Austria
Methodology for Efficient Parametrisation of Electrochemical PEMFC Model for Virtual Observers: Model Based Optimal Design of Experiments Supported by Parameter Sensitivity Analysis
Nov 2020
Publication
Determination of the optimal design of experiments that enables efficient parametrisation of fuel cell (FC) model with a minimum parametrisation data-set is one of the key prerequisites for minimizing costs and effort of the parametrisation procedure. To efficiently tackle this challenge the paper present an innovative methodology based on the electrochemical FC model parameter sensitivity analysis and application of D-optimal design plan. Relying on this consistent methodological basis the paper answers fundamental questions: a) on a minimum required data-set to optimally parametrise the FC model and b) on the impact of reduced space of operational points on identifiability of individual calibration parameters. Results reveal that application of D-optimal DoE enables enhancement of calibration parameters information resulting in up to order of magnitude lower relative standard errors on smaller data-sets. In addition it was shown that increased information and thus identifiability inherently leads to improved robustness of the FC electrochemical model.
The Future Potential Hydrogen Demand in Energy-intensive Industries - A Site-specific Approach Applied to Germany
Dec 2021
Publication
Hydrogen when based on renewable electricity can play a key role in the transition towards CO2-neutral industrial production since its use as an energy carrier as well as a feedstock in various industrial process routes is promising. At the same time a large-scale roll-out of hydrogen for industrial use would entail substantial impacts on the energy system which can only be assessed if the regional distribution of future hydrogen demand is considered. Here we assess the technical potential of hydrogen-based technologies for energy-intensive industries in Germany. The site-specific and process-specific bottom-up calculation considers 615 individual plants at 367 sites and results in a total potential hydrogen demand of 326 TWh/a. The results are available as an open dataset. Using hydrogen for non-energy-intensive sectors as well increases the potential hydrogen demand to between 482 and 534 TWh/a for Germany - based on today’s industrial structure and production output. This assumes that fossil fuels are almost completely replaced by hydrogen for process heating and feedstocks. The resulting hydrogen demand is very unevenly distributed: a few sites account for the majority of the overall potential and similarly the bulk of demand is concentrated in a few regions with steel and chemical clusters.
Asymmetric Solvation of the Zinc Dimer Cation Revealed by Infrared Multiple Photon Dissociation Spectroscopy of Zn2+(H2O)n (n = 1–20)
Jun 2021
Publication
Investigating metal-ion solvation—in particular the fundamental binding interactions—enhances the understanding of many processes including hydrogen production via catalysis at metal centers and metal corrosion. Infrared spectra of the hydrated zinc dimer (Zn2+(H2O)n; n = 1–20) were measured in the O–H stretching region using infrared multiple photon dissociation (IRMPD) spectroscopy. These spectra were then compared with those calculated by using density functional theory. For all cluster sizes calculated structures adopting asymmetric solvation to one Zn atom in the dimer were found to lie lower in energy than structures adopting symmetric solvation to both Zn atoms. Combining experiment and theory the spectra show that water molecules preferentially bind to one Zn atom adopting water binding motifs similar to the Zn+(H2O)n complexes studied previously. A lower coordination number of 2 was observed for Zn2+(H2O)3 evident from the highly red-shifted band in the hydrogen bonding region. Photodissociation leading to loss of a neutral Zn atom was observed only for n = 3 attributed to a particularly low calculated Zn binding energy for this cluster size.
The Influence of Hydrogen Sulfide Contaminations on Hydrogen Production in Chemical Looping Processes
Aug 2021
Publication
Chemical looping with iron-based oxygen carriers enables the production of hydrogen from various fossil and biogenic primary energy sources. In applications with real producer gases such as biogas or gasified biomass hydrogen sulfide represents one of the most challenging contaminants. The impact of H2S on the reactivity of a Fe2O3/Al2O3 oxygen carrier material in chemical looping hydrogen production was investigated in the present work. First potential sulfur deactivation mechanisms are discussed in detail on the basis of thermodynamic data. Afterwards an experimental study in a fixed-bed reactor system gave experimental evidence on the fate of sulfur in chemical looping hydrogen systems. The chemisorption of hydrogen sulfide (H2S) was identified as the main cause for the accumulative adsorption of H2S in the reduction phase and was confirmed by ex-situ ICP-EOS analysis. In the subsequent steam oxidation step significant quantities of H2S were released resulting in an undesirable contamination of the hydrogen product gas. The reason was found as weakened sulfur bonds through increasing reactor temperatures caused by the exothermic oxidation reactions. In additional air oxidation steps no further contaminants as sulfur dioxide were identified. A profound interpretation was achieved through the fulfillment of the overall sulfur mass balance within a mean deviation of 3.7%. Quantitative investigations showed that the hydrogen consumption decreased by 12% throughout the reduction phase in the event of 100 ppm H2S in the feed gas
Critical Review of Models for H2-permeation Through Polymers with Focus on the Differential Pressure Method
May 2021
Publication
To reduce loss of hydrogen in storage vessels with high energy-to-weight-ratio new materials especially polymers have to be developed as barrier materials. Very established methods for characterization of barrier materials with permeation measurements are the time-lag and flow rate method along with the differential pressure method which resembles the nature of hydrogen vessel systems very well. Long measurement durations are necessary to gain suitable measurement data for these evaluation methods and often restrictive conditions have to be fulfilled. For these reasons common models for hydrogen permeation through single-layer and multi-layer membranes as well as models for hydrogen gas properties were collected and reviewed. Using current computer power together with these models can reduce measurement time for characterization of the barrier properties of materials while additional information about the quality of the measurement results is obtained.
Validation of Selected Optical Methods for Assessing Polyethylene (PE) Liners Used in High Pressure Vessels for Hydrogen Storage
Jun 2021
Publication
A polyethylene (PE) liner is the basic element in high-pressure type 4 composite vessels designed for hydrogen or compressed natural gas (CNG) storage systems. Liner defects may result in the elimination of the whole vessel from use which is very expensive both at the manufacturing and exploitation stage. The goal is therefore the development of efficient non-destructive testing (NDT) methods to test a liner immediately after its manufacturing before applying a composite reinforcement. It should be noted that the current regulations codes and standards (RC&S) do not specify liner testing methods after manufacturing. It was considered especially important to find a way of locating and assessing the size of air bubbles and inclusions and the field of deformations in liner walls. It was also expected that these methods would be easily applicable to mass-produced liners. The paper proposes the use of three optical methods namely visual inspection digital image correlation (DIC) and optical fiber sensing based on Bragg gratings (FBG). Deformation measurements are validated with finite element analysis (FEA). The tested object was a prototype of a hydrogen liner for high-pressure storage (700 bar). The mentioned optical methods were used to identify defects and measure deformations.
Magnesium Gasar as a Potential Monolithic Hydrogen Absorbent
Feb 2021
Publication
The study focuses on the aspect of using the structure of gasars i.e. materials with directed open porosity as a potential hydrogen storage. The structure of the tested gasar is composed of a large number of thin open tubular pores running through the entire longitudinal section of the sample. This allows hydrogen to easily penetrate into the entire sample volume. The analysis of pore distribution showed that the longest diffusion path needed for full penetration of the metal structure with hydrogen is about L = 50–70 μm regardless of the external dimensions of the sample. Attempts to hydrogenate the magnesium gasar structure have shown its ability to accumulate hydrogen at a level of 1 wt%. The obtained results were compared with the best result was obtained for the ZK60 alloy after equal channel angular pressing (ECAP) and crushed to a powder form. The result obtained exceeded 4 wt% of hydrogen accumulated in the metal structure at theoretical 6.9 wt% maximum capacity. A model analysis of the theoretic absorption capacity of pure magnesium was also carried out based on the concentration of vacancies in the metal structure. The theoretical results obtained correlate well with experimental data.
Critical Assessment of the Effect of Atmospheric Corrosion Induced Hydrogen on Mechanical Properties of Advanced High Strength Steel
Dec 2020
Publication
Hydrogen absorption into steel during atmospheric corrosion has been of a strong concern during last decades. It is technically important to investigate if hydrogen absorbed under atmospheric exposure conditions can significantly affect mechanical properties of steels. The present work studies changes of mechanical properties of dual phase (DP) advanced high strength steel specimens with sodium chloride deposits during corrosion in humid air using Slow Strain Rate Test (SSRT). Additional annealed specimens were used as reference in order to separate the possible effect of absorbed hydrogen from that of corrosion deterioration. Hydrogen entry was monitored in parallel experiments using hydrogen electric resistance sensor (HERS) and thermal desorption mass spectrometry (TDMS). SSRT results showed a drop in elongation and tensile strength by 42% and 6% respectively in 27 days of atmospheric exposure. However this decrease cannot be attributed to the effect of absorbed hydrogen despite the increase in hydrogen content with time of exposure. Cross-cut analysis revealed considerable pitting which was suggested to be the main reason for the degradation of mechanical properties
High-pressure Hydrogen Production with Inherent Sequestration of a Pure Carbon Dioxide Stream Via Fixed Bed Chemical Looping
Feb 2019
Publication
The proof of concept for the production of pure pressurized hydrogen from hydrocarbons in combination with the sequestration of a pure stream of carbon dioxide with the reformer steam iron cycle is presented. The iron oxide based oxygen carrier (95% Fe2O3 5% Al2O3) is reduced with syngas and oxidized with steam at 1023 K. The carbon dioxide separation is achieved via partial reduction of the oxygen carrier from Fe2O3 to Fe3O4 yielding thermodynamically to a product gas only containing CO2 and H2O. By the subsequent condensation of steam pure CO2 is sequestrated. After each steam oxidation phase an air oxidation was applied to restore the oxygen carrier to hematite level. Product gas pressures of up to 30.1 bar and hydrogen purities exceeding 99% were achieved via steam oxidations. The main impurities in the product gas are carbon monoxide and carbon dioxide which originate from solid carbon depositions or from stored carbonaceous molecules inside the pores of the contact mass. The oxygen carrier samples were characterized using elemental analysis BET surface area measurement XRD powder diffraction SEM and light microscopy. The maximum pressure of 95 bar was demonstrated for hydrogen production in the steam oxidation phase after the full oxygen carrier reduction significantly reducing the energy demand for compressors in mobility applications.
Hydrogen Storage Performance of the Multi-principal-component CoFeMnTiVZr Alloy in Electrochemical and Gas–solid Reactions
Jun 2020
Publication
The single-phase multi-principal-component CoFeMnTiVZr alloy was obtained by rapid solidification and examined by a combination of electrochemical methods and gas–solid reactions. X-ray diffraction and high-resolution transmission electron microscopy analyses reveal a hexagonal Laves-phase structure (type C14). Cyclic voltammetry and electrochemical impedance spectroscopy investigations in the hydrogen absorption/desorption region give insight into the absorption/desorption kinetics and the change in the desorption charge in terms of the applied potential. The thickness of the hydrogen absorption layer obtained by the electrochemical reaction is estimated by high-resolution transmission electron microscopy. The electrochemical hydrogen storage capacity for a given applied voltage is calculated from a series of chronoamperometry and cyclic voltammetry measurements. The selected alloy exhibits good stability for reversible hydrogen absorption and demonstrates a maximum hydrogen capacity of ∼1.9 wt% at room temperature. The amount of hydrogen absorbed in the gas–solid reaction reaches 1.7 wt% at 298 K and 5 MPa evidencing a good correlation with the electrochemical results.
Accelerated Degradation for Solid Oxide Electrolysers: Analysis and Prediction of Performance for Varying Operating Environments
Jan 2022
Publication
Solid oxide electrolysis cells (SOECs) are an efficient technology for the production of green hydrogen that has great potential to contribute to the energy transition and decarbonization of industry. To date however time- and resource-intensive experimental campaigns slow down the development and market penetration of the technology. In order to speed-up the evaluation of SOEC performance and durability accelerated testing protocols are required. This work provides the results of experimental studies on the performance of a SOEC stack operated under accelerated degradation conditions. In order to initiate and accelerate degradation experiments were performed with high steam partial pressures at the gas inlet higher voltages and lower temperatures and high steam conversion rates. Thereby different types and degrees of impact on performance were observed which were analyzed in detail and linked to the underlying processes and degradation mechanisms. In this context significantly higher degradation rates were found compared to operation under moderate operating conditions with the different operating strategies varying in their degradation acceleration potential. The results also suggest that a few hundred hours of operation may be sufficient to predict long-term performance with the proposed operating strategies providing a solid basis for accelerated assessment of SOEC performance evolution and lifetime.
Characterization of Materials in Pressurized Hydrogen Under Cyclic Loading at Service Conditions in Hydrogen Powered Engines
Sep 2005
Publication
A new testing device for cyclic loading of specimens with a novel shape design is presented. The device was applied for investigations of fatigue of metallic specimens under pressurized hydrogen up to 300 bar at temperatures up to 200 °C. Main advantage of the specimen design is the very small amount of medium here hydrogen used for testing. This allows experiments with hazardous substances at lower safety level. Additionally no gasket for the load transmission is required. Woehler curves which show the influence of hydrogen on the fatigue behaviour of austenitic steel specimens at relevant service conditions in hydrogen powered engines are presented. Material and test conditions are in agreement with the cooperating industry.
Data-driven Parameterization of Polymer Electrolyte Membrane fuel Cell Models Via Simultaneous Local Linear Structured State Space Identification
Feb 2021
Publication
In order to mitigate the degradation and prolong the lifetime of polymer electrolyte membrane fuel cells advanced model-based control strategies are becoming indispensable. Thereby the availability of accurate yet computationally efficient fuel cell models is of crucial importance. Associated with this is the need to efficiently parameterize a given model to a concise and cost-effective experimental data set. A challenging task due to the large number of unknown parameters and the resulting complex optimization problem. In this work a parameterization scheme based on the simultaneous estimation of multiple structured state space models obtained by analytic linearization of a candidate fuel cell stack model is proposed. These local linear models have the advantage of high computational efficiency regaining the desired flexibility required for the typically iterative task of model parameterization. Due to the analytic derivation of the local linear models the relation to the original parameters of the non-linear model is retained. Furthermore the local linear models enable a straight-forward parameter significance and identifiability analysis with respect to experimental data. The proposed method is demonstrated using experimental data from a 30 kW commercial polymer electrolyte membrane fuel cell stack.
Recent Advancements in Chemical Looping Water Splitting for the Production of Hydrogen
Oct 2016
Publication
Chemical looping water splitting or chemical looping hydrogen is a very promising technology for the production of hydrogen. In recent years extensive research has enabled remarkable leaps towards a successful integration of the chemical looping technology into a future hydrogen infrastructure. Progress has been reported with iron based oxygen carriers for stable hydrogen production capacity over consecutive cycles without significant signs of degradation. The high stability improvements were achieved by adding alien metal oxides or by integrating the active component into a mineral structure which offers excellent resistance towards thermal stress. Prototype systems from small μ-systems up to 50 kW have been operated with promising results. The chemical looping water splitting process was broadened in terms of its application area and utilization of feedstocks using a variety of renewable and fossil resources. The three-reactor system was clearly advantageous due to its flexibility heat integration capabilities and possibility to produce separate pure streams of hydrogen CO2 and N2. However two-reactor and single fixed-bed reactor systems were successfully operated as well. This review aims to survey the recently presented literature in detail and systematically summarize the gathered data.
Hydrocarbon Production by Continuous Hydrodeoxygenation of Liquid Phase Pyrolysis Oil with Biogenous Hydrogen Rich Synthesis Gas
Feb 2019
Publication
This paper presents a beneficial combination of biomass gasification and pyrolysis oil hydrodeoxygenation for advanced biofuel production. Hydrogen for hydrodeoxygenation (HDO) of liquid phase pyrolysis oil (LPP oil) was generated by gasification of softwood. The process merges dual fluidized bed (DFB) steam gasification which produces a hydrogen rich product gas and the HDO of LPP oil. Synthesis gas was used directly without further cleaning and upgrading by making use of the water gas-shift (WGS) reaction. The water needed for the water gas-shift reaction was provided by LPP oil. HDO was successfully performed in a lab scale over 36 h time on stream (TOS). Competing reactions like the Boudouard reaction and Sabatier reaction were not observed. Product quality was close to Diesel fuel specification according to EN 590 with a carbon content of 85.4 w% and a residual water content of 0.28 w%. The water-gas shift reaction was confirmed by CO/CO2-balance high water consumption and 28% less hydrogen consumption during HDO.
Sustainable Hydrogen Society - Vision, Findings and Development of a Hydrogen Economy Using the Example of Austria
Oct 2021
Publication
Based on technical environmental economic and social facts and recent findings the feasibility of the transition from our current fossil age to the new green age is analyzed in detail at both global and local level. To avert the threats of health problems environmental pollution and climate change to our quality and standard of life a twofold radical paradigm shift is outlined: Green Energy Revolution means the complete change from fossil-based to green primary energy sources such as sun wind water environmental heat and biomass; Green Hydrogen Society means the complete change from fossil-based final energy to green electricity and green hydrogen in all areas of mobility industries households and energy services. Renewable energies offer a green future and are in combination with electrochemical machines such as electrolysers batteries and fuel cells able to achieve higher efficiencies and zero emissions.
Safety Demands for Automotive Hydrogen Storage Systems
Sep 2005
Publication
Fuel storage systems for vehicles require a fail-safe design strategy. In case of system failures or accidents the control electronics have to switch the system into a safe operation mode. Failure Mode and Effect Analysis (FMEA) or Failure Tree Analysis (FTA) are performed already in the early design phase in order to minimize the risk of design failures in the fuel storage system. Currently the specifications of requirements for pressurized and liquid hydrogen fuel tanks are based on draft UN-ECE Regulations developed by the European Integrated Hydrogen Project (EIHP). Used materials and accessories shall be compatible with hydrogen. A selection of metallic and non-metallic materials will be presented. Complex components have to be optimised by FEM simulations in order to determine weak spots in the design which will be overstressed in case of pressure thermal expansion or dynamic vibrations. According to automotive standards the performance of liquid hydrogen fuel tank systems has to be verified in various destructive and non-destructive tests.
Addressing H-Material Interaction in Fast Diffusion Materials—A Feasibility Study on a Complex Phase Steel
Oct 2020
Publication
Hydrogen embrittlement (HE) is one of the main limitations in the use of advanced high-strength steels in the automotive industry. To have a better understanding of the interaction between hydrogen (H) and a complex phase steel an in-situ method with plasma charging was applied in order to provide continuous H supply during mechanical testing in order to avoid H outgassing. For such fast-H diffusion materials only direct observation during in-situ charging allows for addressing H effects on materials. Different plasma charging conditions were analysed yet there was not a pronounced effect on the mechanical properties. The H concentration was calculated while using a simple analytical model as well as a simulation approach resulting in consistent low H values below the critical concentration to produce embrittlement. However the dimple size decreased in the presence of H and with increasing charging time the crack propagation rate increased. The rate dependence of flow properties of the material was also investigated proving that the material has no strain rate sensitivity which confirmed that the crack propagation rate increased due to H effects. Even though the H concentration was low in the experiments that are presented here different technological alternatives can be implemented in order to increase the maximum solute concentration.
Prospects of Enhancing the Understanding of Material-hydrogen Interaction by Novel In-situ and In-operando Methods
Jan 2022
Publication
A main scientific and technical challenge facing the implementation of new and sustainable energy sources is the development and improvement of materials and components. In order to provide commercial viability of these applications an intensive research in material-hydrogen (H) interaction is required. This work provides an overview of recently developed in-situ and in-operando H-charging methods and their applicability to investigate mechanical properties H-absorption characteristics and H embrittlement (HE) susceptibility of a wide range of materials employed in H-related technologies such as subsea oil and gas applications nuclear fusion and fuel cells.
Combination of b-Fuels and e-Fuels—A Technological Feasibility Study
Aug 2021
Publication
The energy supply in Austria is significantly based on fossil natural gas. Due to the necessary decarbonization of the heat and energy sector a switch to a green substitute is necessary to limit CO2 emissions. Especially innovative concepts such as power-to-gas establish the connection between the storage of volatile renewable energy and its conversion into green gases. In this paper different methanation strategies are applied on syngas from biomass gasification. The investigated syngas compositions range from traditional steam gasification sorption-enhanced reforming to the innovative CO2 gasification. As the producer gases show different compositions regarding the H2/COx ratio three possible methanation strategies (direct sub-stoichiometric and over-stoichiometric methanation) are defined and assessed with technological evaluation tools for possible future large-scale set-ups consisting of a gasification an electrolysis and a methanation unit. Due to its relative high share of hydrogen and the high technical maturity of this gasification mode syngas from steam gasification represents the most promising gas composition for downstream methanation. Sub-stoichiometric operation of this syngas with limited H2 dosage represents an attractive methanation strategy since the hydrogen utilization is optimized. The overall efficiency of the sub-stoichiometric methanation lies at 59.9%. Determined by laboratory methanation experiments a share of nearly 17 mol.% of CO2 needs to be separated to make injection into the natural gas grid possible. A technical feasible alternative avoiding possible carbon formation in the methanation reactor is the direct methanation of sorption-enhanced reforming syngas with an overall process efficiency in large-scale applications of 55.9%.
Advanced Optimal Planning for Microgrid Technologies Including Hydrogen and Mobility at a Real Microgrid Testbed
Apr 2021
Publication
This paper investigates the optimal planning of microgrids including the hydrogen energy system through mixed-integer linear programming model. A real case study is analyzed by extending the only microgrid lab facility in Austria. The case study considers the hydrogen production via electrolysis seasonal storage and fuelling station for meeting the hydrogen fuel demand of fuel cell vehicles busses and trucks. The optimization is performed relative to two different reference cases which satisfy the mobility demand by diesel fuel and utility electricity based hydrogen fuel production respectively. The key results indicate that the low emission hydrogen mobility framework is achieved by high share of renewable energy sources and seasonal hydrogen storage in the microgrid. The investment optimization scenarios provide at least 66% and at most 99% carbon emission savings at increased costs of 30% and 100% respectively relative to the costs of the diesel reference case (current situation)
Characterization of the Inducible and Slow-Releasing Hydrogen Sulfide and Persulfide Donor P*: Insights into Hydrogen Sulfide Signaling
Jun 2021
Publication
Hydrogen sulfide (H2S) is an important mediator of inflammatory processes. However controversial findings also exist and its underlying molecular mechanisms are largely unknown. Recently the byproducts of H2S per-/polysulfides emerged as biological mediators themselves highlighting the complex chemistry of H2S. In this study we characterized the biological effects of P* a slow-releasing H2S and persulfide donor. To differentiate between H2S and polysulfide-derived effects we decomposed P* into polysulfides. P* was further compared to the commonly used fast-releasing H2S donor sodium hydrogen sulfide (NaHS). The effects on oxidative stress and interleukin-6 (IL-6) expression were assessed in ATDC5 cells using superoxide measurement qPCR ELISA and Western blotting. The findings on IL-6 expression were corroborated in primary chondrocytes from osteoarthritis patients. In ATDC5 cells P* not only induced the expression of the antioxidant enzyme heme oxygenase-1 via per-/polysulfides but also induced activation of Akt and p38 MAPK. NaHS and P* significantly impaired menadione-induced superoxide production. P* reduced IL-6 levels in both ATDC5 cells and primary chondrocytes dependent on H2Srelease. Taken together P* provides a valuable research tool for the investigation of H2S and per-/polysulfide signalling. These data demonstrate the importance of not only H2S but also per-/polysulfides as bioactive signaling molecules with potent anti-inflammatory and in particular antioxidant properties.
Hydrogen in Grid Balancing: The European Market Potential for Pressurized Alkaline Electrolyzers
Jan 2022
Publication
To limit the global temperature change to no more than 2 ◦C by reducing global emissions the European Union (EU) set up a goal of a 20% improvement on energy efficiency a 20% cut of greenhouse gas emissions and a 20% share of energy from renewable sources by 2020 (10% share of renewable energy (RE) specifically in the transport sector). By 2030 the goal is a 27% improvement in energy efficiency a 40% cut of greenhouse gas emissions and a 27% share of RE. However the integration of RE in energy system faces multiple challenges. The geographical distribution of energy supply changes significantly the availability of the primary energy source (wind solar water) and is the determining factor rather than where the consumers are. This leads to an increasing demand to match supply and demand for power. Especially intermittent RE like wind and solar power face the issue of energy production unrelated to demand (issue of excess energy production beyond demand and/or grid capacity) and forecast errors leading to an increasing demand for grid services like balancing power. Megawatt electrolyzer units (beyond 3 MW) can provide a technical solution to convert large amounts of excess electricity into hydrogen for industrial applications substitute for natural gas or the decarbonization of the mobility sector. The demonstration of successful MW electrolyzer operation providing grid services under dynamic conditions as request by the grid can broaden the opportunities of new business models that demonstrate the profitability of an electrolyzer in these market conditions. The aim of this work is the demonstration of a technical solution utilizing Pressurized Alkaline Electrolyzer (PAE) technology for providing grid balancing services and harvesting Renewable Energy Sources (RES) under realistic circumstances. In order to identify any differences between local market and grid requirements the work focused on a demonstration site located in Austria deemed as a viable business case for the operation of a largescale electrolyzer. The site is adapted to specific local conditions commonly found throughout Europe. To achieve this this study uses a market-based solution that aims at providing value-adding services and cash inflows stemming from the grid balancing services it provides. Moreover the work assesses the viability of various business cases by analyzing (qualitatively and quantitatively) additional business models (in terms of business opportunities/energy source potential grid service provision and hydrogen demand) and analyzing the value and size of the markets developing recommendations for relevant stakeholder to decrease market barriers.
Hydrogen-assisted Cracking of GMA Welded 960 & A Grade High-strength Steels
Jan 2020
Publication
High-strength steels with yield strength of 960 MPa are susceptible to hydrogen-assisted cracking (HAC) during welding processing. In the present paper the implant test is used to study HAC in a quenched and tempered steel S960QL and a high-strength steel produced by thermo-mechanical controlled process S960MC. Welding is performed using the gas-metal arc welding process. Furthermore diffusible hydrogen concentration (HD) in arc weld metal is determined. Based on the implant test results lower critical stress (LCS) for complete fracture critical implant stress (σkrit) for crack initiation and embrittlement index (EI) are determined. At HD of 1.66 ml/100 g LCS is 605 MPa and 817 MPa for S960QL and S960MC respectively. EI is 0.30 and 0.46 for S960QL and S960MC respectively. Fracture surfaces of S960QL show higher degradation with reduced deformation. Both higher EI of S960MC and fractography show better resistance to HAC in the HAZ of S960MC compared to S960QL.
Using the Jet Stream for Sustainable Airship and Balloon Transportation of Cargo and Hydrogen
Jul 2019
Publication
The maritime shipping sector is a major contributor to CO2 emissions and this figure is expected to rise in coming decades. With the intent of reducing emissions from this sector this research proposes the utilization of the jet stream to transport a combination of cargo and hydrogen using airships or balloons at altitudes of 10–20 km. The jet streams flow in the mid-latitudes predominantly in a west–east direction reaching an average wind speed of 165 km/h. Using this combination of high wind speeds and reliable direction hydrogen-filled airships or balloons could carry hydrogen with a lower fuel requirement and shorter travel time compared to conventional shipping. Jet streams at different altitudes in the atmosphere were used to identify the most appropriate circular routes for global airship travel. Round-the-world trips would take 16 days in the Northern Hemisphere and 14 in the Southern Hemisphere. Hydrogen transport via the jet stream due to its lower energy consumption and shorter cargo delivery time access to cities far from the coast could be a competitive alternative to maritime shipping and liquefied hydrogen tankers in the development of a sustainable future hydrogen economy.
Macroeconomic Implications of Switching to process-emission-free Iron and Steel Production in Europe
Nov 2018
Publication
Climate change is one of the most serious threats to the human habitat. The required structural change to limit anthropogenic forcing is expected to fundamentally change daily social and economic life. The production of iron and steel is a special case of economic activities since it is not only associated with combustion but particularly with process emissions of greenhouse gases which have to be dealt with likewise. Traditional mitigation options of the sector like efficiency measures substitution with less emission-intensive materials or scrap-based production are bounded and thus insufficient for rapid decarbonization necessary for complying with long-term climate policy targets. Iron and steel products are basic materials at the core of modern socio-economic systems additionally being essential also for other mitigation options like hydro and wind power. Therefore a system-wide assessment of recent technological developments enabling almost complete decarbonization of the sector is substantially relevant. Deploying a recursive-dynamic multi-region multi-sector computable general equilibrium approach we investigate switches from coke-to hydrogen-based iron and steel technologies in a scenario framework where industry decisions (technological choice and timing) and climate policies are mis-aligned. Overall we find that the costs of industry transition are moderate but still ones that may represent a barrier for implementation because the generation deciding on low-carbon technologies and bearing (macro)economic costs might not be the generation benefitting from it. Our macroeconomic assessment further indicates that anticipated bottom-up estimates of required additional domestic renewable electricity tend to be overestimated. Relative price changes in the economy induce electricity substitution effects and trigger increased electricity imports. Sectoral carbon leakage is an imminent risk and calls for aligned course of action of private and public actors.
Hydrogen Trapping in bcc Iron
May 2020
Publication
Fundamental understanding of H localization in steel is an important step towards theoretical descriptions of hydrogen embrittlement mechanisms at the atomic level. In this paper we investigate the interaction between atomic H and defects in ferromagnetic body-centered cubic (bcc) iron using density functional theory (DFT) calculations. Hydrogen trapping profiles in the bulk lattice at vacancies dislocations and grain boundaries (GBs) are calculated and used to evaluate the concentrations of H at these defects as a function of temperature. The results on H-trapping at GBs enable further investigating H-enhanced decohesion at GBs in Fe. A hierarchy map of trapping energies associated with the most common crystal lattice defects is presented and the most attractive H-trapping sites are identified.
Hydrogen Uptake and Embrittlement of Carbon Steels in Various Environments
Aug 2020
Publication
To avoid failures due to hydrogen embrittlement it is important to know the amount of hydrogen absorbed by certain steel grades under service conditions. When a critical hydrogen content is reached the material properties begin to deteriorate. The hydrogen uptake and embrittlement of three different carbon steels (API 5CT L80 Type 1 P110 and 42CrMo4) was investigated in autoclave tests with hydrogen gas (H2) at elevated pressure and in ambient pressure tests with hydrogen sulfide (H2S). H2 gas with a pressure of up to 100 bar resulted in an overall low but still detectable hydrogen absorption which did not cause any substantial hydrogen embrittlement in specimens under a constant load of 90% of the specified minimum yield strength (SMYS). The amount of hydrogen absorbed under conditions with H2S was approximately one order of magnitude larger than under conditions with H2 gas. The high hydrogen content led to failures of the 42CrMo4 and P110 specimens.
Scenarios to Decarbonize Austria’s Energy Consumption and the Role of Underground Hydrogen Storage
May 2022
Publication
The European Union is aiming at reaching greenhouse gas (GHG) emission neutrality in 2050. Austria’s current greenhouse gas emissions are 80 million t/year. Renewable Energy (REN) contributes 32% to Austria’s total energy consumption. To decarbonize energy consumption a substantial increase in energy generation from renewable energy is required. This increase will add to the seasonality of energy supply and amplifies the seasonality in energy demand. In this paper the seasonality of energy supply and demand in a Net-Zero Scenario are analyzed for Austria and requirements for hydrogen storage derived. We looked into the potential usage of hydrogen in Austria and the economics of hydrogen generation and technology and market developments to assess the Levelized Cost of Hydrogen (LCOH). Then we cover the energy consumption in Austria followed by the REN potential. The results show that incremental potential of up to 140 TWh for hydropower photovoltaic (PV) and wind exists in Austria. Hydropower generation and PV is higher in summer- than in wintertime while wind energy leads to higher energy generation in wintertime. The largest incremental potential is PV with agrivoltaic systems significantly increasing the area amenable for PV compared with PV usage only. Battery Electric Vehicles (BEV) and Fuel Cell Vehicles (FCV) use energy more efficiently than Internal Combustion Engine (ICE) cars; however the use of hydrogen for electricity generation significantly decreases the efficiency due to electricity–hydrogen– electricity conversion. The increase in REN use and the higher demand for energy in Austria in wintertime require seasonal storage of energy. We developed three scenarios Externally Dependent Scenario (EDS) Balanced Energy Scenario (BES) or Self-Sustained Scenario (SSS) for Austria. The EDS scenario assumes significant REN import to Austria whereas the SSS scenario relies on REN generation within Austria. The required hydrogen storage would be 10.82 bn m3 for EDS 13.34 bn m3 for BES and 18.69 bn m3 for SSS. Gas and oil production in Austria and the presence of aquifers indicates that sufficient storage capacity might be available. Significant technology development is required to be able to implement hydrogen as an energy carrier and to balance seasonal energy demand and supply.
The Sector Coupling Concept: A Critical Review
Jun 2020
Publication
Pursued climate goals require reduced greenhouse gas emissions by substituting fossil fuels with energy from renewable sources in all energy-consuming processes. On a large-scale this can mainly be achieved through electricity from wind and sun which are subject to intermittency. To efficiently integrate this variable energy a coupling of the power sector to the residential transport industry and commercial/trade sector is often promoted called sector coupling (SC). Nevertheless our literature review indicates that SC is frequently misinterpreted and its scope varies among available research from exclusively considering the use of excess renewable electricity to a rather holistic view of integrated energy systems including excess heat or even biomass sources. The core objective of this article is to provide a thorough understanding of the SC concept through an analysis of its origin and its main purpose as described in the current literature. We provide a structured categorization of SC derived from our findings and critically discuss its remaining challenges as well as its value for renewable energy systems. We find that SC is rooted in the increasing use of variable renewable energy sources and its main assets are the flexibility it provides for renewable energy systems decarbonization potential for fossil-fuel-based end-consumption sectors and consequently reduced dependency on oil and gas extracting countries. However the enabling technologies face great challenges in their economic feasibility because of the uncertain future development of competing solutions.
Economic Evaluation of Renewable Hydrogen Integration into Steelworks for the Production of Methanol and Methane
Jun 2022
Publication
This work investigates the cost-efficient integration of renewable hydrogen into steelworks for the production of methane and methanol as an efficient way to decarbonize the steel industry. Three case studies that utilize a mixture of steelworks off-gases (blast furnace gas coke oven gas and basic oxygen furnace gas) which differ on the amount of used off-gases as well as on the end product (methane and/or methanol) are analyzed and evaluated in terms of their economic performance. The most influential cost factors are identified and sensitivity analyses are conducted for different operating and economic parameters. Renewable hydrogen produced by PEM electrolysis is the most expensive component in this scheme and responsible for over 80% of the total costs. Progress in the hydrogen economy (lower electrolyzer capital costs improved electrolyzer efficiency and lower electricity prices) is necessary to establish this technology in the future.
Risk Assessment of the Low-carbon Transition of Austria’s Steel and Electricity Sectors
Dec 2018
Publication
To limit global temperature increase below +2°C societies need to reduce greenhouse gas emissions radically within the next few decades. Amongst other mitigation measures this requires transforming process-emission intensive industries towards emission neutrality. One way to this end is the renewables-based electrification of industries. We present results of a recent coproduction process which brought together stakeholders from industry policy administration and science to co-create climate-neutral transition pathways for the steel and electricity sectors in Austria. The results summarized here are the definition of reliable pathways and the identification of associated risks pertaining to pathway implementation including a macro-economic quantification. We find that risks to implementation (barriers) are at least as important as risks of implementation (negative consequences). From the quantitative analysis we find that provided that barriers can be reduced macroeconomic costs of the transition are only moderate and that stakeholders might overestimate risks when neglecting economy-wide feedbacks.
Decarbonization of Australia’s Energy System: Integrated Modelling of the Transformation of Electricity, Transportation, and Industrial Sectors
Jul 2020
Publication
To achieve the Paris Agreement’s long-term temperature goal current energy systems must be transformed. Australia represents an interesting case for energy system transformation modelling: with a power system dominated by fossil fuels and specifically with a heavy coal component there is at the same time a vast potential for expansion and use of renewables. We used the multi-sectoral Australian Energy Modelling System (AUSeMOSYS) to perform an integrated analysis of implications for the electricity transport and selected industry sectors to the mid-century. The state-level resolution allows representation of regional discrepancies in renewable supply and the quantification of inter-regional grid extensions necessary for the physical integration of variable renewables. We investigated the impacts of different CO2 budgets and selected key factors on energy system transformation. Results indicate that coal-fired generation has to be phased out completely by 2030 and a fully renewable electricity supply achieved in the 2030s according to the cost-optimal pathway implied by the 1.5 °C Paris Agreement-compatible carbon budget. Wind and solar PV can play a dominant role in decarbonizing Australia’s energy system with continuous growth of demand due to the strong electrification of linked energy sectors.
Constrained Extended Kalman Filter Design and Application for On-line State Estimation of High-order Polymer Electrolyte Membrane Fuel Cell Systems
Jun 2021
Publication
In this paper an alternative approach to extended Kalman filtering (EKF) for polymer electrolyte membrane fuel cell (FC) systems is proposed. The goal is to obtain robust real-time capable state estimations of a high-order FC model for observer applications mixed with control or fault detection. The introduced formulation resolves dependencies on operating conditions by successive linearization and constraints allowing to run the nonlinear FC model at significantly lower sampling rates than with standard approaches. The proposed method provides state estimates for challenging operating conditions such as shut-down and start-up of the fuel cell for which the unconstrained EKF fails. A detailed comparison with the unscented Kalman filter shows that the proposed EKF reconstructs the outputs equally accurate but nine times faster. An application to measured data from an FC powered passenger car is presented yielding state estimates of a real FC system which are validated based on the applied model.
Solid Air Hydrogen Liquefaction, the Missing Link of the Hydrogen Economy
Mar 2023
Publication
The most challenging aspect of developing a green hydrogen economy is long-distance oceanic transportation. Hydrogen liquefaction is a transportation alternative. However the cost and energy consumption for liquefaction is currently prohibitively high creating a major barrier to hydrogen supply chains. This paper proposes using solid nitrogen or oxygen as a medium for recycling cold energy across the hydrogen liquefaction supply chain. When a liquid hydrogen (LH2) carrier reaches its destination the regasification process of the hydrogen produces solid nitrogen or oxygen. The solid nitrogen or oxygen is then transported in the LH2 carrier back to the hydrogen liquefaction facility and used to reduce the energy consumption cooling gaseous hydrogen. As a result the energy required to liquefy hydrogen can be reduced by 25.4% using N2 and 27.3% using O2. Solid air hydrogen liquefaction (SAHL) can be the missing link for implementing a global hydrogen economy.
Reduction of Iron Oxides with Hydrogen - A Review
Aug 2019
Publication
This review focuses on the reduction of iron oxides using hydrogen as a reducing agent. Due to increasing requirements from environmental issues a change of process concepts in the iron and steel industry is necessary within the next few years. Currently crude steel production is mainly based on fossil fuels and emitting of the climate-relevant gas carbon dioxide is integral. One opportunity to avoid or reduce greenhouse gas emissions is substituting hydrogen for carbon as an energy source and reducing agent. Hydrogen produced via renewable energies allows carbon-free reduction and avoids forming harmful greenhouse gases during the reduction process. The thermodynamic and kinetic behaviors of reduction with hydrogen are summarized and discussed in this review. The effects of influencing parameters such as temperature type of iron oxide grain size etc. are shown and compared with the reduction behavior of iron oxides with carbon monoxide. Different methods to describe the kinetics of the reduction progress and the role of the apparent activation energy are shown and proofed regarding their plausibility.
Repurposing Fischer-Tropsch and Natural Gas as Bridging Technologies for the Energy Revolution
Jun 2022
Publication
Immediate and widespread changes in energy generation and use are critical to safeguard our future on this planet. However while the necessity of renewable electricity generation is clear the aviation transport and mobility chemical and material sectors are challenging to fully electrify. The age-old Fischer-Tropsch process and natural gas industry could be the bridging solution needed to accelerate the energy revolution in these sectors – temporarily powering obsolete vehicles acting as renewable energy’s battery supporting expansion of hydrogen fuel cell technologies and the agricultural and waste sectors as they struggle to keep up with a full switch to biofuels. Natural gas can be converted into hydrogen synthetic natural gas or heat during periods of low electricity demand and converted back to electricity again when needed. Moving methane through existing networks and converting it to hydrogen on-site at tanking stations also overcomes hydrogen distribution storage problems and infrastructure deficiencies. Useful co-products include carbon nanotubes a valuable engineering material that offset emissions in the carbon nanotube and black industries. Finally excess carbon can be converted back into syngas if desired. This flexibility and the compatibility of natural gas with both existing and future technologies provides a unique opportunity to rapidly decarbonise sectors struggling with complex requirements.
Establishment of Austria’s First Regional Green Hydrogen Economy: WIVA P&G HyWest
Apr 2023
Publication
The regional parliament of Tyrol in Austria adopted the climate energy and resources strategy “Tyrol 2050 energy autonomous” in 2014 with the aim to become climate neutral and energy autonomous. “Use of own resources before others do or have to do” is the main principle within this long-term strategic approach in which the “power on demand” process is a main building block and the “power-to-hydrogen” process covers the intrinsic lack of a long-term large-scale storage of electricity. Within this long-term strategy the national research and development (R&D) flagship project WIVA P&G HyWest (ongoing since 2018) aims at the establishment of the first sustainable business-case-driven regional green hydrogen economy in central Europe. This project is mainly based on the logistic principle and is a result of synergies between three ongoing complementary implementation projects. Among these three projects to date the industrial research within “MPREIS Hydrogen” resulted in the first green hydrogen economy. One hydrogen truck is operational as of January 2023 in the region of Tyrol for food distribution and related monitoring studies have been initiated. To fulfil the logistic principle as the main outcome another two complementary projects are currently being further implemented.
Just Energy Transition: Learning from the Past for a More Just and Sustainable Hydrogen Transition in West Africa
Dec 2022
Publication
The rising demand for energy and the aim of moving away from fossil fuels and to low-carbon power have led many countries to move to alternative sources including solar energy wind geothermal energy biomass and hydrogen. Hydrogen is often considered a “missing link” in guaranteeing the energy transition providing storage and covering the volatility and intermittency of renewable energy generation. However due to potential injustice with regard to the distribution of risks benefits and costs (i.e. in regard to competing for land use) the large-scale deployment of hydrogen is a contested policy issue. This paper draws from a historical analysis of past energy projects to contribute to a more informed policy-making process toward a more just transition to the hydrogen economy. We perform a systematic literature review to identify relevant conflict factors that can influence the outcome of hydrogen energy transition projects in selected Economic Community of West African States countries namely Nigeria and Mali. To better address potential challenges policymakers must not only facilitate technology development access and market structures for hydrogen energy policies but also focus on energy access to affected communities. Further research should monitor hydrogen implementation with a special focus on societal impacts in producing countries.
Natural Iron Ores for Large-scale Thermochemical Hydrogen and Energy Storage
Jun 2022
Publication
A stable energy supply will require balancing the fluctuations of renewable energy generation due to the transition to renewable energy sources. Intraday and seasonal storage systems are often limited to local geographical or infrastructural circumstances. This study experimentally verifies the application of inexpensive and abundant natural iron ores for energy storage with combined hydrogen and heat release. The incorporated iron oxides are reduced with hydrogen from electrolysis to store energy in chemically bonded form. The on–demand reoxidation releases either pure hydrogen or high-temperature heat as valuable products. Natural iron ores as storage material are beneficial as the specific costs are lower by an order of magnitude compared to synthetic iron oxide-based materials. Suitable iron ores were tested in TG analysis and in a 1 kW fixed-bed reactor. Siderite a carbonate iron ore was verified as promising candidate as it shows significantly lower reaction temperatures and twice the storage capacity over other commercial iron ores such as ilmenite. The specific storage costs are as low as 80–150 $ per MWh hydrogen stored based on the experimental in-situ tests. The experimentally determined volumetric energy storage capacity for the bulk material was 1.7 and 1.8 MWh m− 3 for hydrogen and heat release respectively. The raw siderite ore was stable for over 50 consecutive cycles at operating temperatures of 500–600 ◦C in in-situ lifetime tests. The combination of high abundance low price and reasonable capacity can thus result in very low specific energy storage costs. The study proofs that suitable natural iron ores are an interesting economic solution for large-scale and seasonal energy storage systems.
A Bird’s-Eye View on Polymer-Based Hydrogen Carriers for Mobile Applications
Oct 2022
Publication
Globally reducing CO2 emissions is an urgent priority. The hydrogen economy is a system that offers long-term solutions for a secure energy future and the CO2 crisis. From hydrogen production to consumption storing systems are the foundation of a viable hydrogen economy. Each step has been the topic of intense research for decades; however the development of a viable safe and efficient strategy for the storage of hydrogen remains the most challenging one. Storing hydrogen in polymer-based carriers can realize a more compact and much safer approach that does not require high pressure and cryogenic temperature with the potential to reach the targets determined by the United States Department of Energy. This review highlights an outline of the major polymeric material groups that are capable of storing and releasing hydrogen reversibly. According to the hydrogen storage results there is no optimal hydrogen storage system for all stationary and automotive applications so far. Additionally a comparison is made between different polymeric carriers and relevant solid-state hydrogen carriers to better understand the amount of hydrogen that can be stored and released realistically.
Hydrogen Deep Ocean Link: A Global Sustainable Interconnected Energy Grid
Mar 2022
Publication
The world is undergoing a substantial energy transition with an increasing share of intermittent sources of energy on the grid which is increasing the challenges to operate the power grid reliably. An option that has been receiving much focus after the COVID pandemic is the development of a hydrogen economy. Challenges for a hydrogen economy are the high investment costs involved in compression storage and long-distance transportation. This paper analyses an innovative proposal for the creation of hydrogen ocean links. It intends to fill existing gaps in the creation of a hydrogen economy with the increase in flexibility and viability for hydrogen production consumption compression storage and transportation. The main concept behind the proposals presented in this paper consists of using the fact that the pressure in the deep sea is very high which allows a thin and cheap HDPE tank to store and transport large amounts of pressurized hydrogen in the deep sea. This is performed by replacing seawater with pressurized hydrogen and maintaining the pressure in the pipes similar to the outside pressure. Hydrogen Deep Ocean Link has the potential of increasing the interconnectivity of different regional energy grids into a global sustainable interconnected energy system.
State-of-the-art Expansion Planning of Integrated Power, Natural Gas, and Hydrogen Systems
Apr 2022
Publication
Renewable hydrogen is considered key in the transition towards a carbon-neutral future. This is due to its spatio-temporal storage and sector coupling potential which has seen it referred to as energy vector. However many unresolved issues remain regarding hydrogen's large-scale deployment e.g. least-cost production optimal facility siting and overall implications on power and energy systems. Expansion planning provides an option to study these issues in the holistic context of energy systems. To this end this article presents a comprehensive review on state-of-the-art expansion planning models that consider integrated power natural gas and hydrogen systems. We cluster the existing literature in terms of modelling themes and scope study the applied systematic modelling characteristics and conduct an in-depth analysis of the technical model features regarding hydrogen technologies and natural gas infrastructure. Finally we identify and discuss research gaps in the existing literature.
Simulation-Assisted Determination of the Start-Up Time of a Polymer Electrolyte Fuel Cell
Nov 2021
Publication
Fuel starvation is a major cause of anode corrosion in low temperature polymer electrolyte fuel cells. The fuel cell start-up is a critical step as hydrogen may not yet be evenly distributed in the active area leading to local starvation. The present work investigates the hydrogen distribution and risk for starvation during start-up and after nitrogen purge by extending an existing computational fluid dynamic model to capture transient behavior. The results of the numerical model are compared with detailed experimental analysis on a 25 cm2 triple serpentine flow field with good agreement in all aspects and a required time step size of 1 s. This is two to three orders of magnitude larger than the time steps used by other works resulting in reasonably quick calculation times (e.g. 3 min calculation time for 1 s of experimental testing time using a 2 million element mesh).
Hydrogen Production by Methane Pyrolysis in Molten Binary Copper Alloys
Sep 2023
Publication
The utilization of hydrogen as an energy carrier and reduction agent in important industrial sectors is considered a key parameter on the way to a sustainable future. Steam reforming of methane is currently the most industrially used process to produce hydrogen. One major drawback of this method is the simultaneous generation of carbon dioxide. Methane pyrolysis represents a viable alternative as the basic reaction produces no CO2 but solid carbon besides hydrogen. The aim of this study is the investigation of different molten copper alloys regarding their efficiency as catalytic media for the pyrolysis of methane in an inductively heated bubble column reactor. The conducted experiments demonstrate a strong influence of the catalyst in use on the one hand on the conversion rate of methane and on the other hand on the properties of the produced carbon. Optimization of these parameters is of crucial importance to achieve the economic competitiveness of the process.
Refurbishment of Natural Gas Pipelines towards 100% Hydrogen—A Thermodynamic-Based Analysis
Dec 2022
Publication
Hydrogen is a key enabler of a sustainable society. Refurbishment of the existing natural gas infrastructure for up to 100% H2 is considered one of the most energy- and resource-efficient energy transportation methods. The question remains whether the transportation of 100% H2 with reasonable adaptions of the infrastructure and comparable energy amounts to natural gas is possible. The well-known critical components for refurbishment such as increased compressor power reduced linepack as well as pipeline transport efficiencies and their influencing factors were considered based on thermodynamic calculations with a step-by-step overview. A H2 content of 20–30% results in comparable operation parameters to pure natural gas. In addition to transport in pipelines decentralized H2 production will also play an important role in addressing future demands.
Green Hydrogen-Based Direct Reduction for Low-Carbon Steelmaking
May 2020
Publication
The European steel industry aims at a CO2 reduction of 80–95% by 2050 ensuring that Europe will meet the requirements of the Paris Agreement. As the reduction potentials of the current steelmaking routes are low the transfer toward breakthrough-technologies is essential to reach these goals. Hydrogen-based steelmaking is one approach to realize CO2-lean steelmaking. Therefore the natural gas (NG)-based direct reduction (DR) acts as a basis for the first step of this transition. The high flexibility of this route allows the gradual addition of hydrogen and in a long-term view runs the process with pure hydrogen. Model-based calculations are performed to assess the possibilities for injecting hydrogen. Therefore NG- and hydrogen-based DR models are developed to create new process know-how and enable an evaluation of these processes in terms of energy demand CO2-reduction potentials and so on. The examinations show that the hydrogen-based route offers a huge potential for green steelmaking which is strongly depending on the carbon footprint of the electricity used for the production of hydrogen. Only if the carbon intensity is less than about 120 g CO2 kWh1 the hydrogen-based process emits less CO2 than the NG-based DR process.
The Economics and the Environmental Benignity of Different Colors of Hydrogen
Feb 2022
Publication
Due to the increasing greenhouse gas emissions as well as due to the rapidly increasing use of renewable energy sources in the electricity generation over the last years interest in hydrogen is rising again. Hydrogen can be used as a storage for renewable energy balancing the whole energy systems and contributing to the decarbonization of the energy system especially of the industry and the transport sector. The major objective of this paper is to discuss various ways of hydrogen production depending on the primary energy sources used. Moreover the economic and environmental performance of three major hydrogen colors as well as major barriers for faster deployment in fuel cell vehicles are analyzed. The major conclusion is that the full environmental benefits of hydrogen use are highly dependent on the hydrogen production methods and primary sources used. Only green hydrogen with electricity from wind PV and hydro has truly low emissions. All other sources like blue hydrogen with CCUS or electrolysis using the electricity grid have substantially higher emissions coming close to grey hydrogen production. Another conclusion is that it is important to introduce an international market for hydrogen to lower costs and to produce hydrogen where conditions are best. Finally the major open question remaining is whether e including all external costs of all energy carriers hydrogen of any color may become economically competitive in any sector of the energy system. The future success of hydrogen is very dependent on technological development and resulting cost reductions as well as on future priorities and the corresponding policy framework. The policy framework should support the shift from grey to green hydrogen.
Achieving Carbon-neutral Iron and Steelmaking in Europe Through the Deployment of Bioenergy with Carbon Capture and Storage
Jan 2019
Publication
The 30 integrated steel plants operating in the European Union (EU) are among the largest single-point CO2 emitters in the region. The deployment of bioenergy with carbon capture and storage (bio-CCS) could significantly reduce their emission intensities. In detail the results demonstrate that CO2 emission reduction targets of up to 20% can be met entirely by biomass deployment. A slow CCS technology introduction on top of biomass deployment is expected as the requirement for emission reduction increases further. Bio-CCS could then be a key technology particularly in terms of meeting targets above 50% with CO2 avoidance costs ranging between €60 and €100 tCO2−1 at full-scale deployment. The future of bio-CCS and its utilisation on a larger scale would therefore only be viable if such CO2 avoidance cost were to become economically appealing. Small and medium plants in particular would economically benefit from sharing CO2 pipeline networks. CO2 transport however makes a relatively small contribution to the total CO2 avoidance cost. In the future the role of bio-CCS in the European iron and steelmaking industry will also be influenced by non-economic conditions such as regulations public acceptance realistic CO2 storage capacity and the progress of other mitigation technologies.
Assessment and Recommendations for a Fossil Free Future for Track Work Machinery
Oct 2021
Publication
Current railway track work machinery is mainly operated with diesel fuel. As a result track maintenance of Austrian Federal Railways (OeBB) amounts to nearly 9000 t CO2 equivalent per year according to calculations from Graz University of Technology. OeBB’s total length of railway lines only accounts for 0.56% of the world’s length of lines. This indicates huge potential for mitigating greenhouse gas emissions considering the need for track maintenance worldwide. Environmental concerns have led to the introduction of alternative drives in the transport sector. Until now R&D (Research & Development) of alternative propulsion technologies for track work machinery has been widely neglected. This paper examines the possibility of achieving zero direct emissions during maintenance and construction work in railways by switching to alternative drives. The goal is to analyze alternative propulsion solutions arising from the transport sector and to assess their applicability to track work machinery. Research results together with a calculation tool show that available battery technology is recommendable for energy demands lower than 300 kWh per construction shift. Hydrogen fuel cell technology is an alternative for energy demands higher than 800 kWh. For machinery with energy requirements in between enhancements in battery technology are necessary and desirable for the coming years.
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