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The introduction of innovative solutions for the energy supply chain is promoting the use of batteries and supercapacitors, posing new challenges from a safety point of view. This work presents bench-scale experiments devoted to the evaluation of the fire behaviour of liquid solvents, employing an in-house procedure for the characterization of the ignition and flame behaviour of liquids either in the presence or absence of ignition sources. Different boundary conditions were tested to identify the most suitable set of values for a standardized assessment of safety parameters for acetonitrile, ethyl acetate, lactic acid, and hexane. The produced vapours and the exhaust gas were analysed together with the evolution in time of the rate of heat generation. The fire behaviour was quantified in terms of time to reach the maximum value of the heat release rate and the peak. The former is related to the flash point, whereas the latter is determined by the thermodynamics and kinetics of the investigated species. In addition, the overall rate and the ruling regimes (e.g., smouldering or flaming) were determined based on the collected data. The comparison between the obtained values and the typical velocities attributed to vaporization, mixing, and gas-phase reactions suggests that vaporization can be considered as the rate-determining step only in the case of flaming.

The partial oxidation of ethylene in a methane atmosphere by pure oxygen is the most important industrial process for the synthesis of ethylene oxide. However, due to the high reactivity and exothermicity of the reaction system, the overall production is limited by kinetic and safety issues. The shift toward mild operative conditions can support the management of undesirable side reactions, enhancing the performance of the whole process. In the future, the direct use of liquefied ethylene and oxygen-enriched air, a low-cost waste in membrane-based nitrogen production, can provide convenient sources for heat removal as well as promote the use of innovative and more sustainable solutions. This work is focused on the experimental and numerical characterization of the oxidation of ethylene/methane/nitrogen/oxygen mixtures at different operative conditions, including extremely low temperatures, and oxidant compositions. To this aim, the laminar burning velocity and flammability limits were first measured utilizing the heat flux burner and compared with detailed kinetic mechanisms and experiments retrieved from the current literature. The reported data were adopted to identify the operational limits for innovative processes, paving the way to unlocking the potential of innovative chemistry at extreme conditions. Eventually, key performance indicators accounting for kinetic and safety aspects were defined to identify the most sustainable and convenient operative conditions.

Soybean oil takes around half of the vegetable oil resources in the world, increasing in importance constantly. Besides, soy oil plants have experienced numerous accidents due to the coexistence of soy flour and hexane (as a solvent) in the extraction process, thus creating a hazardous environment. This study aims to find the maximum pressure, the maximum rate of pressure rise, and the minimum ignition energy of soy flour–hexane mixtures through specific experiments by varying the concentration of fuels in air and ignition mechanism (chemical igniters or exploding wires). The results have shown that soy flour alone is hard to ignite, whereas adding hexane even in small amounts increases the hazard and the severity of the explosions considerably. Eventually, the substitution of hexane with a greener and safer extraction agent should be of utmost focus.

Epoxidized vegetable oils are largely employed as plasticizers instead of harmful phthalates, and they can be a sustainable choice to produce lubricants and intermediates. The aim of this work is to study the reaction of soybean oil epoxidation of soybean using safer reactants. The reaction was carried out using hydrogen peroxide 34 wt % and acetic acid instead of the commonly used hydrogen peroxide at 60 wt % and formic acid to reduce the risk of detonation and corrosion. Moreover, the study focuses on the efficacy of the presence of an acid catalyst and sulfuric acid and the effect of its concentration. It was found that it is not possible to carry out the process without acid catalyst with those reactants. In addition, a proper mixing program was set up to improve the selectivity of the reaction.

Methane consumption is strongly increasing as a result of its abundance from natural gas, thus leading to reduced costs, and as a result of the reduced environmental impact in the case of combustion, with a lower carbon content with respect to traditional fuels. These advantages encourage its utilization in several industrial applications, such as methane steam reforming for the production of hydrogen and automotive applications. The necessity of transporting the gases and large-scale distribution systems is however one of the main issues. Innovative processes, such as cryogenic storage, cryo-compression, and liquefaction, require detailed information on the thermal and chemical properties of the methane–hydrogen mixture at low and ultralow temperatures. In this framework, detailed kinetic models for the total and partial oxidation of methane, hydrogen, and methane–hydrogen mixtures in air at low (273 > T> 200 K) and ultralow (T< 200 K) temperatures must be developed and validated. In this work, the laminar burning velocity of these gases has been simulated and compared to the few available experimental data retrieved from the literature. Hence, simplified correlations for the burning velocity with respect to the initial composition and temperature have been adopted and further developed. The simplified approach proposed in this work reduces the number of degrees of freedom required for the application of the modified Gülder equation. Moreover, it is suitable for the description of the combined effect of the initial temperature and gaseous composition. The performed analysis of the concentration and temperature profiles with respect to burner head distance indicates, as a possible explanation for the methane-dominated regime, the presence of a limitation in the hydrogen concentration hindering its production. A sensitivity analysis was performed to evaluate the effect of hydrogen addition and initial temperature on the methane kinetic mechanism in the presence of air. The results show that, although the hydrogen production rate does not change, the reaction mechanism is strongly affected by the studied parameters.

Nowadays, the knowledge of the gas-phase chemistry of formic acid is paramount for several industrial sectors, including energy supply and the production of bulk chemicals. In this work, a simplified kinetic mechanism and a detailed kinetic mechanism deriving from a rate-based selection algorithm were developed and tested against experimental data available in the literature. The former contains 141 species and 453 reactions, whereas the latter comprises 90 species and 1047 reactions. A focus on a low initial temperature (i.e., up to 500 K) was provided by comparing the numerical estimations with laminar burning velocity and jet-stirred measurements at several conditions. A good agreement among numerical predictions and experimental data was observed, especially for the simplified kinetic mechanism. The accuracy of the generated mechanism allowed for further analysis of the chemistry of the system, enlightening some determining aspects of the chemistry of formic acid. The produced mechanism can be also intended as per seed mechanism for the generation of kinetic models focused on the chemistry of biofuels. Indeed, the characterization of chemical aspects of formic acid occurring in an oxidative environment is crucial due to its relevance as an energy vector as well as an intermediate compound in the decomposition of larger hydrocarbons and bio-oils.

Venting systems are useful for the mitigation of accidental explosions. Vent ducts should be used if equipment is located indoors, as NFPA 68 (2007) suggests, for discharging combustion products to safe location. However, the presence of a duct is likely to increase the severity of the explosion with respect to simply vented vessels.

Alkoxylations are commonly performed in industry for the production of surfactants and polyglycols by means of a simple semi‐batch liquid‐stirred reactor. More recent processes use semi‐batch Venturi Loop Reactors (VCR) or Spray Tower Loop Reactors (SLR), where liquid phase is dispersed into the gaseous oxides through recirculation loops. In this article, a risk analysis is made on the recirculation loops to compare these three reactor types. More specifically, the analysis of consequences for the ethoxylation of dodecanol with different ethylene oxide partial pressures and process temperatures are studied. The atmospheric wind velocity was varied for a range of releases from the recirculation loop or from small releases from flanges and valves along the same pipeline.

Literature results show that the pressure piling phenomenon is the result of the combination of: (1) the precompression effect arising from the jet flow from the ignition vessel); (2) the turbulence induced by the fast flame propagation (jet ignition) in the secondary vessel; and (3) the vent flowing toward the ignition vessel, which mitigates the peak pressure. To control the severity of the explosion in the second vessel it is possible to either limit precompression or to reduce the characteristic ratio between the “reaction” and “venting” times.