U na perdita di controllo della temperatura di reazione tale da generare fenomeni runaway è il pr... more U na perdita di controllo della temperatura di reazione tale da generare fenomeni runaway è il problema che fre-quentemente si riscontra nei reattori chimici industriali utilizzati per processi esotermici. Se durante il corso della reazione, la velocità con cui si sviluppa il calore supera quella con cui lo stesso viene smaltito dal sistema di raffreddamento, l'ac-cumulo di calore nella massa reagente può essere tale da determi-nare un aumento incontrollato della temperatura e di conseguenza della velocità di reazione fino a generare esplosioni termiche o rea-zioni runaway. In questa situazione, se non vengono adottate le giu-ste contromisure, si può incorrere in situazioni pericolose [1]. Da un'analisi particolareggiata degli incidenti dovuti a fenomeni runaway è emerso che essi avvengono prevalentemente durante i processi di polimerizzazione e che le cause scatenanti sono [2]: -mancanza di conoscenze sulla chimica/termodinamica del processo; -influenza di contaminanti; -in...
NATO Science for Peace and Security Series C Environmental Security, 2008
ABSTRACT Terrorist actions have increased in recent years. In the past, terrorist attacks or sabo... more ABSTRACT Terrorist actions have increased in recent years. In the past, terrorist attacks or sabotage have been considered as a security problem but their frequency means they must also be considered from the safety point of view. A complete risk analysis must include scenarios caused by terrorist attack or sabotage. As well as chemical plants and storage facilities, characterized by the presence of large quantities of dangerous substances, also road/rail tankers used for their transport constitute potential targets. The hazard associated with transportation depends on the vulnerability of the territory. This paper focuses attention on the description of a methodology for the analysis of incidental scenarios caused by terrorist attacks in urban areas and the identification of some aspects where improvements can be made. Finally, an application of this method is illustrated. Furthermore, in order to obtain a complete risk analysis, it is necessary to take into account that, beyond substances transported, the consequences depend on the mode of attack and the characteristics of the infrastructure and territory.
ABSTRACT In this last decade, worldwide attention has been focused on the hazards derived from th... more ABSTRACT In this last decade, worldwide attention has been focused on the hazards derived from the interaction between extreme natural phenomena and critical infrastructures and/or chemical and process industry (natural-technological hazards or Na-Tech). Due to the recent occurrence of significant events, great attention has also been given to Na-Tech hazards triggered by volcanic eruptions; in particular, the eruption of the Icelandic volcano alarmed the European community due to the ash fallout over the continent, which caused significant problems for the population, road, rail and air traffic and production activities. This study aims at defining a procedure for the representation of the vulnerability of industrial facilities to potential volcanic ash fallouts. Its implementation on a Geographical Information System has also been executed and a semi-automatic procedure for the vulnerability mapping has been constructed.
ABSTRACT Very promising results have been obtained in pyrolysis experiments carried out in a siev... more ABSTRACT Very promising results have been obtained in pyrolysis experiments carried out in a sieve-tray reactor, of our design, in the temperature range 400–700°C, employing a suitable gas stream in order to rapidly remove the pyrolysis products from the reactor and at the same time to activate the char. By pyrolysis of shredded rubber from scrap tires 36–38% of activated carbon, 49-38% of oil products and 15–30% of gas were obtained.The pyrolysis carbon shows specific adsorption, towards dyes for industrial uses, which seems higher than those of commercial active carbon and yields adsorption isotherms with a usual slope. The oils are characterized by high aromatic hydrocarbons and low sulphur contents (0.6% with nitrogen as a carrier gas, 0.2% with carbon dioxide); they could be used as plasticizers for rubber. The pyrolysis gases (mainly methane, hydrogen, ethylene, hydrogen sulphide) have a heat value of 6,000–7,000 kcal m−3.
ABSTRACT Applicability of oscillation calorimetry techniques for the evaluation of time varying p... more ABSTRACT Applicability of oscillation calorimetry techniques for the evaluation of time varying parameters during the course of the reaction, is analysed by referring to experimental data from a MMA polymerisation reactor. Different algorithms for the elaboration of experimental data and their sensitivity to external causes of error is evaluated in order to choose the most robust to perturbations.
U na perdita di controllo della temperatura di reazione tale da generare fenomeni runaway è il pr... more U na perdita di controllo della temperatura di reazione tale da generare fenomeni runaway è il problema che fre-quentemente si riscontra nei reattori chimici industriali utilizzati per processi esotermici. Se durante il corso della reazione, la velocità con cui si sviluppa il calore supera quella con cui lo stesso viene smaltito dal sistema di raffreddamento, l'ac-cumulo di calore nella massa reagente può essere tale da determi-nare un aumento incontrollato della temperatura e di conseguenza della velocità di reazione fino a generare esplosioni termiche o rea-zioni runaway. In questa situazione, se non vengono adottate le giu-ste contromisure, si può incorrere in situazioni pericolose [1]. Da un'analisi particolareggiata degli incidenti dovuti a fenomeni runaway è emerso che essi avvengono prevalentemente durante i processi di polimerizzazione e che le cause scatenanti sono [2]: -mancanza di conoscenze sulla chimica/termodinamica del processo; -influenza di contaminanti; -in...
NATO Science for Peace and Security Series C Environmental Security, 2008
ABSTRACT Terrorist actions have increased in recent years. In the past, terrorist attacks or sabo... more ABSTRACT Terrorist actions have increased in recent years. In the past, terrorist attacks or sabotage have been considered as a security problem but their frequency means they must also be considered from the safety point of view. A complete risk analysis must include scenarios caused by terrorist attack or sabotage. As well as chemical plants and storage facilities, characterized by the presence of large quantities of dangerous substances, also road/rail tankers used for their transport constitute potential targets. The hazard associated with transportation depends on the vulnerability of the territory. This paper focuses attention on the description of a methodology for the analysis of incidental scenarios caused by terrorist attacks in urban areas and the identification of some aspects where improvements can be made. Finally, an application of this method is illustrated. Furthermore, in order to obtain a complete risk analysis, it is necessary to take into account that, beyond substances transported, the consequences depend on the mode of attack and the characteristics of the infrastructure and territory.
ABSTRACT In this last decade, worldwide attention has been focused on the hazards derived from th... more ABSTRACT In this last decade, worldwide attention has been focused on the hazards derived from the interaction between extreme natural phenomena and critical infrastructures and/or chemical and process industry (natural-technological hazards or Na-Tech). Due to the recent occurrence of significant events, great attention has also been given to Na-Tech hazards triggered by volcanic eruptions; in particular, the eruption of the Icelandic volcano alarmed the European community due to the ash fallout over the continent, which caused significant problems for the population, road, rail and air traffic and production activities. This study aims at defining a procedure for the representation of the vulnerability of industrial facilities to potential volcanic ash fallouts. Its implementation on a Geographical Information System has also been executed and a semi-automatic procedure for the vulnerability mapping has been constructed.
ABSTRACT Very promising results have been obtained in pyrolysis experiments carried out in a siev... more ABSTRACT Very promising results have been obtained in pyrolysis experiments carried out in a sieve-tray reactor, of our design, in the temperature range 400–700°C, employing a suitable gas stream in order to rapidly remove the pyrolysis products from the reactor and at the same time to activate the char. By pyrolysis of shredded rubber from scrap tires 36–38% of activated carbon, 49-38% of oil products and 15–30% of gas were obtained.The pyrolysis carbon shows specific adsorption, towards dyes for industrial uses, which seems higher than those of commercial active carbon and yields adsorption isotherms with a usual slope. The oils are characterized by high aromatic hydrocarbons and low sulphur contents (0.6% with nitrogen as a carrier gas, 0.2% with carbon dioxide); they could be used as plasticizers for rubber. The pyrolysis gases (mainly methane, hydrogen, ethylene, hydrogen sulphide) have a heat value of 6,000–7,000 kcal m−3.
ABSTRACT Applicability of oscillation calorimetry techniques for the evaluation of time varying p... more ABSTRACT Applicability of oscillation calorimetry techniques for the evaluation of time varying parameters during the course of the reaction, is analysed by referring to experimental data from a MMA polymerisation reactor. Different algorithms for the elaboration of experimental data and their sensitivity to external causes of error is evaluated in order to choose the most robust to perturbations.
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Papers by Giuseppe Maschio