Stazione Sperimentale per i Combustibili

San Donato Milanese, Italy

Stazione Sperimentale per i Combustibili

San Donato Milanese, Italy
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Copelli S.,Polytechnic of Milan | Derudi M.,Polytechnic of Milan | Sempere J.,Ramon Llull University | Serra E.,Ramon Llull University | And 3 more authors.
Journal of Hazardous Materials | Year: 2011

Fast and exothermic discontinuous emulsion polymerization processes are particularly difficult to optimize from both safety and productivity point of view because of the occurrence of side undesired reactions (e.g. chain transfer to monomer, backbiting, propagation of tertiary radicals, termination by disproportion, etc.) and the hazards of boiling phenomena and stable foam formation under atmospheric pressure. Moreover, the relevant number of loading, heating and cooling steps, required before starting the monomer addition (that is, the desired reaction), makes a strict product quality reproducibility very difficult to obtain. Under these operating conditions, it is necessary to employ a suitable combined theoretical and experimental procedure able to detect the optimum process dosing time at both the laboratory and the industrial scale. In this work, it is shown how to use the topological criterion theory together with proper adiabatic calorimeter and RC1 experimental data to safely optimize the synthesis of polyvinyl acetate through the radical emulsion polymerization of vinyl acetate by the means of an indirectly cooled isoperibolic semibatch reactor. © 2011 Elsevier B.V.

Dellavedova M.,Stazione Sperimentale per i Combustibili | Gigante L.,Stazione Sperimentale per i Combustibili | Lunghi A.,Stazione Sperimentale per i Combustibili | Pasturenzi C.,Stazione Sperimentale per i Combustibili | And 3 more authors.
Journal of Loss Prevention in the Process Industries | Year: 2010

Nowadays many chemical industries are SMEs where multi-purpose batch or semi-batch reactors are commonly used. Vent sizing for realistic runaway scenario is not an easy task for such enterprises since they have usually few resources and use multi-purpose reactors with fast process turnovers. As a consequence these batch and semi-batch reactors are usually equipped with emergency relief systems sized once forever when the reactor is designed. This can lead to a large underestimation of the vent area in case of runaway reactions occurring when processes different from the ones considered for originally sizing the vent are carried out. The approach proposed in this work aims to identify the maximum reactor load leading to safe conditions even in case of runaway phenomena to be handled with the emergency relief system already installed (or even with a smaller vent area). This approach allows avoiding the change of the emergency relief system with a larger vent area (as required every time a new more hazardous process has to be carried out on existing reactors) at the price of lower plant productivity. © 2010 Elsevier Ltd.

Dellavedova M.,Polytechnic of Milan | Derudi M.,Polytechnic of Milan | Biesuz R.,University of Pavia | Lunghi A.,Stazione Sperimentale per i Combustibili | Rota R.,Polytechnic of Milan
Process Safety and Environmental Protection | Year: 2012

The use of solid wastes as a way to produce energy and chemicals is one of the frontiers in chemistry. One of these methods is the biomass gasification. In this thermal treatment the biomass is heated in a partially oxidising environment using different process conditions. The variability of both biomass composition and process conditions can lead the thermal treatment to several different results. In order to find a methodology for the classification of all the involved data a dataset containing biomass characterization, gasification process conditions and obtained syngas properties have been gathered from the literature. This dataset has been analysed through multivariate analysis. Principal component analysis (PCA) and a partial least square analysis (PLS) have been performed. Several correlations among different biomass and their gasification products have been found among input parameters, such as biomass properties and process conditions, and output variables like products composition and properties. © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Copelli S.,Polytechnic of Milan | Derudi M.,Polytechnic of Milan | Rota R.,Polytechnic of Milan | Lunghi A.,Stazione Sperimentale per i Combustibili | Pasturenzi C.,Stazione Sperimentale per i Combustibili
Industrial and Engineering Chemistry Research | Year: 2011

Strongly exothermic solution homopolymerizations are a class of chain reactions particularly difficult to be optimized from both a safety and a productivity viewpoint. Particularly, lots of side undesired reactions (e.g., backbiting, propagation of tertiary radicals, chain transfer to monomer or solvent, etc.), which affect the selectivity with respect to the desired product, and relevant mass and heat transfer problems, due to the increasing system viscosity, take place during such syntheses. Under these unavoidable operating conditions, it is difficult to employ theoretical procedures that are able to safely optimize the analyzed process, because the development of a reliable mathematical model is often not affordable or too time-consuming. In this work, it is shown that the topological criterion theory and its related optimization procedure can be used to optimize experimentally (through a dedicated set of isoperibolic reaction calorimetry tests) a complex reacting system even if its reaction scheme and all information about the kinetics are not available. © 2011 American Chemical Society.

Macor A.,University of Padua | Avella F.,Stazione Sperimentale per i Combustibili | Faedo D.,Stazione Sperimentale per i Combustibili
Applied Energy | Year: 2011

Two Euro 3 commercial trucks fuelled with a 30% v/v biodiesel/diesel fuel blend (B30) and pure diesel fuel were tested in laboratory under the standard driving conditions (UDC and EUDC driving cycles) and the CADC " URBAN" test cycle, in order to evaluate the fuel consumption, regulated (CO, HC, NO. x, PM) and unregulated emissions (aldehydes and polycyclic aromatic hydrocarbons).After substitution of diesel fuel with B30 the following results were observed.The fuel economy increased proportionally to the deficit of the fuel heating value; so the average efficiency of the engine can be considered almost unchanged.In partial disagreement with the literature data, CO and HC emissions showed a slight increase, whereas NO. x emissions did not vary. It must be noted that these variations did not pass the statistical significance test.On the contrary, PM, soot fraction and particle number showed a significant reduction; furthermore, nearly 90% of the emitted particles had an aerodynamic diameter less than 0.1 μm.The formaldehyde emission markedly increased for both vehicles, whereas acetaldehyde emissions showed ambiguous trends. Since the remaining aldehydes were under the instrumental detection limit, the ozone formation potential analysis with B30 showed a raise almost proportional to the formaldehyde emission increase.Moreover the lightest and most abundant PAHs species (3-4 benzene rings) showed high increases even if to different extent for the two vehicles. The species with 4-5 rings (such as benzo(a)pyrene) showed a net reduction, often under the instrumental limit. Finally, the carcinogenic risk evaluation of PAHs exhibited a clear toxicity reduction, specially in the cold start cycle, when the catalytic converter's efficiency was not fully reached. © 2011 Elsevier Ltd.

Jim G.,Tshwane University of Technology | Katskov D.,Tshwane University of Technology | Tittarelli P.,Stazione Sperimentale per i Combustibili
Talanta | Year: 2011

The vaporization of sulfur containing samples in graphite vaporizers for atomic absorption spectrometry is accompanied by modification of sulfur by carbon and, respectively, appearance at high temperature of structured molecular absorption in 200-210 nm wavelength range. It has been proposed to employ the spectrum for direct determination of sulfur in coal; soundness of the suggestion is evaluated by analysis of coal slurry using low resolution CCD spectrometer with continuum light source coupled to platform or filter furnace vaporizers. For coal in platform furnace losses of the analyte at low temperature and strong spectral background from the coal matrix hinder the determination. Both negative effects are significantly reduced in filter furnace, in which sample vapor efficiently interacts with carbon when transferred through the heated graphite filter. The method is verified by analysis of coals with sulfur content within 0.13-1.5% (m/m) range. The use of coal certified reference material for sulfur analyte addition to coal slurry permitted determination with random error 5-12%. Absolute and relative detection limits for sulfur in coal are 0.16 μg and 0.02 mass%, respectively. © 2010 Elsevier B.V. All rights reserved.

Marini S.,Center for Colloid and Surface Science | Marini S.,University of Bergamo | Strada C.,Center for Colloid and Surface Science | Strada C.,University of Bergamo | And 4 more authors.
Energy Conversion and Management | Year: 2014

The policies of curbing CO2 emissions have worked poorly on a global scale and an economically sound proposal of bringing electric power to Europe from an Algerian solar hub has just been dismissed. With reference to the Algerian - European relationships, we analyze the broad context where an environmental policy benefitting both developing and developed countries can be put in place. We then discuss the connection between anthropogenic CO2 emissions and acidification of Oceans along with a geo-engineering proposal aimed at solving these pressing problems with large-scale solar-powered chloralkali plants. While the cost of sequestering a ton of CO2 with dedicated chloralkali plants is unacceptably high, it is economically and environmentally sound to replace an existing European Cl2 plant (consuming fossils) with a solar-powered plant in Algeria. If the Algerian plant uses a new, more efficient chloralkali process, it will be competitive with existing European plants even at the current low market value of the carbon emission credits. We finally explore the possibility of coupling Cl2 production with CO2 reuse and syngas production through a novel electrochemical process. © 2014 Elsevier Ltd.

Marengo S.,Stazione Sperimentale per i Combustibili | Migliavacca G.,Stazione Sperimentale per i Combustibili | Hugony F.,Stazione Sperimentale per i Combustibili | Maggioni A.,Stazione Sperimentale per i Combustibili | Morreale C.,Stazione Sperimentale per i Combustibili
International Journal of Hydrogen Energy | Year: 2010

This paper reports on a systematic study of hydrogen oxidation in the presence of different materials, ranging from quartz to carbon steel. The reactivity tests conducted at low hydrogen concentration revealed significant promotion of the oxidation reaction by carbon steel in a temperature range (300-400 °C) where gas phase reactions occur to a limited extent. This effect is strongly enhanced by surface modifications induced by acid corrosion. Stainless steel surfaces behaved quite differently under similar reaction conditions, showing rather an inhibiting role in H2 oxidation. The physicochemical characterization of carbon steel samples before and after acid treatment revealed that the surface area undergoes a strong increase due to corrosion, and also the structure is modified with surface enrichment of trace metal components, which can exert a catalytic role. The potential risk represented by the oxidation properties of these widely used materials is mitigated by the low value of the heat of combustion of hydrogen per unit volume; with a composition below the lower flammability limit, weak thermal effects were in fact observed by infrared measurements of the surface temperature. However, using a simplified kinetic expression, it can be estimated that when hydrogen-rich mixtures come into contact with an overheated metal surface, the exothermic reaction can generate dangerous hot spots. © 2010 Published by Elsevier Ltd on behalf of Professor T. Nejat Veziroglu.

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