventional light oil resources, in the future unconventional oils are due to become one of the major hydrocarbon source. In order to extract crude oil from these resources, a sufficiently low viscosity must be achieved, for instance through temperature increase. Electromagnetic irradiation can be a suitable method for in situ heating of reservoirs: major problems connected with this technique are the extremely high temperatures that can be reached at the well and the strong dependence on local variations of reservoir material properties. These problems can be solved to a large extent by inserting around the well, in proximity of the radiating element, a tight shell made of low-loss dielectric materials. The experimental work described in this paper aims to study the phenomena connected with the electromagnetic heating of an oil sand reservoir up to 150 °C, in order to assess the effectiveness of the novel tight shell conceptual design. Over 2000 kg of oil sand were inserted in a steel box and irradiated at 2.45 GHz frequency. The radiating element is a dipolar antenna inserted in the center of the oil sand volume. The temperature in the oil sand was recorded throughout the test in several points, in order to estimate temperature profiles along the distance from the antenna. Results confirm that electromagnetic irradiation is capable of heating both wet and dry oil sands, since the temperature in the sample rises well above connate water boiling temperature. Water vaporization significantly impacts on temperature profiles and contributes to limit the temperature near the well. An even larger positive effect on energy distribution and heating homogeneity is assured by the low-loss shell realized around the antenna, that is extremely efficient in lowering the temperature in this critical zone. Copyright © 2013, AIDIC Servizi S.r.l.

Cerutti A.,IDS Ingegneria Dei Sistemi | Bandinelli M.,IDS Ingegneria Dei Sistemi | Bientinesi M.,Consorzio Polo Tecnologico Magona | Petarca L.,University of Pisa | And 3 more authors.
Chemical Engineering Transactions | Year: 2013

The importance of heavy oils as energy resource is continuously increasing, thanks to the development of enhanced oil recovery methods, such as thermal recovery. Radiofrequency reservoir heating through a downhole antenna system can be an effective alternative to steam injection methods, giving advantages such as good energy distribution, greater independence from reservoir properties, equipment compactness, high efficiency and possibility to focus the energy on the oil bed. In this paper we present a numerical study of a new electromagnetic heating method, which combines a radiating antenna with a well-reservoir interface structure, called tight shell. The study was conducted adopting dielectric and physical parameters measured on real oil sand samples and heating requirements relative to an actual oil sand reservoir. The study aims to evaluate the optimal operating irradiation frequency, as well as the effectiveness of the tight shell interface. Results show that, with a proper system design, a considerable volume of reservoir can be uniformly heated by a single downhole antenna. Frequencies in the 10-20 MHz range give the best results, and the use of a tight shell made of a low-loss dielectric material surrounding the irradiating element proves extremely efficient in lowering peak temperatures at the radiating well, preserving well completion and extending the heated volume. The use of a tight shell makes also the method much less sensitive to possible dishomogeneities in the dielectric properties of the reservoir material. Copyright © 2013, AIDIC Servizi S.r.l.

Bientinesi M.,Consorzio Polo Tecnologico Magona | Nicolella C.,University of Pisa | Maccone P.,Solvay Group | Boccaletti G.,Solvay Group
Chemical Engineering Research and Design | Year: 2016

The main objective of this work was to obtain new data for equilibrium and transport properties in the absorption of carbon dioxide into liquid solvents not yet investigated to this purpose. To this end, an experimental setup for measuring gas solubility and diffusivity in non-volatile solvents was designed, realized, and tested by comparison with literature data for the methane/. n-dodecane pair. The solubility of carbon dioxide, nitrogen and oxygen in two different perfluoropolyethers, Fomblin® M03 and Fomblin® Y04, was measured at different temperature ranging from 10°C to 100°C and for pressures up to 7bar. The diffusivity of carbon dioxide in the solvents was measured at 25°C and 50°C, through a pressure decay method. The results obtained in terms of carbon dioxide solubility and selectivity over other gases are encouraging for the possible use of Fomblin® perfluoropolyethers for the absorption of carbon dioxide from flue gases of industrial plants, also due to the complete immiscibility with water of this solvents. New compounds with similar chemical structure are being developed and tested in order to maximize the performances of the absorption process. © 2015 The Institution of Chemical Engineers.

Bientinesi M.,Consorzio Polo Tecnologico Magona | Petarca L.,University of Pisa
Chemical Engineering Transactions | Year: 2011

Thin-film palladium membranes are one of the most promising technologies for hydrogen separation from gas mixtures, involving advantages, such as a separation efficiency approaching 100%, high permeability, and operating conditions compatible with upstream fuel conversion processes. In this work, palladium films, with thickness between 10 μm and 40 μm, were deposited above stainless steel porous tubular supports using a modified electroless plating technique. The application of vacuum during palladium deposition, together with support abrasion and oxidation above 700°C, were demonstrated to be effective in limiting the presence of film defects. The prepared membranes were then tested in an experimental set-up using a wide range of operating conditions (transmembranal pressure 2-20 bar, temperature 300-550°C) in order to evaluate their performances. A hydrogen permeation flow rate of 0.25 mol/m2s, with a selectivity with respect to C02 as high as 5000, was obtained at 450°C and 10 bar of partial transmembranal pressure. A mathematical model was set in order to interpolate the experimental data and simulate the permeation of hydrogen through palladium. A good agreement between experimental and simulation results was obtained. © 2011, AIDIC Servizi S.r.l.

Discover hidden collaborations