7 results on '"Järvinen, Lauri"'
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2. Experimental study of alkaline water electrolyzer performance and frequency behavior under high frequency dynamic operation.
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Järvinen, Lauri, Puranen, Pietari, Ruuskanen, Vesa, Kosonen, Antti, Kauranen, Pertti, Ahola, Jero, and Chatzichristodoulou, Christodoulos
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THYRISTORS , *ELECTRIC current rectifiers , *ELECTROLYTIC cells , *GREEN fuels , *LOW voltage systems , *WATER use , *WATER electrolysis - Abstract
Industrial water electrolyzers mainly use old thyristor-based rectifiers to obtain the DC current required to run because of the low voltage level and high current requirements of the processes. These rectifiers cause significant ripple in the electrolyzer input current, leading to dynamic operation of the electrolyzer. Even though industrial-scale water electrolyzers are operated under such dynamic conditions, the effect on the electrolyzer performance is not well explored. In this study, current measurements from an industrial alkaline electrolyzer plant were used to define the common current ripple amplitude and frequency caused by the thyristor-based rectification. Based on the parameters obtained, laboratory measurements were conducted using an alkaline water electrolyzer to define the power losses incurred at various ripple amplitudes and frequencies. Additionally, the linearization of the electrolyzer current–voltage behavior as a function of frequency was studied using two electrode sets made of different materials. The laboratory measurements carried out in the study show that the ripple amplitude has a significant effect on increasing the losses, whereas the ripple frequency counteracts this. Thus, dynamic operation can have a large impact on losses, especially at partial loads, where the ripple current amplitudes increase significantly when using thyristor rectifiers. Lastly, the frequencies where the electrolyzer starts to behave linearly were observed to be at 68 Hz with the first electrode set and at 5 Hz with the second one. The considerable difference between the electrode sets indicates that the electrode materials and microstructure play a significant role in defining the electrolyzer frequency behavior. Because common thyristor-based power delivery systems operate at 300 Hz or 600 Hz, the results also imply that when modeling these systems, a linear model can be used for the electrolyzer to simplify the simulation. [Display omitted] • Large amplitude current ripple on alkaline electrolyzers is studied. • Ripple amplitude increases power losses, while frequency counteracts it. • As ripple frequency is increased, the electrolyzer starts to behave linearly. • The linear slope is determined purely based on the impedance. • At high frequencies, power usage can be determined from EIS measurement. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Automized parametrization of PEM and alkaline water electrolyzer polarisation curves.
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Järvinen, Lauri, Puranen, Pietari, Kosonen, Antti, Ruuskanen, Vesa, Ahola, Jero, Kauranen, Pertti, and Hehemann, Michael
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ELECTROLYTIC cells , *WATER currents , *WATER electrolysis , *LITERATURE reviews , *MISSING data (Statistics) - Abstract
A comprehensive literature review of current water electrolyzer modelling research was conducted and presented models critically evaluated. Based on the literature review this paper presents an open-source MATLAB toolbox for water electrolyzer polarisation curve parametrization and modelling. The modelling capabilities of the tooling were verified using measured PEM and alkaline water electrolyzer polarisation data. As real-world measurement data is rarely ideal, tests were also conducted using suboptimal data, first with data sets that have a low number of measurement points and secondly with data sets that have low or high current densities missing. The tooling is shown to work with a wide variety of use cases and provides an automated method for modelling and parametrization of electrolyzer polarisation curves. • Critical review of the water electrolyzer polarisation curve modelling is conducted. • Open source MATLAB toolbox for automated parametrization of models is presented. • Measured alkaline and PEM water electrolyzer data is used to verify fit accuracy. • Data sets of variable quality are used to verify fitting robustness. [ABSTRACT FROM AUTHOR]
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- 2022
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4. Off-grid solar PV–wind power–battery–water electrolyzer plant: Simultaneous optimization of component capacities and system control.
- Author
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Ibáñez-Rioja, Alejandro, Järvinen, Lauri, Puranen, Pietari, Kosonen, Antti, Ruuskanen, Vesa, Hynynen, Katja, Ahola, Jero, and Kauranen, Pertti
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BATTERY storage plants , *WIND power , *PHOTOVOLTAIC power generation , *POWER resources , *HYDROGEN production , *OPERATING costs , *WIND power plants - Abstract
Green hydrogen production systems will play an important role in the energy transition from fossil-based fuels to zero-carbon technologies. This paper investigates a concept of an off-grid alkaline water electrolyzer plant integrated with solar photovoltaic (PV), wind power, and a battery energy storage system (BESS). The operation of the plant is simulated over 30 years with 5 min time resolution based on measured power generation data collected from a solar photovoltaic installation and a wind farm located in southeastern Finland. Levelized cost of hydrogen (LCOH) is calculated based on the capital expenditures (CAPEX), the operating expenses (OPEX), and the respective learning curves for each of the components. Component degradation and replacements during the operational lifetime are included in the model, and the capacity of the components and the system control are simultaneously optimized to obtain the minimum LCOH. A sensitivity analysis performed over different installation years and discount rates reveals that for the off-grid alkaline system, the implementation of a wind farm as the sole power supply is the most economical solution until the installation years 2035–2040. Solar PV and a BESS are found to increase the full-load hours of the electrolyzer and reduce the electricity curtailed in the off-grid plant to less than 8%. However, with the current component prices and the climate in the studied region, they are not economically beneficial. It is found that the cost of hydrogen can be reduced to 2 €/kg by the year 2030. • Optimal control and component capacities for a green hydrogen production plant. • Simulations use measured power from a solar PV installation and a wind farm. • Levelized cost of hydrogen is less than 2 €/kg by the year 2030. • Purely wind based system is the most cost-effective solution until the years 2035–2040. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Simulation methodology for an off-grid solar–battery–water electrolyzer plant: Simultaneous optimization of component capacities and system control.
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Ibáñez-Rioja, Alejandro, Puranen, Pietari, Järvinen, Lauri, Kosonen, Antti, Ruuskanen, Vesa, Ahola, Jero, and Koponen, Joonas
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BATTERY storage plants , *PARTICLE swarm optimization , *HYDROGEN production , *MATHEMATICAL optimization , *SOLAR batteries , *INDUSTRIAL costs - Abstract
The capacity of each component in an off-grid water electrolyzer hydrogen production plant integrated with solar photovoltaics and a battery energy storage system represents a significant factor affecting the viability and reliability of the system. This paper describes a novel method that optimizes simultaneously the component capacities and finite-state machine based control of the system to minimize the cost of green hydrogen production. The components and control in the system are referenced to a proton exchange membrane water electrolyzer stack with a fixed nominal power of 4.5 kW. The end results are thus scalable by changing the nominal power of the electrolyzer. Simulations are carried out based on data collected from a residential solar photovoltaic installation with 300 s time resolution. Optimization of the system is performed with particle swarm optimization algorithm. A sensitivity analysis performed over the prices of the different components reveals that the price of the water electrolyzer has the greatest impact on the green hydrogen production cost. It is found that the price of the battery has to be below 0.3 €/Wh to become a feasible solution as overnight energy storage. • System components and control are optimized simultaneously using PSO algorithm. • Simulations are based on data collected from an existing solar PV installation. • Electrolyzer price has the strongest effect on off-grid hydrogen production cost. • Overnight hydrogen production becomes economic below 0.3 €/Wh battery system price. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Sensitivity analysis of the process conditions affecting the shunt currents and the SEC in an industrial-scale alkaline water electrolyzer plant.
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Sakas, Georgios, Ibáñez-Rioja, Alejandro, Pöyhönen, Santeri, Järvinen, Lauri, Kosonen, Antti, Ruuskanen, Vesa, Kauranen, Pertti, and Ahola, Jero
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THERMODYNAMICS , *PLANT-water relationships , *SENSITIVITY analysis , *ELECTROCHEMICAL analysis , *AQUATIC plants - Abstract
Bipolar configuration electrochemical stacks with a common or circulating electrolyte supply usually embody a high amount of shunt currents that escape from the main current path to the manifold nozzles. This paper suggests a novel and simplified semiempirical model to reasonably predict the total shunt currents in industrial alkaline water electrolyzers (AWE). The aim of the study is to perform a sensitivity analysis of the model parameters and the process conditions that affect the shunt currents and the plant's specific energy consumption (SEC), and to determine the most important ones by analyzing the thermodynamic and fluidic properties of the stack. An in-house MATLAB dynamic energy and mass balance model of an industrial 3 M W , 16 b a r AWE plant process was developed. The semiempirical dynamic process model is updated with the essential shunt currents and electrochemical, fluidic, and circulation impurity models. The study revealed the influence of the supplied current, the electrolyte temperature, the process pressure, the electrolyte flow rate, and the potassium hydroxide concentration on the shunt currents and the plant's SEC. • Simulation of a validated 3 MW industrial-scale AWE semi-empirical transient model. • Sensitivity analysis of the process conditions affecting the shunt currents in bipolar-configuration stacks. • Effect of the current supply, stack temperature, and electrolyte flow rate on the plant SEC. • Plant model parametrization and uncertainty analysis for the electrochemical model. • At partial loads, the shunt currents are the major source of energy loss in the system. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Neo-Carbon Food concept: A pilot-scale hybrid biological–inorganic system with direct air capture of carbon dioxide.
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Ruuskanen, Vesa, Givirovskiy, Georgy, Elfving, Jere, Kokkonen, Petteri, Karvinen, Aku, Järvinen, Lauri, Sillman, Jani, Vainikka, Miika, and Ahola, Jero
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CARBON dioxide , *HYBRID systems , *WATER electrolysis , *ENERGY consumption , *HYDROGEN production - Abstract
The pace at which the human population is growing raises serious concerns related to food security while at the same time conventional agriculture-based food production is becoming a major cause of environmental pollution and greenhouse gas emissions. Numerous solutions have been proposed to boost food production among which edible microbial biomass is considered a promising alternative to conventional sources of food and feed with lower environmental footprint. This work introduces the Neo-Carbon Food concept that is a pilot-scale hybrid biological–inorganic process suitable for the production of microbial biomass. The concept includes integrated hydrogen production by water electrolysis, direct air capture (DAC) of carbon dioxide, and its subsequent assimilation by autotrophic hydrogen-oxidizing bacteria (HOB). The hydrogen production with in situ electrolysis achieved specific energy consumption just below 100 kWh/kgH 2 while the specific energy consumption of DAC was around 20 kWh/kg CO 2. Image 1 • Microbial protein could be a sustainable source of protein. • A pilot-scale hybrid biological-inorganic system is presented. • Novel in situ water electrolysis stack is introduced. • Energy consumption of hydrogen production and direct air capture of CO2 is studied. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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