Records with Keyword: Hydrogen
Showing records 1 to 25 of 231. [First] Page: 1 2 3 4 5 Last
Thermophilic Co-Fermentation of Wood Wastes and High in Nitrogen Animal Manures into Bio-Methane with the Aid of Fungi and its Potential in the USA
John G. Ingersoll
March 31, 2023 (v1)
Subject: Biosystems
Keywords: archaea and fungi, bio-fertilizers, bio-methane, Carbon Dioxide, Fermentation, Hydrogen, modular industrial plant design, nitrogen-rich animal manures, thermophilic bacteria, water electrolysis, wind power, wood
A novel process is proposed whereby wood wastes from forest tree mortalities and improved forest management are co-digested with high in nitrogen content animal manures to yield bio-methane along with nitrogen, phosphorous, and potassium bio-fertilizers. The process mimics the well-known wood conversion to methane process in lower termites but relies on thermophilic fungi, bacteria, and archaea instead. It is based on the modified state-of-the art two-step, hyperthermophilic (70 °C) hydrolysis and thermophilic (55 °C) fermentation, dry (30% TS), anaerobic digestion technology with a high organic loading and shortened retention time. The process is augmented with the thermophilic fermentation of carbon dioxide in the biogas into secondary bio-methane by employing hydrogen produced via wind-powered electrolysis. The entire process comprised of five distinct steps is designated as “Wood to Methane 3 + 2”. An industrial type, standardized plant unit has been developed that can be employed... [more]
Review on the Status of the Research on Power-to-Gas Experimental Activities
Andrea Barbaresi, Mirko Morini, Agostino Gambarotta
March 28, 2023 (v1)
Keywords: Energy Storage, Hydrogen, methanation, power-to-gas, project overview, smart energy systems
In recent years, power-to-gas technologies have been gaining ground and are increasingly proving their reliability. The possibility of implementing long-term energy storage and that of being able to capture and utilize carbon dioxide are currently too important to be ignored. However, systems of this type are not yet experiencing extensive realization in practice. In this study, an overview of the experimental research projects and the research and development activities that are currently part of the power-to-gas research line is presented. By means of a bibliographical and sitographical analysis, it was possible to identify the characteristics of these projects and their distinctive points. In addition, the main research targets distinguishing these projects are presented. This provides an insight into the research direction in this regard, where a certain technological maturity has been achieved and where there is still work to be done. The projects found and analyzed amount to 87,... [more]
Strategies for the Adoption of Hydrogen-Based Energy Storage Systems: An Exploratory Study in Australia
Cameron Wells, Roberto Minunno, Heap-Yih Chong, Gregory M. Morrison
March 28, 2023 (v1)
Keywords: Australia, distributed energy resources, energy systems, exploratory study, Hydrogen, mixed methodology
A significant contribution to the reduction of carbon emissions will be enabled through the transition from a centralised fossil fuel system to a decentralised, renewable electricity system. However, due to the intermittent nature of renewable energy, storage is required to provide a suitable response to dynamic loads and manage the excess generated electricity with utilisation during periods of low generation. This paper investigates the use of stationary hydrogen-based energy storage systems for microgrids and distributed energy resource systems. An exploratory study was conducted in Australia based on a mixed methodology. Ten Australian industry experts were interviewed to determine use cases for hydrogen-based energy storage systems’ requirements, barriers, methods, and recommendations. This study suggests that the current cost of the electrolyser, fuel cell, and storage medium, and the current low round-trip efficiency, are the main elements inhibiting hydrogen-based energy storag... [more]
Heat to Hydrogen by Reverse Electrodialysis—Using a Non-Equilibrium Thermodynamics Model to Evaluate Hydrogen Production Concepts Utilising Waste Heat
Simon B. B. Solberg, Pauline Zimmermann, Øivind Wilhelmsen, Jacob J. Lamb, Robert Bock, Odne S. Burheim
March 28, 2023 (v1)
Keywords: Hydrogen, ion-exchange membranes, non-equilibrium thermodynamics, reverse electrodialysis heat engine
The reverse electrodialysis heat engine (REDHE) is a promising salinity gradient energy technology, capable of producing hydrogen with an input of waste heat at temperatures below 100 °C. A salinity gradient drives water electrolysis in the reverse electrodialysis (RED) cell, and spent solutions are regenerated using waste heat in a precipitation or evaporation unit. This work presents a non-equilibrium thermodynamics model for the RED cell, and the hydrogen production is investigated for KCl/water solutions. The results show that the evaporation concept requires 40 times less waste heat and produces three times more hydrogen than the precipitation concept. With commercial evaporation technology, a system efficiency of 2% is obtained, with a hydrogen production rate of 0.38 gH2 m−2h−1 and a waste heat requirement of 1.7 kWh gH2−1. The water transference coefficient and the salt diffusion coefficient are identified as membrane properties with a large negative impact on hydrogen producti... [more]
Sizing and Performance Analysis of Hydrogen- and Battery-Based Powertrains, Integrated into a Passenger Train for a Regional Track, Located in Calabria (Italy)
Petronilla Fragiacomo, Francesco Piraino, Matteo Genovese, Lorenzo Flaccomio Nardi Dei, Daria Donati, Michele Vincenzo Migliarese Caputi, Domenico Borello
March 28, 2023 (v1)
Keywords: battery vehicle, fuel cell-based powertrain, Hydrogen, performance analysis, railway decarbonization
In order to decarbonize the rail industry, the development of innovative locomotives with the ability to use multiple energy sources, constituting hybrid powertrains, plays a central role in transitioning from conventional diesel trains. In this paper, four configurations based on suitable combinations of fuel cells and/or batteries are designed to replace or supplement a diesel/overhead line powertrain on a real passenger train (the Hitachi Blues) tested on an existing regional track, the Catanzaro Lido−Reggio Calabria line (Italy), managed by Trenitalia SpA. (Italy). The configurations (namely battery−electrified line, full-battery, fuel cell−battery−electrified line, and fuel cell−battery) are first sized with the intention of completing a round trip, then integrated on board with diesel engine replacement in mind, and finally occupy a portion of the passenger area within two locomotives. The achieved performance is thoroughly examined in terms of fuel cell efficiency (greater than... [more]
Underground Storage of Green Hydrogen—Boundary Conditions for Compressor Systems
Heinz Bekebrok, Hendrik Langnickel, Adam Pluta, Marco Zobel, Alexander Dyck
March 28, 2023 (v1)
Keywords: compressor, Energy Storage, Hydrogen, hydrogen infrastructure, salt cavern, storage demand profile, underground storage
The large-scale storage of hydrogen in salt caverns, modelled on today’s natural gas storage, is a promising approach to storing renewable energy over a large power range and for the required time period. An essential subsystem of the overall gas storage is the surface facility and, in particular, the compressor system. The future design of compressor systems for hydrogen storage strongly depends on the respective boundary conditions. Therefore, this work analyses the requirements of compressor systems for cavern storage facilities for the storage of green hydrogen, i.e., hydrogen produced from renewable energy sources, using the example of Lower Saxony in Germany. In this course, a hydrogen storage demand profile of one year is developed in hourly resolution from feed-in time series of renewable energy sources. The injection profile relevant for compressor operation is compared with current natural gas injection operation modes.
Gasification of Spruce Wood Chips in a 1.5 MWth Fluidised Bed Reactor
Fabio Montagnaro, Lucio Zaccariello
March 28, 2023 (v1)
Keywords: Biomass, equivalence ratio, fluidised bed, gasification, Hydrogen, spruce wood chips, Syngas, tar
Production of syngas from the gasification of a biomass is attracting attention with an eye to the concepts of circularity, sustainability, and recent needs, triggered by socio-political events, to increase the level of self-sufficiency of energy sources for a given community. This manuscript reports on the gasification of spruce wood chips in a demonstration fluidised bed gasifier (1.5 MWth, height of 5.40 m, internal diameter of 1.2 m), with 0.2−0.4 mm olivine inventory (1000 kg). Gasification was carried out in air, at four different values of equivalence ratio (from 27% to 36%). The bed was fluidised at about 0.6 m/s, and the bed temperature resulted in the range of about 960−1030 °C as a function of the different tests. A mass flow rate of biomass in the range of about 360−480 kg/h (as a function of the different tests) was fed to the fluidised bed gasifier. Syngas lower heating value, specific mass and energetic yield, and chemical composition, were reported along with data on th... [more]
Impacts of Low-Carbon Targets and Hydrogen Production Alternatives on Energy Supply System Transition: An Infrastructure-Based Optimization Approach and a Case Study of China
Tianxiao Li, Pei Liu, Zheng Li
March 28, 2023 (v1)
Subject: Optimization
Keywords: energy supply system, Hydrogen, infrastructure, Optimization, transition costs, transition target
Low-carbon transition pathways oriented from different transition targets would result in a huge variation of energy system deployment and transition costs. Hydrogen is widely considered as an imperative energy carrier to reach carbon neutral targets. However, hydrogen production, either from non-fossil power or fossil fuels with carbon capture, is closely linked with an energy supply system and has great impacts on its structure. Identifying an economically affordable transition pathway is attractive, and energy infrastructure is critical due to massive investment and long life-span. In this paper, a multi-regional, multi-period, and infrastructure-based model is proposed to quantify energy supply system transition costs with different low-carbon targets and hydrogen production alternatives, and China is taken as a case study. Results show that, fulfilling 2-degree and 1.5-degree temperature increase targets would result in 84% and 151% increases in system transition costs, 114% and 2... [more]
State-of-Art Review of NO Reduction Technologies by CO, CH4 and H2
Jialin Song, Ziliang Wang, Xingxing Cheng, Xiuping Wang
March 28, 2023 (v1)
Keywords: carbon monoxide, catalyst, Hydrogen, methane, NO reduction
Removal of nitrogen oxides during coal combustion is a subject of great concerns. The present study reviews the state-of-art catalysts for NO reduction by CO, CH4, and H2. In terms of NO reduction by CO and CH4, it focuses on the preparation methodologies and catalytic properties of noble metal catalysts and non-noble metal catalysts. In the technology of NO removal by H2, the NO removal performance of the noble metal catalyst is mainly discussed from the traditional carrier and the new carrier, such as Al2O3, ZSM-5, OMS-2, MOFs, perovskite oxide, etc. By adopting new preparation methodologies and introducing the secondary metal component, the catalysts supported by a traditional carrier could achieve a much higher activity. New carrier for catalyst design seems a promising aspect for improving the catalyst performance, i.e., catalytic activity and stability, in future. Moreover, mechanisms of catalytic NO reduction by these three agents are discussed in-depth. Through the critical rev... [more]
Techno-Economic Assessment of Solar-Driven Steam Gasification of Biomass for Large-Scale Hydrogen Production
Houssame Boujjat, Sylvain Rodat, Stéphane Abanades
March 28, 2023 (v1)
Keywords: biomass/waste conversion, economics, hybridization, Hydrogen, solar gasification, Syngas
Solar biomass gasification is an attractive pathway to promote biomass valorization while chemically storing intermittent solar energy into solar fuels. The economic feasibility of a solar gasification process at a large scale for centralized H2 production was assessed, based on the discounted cash-flow rate of return method to calculate the minimum H2 production cost. H2 production costs from solar-only, hybrid and conventional autothermal biomass gasification were evaluated under various economic scenarios. Considering a biomass reference cost of 0.1 €/kg, and a land cost of 12.9 €/m2, H2 minimum price was estimated at 2.99 €/kgH2 and 2.48 €/kgH2 for the allothermal and hybrid processes, respectively, against 2.25 €/kgH2 in the conventional process. A sensitivity study showed that a 50% reduction in the heliostats and solar tower costs, combined with a lower land cost of below 0.5 €/m2, allowed reaching an area of competitiveness where the three processes meet. Furthermore, an increa... [more]
The Effect of Hydrogen Addition on Low-Temperature Combustion of Light Hydrocarbons and Alcohols
Fekadu Mosisa Wako, Gianmaria Pio, Ernesto Salzano
March 28, 2023 (v1)
Subject: Other
Keywords: alcohols combustion, alkanes combustion, combustion, Hydrogen, kinetic mechanisms, laminar burning velocity
Hydrogen is largely considered as an attractive additive fuel for hydrocarbons and alcohol-fueled engines. Nevertheless, a complete understanding of the interactions between blended fuel mechanisms under oxidative conditions at low initial temperature is still lacking. This study is devoted to the numerical investigation of the laminar burning velocity of hydrogen−hydrocarbon and hydrogen−alcohol fuels under several compositions. Estimations were compared with experimental data reported in the current literature. Additionally, the effects of hydrogen addition on engine performance, NOX, and other pollutant emissions of the mentioned fuels have been thermodynamically analyzed. From the study, it has been observed that the laminar burning velocity of the fuel mixtures increased with increasing hydrogen fractions and the peak value shifted to richer conditions. Besides, hydrogen fraction was found to increase the adiabatic flame temperatures eventually favoring the NOX formation for all f... [more]
Efficient Production of Clean Power and Hydrogen Through Synergistic Integration of Chemical Looping Combustion and Reforming
Mohammed N. Khan, Schalk Cloete, Shahriar Amini
March 27, 2023 (v1)
Keywords: Carbon Dioxide Capture, chemical looping combustion, energy penalty, Hydrogen, natural gas combined cycle, power plant
Chemical looping combustion (CLC) technology generates power while capturing CO2 inherently with no direct energy penalty. However, previous studies have shown significant energy penalties due to low turbine inlet temperature (TIT) relative to a standard natural gas combined cycle plant. The low TIT is limited by the oxygen carrier material used in the CLC process. Therefore, in the current study, an additional combustor is included downstream of the CLC air reactor to raise the TIT. The efficient production of clean hydrogen for firing the added combustor is key to the success of this strategy. Therefore, the highly efficient membrane-assisted chemical looping reforming (MA-CLR) technology was selected. Five different integrations between CLC and MA-CLR were investigated, capitalizing on the steam in the CLC fuel reactor outlet stream to achieve highly efficient reforming in MA-CLR. This integration reduced the energy penalty as low as 3.6%-points for power production only (case 2) an... [more]
Ammonia as Effective Hydrogen Storage: A Review on Production, Storage and Utilization
Muhammad Aziz, Agung Tri Wijayanta, Asep Bayu Dani Nandiyanto
March 27, 2023 (v1)
Keywords: ammonia, CO2 free, Hydrogen, production, storage, utilization
Ammonia is considered to be a potential medium for hydrogen storage, facilitating CO2-free energy systems in the future. Its high volumetric hydrogen density, low storage pressure and stability for long-term storage are among the beneficial characteristics of ammonia for hydrogen storage. Furthermore, ammonia is also considered safe due to its high auto ignition temperature, low condensation pressure and lower gas density than air. Ammonia can be produced from many different types of primary energy sources, including renewables, fossil fuels and surplus energy (especially surplus electricity from the grid). In the utilization site, the energy from ammonia can be harvested directly as fuel or initially decomposed to hydrogen for many options of hydrogen utilization. This review describes several potential technologies, in current conditions and in the future, for ammonia production, storage and utilization. Ammonia production includes the currently adopted Haber−Bosch, electrochemical a... [more]
Hyperthermophilic Treatment of Grass and Leaves to Produce Hydrogen, Methane and VFA-Rich Digestate: Preliminary Results
Przemysław Liczbiński, Sebastian Borowski
March 27, 2023 (v1)
Keywords: grass, Hydrogen, hyperthermophilic treatment, leaves, methane
In this study, the feasibility of hydrogen and methane production from grass and leaves via hyperthermophilic anaerobic digestion was investigated. The hyperthermophilic treatment of grass at 70 °C resulted in the highest concentrations of volatile fatty acids (TVFA) and reducing sugars in the supernatant of over 21 and 6.5 g/L reported on day 3 and 4 of the experiment. In contrast, hydrolysis and acidification of leaves performed slower and with lower efficiency, as the peak concentrations of TVFA and reducing sugars were observed at the end of the process. However, the highest cumulative hydrogen and methane yields of 69.64 mLH2/gVS and 38.63 mLCH4/gVS were reported for leaves digested at 70 °C, whereas the corresponding maximum productions observed for grass were 50 mLH2/gVS and 1.98 mLCH4/gVS, respectively. A temperature increase to 80 °C hampered hydrogen and methane production and also resulted in lower yields of volatile fatty acids, reducing sugars and ammonia as compared to th... [more]
A Study on CO2 Methanation and Steam Methane Reforming over Commercial Ni/Calcium Aluminate Catalysts
Gabriella Garbarino, Federico Pugliese, Tullio Cavattoni, Guido Busca, Paola Costamagna
March 27, 2023 (v1)
Keywords: chemical reactor modeling, CO2 hydrogenation, Hydrogen, Ni-based catalysts, steam methane reforming
Three Ni-based natural gas steam reforming catalysts, i.e., commercial JM25-4Q and JM57-4Q, and a laboratory-made catalyst (26% Ni on a 5% SiO2−95% Al2O3), are tested in a laboratory reactor, under carbon dioxide methanation and methane steam reforming operating conditions. The laboratory catalyst is more active in both CO2 methanation (equilibrium is reached at 623 K with 100% selectivity) and methane steam reforming (92% hydrogen yield at 890 K) than the two commercial catalysts, likely due to its higher nickel loading. In any case, commercial steam reforming catalysts also show interesting activity in CO2 methanation, reduced by K-doping. The interpretation of the experimental results is supported by a one-dimensional (1D) pseudo-homogeneous packed-bed reactor model, embedding the Xu and Froment local kinetics, with appropriate kinetic parameters for each catalyst. In particular, the H2O adsorption coefficient adopted for the commercial catalysts is about two orders of magnitude hig... [more]
Potential Sites for Underground Energy and CO2 Storage in Greece: A Geological and Petrological Approach
Apostolos Arvanitis, Petros Koutsovitis, Nikolaos Koukouzas, Pavlos Tyrologou, Dimitris Karapanos, Christos Karkalis, Panagiotis Pomonis
March 27, 2023 (v1)
Keywords: Carbon Dioxide, carbon storage, Energy Storage, Hydrogen, Natural Gas, thermal energy, underground
Underground geological energy and CO2 storage contribute to mitigation of anthropogenic greenhouse-gas emissions and climate change effects. The present study aims to present specific underground energy and CO2 storage sites in Greece. Thermal capacity calculations from twenty-two studied aquifers (4 × 10−4−25 × 10−3 MJ) indicate that those of Mesohellenic Trough (Northwest Greece), Western Thessaloniki basin and Botsara flysch (Northwestern Greece) exhibit the best performance. Heat capacity was investigated in fourteen aquifers (throughout North and South Greece) and three abandoned mines of Central Greece. Results indicate that aquifers present higher average total heat energy values (up to ~6.05 × 106 MWh(th)), whereas abandoned mines present significantly higher average area heat energy contents (up to ~5.44 × 106 MWh(th)). Estimations indicate that the Sappes, Serres and Komotini aquifers could cover the space heating energy consumption of East Macedonia-Thrace region. Undergroun... [more]
Modeling of Laboratory Steam Methane Reforming and CO2 Methanation Reactors
Paola Costamagna, Federico Pugliese, Tullio Cavattoni, Guido Busca, Gabriella Garbarino
March 27, 2023 (v1)
Keywords: chemical reactor modeling, CO2 methanation, Hydrogen, Ni-based catalysts, Power-to-X, steam methane reforming
To support the interpretation of the experimental results obtained from two laboratory-scale reactors, one working in the steam methane reforming (SMR) mode, and the other in the CO2 hydrogenation (MCO2) mode, a steady-state pseudo-homogeneous 1D non-isothermal packed-bed reactor model is developed, embedding the classical Xu and Froment local kinetics. The laboratory reactors are operated with three different catalysts, two commercial and one homemade. The simulation model makes it possible to identify and account for thermal effects occurring inside the catalytic zone of the reactor and along the exit line. The model is intended to guide the development of small size SMR and MCO2 reactors in the context of Power-to-X (P2X) studies.
At What Cost Can Renewable Hydrogen Offset Fossil Fuel Use in Ireland’s Gas Network?
Tubagus Aryandi Gunawan, Alessandro Singlitico, Paul Blount, James Burchill, James G. Carton, Rory F. D. Monaghan
March 24, 2023 (v1)
Keywords: Energy Storage, energy system, geographic information system, Hydrogen, natural gas network, water electrolysis, wind energy
The results of a techno-economic model of distributed wind-hydrogen systems (WHS) located at each existing wind farm on the island of Ireland are presented in this paper. Hydrogen is produced by water electrolysis from wind energy and backed up by grid electricity, compressed before temporarily stored, then transported to the nearest injection location on the natural gas network. The model employs a novel correlation-based approach to select an optimum electrolyser capacity that generates a minimum levelised cost of hydrogen production (LCOH) for each WHS. Three scenarios of electrolyser operation are studied: (1) curtailed wind, (2) available wind, and (3) full capacity operations. Additionally, two sets of input parameters are used: (1) current and (2) future techno-economic parameters. Additionally, two electricity prices are considered: (1) low and (2) high prices. A closest facility algorithm in a geographic information system (GIS) package identifies the shortest routes from each... [more]
Integration of Hydrogen into Multi-Energy Systems Optimisation
Peng Fu, Danny Pudjianto, Xi Zhang, Goran Strbac
March 24, 2023 (v1)
Keywords: Hydrogen, multi-energy systems, power system economics, renewable energy generation, whole system modelling
Hydrogen presents an attractive option to decarbonise the present energy system. Hydrogen can extend the usage of the existing gas infrastructure with low-cost energy storability and flexibility. Excess electricity generated by renewables can be converted into hydrogen. In this paper, a novel multi-energy systems optimisation model was proposed to maximise investment and operating synergy in the electricity, heating, and transport sectors, considering the integration of a hydrogen system to minimise the overall costs. The model considers two hydrogen production processes: (i) gas-to-gas (G2G) with carbon capture and storage (CCS), and (ii) power-to-gas (P2G). The proposed model was applied in a future Great Britain (GB) system. Through a comparison with the system without hydrogen, the results showed that the G2G process could reduce £3.9 bn/year, and that the P2G process could bring £2.1 bn/year in cost-savings under a 30 Mt carbon target. The results also demonstrate the system impli... [more]
Validation of GreenH2armony® as a Tool for the Computation of Harmonised Life-Cycle Indicators of Hydrogen
Antonio Valente, Diego Iribarren, Javier Dufour
March 24, 2023 (v1)
Subject: Environment
Keywords: acidification, carbon footprint, energy footprint, harmonisation, Hydrogen, life cycle assessment
The Life Cycle Assessment (LCA) methodology is often used to check the environmental suitability of hydrogen energy systems, usually involving comparative studies. However, these comparative studies are typically affected by inconsistent methodological choices between the case studies under comparison. In this regard, protocols for the harmonisation of methodological choices in LCA of hydrogen are available. The step-by-step application of these protocols to a large number of case studies has already resulted in libraries of harmonised carbon, energy, and acidification footprints of hydrogen. In order to foster the applicability of these harmonisation protocols, a web-based software for the calculation of harmonised life-cycle indicators of hydrogen has recently been developed. This work addresses—for the first time—the validation of such a tool by checking the deviation between the available libraries of harmonised carbon, energy, and acidification footprints of hydrogen and the corre... [more]
Optimal Energy Management in a Standalone Microgrid, with Photovoltaic Generation, Short-Term Storage, and Hydrogen Production
Andreu Cecilia, Javier Carroquino, Vicente Roda, Ramon Costa-Castelló, Félix Barreras
March 23, 2023 (v1)
Keywords: deferrable loads, demand side management, Fuel Cells, Hydrogen, Model Predictive Control, solar photovoltaic energy, standalone renewable energy systems
This paper addresses the energy management of a standalone renewable energy system. The system is configured as a microgrid, including photovoltaic generation, a lead-acid battery as a short term energy storage system, hydrogen production, and several loads. In this microgrid, an energy management strategy has been incorporated that pursues several objectives. On the one hand, it aims to minimize the amount of energy cycled in the battery, in order to reduce the associated losses and battery size. On the other hand, it seeks to take advantage of the long-term surplus energy, producing hydrogen and extracting it from the system, to be used in a fuel cell hybrid electric vehicle. A crucial factor in this approach is to accommodate the energy consumption to the energy demand and to achieve this, a model predictive control (MPC) scheme is proposed. In this context, proper models for solar estimation, hydrogen production, and battery energy storage will be presented. Moreover, the controlle... [more]
Product Inhibition of Biological Hydrogen Production in Batch Reactors
Subhashis Das, Rajnish Kaur Calay, Ranjana Chowdhury, Kaustav Nath, Fasil Ejigu Eregno
March 23, 2023 (v1)
Keywords: clostridium acetobutylicum, Hydrogen, kinetic modelling, product inhibition, reactor headspace
In this paper, the inhibitory effects of added hydrogen in reactor headspace on fermentative hydrogen production from acidogenesis of glucose by a bacterium, Clostridium acetobutylicum, was investigated experimentally in a batch reactor. It was observed that hydrogen itself became an acute inhibitor of hydrogen production if it accumulated excessively in the reactor headspace. A mathematical model to simulate and predict biological hydrogen production process was developed. The Monod model, which is a simple growth model, was modified to take inhibition kinetics on microbial growth into account. The modified model was then used to investigate the effect of hydrogen concentration on microbial growth and production rate of hydrogen. The inhibition was moderate as hydrogen concentration increased from 10% to 30% (v/v). However, a strong inhibition in microbial growth and hydrogen production rate was observed as the addition of H2 increased from 30% to 40% (v/v). Practically, an extended l... [more]
Cost Optimization of a Stand-Alone Hybrid Energy System with Fuel Cell and PV
Shakti Singh, Prachi Chauhan, Mohd Asim Aftab, Ikbal Ali, S. M. Suhail Hussain, Taha Selim Ustun
March 23, 2023 (v1)
Subject: Optimization
Keywords: ABC-PSO algorithm, Fuel Cells, Hydrogen, IEC 61850, Optimization, sizing
Renewable energy has become very popular in recent years. The amount of renewable generation has increased in both grid-connected and stand-alone systems. This is because it can provide clean energy in a cost-effective and environmentally friendly fashion. Among all varieties, photovoltaic (PV) is the ultimate rising star. Integration of other technologies with solar is enhancing the efficiency and reliability of the system. In this paper a fuel cell−solar photovoltaic (FC-PV)-based hybrid energy system has been proposed to meet the electrical load demand of a small community center in India. The system is developed with PV panels, fuel cell, an electrolyzer and hydrogen storage tank. Detailed mathematical modeling of this system as well as its operation algorithm have been presented. Furthermore, cost optimization has been performed to determine ratings of PV and Hydrogen system components. The objective is to minimize the levelized cost of electricity (LCOE) of this standalone system... [more]
Biomass Thermochemical Conversion via Pyrolysis with Integrated CO2 Capture
Małgorzata Sieradzka, Ningbo Gao, Cui Quan, Agata Mlonka-Mędrala, Aneta Magdziarz
March 23, 2023 (v1)
Keywords: Biomass, CaO solid sorbent, Carbon Dioxide Capture, chars, Hydrogen, physicochemical structure, pine wood, pyrolysis, Syngas
The presented work is focused on biomass thermochemical conversion with integrated CO2 capture. The main aim of this study was the in-depth investigation of the impact of pyrolysis temperature (500, 600 and 700 °C) and CaO sorbent addition on the chemical and physical properties of obtained char and syngas. Under the effect of the pyrolysis temperature, the properties of biomass chars were gradually changed, and this was confirmed by examination using thermal analysis, scanning electron microscopy, X-ray diffraction, and porosimetry methods. The chars were characterised by a noticeable carbon content (two times at 700 °C) resulting in a lower O/C ratio. The calculated combustion indexes indicated the better combustible properties of chars. In addition, structural morphology changes were observed. However, the increasing pyrolysis temperature resulted in changes of solid products; the differences of char properties were not significant in the range of 500 to 700 °C. Syngas was analysed... [more]
Future Fuels—Analyses of the Future Prospects of Renewable Synthetic Fuels
Thomas Pregger, Günter Schiller, Felix Cebulla, Ralph-Uwe Dietrich, Simon Maier, André Thess, Andreas Lischke, Nathalie Monnerie, Christian Sattler, Patrick Le Clercq, Bastian Rauch, Markus Köhler, Michael Severin, Peter Kutne, Christiane Voigt, Hans Schlager, Simone Ehrenberger, Mario Feinauer, Lukas Werling, Victor P. Zhukov, Christoph Kirchberger, Helmut K. Ciezki, Florian Linke, Torsten Methling, Uwe Riedel, Manfred Aigner
March 22, 2023 (v1)
Keywords: aviation fuel, green propellant, Hydrogen, power-to-liquid, Renewable and Sustainable Energy, solar fuel, synthetic fuel, systems analysis, technology assessment
The Future Fuels project combines research in several institutes of the German Aerospace Center (DLR) on the production and use of synthetic fuels for space, energy, transportation, and aviation. This article gives an overview of the research questions considered and results achieved so far and also provides insight into the multidimensional and interdisciplinary project approach. Various methods and models were used which are embedded in the research context and based on established approaches. The prospects for large-scale fuel production using renewable electricity and solar radiation played a key role in the project. Empirical and model-based investigations of the technological and cost-related aspects were supplemented by modelling of the integration into a future electricity system. The composition, properties, and the related performance and emissions of synthetic fuels play an important role both for potential oxygenated drop-in fuels in road transport and for the design and ce... [more]
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