Hydrogen Supply Research Articles

Parameter Analysis of Anion Exchange Membrane Water Electrolysis System by Numerical Simulation

Anion exchange membrane electrolysis, which combines the advantages of both alkaline electrolysis and proton-exchange membrane electrolysis, is a promising technology to reduce the cost of hydrogen production. The present work focused on the study of the electrochemical phenomena of AEM electrolysis and the investigation of the key factors of the AEM hydrogen production system. The numerical model is established according to electrochemical reactions, polarization phenomena, and the power consumption of the balance of plant components of the system. The effects of operation parameters, including the temperature and hydrogen pressure of the electrolyzer, electrolyte concentration, and hydrogen supply pressure on the energy efficiency are studied. The basic electrochemical phenomena of AEM water electrolysis cells are analyzed by simulations of reversible potential and activation, and ohmic and concentration polarizations. The results reveal that increasing the operating temperature and hydrogen production pressure of the AEM electrolyzer has positive effects on the system’s efficiency. By conducting an optimization analysis of the electrolyzer temperature—which uses the heat energy generated by the electrochemical reaction of the electrolyzer to minimize the power consumption of the electrolyte pump and heater—the AEM system with an electrolyzer operating at 328 K and 30 bar can deliver hydrogen of pressure up to 200 bar under an energy efficiency of 56.4%.

Research on Deoxygenation Pyrolysis of Larch Based on Microwave Heating

Aiming at problems such as low energy utilization efficiency and the high oxygen content of liquid products in the process of conventional biomass conversion to prepare liquid fuels, the deoxygenation pyrolysis technology route of larch based on microwave heating was proposed in this paper. Two kinds of calcium–iron composite oxygen carriers, including Ca2Fe2O5 with iron ore structure and CaFe2O4 with spinel structure, were successfully synthesized. The results showed that the selectivity of ideal products was improved under the action of single iron-based oxygen carriers; however, the deoxygenation effect was undesirable. Under the action of CaFe2O4, the selectivity of aromatics was increased to 27.17% and the selectivity of phenols was decreased to 36.46%, which mainly existed in the form of O1P with low oxygen content. The oxygen content of bio-oil was reduced to 27.70% and the calorific value was increased to 29.05 MJ/kg, thus leading to a great improvement in the quality of liquid products. After the pyrolysis reaction, the Fe2P3/2 XPS peak of CaFe2O4 shifted to a higher binding energy and was characterized as higher valence of iron oxide, which proved its “oxygen grabbing” capacity in microwave pyrolysis. The deoxygenation conversion of larch without an external hydrogen supply was achieved.

New Study Mapping Hydrogen Pipelines Between Poland And Ukraine

Abstract This study focuses on developing the appropriate infrastructure between Poland and Ukraine to enable the import and export of hydrogen, ensuring EU consumers have access to sufficient quantities. Such infrastructure is crucial in achieving climate neutrality goals, as it will serve as a key transit area for hydrogen, thereby contributing to sustainable energy development in Europe. To address this, the article reviews existing solutions for hydrogen transportation via pipelines and proposes mapping the hydrogen transportation system between Poland and Ukraine. Specifically, it examines the possibility of constructing a hydrogen pipeline from Ukraine to Poland, with potential connections to the designated hydrogen supply corridors of the European Hydrogen Backbone (EHB) infrastructure. Through the use of Python-created maps and algorithms, the study demonstrates how a hydrogen supply corridor can be established between Poland and Ukraine and effectively integrated with the broader EU hydrogen supply corridors. Furthermore, the article discusses the complex challenges involved in building hydrogen pipelines, particularly the unification of design standards between EU and non-EU countries. Equally critical is the management of hydrogen export and import, given that no platform currently exists between Poland and Ukraine for this purpose. The integration of hydrogen pipeline transport systems is thus highlighted as a matter of international importance, providing a platform for cooperation between the two countries and facilitating the creation of a hydrogen corridor linked to the EU infrastructure. An original contribution of this study is the presentation of a map illustrating the potential corridor connecting the hydrogen pipeline systems between countries, along with the development of algorithms using Python, which open up possibilities for future expansion of the map.

Using magnesium hydride as the future dual-mode propellant for spacecraft: A simulation investigation

A dual-mode propulsion system stands as the important viable pathway for future multi-purpose deep space missions by the spacecraft, encompassing both nuclear thermal propulsion and nuclear electric propulsion. H2 and Mg emerge as potential mediums for nuclear thermal propulsion and nuclear electric propulsion, respectively, with the possibility of utilizing a single material, magnesium hydride (MgH2), to serve both purposes. However, how to release hydrogen completely and effectively in high hydrogen desorption pressure while retaining magnesium is the key problem. In this work, we proposed a novel MgH2 storage tank for zero gravity environments and investigated its hydrogen desorption process at high pressures of 4 ∼ 8 MPa using simulation, which is crucial for the hydrogen supply of nuclear thermal propulsion. We examined the effects of hydrogen desorption pressure, inlet temperature, and flow velocity of argon (Ar) on the desorption process. The simulation results indicated complete decomposition of MgH2 can be realized under 4 ∼ 8 MPa at 873 K. Moreover, the desorption pressure, inlet temperatures, and high flow velocities of Ar are suggested as 4 MPa, 773 ∼ 785 K, and 45 ∼ 100 m s−1 to achieve an average hydrogen desorption rate per unit thermal power of ≥ 20 mgH2 s−1. This work marks the first confirmation that MgH2 can decompose into H2 and Mg under high hydrogen desorption pressure at suitable thermal power, paving the way for its application as the hydrogen and Mg storage media in the dual-mode propulsion system of spacecraft.

Spatial feasibility prediction of green hydrogen scale-up in China under decarbonization policies: Based on improved diffusion model

Hydrogen production from renewable electrolysis is a suitable transformative technology for driving a cleaner energy mix, mitigating climate change, and achieving sustainable development and has been given the color value definition of "green hydrogen". However, this low-carbon technology is still in its infancy, and the pathways for expanding market supply have not been analyzed. To address the problems of unclear factors influencing the diffusion of green hydrogen technology innovation, unclear technology diffusion laws, and inaccurate predictions of regional green hydrogen production capacity under the goal of decarbonization policy, this work constructs a spatial assessment framework of the feasibility of low-carbon technology development in response to climate change on the basis of the theory of technological innovation systems, the improved technology diffusion model, and the feasibility of climate change spatial concepts to analyze and predict the diffusion law and regional green hydrogen production capacity of hydrogen production by renewable energy under the goal of carbon neutrality. The results of the study on the development of renewable hydrogen technology in China show that it follows the law of diffusion of low-carbon technologies in both the formation and growth stages. The diffusion of green hydrogen technology in the formation stage is slow, and the regional green hydrogen capacity in the near term cannot meet the decarbonization policy target demand in 2030. Before the spatial inflection point of technology diffusion feasibility, the demand-pull of the phase decarbonization policy target dominated the stability and sustainability of the green hydrogen supply market. After the inflection point, the internal growth of technology diffusion plays a key role in market diffusion and ultimately reaches a saturation value under the joint regulation of policy and the market to realize a carbon-neutral target capacity demand in 2060. The uncertainty of diffusion model parameters leads to anomalies in the feasibility space of technology diffusion, and risks such as overcapacity or insufficient demand in some regions may occur. Overall, this work provides a systematic assessment system for analyzing and predicting the pathways and characteristics of expanding renewable hydrogen production in specific regions under decarbonization policy objectives.

A prospective approach to the optimal deployment of a hydrogen supply chain for sustainable mobility in island territories: Application to Corsica

This study develops a framework for designing hydrogen supply chains (HSC) in island territories using Mixed Integer Linear Programming (MILP) with a multi-period approach. The framework minimizes system costs, greenhouse gas emissions, and a risk-based index. Corsica is used as a case study, with a Geographic Information System (GIS) identifying hydrogen demand regions and potential sites for production, storage, and distribution. The results provide an optimal HSC configuration for 2050, specifying the size, location, and technology while accounting for techno-economic factors. This work integrates the unique geographical characteristics of islands using a GIS-based approach, incorporates technology readiness levels, and utilizes renewable electricity from neighboring regions. The model proposes decentralized configurations that avoid hydrogen transport between grids, achieving a levelized cost of hydrogen (LCOH) of €8.54/kg. This approach offers insight into future options and incentive mechanisms to support the development of hydrogen economies in isolated territories.

Основные направления и инструменты политики низкоуглеродного развития Бразилии

Brazil has a strong potential to achieve national climate goals and can also be an important decarbonization partner for other countries, especially in the supply of green hydrogen and critical raw materials for the production of new climate- neutral technologies. This article highlights the main tools and policies for Brazilʼs decarbonization and identifies potential areas in which the country can not only achieve its nationally determined contributions (NDCs), but also ensure innovative green economic growth. Low carbon intensity energy sources can ensure a low carbon footprint for industrial products, which can make goods more attractive in the face of increasing requirements and the introduction of measures such as the European Unionʼs (EU) carbon border adjustment mechanism (CBAM). Extensive deployment of renewable energy creates opportunities for the country to produce sustainable hydrogen, which will be in demand both domestically and globally. The main challenge for Brazilʼs decarbonization is its extensive agriculture, as well as widespread deforestation, the rate of which increased under the Bolsonaro administration. For agricultural products,which make up a large share of exports, deforestation regulations like those adopted in the EU would be a real barrier and could close European and other markets. The min- ing and processing of critical raw materials could be a potential breakthrough for the countryʼs economic growth due to the widespread decarbonization of the global economy. The low carbon intensity of the countryʼs industry, including mining, due to renewable energy sources appears to be a significant advantage. Lulaʼs return has given the international community hope that, at least in forestry and agriculture, significant efforts can be expected from Brazil, including international support, financing, and auditing.

Key Process of Ethanol Hydrogen Donor Promoting the Conversion of Organic Matter in Sludge to Bio-Oil

To develop clean energy utilization of sewage sludge, this study investigated the conversion behavior of organics and energy in supercritical sludge-ethanol system. The influence of liquefied parameters on products distribution, hydrogen supply process of ethanol for sludge liquefaction, migration of organics, and energy transformation were investigated. Results indicated that ethanol acted as both a solvent and a hydrogen donor. It providing H⋅ to promote organics dissociation for bio-oil production through radical reactions. Formation of new products in bio-oil such as C20H38O2 and C20H38O2 may be caused by H⋅ generated from -OH and -CH in ethanol. The increase in dodecanes and hexadecanes in bio-oil may be formed by recombination of smaller radicals such as HO·, H·, CH3⋅, CH3CH2⋅ from dissociation of ethanol and organics. Additionally, energy migration process indicated that higher temperatures increased carbon content in bio-oil from 40.88 to 48.92%, decreased oxygen content from 48.6 to 39.56%, and raised the calorific value of bio-oil from 29.63 to 30.11 MJ/kg. Besides, approximately 74.14% of sludge energy transferred to bio-oil, while about 71.94% of oxygen moved to bio-char, reducing the calorific value of bio-char to 0.03 MJ/kg. Notably, about 240.5kg of bio-oil can be produced from 1t of sludge, reducing net carbon emissions by 43.583kg, and presenting a sustainable alternative to fossil fuels. This study innovatively investigated the dual role of ethanol for sludge liquefaction, providing an efficient and sustainable method for energy recovery from sludge.

Green certificates for optimizing low-carbon hydrogen supply chain

Green certificates for optimizing low-carbon hydrogen supply chain

A Study of Heat Recovery and Hydrogen Generation Systems for Methanol Engines

Biofuels are the most essential types of alternative fuels, which currently have significant potential to reduce CO2 emissions compared to fossil fuels. Methanol is a more efficient fuel than petrol due to its physicochemical properties, such as a higher latent heat of vaporization, research octane number, and heat of combustion of the fuel–air mixture. Also, biomethanol is cheaper than traditional petrol and diesel fuel for agricultural countries. The authors have proposed a new approach to improve the characteristics and efficiency of methanol diesel engines by using biomethanol mixed with hydrogen instead of pure biomethanol. Using a hydrogen–biomethanol mixture in modern engines is an effective method because hydrogen is a carbon-free, low-ignition, highest-flame-rate, high-octane fuel. A small quantity of hydrogen added to biomethanol and its combustion in an engine with a heat exchanger increases the combustion temperature and heat release, increases engine power, and reduces fuel consumption. This article presents experimental results of methanol combustion and a hydrogen-in-methanol mixture if hydrogen was retained due to the utilization of the heat of the exhaust gases. The tests were carried on a single-cylinder experimental engine with an injection of liquid methanol and gaseous hydrogen mixtures. The experiments showed that green hydrogen generated onboard the car due to the utilization of heat significantly reduced fuel costs of engines of vehicles and technological installations. It was established a hydrogen gaseous mixture addition of up to 5% by mass to methanol requires a corresponding change in the coefficient of excess air to λ = 1.25. Also, using an additional hydrogen mixture requires adjustment at the ignition moment in the direction of its decrease by 4–5 degrees of the engine crankshaft. Hydrogen gas mixture addition reduced methanol consumption, reaching a maximum reduction of 24%. The maximum increase in power was 30.5% based on experimental data. The reduction in the specified fuel consumption, obtained after experimental tests of the methanol research engine on the stand, can be implemented on the vehicle engines and technological installations equipped with an onboard heat recovery system. Such a system, due to the utilization of heat and the supply of additional hydrogen, can be implemented for engines that work on any alternative or traditional fuels.

Performance evaluation and energy management strategy of drone methanol reforming fuel cell hybrid power system: A case study

The performance of hydrogen production by methanol steam reforming and high temperature proton exchange membrane fuel cells on drone lacks the comparison of experimental data, resulting in the overall performance improvement of the system is difficult to evaluate. Therefore, the energy management strategy of methanol reforming high temperature proton exchange membrane fuel cell hybrid power system and state machine is designed and optimized. The performance of this system is analyzed and compared with the flight experiment data of a proton exchange membrane fuel cell hybrid UAV. The results show that the SOC of the system can be stabilized between 70 and 80 during the long cruise phase. The test results show that the maximum hydrogen storage mass density of the hydrogen supply system is increased by 67.6%. The flight time of the system under economic cruise flight of the drone is improved by 29.1%–44.9% with different quality of fuel. Under the maximum flight speed of a certain wind speed, the system can meet the flight requirements and increase the flight time by 31.9% and 17.6% respectively under the wind speed of 1.5 m/s and 4 m/s. Its flight time has been greatly improved, and it has great potential as a drone system.

Strategic supply and transportation planning of a supply chain for agricultural biomass to hydrogen and syngas

Strategic supply and transportation planning of agricultural biomass to hydrogen and syngas supply chain with inter-fuel and inter-biomass substitution was studied in this paper. The sourcing and transportation decision was modeled, according to bi-level optimization, where suppliers competed on supply capacity by maximizing their profits at minimum transportation and holding cost. Considering supply chain superstructure, dual biomass suppliers were modeled to supply a biofuel producer who produced two different types of biofuels. The supply planning was combined with transportation planning to minimize total supply chain costs. The results showed that the model was capable of finding optimum purchase and selling prices and production capacity, by maximizing inter-fuel and inter-biomass substitutability. Another key finding was that the proposed model was capable of finding optimum order allocation to both biomass suppliers in such a way that there was an equal profit distribution between suppliers and biofuel producers.

Designing a resilient hydrogen hub under disruption risks and non-stationary demand distribution

Hydrogen is a viable and sustainable energy alternative. It offers a solution to mitigate greenhouse gases and fortify energy security. However, its supply chain faces many uncertainties and challenges, including demand fluctuations and sourcing disruptions. This paper introduces an innovative two-stage stochastic model to plan hydrogen hub procurement, storage, and sales. In the first stage, the model optimises the order quantities by considering real-time inventory levels. This forward-thinking strategy aims to improve operational efficiency and adaptability. In the second stage, the model refines the hub operations by incorporating supplier resilience, exploration of alternative markets, emission considerations from each source, and terminal connection planning. Integrating these elements contributes to a comprehensive framework for robust hydrogen hub scheduling. This paper adopts a Benders decomposition algorithm to address the mathematical complexity of the model. This approach is necessary to ensure a smooth and efficient computational process. Empirical testing and validation of the developed model, along with the robustness of the solution methodology, emphasise its effectiveness in handling uncertainties and disruptions. This paper contributes to the existing literature by shedding light on critical facets of disruption management, supplier resilience, and emissions reduction within the hydrogen supply chain design.

Quantitative analysis of hydrogen leakage flow measurement and calculation in the on-board hydrogen system pipelines

The mass flow rate of hydrogen leakage directly affects hydrogen diffusion and concentration distribution. In this paper, a test platform was constructed to measure mass flow rates during hydrogen leakage in the supply pipelines of the on-board hydrogen system. Hydrogen leakage tests were conducted under two different conditions. Mass flow rates were measured for tube fittings with various loosening angles and hydrogen supply pressures. The data were then fitted to extrapolate mass flow rates of hydrogen leakage beyond the tested conditions. Additionally, mass flow rates were measured for hydrogen supply pipelines with small holes of different shapes and sizes. The effects of pipeline size, hydrogen supply pressure, hole shape, and size on the hydrogen leakage mass flow rate were analyzed. Hydrogen leakage flow coefficients were corrected, and the accuracy of three calculation methods for hydrogen leakage flow was compared and analyzed based on the test results. The results provide a foundation for future numerical simulation models of hydrogen leakage diffusion.

Comparative techno-economic assessment of renewable diesel production integrated with alternative hydrogen supply

The hydrodeoxygenation of triglycerides and fatty acids (HEFA) represents a well-established technological pathway for producing renewable drop-in fuels, such as renewable diesel, aviation fuel, or renewable light ends, like naphtha and LPG. A hydrogen supply is required, and the conventional method involves steam methane reforming (SMR) from natural gas. Both HEFA and SMR processes have been investigated in the literature separately. In this context, the goal of this work is to assess the hydrodeoxygenation process (HDO) of triglycerides/fatty acids integrated with hydrogen production. Two scenarios are compared by process simulation, equipment sizing, and economic analysis: one with traditional SMR (SC-A) and another with electrified SMR (SC–B), which is a recent alternative for hydrogen production with no natural gas. The HDO capacity was 6220 BPSD (38000 kg/h) of soybean oil, and the average yields for renewable diesel, naphtha, and LPG were 71.23 %-wt, 1.80 %-wt, and 5.87 %-wt, accordingly. Both scenarios were technical feasible and may be economically attractive. However, the grey hydrogen source was more profitable per its plant simplicity — although the CO2 taxation may impact its profitability.

Analysis of the co-hydrogenation process of coal tar and kitchen waste oil based on reaction kinetics model

Kitchen waste oil (KWO) and coal tar (CT) are two commonly used alternatives to crude oil for fuel production through hydrogenation. If these two raw materials can be co-hydrogenated, it will help broaden the company's sources of raw materials. Therefore, in order to reveal the positive and negative impacts of the co-hydrogenation process of these two materials and to conduct a quantitative analysis of these phenomena, co-hydrogenation experiments of CT and KWO were completed in this study. The reaction kinetics parameters of the co-hydrogenation reaction were calculated. Experiments have shown that co-hydrogenation with coal tar hydrogenation products (CTHP) can increase the hydrogenation efficiency of KWO by approximately 1.5%. This promoting effect is mainly attributed to the hydrogen-supplying properties of compounds such as tetralin and hexahydro naphthalene present in the CTHP. Through a combined model of reaction kinetics and thermodynamics, it is calculated that the activation energy of KWO hydrodeoxygenation under the action of catalysts is 50.936kJ·mol-1, while under the action of CTHP hydrogen supply, it is 148.429kJ·mol-1, and this promoting effect accounts for 19.3% of the total reaction (as deduced from comparing reaction rate constants). The experimental data presented in this paper and the calculated reaction parameters can provide a basis for design improvements in technology.

Whole system impacts of decarbonising transport with hydrogen: A Swedish case study

This study aims to carry out a techno-economic analysis of different hydrogen supply chain designs coupled with the Swedish electricity system to study the inter-dependencies between them. Both the hydrogen supply chain designs and the electricity system were parameterized with data for 2030. The supply chain designs comprehend centralised production, decentralised production, a combination of both, and with/without seasonal variation in hydrogen demand. The supply chain design is modelled to minimize the overall cost while meeting the hydrogen demands. The outputs of the supply chain model include the hydrogen refuelling stations' locations, the electrolyser's locations and their respective sizes as well as the operational schedule. The electricity system model shows that the average electricity prices in Sweden for zones SE1, SE2, SE3 and SE4 will be 4.28, 1.88, 8.21, and 8.19 €/MWh respectively. The electricity is mainly generated from wind and hydropower (around 42% each), followed by nuclear (14%), solar (2%) and then bio-energy (0.3%). In addition, the hydrogen supply chain design that leads to a lower overall cost is the decentralised design, with a cost of 1.48 and 1.68 €/kgH2 in scenarios without and with seasonal variation respectively. The seasonal variation in hydrogen demand increases the cost of hydrogen, regardless of the supply chain design.

Formation and evolution of coke of pyrolytic volatiles of low-rank coal on the carbon-based catalysts

The catalytic upgrading of coal pyrolysis volatiles is an effective technique to achieve clean and efficient conversion of low-rank coal. However, a major problem in this process is catalyst deactivation caused by coke deposition. This study investigated the catalytic cracking effect of activated carbon and metal-modified activated carbon on coal pyrolysis volatiles. It also explained the physical and chemical properties of coke and its formation mechanism related to volatile cracking. The results indicate that phenolic oils, pitch, oxygen-containing compounds, and polycyclic aromatics are linearly related to the coke deposited on the surface of carbon-based catalysts. These compounds act as precursors and are easily transformed into coke via cracking, deoxidation, crosslinking, and polycondensation reactions when the cracking rate of volatiles does not match the hydrogen supply rate. The micro-morphology of coke is primarily composed of amorphous carbon, which is mainly found in pores ranging from 0.50 to 5.00 nm and on the outer surface of carbon-based catalysts. The chemical structure of coke primarily consists of large aromatic clusters containing at least six benzene rings and oxygen-containing cross-linking compounds with a high degree of graphitization and a low number of carbon structural defects. This results in an increase in radical concentration of carbon-based catalysts, as well as a decrease in combustion reactivity. The outcomes will aid in controlling coke deposition during catalytic cracking of pyrolytic volatiles of low-rank coal.

Dynamic characteristics of the hydrogen injector-ejector unit in a PEM fuel cell system

The ejector, as a fluid-dynamics controlled passive component, is a promising hydrogen recirculation device in proton exchange membrane (PEM) fuel cell systems. Nevertheless, its performance is significantly affected by dynamic operating conditions and the behavior of the injector. This study investigates the dynamic performance of an ejector integrated with a hydrogen injector in a 100 kW PEM fuel cell system. A dynamic computational fluid dynamics (CFD) model of the integrated injector-ejector unit is developed using a dynamic mesh method and validated through theoretical analysis and experimental data. A thorough analysis of the global performance and local fluid flow characteristics of the injector-ejector unit is conducted. The results show that the hydrogen injector, with a throat diameter of 2.00 mm, exhibits an adjustable linear flow range from 0 to 1.62 g/s under an inlet pressure of 2.0 MPa. Additionally, the primary mass flow rate can be linearly regulated by adjusting the valve gap, while the secondary mass flow rate exhibits asynchronous behavior with the primary flow. The velocity and temperature distributions within the injector-ejector unit undergo significant changes under dynamic conditions. These findings contribute to optimizing the design and control strategies of hydrogen supply components in PEM fuel cell systems.

Study on the planning and scheduling strategies of the hydrogen supply network for road transportation in deep decarbonization scenarios

As the energy decarbonization continues to advance, hydrogen is gaining momentum. With the increasing demand for hydrogen and the lack of hydrogen infrastructure, it is urgent to solve the problem of hydrogen supply network layout planning. In order to reduce redundant construction of hydrogen supply network infrastructure and increase the rationality of its layout, this paper conducts research on the optimal layout planning of hydrogen supply network infrastructure in the transportation sector. By constructing a two-stage real-time scheduling model of hydrogen supply network, the unit cost composition of hydrogen supply network is more complete and accurate, and the location, technology type and quantity of each link of hydrogen supply network are obtained. The results show that the unit cost of China's hydrogen supply network is 27.8 CNY/kg in 2035 and 19.04 CNY/kg in 2050 under the baseline scenario. Compared with the results of existing literature, the two-stage real-time scheduling model can reduce by 7 % of the hydrogen energy supply network unit cost by decreasing the transportation vehicles and the investment capacity of fixed hydrogen storage equipment. The proposed method of the hydrogen supply network planning can provide policy-makers with the selection of sustainability pathways for dynamic hydrogen infrastructure development planning.