Green Hydrogen Production Routes: an Inherent Safety Assessment

In the framework of energy transition, safety is a key requirement to be satisfied by novel process technologies. The aim of this study is to compare, from an inherent safety standpoint, three technologies for the production of green hydrogen via water splitting, powered by Renewable Energy Sources (RESs), in order to identify the inherently safest option and the critical equipment and/or operating conditions to be considered in the scale-up and industrialization of such technologies. The technologies considered for green hydrogen production are: alkaline electrolysis, proton exchange membrane electrolysis and reversible Solid Oxide Cells. The application of a consolidated methodology for inherent safety assessment based on Inherent Safety Key Performance Indicators (IS-KPIs) enabled to identify the most critical units within each process scheme and to select the inherently safest technological solution presently available for green hydrogen production

A Comparative Inherent Safety Assessment of Innovative CO2-based Production Processes of Dimethyl Ether and Methanol

Dimethyl ether (DME) and methanol are proposed as synthetic fuels prone to substitute present fossil propellants in the energy transition framework. Methanol and DME are traditionally synthesised starting from syngas but nowadays new production processes based on the efficient catalytic hydrogenation of CO2 have been introduced. Multiple catalysts, reaction conditions and reactor configurations have been tested to enhance the production performance of both fuels, especially for the case of DME. In fact, DME can be produced indirectly from CO2, i.e. after methanol synthesis and purification. Alternatively, it can be synthesised in a one-pot conversion mode by means of bifunctional catalysts directly receiving CO2. The latter route, avoiding several intermediate separation operations, appears promising from the process intensification viewpoint, thus favouring DME production with respect to methanol. Since safety plays an important role from the standpoint of societal acceptability, it needs to be considered in the selection of sustainable alternatives. This contribution aims to address an inherent safety assessment of the processes for methanol and DME production via CO2 hydrogenation. Inherent safety is evaluated through a consequence-based approach using specific Inherent Safety Key Performance Indicators, which proved to be effective in several applications to early process design. The results obtained shed light on the inherent safety performance of these alternative routes, thus helping decision-makers in accounting for process safety issues in the assessment of the sustainability of these alternative energy vectors and in the selection of the best technological alternative

Analysis of an Integrated Energy System Aimed at the Offshore Production of Methanol

The results of the offshore integration of fossil and renewable energy sources (RESs) to produce an energy vector, namely methanol, are discussed. The methodology developed and hereby presented, allowed at first the selection of the best technology for offshore RESs exploitation, where a near-to-decommissioning platform is used as an energy hub. Based on the availability of natural gas from the depleted reservoir, the most suitable process for offshore methanol production was chosen among various alternative innovative processes. The optimal mix for energy production was then identified by varying the number of converters for each RES. Finally, the methanol production process was designed on the basis of the available electric power, including a backup system based on natural gas, to perform RESs valley filling and to achieve a steady state process

The quantitative assessment of damage to the environment in major accidents caused by natural events

The release of hazardous materials induced by natural events affecting industrial facilities presents peculiar characteristics because of the huge potential extension of the affected areas. The reduction of both the likelihood and the magnitude of such events represents an essential step to reduce the risk associated with Natech accidents. Nevertheless, the evaluation of damage to the environment in Natech events has been poorly addressed. In the present study, past accidents analysis was carried out, using both a detailed description of specific accidents and an extended database of Natech events. Lessons learnt as well as possible common patterns and main features related to such accidents were identified and discussed. The results of the present study can be intended as a preliminary step for the development of models for the quantitative assessment of damage to the environment in major accidents caused by natural events

Optimized Renewable Energy Mixes: Facing Energy Scarcity in Remote Islands

The actual energy transition calls for the highest ever engagement of institutions and private sectors in the adoption of renewable energy systems in order to decarbonize all production chains. The high potential of renewable energy sources (RESs) in several locations worldwide is looked at as an important opportunity to both limit the energy supply issues and shift towards a greener society. On the other hand, it is also accompanied by the issues of resource variability, forecasting need and difficult management of the energy surpluses. The contemporary exploitation of multiple RESs in a hybrid renewable energy system (HRES) is a strategic initiative aimed at reducing the energy supply risk in a specific location, while decarbonizing the power generation facilities that satisfy specific energy requests. By means of systems optimally designed that valorize the RESs site-specific features and time trends, it is possible to comply with the identified energy demands while obtaining increased reliability. This contribution introduces an approach for the preliminary design of HRESs which is capable of accounting for the specific geographical constraints and the energy requests to be fulfilled. The approach is simulation-based, thus analyses the performance of all the possible combinations of renewable energy conversion technologies in terms of supply reliability and assesses their sustainability profile through key indicators. The application of the method is exemplified through a case study located on the island of Crete, Greece, for the valorization of the combined exploitation of offshore wind and wave energy. The most sustainable designs of the HRES in the site foresee the installation of 12 offshore wind turbines and maximum 10 wave energy converters for an overall system potentiality higher than 110 MW

Optimized Renewable Energy Mixes: Facing Energy Scarcity in Remote Islands

The actual energy transition calls for the highest ever engagement of institutions and private sectors in the adoption of renewable energy systems in order to decarbonize all production chains. The high potential of renewable energy sources (RESs) in several locations worldwide is looked at as an important opportunity to both limit the energy supply issues and shift towards a greener society. On the other hand, it is also accompanied by the issues of resource variability, forecasting need and difficult management of the energy surpluses. The contemporary exploitation of multiple RESs in a hybrid renewable energy system (HRES) is a strategic initiative aimed at reducing the energy supply risk in a specific location, while decarbonizing the power generation facilities that satisfy specific energy requests. By means of systems optimally designed that valorize the RESs site-specific features and time trends, it is possible to comply with the identified energy demands while obtaining increased reliability. This contribution introduces an approach for the preliminary design of HRESs which is capable of accounting for the specific geographical constraints and the energy requests to be fulfilled. The approach is simulation-based, thus analyses the performance of all the possible combinations of renewable energy conversion technologies in terms of supply reliability and assesses their sustainability profile through key indicators. The application of the method is exemplified through a case study located on the island of Crete, Greece, for the valorization of the combined exploitation of offshore wind and wave energy. The most sustainable designs of the HRES in the site foresee the installation of 12 offshore wind turbines and maximum 10 wave energy converters for an overall system potentiality higher than 110 MW

Real-time Assessment of Integrated Safety-security Scenarios Triggering Cascading Events in the Process Industries

Industrial sites processing and storing hazardous chemicals can be attractive targets of malicious acts of interference. The consequences successful intentional attacks to chemical facilities can be severe and could escalate generating domino effects, potentially affecting people and the environment. Moreover, intentional attacks have a dynamic escalation that is not well depicted by conventional analyses, which are instead static. This works focuses on the development of a comprehensive tool for Integrated Safety-Security risk assessment and related domino effects based on a three-dimensional (3D) real-time approach. Firstly, the plant is inspected using a drone to generate the graphic interface of the tool, which is the 3D reconstruction of the plant. Real-time data are associated with each mapped element, e.g., pressure/temperature conditions. The tool allows for the evaluation of probabilities and 3D consequences of accidents given real time and/or user input data. Potential domino effects of integrated safety-security scenarios will also be included in the tool, allowing for the mapping of plant vulnerability, risk and supporting the evaluation of weaknesses and need of additional countermeasures. In order to provide a sample application, a simplified version of the tool was used on a case study

Hazard and safety management in industrial bio-based processes

Despite the importance that biotechnological process (bioprocesses) are assuming worldwide in the last decades, process safety aspects are not evolving at the same pace as the scale-up of related technologies. In the present paper, a novel methodology for hazard identification and safety management in biotechnological processes is described addressing both conventional hazards and specific biohazards. The focus is on major accidents prevention and safety management. The results of the methodology can be used, as shown in the present work, in the framework of emergency planning