Applications & Pathways

Hydrogen consumption and mileage are important economic indicators of fuel cell vehicles. Hydrogen consumption is the fundamental reason that restricts mileage. Since there are few quantitative studies on hydrogen consumption during actual vehicle operation the high cost of hydrogen consumption in outdoor testing makes it impossible to guarantee the accuracy of the test. Therefore this study puts forward a test method based on the hydrogen consumption of fuel cell vehicles under CLTC-P operating conditions to test the hydrogen consumption of fuel cell vehicles per 100 km. Finally the experiment shows that the mileage calculated by hydrogen consumption has a higher consistency with the actual mileage. Based on this hydrogen consumption test method the hydrogen consumption can be accurately measured and the test time and cost can be effectively reduced.

With the clear adverse impacts of fossil fuel-based energy systems on the climate and environment ever-growing interest and rapid developments are taking place toward full or nearly full dependence on renewable energies in the next few decades. Estonia is a European country with large demands for electricity and thermal energy for district heating. Considering it as the case study this work explores the feasibility and full potential of optimally sized photovoltaic (PV) wind and PV/wind systems equipped with electric and thermal storage to fulfill those demands. Given the large excess energy from 100% renewable energy systems for an entire country this excess is utilized to first meet the district heating demand and then to produce hydrogen fuel. Using simplified models for PV and wind systems and considering polymer electrolyte membrane (PEM) electrolysis a genetic optimizer is employed for scanning Estonia for optimal installation sites of the three systems that maximize the fulfillment of the demand and the supply–demand matching while minimizing the cost of energy. The results demonstrate the feasibility of all systems fully covering the two demands while making a profit compared to selling the excess produced electricity directly. However the PV-driven system showed enormous required system capacity and amounts of excess energy with the limited solar resources in Estonia. The wind system showed relatively closer characteristics to the hybrid system but required a higher storage capacity by 75.77%. The hybrid PV/wind-driven system required a total capacity of 194 GW most of which belong to the wind system. It was also superior concerning the amount (15.05 × 109 tons) and cost (1.42 USD/kg) of the produced green hydrogen. With such full mapping of the installation capacities and techno-economic parameters of the three systems across the country this study can assist policymakers when planning different country-scale cogeneration systems.

We present a numerical simulation procedure for analyzing hydrogen oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blastfurnace considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF considered as a multiphase reactor treats the lump solids (sinter small coke pellets granular coke and iron ores) gas liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum mass chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kg per ton of hot metal (kg thm−1). Thus combined injections of varying concentrations of gaseous fuels with H2 O2 and CO2 are simulated with 220 kg thm−1 and 250 kg thm−1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of 60%. Finally we demonstrated that the net carbon utilization per ton of hot metal decreased 12%.

Hydrogen has the potential to decarbonize a variety of energy-intensive sectors including steel production. Using the life cycle assessment (LCA) methodology the state of the art is given for current hydrogen production with a focus on the hydrogen carbon footprint. Beside the state of the art the outlook on different European scenarios up to the year 2040 is presented. A case study of the transformation of steel production from coal-based towards hydrogen- and electricity-based metallurgy is presented. Direct reduction plants with integrated electric arc furnaces enable steel production which is almost exclusively based on hydrogen and electricity or rather on electricity alone if hydrogen stems from electrolysis. Thus an integrated steel site has a demand of 4.9 kWh of electric energy per kilogram of steel. The carbon footprint of steel considering a European sustainable development scenario concerning the electricity mix is 0.75 kg CO2eq/kg steel in 2040. From a novel perspective a break-even analysis is given comparing the use of natural gas and hydrogen using different electricity mixes. The results concerning hydrogen production presented in this paper can also be transferred to application fields other than steel.

This paper reviews the relationship between the production of steel and the environment as it stands today. It deals with raw material issues (availability scarcity) energy resources and generation of by-products i.e. the circular economy the anthropogenic iron mine and the energy transition. The paper also deals with emissions to air (dust Particulate Matter heavy metals Persistant Organics Pollutants) water and soil i.e. with toxicity ecotoxicity epidemiology and health issues but also greenhouse gas emissions i.e. climate change. The loss of biodiversity is also mentioned. All these topics are analyzed with historical hindsight and the present understanding of their physics and chemistry is discussed stressing areas where knowledge is still lacking. In the face of all these issues technological solutions were sought to alleviate their effects: many areas are presently satisfactorily handled (the circular economy—a historical’ practice in the case of steel energy conservation air/water/soil emissions) and in line with present environmental regulations; on the other hand there are important hanging issues such as the generation of mine tailings (and tailings dam failures) the emissions of greenhouse gases (the steel industry plans to become carbon-neutral by 2050 at least in the EU) and the emission of fine PM which WHO correlates with premature deaths. Moreover present regulatory levels of emissions will necessarily become much stricter.

This study proposes a data-driven methodology for modeling power and hydrogen generation of a sustainable energy converter. The wave and hydrogen production at different wave heights and wind speeds are predicted. Furthermore this research emphasizes and encourages the possibility of extracting hydrogen from ocean waves. By using the extracted data from the FLOW-3D software simulation and the experimental data from the special test in the ocean the comparison analysis of two data-driven learning methods is conducted. The results show that the amount of hydrogen production is proportional to the amount of generated electrical power. The reliability of the proposed renewable energy converter is further discussed as a sustainable smart grid application.

Energy consumption is essential for evaluating the competitiveness of fuel cell electric vehicles. A critical step in energy consumption measurement is measuring hydrogen consumption including the mass method the P/T method and the flowmeter method. The flowmeter method has always been a research focus because of its simple operation low cost and solid real-time performance. Current research has shown the accuracy of the flowmeter method under specific conditions. However many factors in the real scenario will influence the test result such as unintended vibration environment temperature and onboard hydrogen capacity calibration. On the other hand the short-cut method is also researched to replace the run-out method to improve test efficiency. To evaluate whether the flowmeter method basing on the short-cut method can genuinely reflect the hydrogen consumption of an actual vehicle we research and test for New European Driving Cycle (NEDC) and China Light-Duty Vehicle Test Cycle (CLTC) using the same vehicle. The results show that the short-cut method can save at least 50% of the test time compared with the run-out method. The error of the short-cut method based on the flowmeter for the NEDC working condition is less than 0.1% and for the CLTC working conditions is 8.12%. After adding a throttle valve and a 4L buffer tank the error is reduced to 4.76% from 8.12%. The test results show that hydrogen consumption measurement based on the flowmeter and short-cut method should adopt corresponding solutions according to the scenarios.

Power-to-X processes where renewable energy is converted into storable liquids or gases are considered to be one of the key approaches for decarbonizing energy systems and compensating for the volatility involved in generating electricity from renewable sources. In this context the production of “green” hydrogen and hydrogen-based derivatives is being discussed and tested as a possible solution for the energy-intensive industry sector in particular. Given the sharp ongoing increases in electricity and gas prices and the need for sustainable energy supplies in production systems non-energy-intensive companies should also be taken into account when considering possible utilization paths for hydrogen. This work focuses on the following three utilization paths: “hydrogen as an energy storage system that can be reconverted into electricity” “hydrogen mobility” for company vehicles and “direct hydrogen use”. These three paths are developed modeled simulated and subsequently evaluated in terms of economic and environmental viability. Different photovoltaic system configurations are set up for the tests with nominal power ratings ranging from 300 kWp to 1000 kWp. Each system is assigned an electrolyzer with a power output ranging between 200 kW and 700 kW and a fuel cell with a power output ranging between 5 kW and 75 kW. There are also additional variations in relation to the battery storage systems within these basic configurations. Furthermore a reference variant without battery storage and hydrogen technologies is simulated for each photovoltaic system size. This means that there are ultimately 16 variants to be simulated for each utilization path. The results show that these utilization paths already constitute a reasonable alternative to fossil fuels in terms of costs in variants with a suitable energy system design. For the “hydrogen as an energy storage system” path electricity production costs of between 43 and 79 ct/kWh can be achieved with the 750 kWp photovoltaic system. The “hydrogen mobility” is associated with costs of 12 to 15 ct/km while the “direct hydrogen use” path resulted in costs of 8.2 €/kg. Environmental benefits are achieved in all three paths by replacing the German electricity mix with renewable energy sources produced on site or by substituting hydrogen for fossil fuels. The results confirm that using hydrogen as a storage medium in manufacturing companies could be economically and environmentally viable. These results also form the basis for further studies e.g. on detailed operating strategies for hydrogen technologies in scenarios involving a combination of multiple utilization paths. The work also presents the simulation-based method developed in this project which can be transferred to comparable applications in further studies.

Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed and the particles were degraded during the reduction. Finally sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore the variation of activation energy value was smoothed after heat treatment of hematite particles.

In contrast to sustainable aviation fuels for use in conventional combustion engines hydrogen-electric powertrains constitute a fundamentally novel approach that requires extensive effort from various engineering disciplines. A transient system analysis has been applied to a 500 kW shaft-power-class powertrain. The model was fed with high-level system requirements to gain a fundamental understanding of the interaction between sub-systems and components. Transient effects such as delays in pressure build up heat transfer and valve operation substantially impact the safe and continuous operation of the propulsion system throughout a typical mission profile which is based on the Daher TBM850. The lumped-parameters network solver provides results quickly which are used to derive requirements for subsystems and components which support their in-depth future development. E.g. heat exchanger transfer rates and pressure drop of the motor's novel hydrogen cooling system are established. Furthermore improvements to the system architecture such as a compartmentalization of the tank are identified.