1,721,026 research outputs found
Modeling, design, testing and analysis of biogas-fed SOFC power plants
Get PDFThe present work is related to the complete analysis of biogas-fed SOFC system. The first part of the work has been related to a review on the concept of polygeneration system and on the analysis of the current status of SOFC installations, especially when fed with biogas. The use of a renewable fuel, coupled with carbon capture, can lead to negative emissions plants, defined as key technologies for reaching the goals set in the Paris Agreement. Furthermore, biogas and SOFC show many affinities which have been discussed in the works: from the high efficiency at low sizes to the availability of already existing subsidy schemes for electricity production. An analysis of the potential biogas production in EU is proposed, with focus on wastewater treatment plants. In this particular area, the work tries to point out the numbers of potential installed power by using SOFCs. The experimental and modeling activities are then proposed. The PhD activity is linked to two European projects, SOFCOM and DEMOSOFC. The first project is related to the analysis of biogas fed SOFC system with carbon capture and re-use. In this context, a demonstration plant has been developed and tested in the SMAT Castiglione wastewater treatment plant. Results show an easy process for the CO2 capture from the SOFC exhaust, thus pointing SOFC as a key technology in the framework of negative carbon emissions plants. More criticalities have been found in the choice of CO2 utilization for production of algae in a photobioreactor: the unstable quality of the inlet wastewater coming from the plant, the fluctuating algae productivity as function of the weather conditions, and the algae attachment to the pipe, pointed out a need for improvements and research on this technology. The experimental activity has been coupled with a modeling activity on the same concept of biogas fed SOFC, with the possibility of a downstream carbon capture and use/ sequestration. Different plant layout and different system sizes have been analyzed from a technical and economical point of view. Finally, the analysis of a real industrial size SOFC system is proposed. This activity has been developed in the framework of the DEMOSOFC EU project, where the first industrial size biogas fed SOFC system will be installed. Being the first installation of its kind, many issued and improvements have been detected. The analysis is related to the system design and description, for what concerning plant integration (electrical and thermal), system operation, and biogas processing. Biogas processing has been especially pointed out as a key component in a biogas-fed SOFC system. Because of the low admissible contaminants levels for fuel cell, a new and dedicated cleaning unit is required, which is not currently available on the market. The processing unit design is proposed and ongoing experimental activity on the adsorption with activated carbons are proposed. The main harmful contaminants found in wastewater biogas are sulphur (in the form of H2S) and siloxanes (mainly D4 and D5)
Carbon recovery from biogas through upgrading and methanation: A techno-economic and environmental assessment
Get PDFReducing the use of fossil fuels is an essential measure to counteract the rise in greenhouse gas emissions. In this context, biofuels and e-fuels make an important contribution to achieving climate neutrality targets, especially if their distribution can take place within existing infrastructure, as in the case of methane.
The aim of this work is to carry out a techno-economic and environmental assessment of the combined production of biological and synthetic methane in a wastewater treatment plant (WWTP). Methane yield from biogas, usually associated only with biogas upgrading, is enhanced by recovering CO2 to produce additional synthetic natural gas (SNG) through a methanation process. The analysis is applied to a medium-sized WWTP in Italy, whose biogas production profile is known throughout the year.
In the current scenario, SNG is not competitive on the gas market. The investment costs of the technologies and the electricity price are then varied in order to better investigate the profitability of SNG production. The results show that, considering long-term cost projections and an electricity price of about 50 €/MWh, SNG can become competitive, with a production cost of 1.4 €/Sm3. Finally, the environmental competitiveness of SNG (direct and indirect CO2 emissions) with respect to fossil natural gas is investigated: results are shown as a function of the carbon intensity of grid electricity and the share of local renewable energy. To make SNG environmentally sustainable, the renewable share must increase to 46% or, alternatively, the carbon intensity of grid electricity must decrease to 187 gCO2eq/kWh
Optimising green hydrogen production across Europe: How renewable energy sources shape plant design and costs
Get PDFGreen hydrogen is widely recognised as a key enabler for decarbonising heavy industry and long-haul transport.
However, producing it cost-competitively from variable renewable energy sources presents design challenges. In
this study, a mixed-integer linear programming (MILP) optimisation framework is developed to minimise the
levelised cost of hydrogen (LCOH) from renewable-powered electrolysers. The analysis covers all European
countries and explores how wind and solar resource availability influences the optimal sizing of renewable
generators, electrolysers, hydrogen storage, and batteries under both current and future scenarios. Results show
that renewable resource quality strongly affects system design and hydrogen costs. At present, solar-only systems
yield LCOH values of 7.4–24.7 €/kg, whereas wind-only systems achieve lower costs (5.1–17.1 €/kg) due to
higher capacity factors and reduced storage requirements. Hybrid systems, combining solar and wind, emerge as
the most cost-effective solution, reducing average LCOH by 57 % compared to solar-only systems and 25 %
compared to wind-only systems, effectively narrowing geographical cost disparities. In the future scenario, LCOH
declines to 3–4 €/kg, confirming renewable hydrogen’s potential to become economically competitive
throughout Europe. A key contribution of this work is the derivation of design guidelines by correlating
renewable resource quality with technical, energy and economic indicators
Modeling and techno-economic analysis of the integration of a FC-based micro-CHP system for residential application with a heat pump
No full textThis work aims to analyse the techno-economic performance of an integrated system for a residential CHP (Combined Heat and Power) application, based on the integration of a Fuel Cell (FC) micro-cogeneration device coupled with an Heat Pump (HP).
The main components of the system are: the Fuel Cell unit, the Heat Pump and the thermal storage – required to cover the thermal peaks, mainly due to the domestic hot water demand. The analysis will be focused on the most diffused FC technologies for residential applications: a low temperature Polymer Electrolyte Membrane Fuel Cell (PEMFC) and a high temperature Solid Oxide Fuel Cell (SOFC).
FC-based cogeneration systems usually produce an electric power surplus respect to the thermal production, because of their high electrical efficiency. Currently, however, the households heating load exceeds significantly the electricity requirements, thus making difficult the sizing of a FC system for a single family house without including large electrical and thermal storages or high grid/boiler integration. The combination of a Fuel Cell and an Heat Pump has been found to be an optimal solution to manage this problematic while achieving a reduction in the primary energy consumption and avoiding energy overproduction.
In the proposed scenario the heat is exploited by feeding both the domestic hot water and a low-temperature radiant floor heating system operating between 35 °C and 45 °C.
An energy and economic analysis has been performed to understand and to evaluate the plant feasibility.
Results have pointed out that the best economic choice, with the current energy tariff scenario, is related to a small size FC-based CHP system able to produce enough electrical power to feed the HP plus a low electrical consumption (<1 kW electrical size), which corresponds to the base electrical household consumption (the electrical power which is near-always requested by the house). The electrical load is in fact deeply changing during the day (with one-minute variable peaks) and with a higher electrical production from the FC, most of the electrical power would be sold to the grid without no energy advantages.
The best PEMFC configuration was able to reach a total efficiency of 75%: if compared to the case with separated energy generation (electricity from the grid and heat from a boiler) the saving is estimated in three years of payback for the current scenario (2015).
With the SOFC system, thanks to its higher total efficiency equal to 81%, the primary energy consumption was reduced (−30% respect to PEMFC) with a consequent reduction in the operating costs. However, from an economic point of view, the payback still results extended because of its not competitive investment cost
Techno-economic Analysis of a Solid Oxide Fuel Cell Installation in a Biogas Plant Fed by Agricultural Residues and Comparison with Alternative Biogas Exploitation Paths
Get PDFTechno-Economic Assessment of Deep Biogas Cleaning For Solid Oxide Fuel Cell Application
Get PDFThe use of biogas in fuel cells could be an attractive alternative to combustion technologies. However, biogas contains sulfur-based compounds that can be detrimental to fuel cells. A techno-economic analysis was conducted to assess the impact of the H2S cleaning system on the plant investment and operational costs
Biogas Resource Potential and Technical Exploitation
No full textBiogas is a renewable or waste fuel that comes from the fermentation of organic matter.
According to recent estimates, the world biogas energy potential is about 12,000 TWh.
Currently, in Europe, biogas covers about 1% of the total primary energy supply.
The primary organic sources for biogas are waste food, sewage sludge, livestock manure,
slaughterhouse residues, the organic fraction of municipal solid waste, municipal solid waste
accumulated in landfills, crop residues, and energy crops. The organic matter is degraded into
reactors called anaerobic digesters in which microorganisms (bacteria) break down
biodegradable material in the absence of oxygen
Mapping Hydrogen Initiatives in Italy: An Overview of Funding and Projects
Get PDFThe global momentum towards hydrogen has led to various initiatives aimed at harnessing hydrogen’s potential. In particular, low-carbon hydrogen is recognized for its crucial role in reducing greenhouse gas emissions across hard-to-abate sectors such as steel, cement and heavy-duty transport. This study focuses on the presentation of all hydrogen-related financing initiatives in Italy, providing a comprehensive overview of the various activities and their geographical locations. The examined funding comes from the National Recovery and Resilience Plan (PNRR), from projects directly funded through the Important Projects of Common European Interest (IPCEI) and from several initiatives supported by private companies or other funding sources (hydrogen valleys). Specific calls for proposals within the PNRR initiative outline the allocation of funds, focusing on hydrogen production in brownfield areas (52 expected hydrogen production plants by 2026), hydrogen use in hard-to-abate sectors and the establishment of hydrogen refuelling stations for both road (48 refuelling stations by 2026) and railway transport (10 hydrogen-based railway lines). A detailed description of the funded initiatives (150 in total) is presented, encompassing their geographical location, typology and size (when available), as well as the funding they have received. This overview sheds light on regions prioritising decarbonisation efforts in heavy-duty transport, especially along cross-border commercial routes, as evident in northern Italy. Conversely, some regions concentrate more on local transport, typically buses, or on the industrial sector, primarily steel and chemical industries. Additionally, the study presents initiatives aimed at strengthening the national manufacturing capacity for hydrogen-related technologies, alongside new regulatory and incentive schemes for hydrogen. The ultimate goal of this analysis is to foster connections among existing and planned projects, stimulate new initiatives along the entire hydrogen value chain, raise an awareness of hydrogen among stakeholders and promote cooperation and international competitiveness
Decarbonizing semiconductor manufacturing: cost-competitiveness of PV-based green hydrogen production
Get PDFHard-to-abate industries heavily depend on fossil fuels and low-cost fossil-based feedstocks, significantly
contributing to energy-related CO2 emissions. Therefore, a cost-effective transition towards low-carbon solutions
becomes imperative. This study investigates the cost-competitiveness of decarbonizing semiconductor
manufacturing by switching from conventional grey hydrogen supply to on-site green hydrogen production in a
power-to-hydrogen (P-t-H) system. A silicon wafer production facility with an annual hydrogen demand of
approximately 110 tonnes is considered as a case study. An optimization framework based on a metaheuristic
approach is developed for the cost-optimal design of the P-t-H system, while the ε-constraint technique is applied
to investigate multiple decarbonization targets. The findings indicate that fully relying on grey hydrogen remains
the most cost-effective strategy, resulting in a levelized cost of hydrogen (LCOH) of 4 €/kg but emitting 1045
tonnes of CO2 annually. As grey hydrogen consumption is limited to reduce CO2 emissions, the LCOH increases
exhibiting distinct trends. For decarbonization targets up to 70 %, the LCOH steadily rises to 6.10 €/kg, while
stricter CO2 emissions constraints cause a steeper increase in the hydrogen production cost, reaching 10.51 €/kg
in the fully decarbonized scenario. Achieving complete decarbonization requires scaling up the P-t-H compo-
nents, particularly the pressurized storage tank, which becomes essential for a reliable hydrogen supply. Grid
electricity import can prevent the system oversizing, thus boosting the cost-competitiveness of green hydrogen
production. Conventional hydrogen supply remains cost-efficient for grey hydrogen purchase prices up to 6 €/kg,
while above this threshold integrating on-site green hydrogen production becomes beneficial
Solid oxide fuel cells for aviation: A comparative evaluation against alternative propulsion technologies
Get PDFConventional aircraft emit high greenhouse gases, hindering aviation decarbonization. Among sustainable so-
lutions, battery-electric planes face range limitations, while renewable fuels can cut emissions without sacrificing
endurance. Fuel cells enable full electrification, powering propulsion and auxiliary systems. Although they have
lower power density than combustion engines, their promising efficiency can potentially reduce overall weight.
This study compares fuel cell and conventional propulsion systems, focusing on Solid Oxide Fuel Cells (SOFCs)
and Proton-Exchange Membrane Fuel Cells (PEMFCs). The initial literature review emphasizes the potential of
SOFCs for aviation and discusses ongoing projects, forming the basis for the subsequent technical analysis. A
break-even analysis examines flight durations in which fuel cell systems match the weight of conventional al-
ternatives. Additionally, various fuels and storage methods, including jet fuel and hydrogen, are assessed. Results
show that jet fuel SOFCs are currently the lightest fuel cell option, while PEMFCs with liquid hydrogen require
higher power density and lighter storage to compete. Looking ahead, liquid hydrogen storage appears most
viable, with PEMFCs better for short-range and SOFCs for long-range flights. An environmental analysis evaluates
CO2 emissions across European countries, identifying break-even grid carbon intensities for jet fuel and hydrogen
SOFCs. These findings highlight fuel cells’ potential to reduce aviation’s environmental footprint
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