China, People’s Republic
Optimal Multi-layer Economical Schedule for Coordinated Multiple Mode Operation of Wind-solar Microgrids with Hybrid Energy Storage Systems
Nov 2023
Publication
The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.
Review of the Status and Prospects of Fiber Optic Hydrogen Sensing Technology
Aug 2023
Publication
With the unprecedented development of green and renewable energy sources the proportion of clean hydrogen (H2 ) applications grows rapidly. Since H2 has physicochemical properties of being highly permeable and combustible high-performance H2 sensors to detect and monitor hydrogen concentration are essential. This review discusses a variety of fiber-optic-based H2 sensor technologies since the year 1984 including: interferometer technology fiber grating technology surface plasma resonance (SPR) technology micro lens technology evanescent field technology integrated optical waveguide technology direct transmission/reflection detection technology etc. These technologies have been evolving from simply pursuing high sensitivity and low detection limits (LDL) to focusing on multiple performance parameters to match various application demands such as: high temperature resistance fast response speed fast recovery speed large concentration range low cross sensitivity excellent long-term stability etc. On the basis of palladium (Pd)-sensitive material alloy metals catalysts or nanoparticles are proposed to improve the performance of fiberoptic-based H2 sensors including gold (Au) silver (Ag) platinum (Pt) zinc oxide (ZnO) titanium oxide (TiO2 ) tungsten oxide (WO3 ) Mg70Ti30 polydimethylsiloxane (PDMS) graphene oxide (GO) etc. Various microstructure processes of the side and end of optical fiber H2 sensors are also discussed in this review.
Electrolyzer Array Alternate Control Strategy Considering Wind Power Prediction
Aug 2022
Publication
Non grid connected wind power hydrogen production technology is of great significance for the large-scale comprehensive utilization of hydrogen energy and accelerating the development of clean energy. In this paper an electrolyzer power allocation and alternate control method for non grid connected wind power hydrogen production is proposed and the optimized control strategy are combined to predict the maximum wind power of certain time interval. While retaining the required data characteristics the instantaneous fluctuation of some wind power data is eliminated which provides a reliable basis for power distribution in the alternation control strategy of electrolyzer array. The case simulation verifies the effectiveness of the electrolyzer array control principle and the prediction of the maximum wind power. While ensuring the absorption effect and hydrogen production rate the service life and operation safety of the electrolyzer array are effectively improved by balancing the working state of each electrolyzer.
Top Level Design and Evaluation of Advanced Low/zero Carbon Fuel Ships Power Technology
Oct 2022
Publication
The greenhouse effect has always been a problem troubling various country many fields have made corresponding technological improvements and regulations and the shipping industry is no exception. In the shipping field governments are actively looking for viable low-carbon/zero-carbon alternative fuels to reduce their dependence on traditional fossil fuels. This paper discusses the challenges and opportunities of replacing fuel oil with clean energies. Firstly the alternative fuels that have been proposed frequently and widely in recent years are summarized and their sources adaptive power systems and relationships among fuels are systematically summarized. Secondly when evaluating the advantages and future development trends of each energy the environmental economic and safety factors are digitally quantified. Results show that the analysis focuses on the efficiency and economics of carbon reduction. Hydrogen ammonia and nuclear energy show advantages in environmental quantification factors while LNG biofuels and alcohols show benefits in economic quantification factors considering calorific value and fuel price and LNG and alcohols received high scores in safety assessment. Finally the study predicts the evolution and development trend of ship fuels in the future and evaluates the most suitable energy for ship development in different periods.
Configuration Optimization of Hydrogen-Based Multi-Microgrid Systems under Electricity Market Trading and Different Hydrogen Production Strategies
Apr 2023
Publication
Hydrogen-based multi-microgrid systems (HBMMSs) are beneficial for energy saving and emission reductions. However the optimal sizing of HBMMSs lacks a practical configuration optimization model and a reasonable solution method. To address these problems we designed a novel structure of HBMMSs that combines conventional energy renewable energy and a hydrogen energy subsystem. Then we established a bi-level multi-objective capacity optimization model while considering electricity market trading and different hydrogen production strategies. The objective of the inner model which is the minimum annual operation cost and the three objectives of the outer model which are the minimum total annual cost (TAC); the annual carbon emission (ACE); and the maximum self-sufficiency rate (SSR) are researched simultaneously. To solve the above optimization model a two-stage solution method which considers the conflicts between objectives and the objectivity of objective weights is proposed. Finally a case study is performed. The results show that when green hydrogen production strategies are adopted the three objectives of the best configuration optimization scheme are USD 404.987 million 1.106 million tons and 0.486 respectively.
Hydrogen Informed Gurson Model for Hydrogen Embrittlement Simulation
Jul 2019
Publication
Hydrogen-microvoid interactions were studied via unit cell analyses with different hydrogen concentrations. The absolute failure strain decreases with hydrogen concentration but the failure loci were found to follow the same trend dependent only on stress triaxiality in other words the effects of geometric constraint and hydrogen on failure are decoupled. Guided by the decoupling principle a hydrogen informed Gurson model is proposed. This model is the first practical hydrogen embrittlement simulation tool based on the hydrogen enhanced localized plasticity (HELP) mechanism. It introduces only one additional hydrogen related parameter into the Gurson model and is able to capture hydrogen enhanced internal necking failure of microvoids with accuracy; its parameter calibration procedure is straightforward and cost efficient for engineering purpose
Optimal Scheduling of Multi-microgrids with Power to Hydrogen Considering Federated Demand Response
Sep 2022
Publication
Hydrogen is regarded as a promising fuel in the transition to clean energy. Nevertheless as the demand for hydrogen increases some microgrids equipped with P2H (MGH) will encounter the issue of primary energy deficiency. Meanwhile some microgrids (MGs) face the difficulty of being unable to consume surplus energy locally. Hence we interconnect MGs with different energy characteristics and then establish a collaborative scheduling model of multi-microgrids (MMGs). In this model a federated demand response (FDR) program considering predictive mean voting is designed to coordinate controllable loads of electricity heat and hydrogen in different MGs. With the coordination of FDR the users’ satisfaction and comfort in each MG are kept within an acceptable range. To further adapt to an actual working condition of the microturbine (MT) in MGH a power interaction method is proposed to maintain the operating power of the MT at the optimum load level and shave peak and shorten the operating periods of MT. In the solution process the sequence operation theory is utilized to deal with the probability density of renewable energy. A series of case studies on a test system of MMG demonstrate the effectiveness of the proposed method.
Exploring Technological Solutions for Onboard Hydrogen Storage Systems Through a Heterogeneous Knowledge Network: From Current State to Future Research Opportunities
Jun 2022
Publication
With the imminent threat of the energy crises innovation in energy technologies is happening world-wide. The aim is to reduce our reliance on fossil fuels. Electric vehicles with fuel-cells that use hydrogen as an energy carrier are touted to be one of the most important potential replacements of the gasoline vehicle in both future transportation scenarios and emerging smart energy grids. However hydrogen storage is a major technical barrier that lies between where we are now and the mass application of hydrogen energy. Further exploration of onboard hydrogen storage systems (OHSS) is urgently needed and in this regard a comprehensive technology opportunity analysis will help. Hence with this research we drew on scientific papers and patents related to OHSS and developed a novel methodology for investigating the past present and future development trends in OHSS. Specifically we constructed a heterogeneous knowledge network using a unique multi-component structure with three core components: hydrogen carriers hydrogen storage materials and fuel cells. From this network we extracted both the developed and underdeveloped technological solutions in the field and applied a well-designed evaluation system and prediction model to score the future development potential of these technological solutions. What emerged was the most promising directions of research in the short medium and long term. The results show that our methodology can effectively identify technology opportunities in OHSS along with providing valuable decision support to researchers and enterprise managers associated with the development and application of OHSS.
Net Hydrogen Consumption Minimization of Fuel Cell Hybrid Trains Using a Time-Based Co-Optimization Model
Apr 2022
Publication
With increasing concerns on transportation decarbonization fuel cell hybrid trains (FCHTs) attract many attentions due to their zero carbon emissions during operation. Since fuel cells alone cannot recover the regenerative braking energy (RBE) energy storage devices (ESDs) are commonly deployed for the recovery of RBE and provide extra traction power to improve the energy efficiency. This paper aims to minimize the net hydrogen consumption (NHC) by co-optimizing both train speed trajectory and onboard energy management using a time-based mixed integer linear programming (MILP) model. In the case with the constraints of speed limits and gradients the NHC of co-optimization reduces by 6.4% compared to the result obtained by the sequential optimization which optimizes train control strategies first and then the energy management. Additionally the relationship between NHC and employed ESD capacity is studied and it is found that with the increase of ESD capacity the NHC can be reduced by up to 30% in a typical route in urban railway transit. The study shows that ESDs play an important role for FCHTs in reducing NHC and the proposed time-based co-optimization model can maximize the energy-saving benefits for such emerging traction systems with hybrid energy sources including both fuel cells and ESD.
A Green Route for Hydrogen Producton from Alkaline Thermal Treatment (ATT) of Biomass with Carbon Storage
Apr 2023
Publication
Hydrogen a green energy carrier is one of the most promising energy sources. However,it is currently mainly produced from depleting fossil fuels with high carbon emissions which has serious negative effects on the economy and environment. To address this issue sustainable hydrogen production from bio-energy with carbon capture and storage (HyBECCS) is an ideal technology to reduce global carbon emissions while meeting energy demand. This review presents an overview of the latest progress in alkaline thermal treatment (ATT) of biomass for hydrogen production with carbon storage especially focusing on the technical characteristics and related challenges from an industrial application perspective. Additionally the roles of alkali and catalyst in the ATT process are critically discussed and several aspects that have great influences on the ATT process such as biomass types reaction parameters and reactors are expounded. Finally the potential solutions to the general challenges and obstacles to the future industrial-scale application of ATT of biomass for hydrogen production are proposed.
Power Scheduling Optimization Method of Wind-Hydrogen Integrated Energy System Based on the Improved AUKF Algorithm test2
Nov 2022
Publication
With the proposal of China’s green energy strategy the research and development technologies of green energy such as wind energy and hydrogen energy are becoming more and more mature. However the phenomenon of wind abandonment and anti-peak shaving characteristics of wind turbines have a great impact on the utilization of wind energy. Therefore this study firstly builds a distributed wind-hydrogen hybrid energy system model then proposes the power dispatching optimization technology of a wind-hydrogen integrated energy system. On this basis a power allocation method based on the AUKF (adaptive unscented Kalman filter) algorithm is proposed. The experiment shows that the power allocation strategy based on the AUKF algorithm can effectively reduce the incidence of battery overcharge and overdischarge. Moreover it can effectively deal with rapid changes in wind speed. The wind hydrogen integrated energy system proposed in this study is one of the important topics of renewable clean energy technology innovation. Its grid-connected power is stable with good controllability and the DC bus is more secure and stable. Compared with previous studies the system developed in this study has effectively reduced the ratio of abandoned air and its performance is significantly better than the system with separate grid connected fans and single hydrogen energy storage. It is hoped that this research can provide some solutions for the research work on power dispatching optimization of energy systems.
Simulation and Control Strategy Study of the Hydrogen Supply System of a Fuel Cell Engine
Jun 2023
Publication
The hydrogen supply system is one of the important components of a hydrogen fuel cell engine and its performance has an important impact on the economy and power of the engine system. In this paper a hydrogen supply system based on cyclic mode is designed for a hydrogen fuel cell stack with a full load power of 150 kW and the corresponding hydrogen fuel cell engine simulation model is built and validated. The control strategy of the fuel cell hydrogen supply system is developed and its effect is verified through bench tests. The results show that the developed control strategy can keep the volume fraction of nitrogen below 6% the hydrogen excess ratio does not exceed 1.5 under medium and high operating conditions the anode pressure is relatively stable and the stack can operate efficiently and reliably.
Multi-Objective Robust Optimization of Integrated Energy System with Hydrogen Energy Storage
Feb 2024
Publication
A novel multi-objective robust optimization model of an integrated energy system with hydrogen storage (HIES) considering source–load uncertainty is proposed to promote the low-carbon economy operation of the integrated energy system of a park. Firstly the lowest total system cost and carbon emissions are selected as the multi-objective optimization functions. The Pareto front solution set of the objective function is applied by compromise planning and the optimal solution among them is obtained by the maximum–minimum fuzzy method. Furthermore the robust optimization (RO) approach is introduced to cope with the source–load uncertainty effectively. Finally it is demonstrated that the illustrated HIES can significantly reduce the total system cost carbon emissions and abandoned wind and solar power. Meanwhile the effectiveness of the proposed model and solution method is verified by analyzing the influence of multi-objective solutions and a robust coefficient on the Chongli Demonstration Project in Hebei Province.
A Comprehensive Resilience Assessment Framework for Hydrogen Energy Infrastructure Development
Jun 2023
Publication
In recent years sustainable development has become a challenge for many societies due to natural or other disruptive events which have disrupted economic environmental and energy infrastructure growth. Developing hydrogen energy infrastructure is crucial for sustainable development because of its numerous benefits over conventional energy sources. However the complexity of hydrogen energy infrastructure including production utilization and storage stages requires accounting for potential vulnerabilities. Therefore resilience needs to be considered along with sustainable development. This paper proposes a decision-making framework to evaluate the resilience of hydrogen energy infrastructure by integrating resilience indicators and sustainability contributing factors. A holistic taxonomy of resilience performance is first developed followed by a qualitative resilience assessment framework using a novel Intuitionistic fuzzy Weighted Influence Nonlinear Gauge System (IFWINGS). The results highlighted that Regulation and legislation Government preparation and Crisis response budget are the most critical resilience indicators in the understudy hydrogen energy infrastructure. A comparative case study demonstrates the practicality capability and effectiveness of the proposed approach. The results suggest that the proposed model can be used for resilience assessment in other areas.
Low-carbon Planning for Park-level Integrated Energy System Considering Optimal Construction Time Sequence and Hydrogen Energy Facility
Apr 2023
Publication
With the increasing concern about global energy crisis and environmental pollution the integrated renewable energy system has gradually become one of the most important ways to achieve energy transition. In the context of the rapid development of hydrogen energy industry the proportion of hydrogen energy in the energy system has gradually increased. The conversion between various energy sources has also become more complicated which poses challenges to the planning and construction of park-level integrated energy systems (PIES). To solve this problem we propose a bi-level planning model for an integrated energy system with hydrogen energy considering multi-stage investment and carbon trading mechanism. First the mathematical models of each energy source and energy storage in the park are established respectively and the independent operation of the equipment is analyzed. Second considering the operation state of multi-energy coordination a bi-level planning optimization model is established. The upper level is the capacity configuration model considering the variable installation time of energy facilities while the lower level is the operation optimization model considering several typical daily operations. Third considering the coupling relationship between upper and lower models the bi-level model is transformed into a solvable single-level mixed integer linear programming (MILP) model by using Karush–Kuhn–Tucker (KKT) condition and big-M method. Finally the proposed model and solution methods are verified by comprehensive case studies. Simulation results show that the proposed model can reduce the operational cost and carbon emission of PIES in the planning horizon and provide insights for the multi-stage investment of PIES.
Review on Ammonia as a Potential Fuel: From Synthesis to Economics
Feb 2021
Publication
Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.
A Comparative Study on Energy Efficiency of the Maritime Supply Chains for Liquefied Hydrogen, Ammonia, Methanol and Natural Gas
Jun 2023
Publication
To cope with climate change emerging fuels- hydrogen ammonia and methanol- have been proposed as promising energy carriers that will replace part of the liquefied natural gas (LNG) in future maritime scenarios. Energy efficiency is an important indicator for evaluating the system but the maritime supply system for emerging fuels has yet to be revealed. In this study the energy efficiency of the maritime supply chain of hydrogen ammonia methanol and natural gas is investigated considering processes including production storage loading transport and unloading. A sensitivity analysis of parameters such as ambient temperature storage time pipeline length and sailing time is also carried out. The results show that hydrogen (2.366%) has the highest daily boil-off gas (BOG) rate and wastes more energy than LNG (0.413%) with ammonia and methanol both being lower than LNG. The recycling of BOG is of great importance to the hydrogen supply chain. When produced from renewable energy sources methanol (98.02%) is the most energy efficient followed by ammonia with hydrogen being the least (89.10%). This assessment shows from an energy efficiency perspective that ammonia and methanol have the potential to replace LNG as the energy carrier of the future and that hydrogen requires efficient BOG handling systems to increase competitiveness. This study provides some inspirations for the design of global maritime supply systems for emerging fuels.
Low Carbon Optimal Operation of Integrated Energy System Based on Concentrating Solar Power Plant and Power to Hydrogen
Mar 2023
Publication
A new integrated energy system (IES) framework is created in order to encourage the consumption of renewable energy which is represented by wind and solar energy and lower carbon emissions. The connection between the units in the composite system is examined in this research. In-depth analysis is done on how energy is transferred between electricity heat gas and hydrogen. The system model and constraints are used to build an objective function with the lowest total operating cost. The calculation of carbon trading includes the ladder carbon trading method. And set up 6 cases for analysis which verifies the effectiveness of the participation of the concentrated solar power plant (CSPP) in the heat supply and power to hydrogen system (P2HS) in reducing the total operating cost of the system reducing wind curtailment and light curtailment and reducing carbon emissions. Under the model considered in this paper reduces the total operating cost reduces by 27.04% when the concentrated solar power plant is involved in the supply of thermal load. And the carbon emission is reduced by 14.529%. Compared with the traditional power to gas considers the power to hydrogen system in this paper which reduces the total operating cost by 4.79%.
Optimal Operation Strategy of PV-Charging-Hydrogenation Composite Energy Station Considering Demand Response
Apr 2023
Publication
Traditional charging stations have a single function which usually does not consider the construction of energy storage facilities and it is difficult to promote the consumption of new energy. With the gradual increase in the number of new energy vehicles (NEVs) to give full play to the complementary advantages of source-load resources and provide safe efficient and economical energy supply services this paper proposes the optimal operation strategy of a PV-charging-hydrogenation composite energy station (CES) that considers demand response (DR). Firstly the operation mode of the CES is analyzed and the CES model including a photovoltaic power generation system fuel cell hydrogen production hydrogen storage hydrogenation and charging is established. The purpose is to provide energy supply services for electric vehicles (EVs) and hydrogen fuel cell vehicles (HFCVs) at the same time. Secondly according to the travel law of EVs and HFCVs the distribution of charging demand and hydrogenation demand at different periods of the day is simulated by the Monte Carlo method. On this basis the following two demand response models are established: charging load demand response based on the price elasticity matrix and interruptible load demand response based on incentives. Finally a multi-objective optimal operation model considering DR is proposed to minimize the comprehensive operating cost and load fluctuation of CES and the maximum–minimum method and analytic hierarchy process (AHP) are used to transform this into a linearly weighted single-objective function which is solved via an improved moth–flame optimization algorithm (IMFO). Through the simulation examples operation results in four different scenarios are obtained. Compared with a situation not considering DR the operation strategy proposed in this paper can reduce the comprehensive operation cost of CES by CNY 1051.5 and reduce the load fluctuation by 17.8% which verifies the effectiveness of the proposed model. In addition the impact of solar radiation and energy recharge demand changes on operations was also studied and the resulting data show that CES operations were more sensitive to energy recharge demand changes.
Numerical Study on a Diesel/Dissociated Methanol Gas Compression Ignition Engine with Exhaust Gas Recirculation
Aug 2023
Publication
Bo Li,
Yihua Chen,
Fei Zhong and
Xu Hao
Hydrogen is the most promising alternative fuel in the field of engines. Exhaust heat assisted methanol dissociation is an attractive approach for generating hydrogen. In this work simulations are conducted on a compression ignition engine fueled with different proportions of diesel-dissociated methanol gas (DMG) blends at intermediate engine speed full load and 0% EGR ratio. The results reveal that the indicated thermal efficiency and indicated mean effective pressure are greatly enhanced combustion efficiency is increased and regular emissions of CO HC and soot are reduced while NOx emissions are reduced with increased DMG substitution. In addition a simulation is conducted at an intermediate engine speed full load 15% DMG substitution ratio and varying EGR ratios of 0–20%. The results indicate that the dual-fuel engine outperforms the original engine with respect to power fuel economy and regular emissions once an optimal EGR rate is adopted.
A Perspective on the Overarching Role of Hydrogen, Ammonia, and Methanol Carbon-Neutral Fuels towards Net Zero Emission in the Next Three Decades
Dec 2022
Publication
Arguably one of the most important issues the world is facing currently is climate change. At the current rate of fossil fuel consumption the world is heading towards extreme levels of global temperature rise if immediate actions are not taken. Transforming the current energy system from one largely based on fossil fuels to a carbon-neutral one requires unprecedented speed. Based on the current state of development direct electrification of the future energy system alone is technically challenging and not enough especially in hard-to-abate sectors like heavy industry road trucking international shipping and aviation. This leaves a considerable demand for alternative carbon-neutral fuels such as green ammonia and hydrogen and renewable methanol. From this perspective we discuss the overarching roles of each fuel in reaching net zero emission within the next three decades. The challenges and future directions associated with the fuels conclude the current perspective paper.
Enhancing Energy Transition through Sector Coupling: A Review of Technologies and Models
Jul 2023
Publication
In order to effectively combat the effects of global warming all sectors must actively reduce greenhouse gas emissions in a sustainable and substantial manner. Sector coupling has emerged as a critical technology that can integrate energy systems and address the temporal imbalances created by intermittent renewable energy sources. Despite its potential current sector coupling capabilities remain underutilized and energy modeling approaches face challenges in understanding the intricacies of sector coupling and in selecting appropriate modeling tools. This paper presents a comprehensive review of sector coupling technologies and their role in the energy transition with a specific focus on the integration of electricity heat/cooling and transportation as well as the importance of hydrogen in sector coupling. Additionally we conducted an analysis of 27 sector coupling models based on renewable energy sources with the goal of aiding deciders in identifying the most appropriate model for their specific modeling needs. Finally the paper highlights the importance of sector coupling in achieving climate protection goals while emphasizing the need for technological openness and market-driven conditions to ensure economically efficient implementation.
Hydrogen-Electric Coupling Coordinated Control Strategy of Multi-Station Integrated System Based on the Honeycomb Topology
Mar 2022
Publication
With the high-proportion accession of renewable energy and randomness of the load side in the new energy power system unbalanced feeder power and heavy overload of the transformer caused by massive access of highly uncertain source loads become more and more serious. In order to solve the aforementioned problems a honeycomb topology of the multi-station integrated system is proposed. The soft open point (SOP) is used as the key integrated equipment of the internal unit of a multi-station integrated system. The honeycomb grid structure is composed of flexible nodes and the multi-station integrated system is composed of multi-network flexible interconnection. Based on the characteristics of the regional resource endowment hydrogen energy flow is deeply coupled in parts of honeycomb grids. In order to improve the reliability and flexibility of the multi-station integrated unit the structure of the new multi-station integrated unit the power balance constraints on the unit and the switching process of SOP control mode are studied. At the same time the hydrogen electricity coupling structure and the coordinated control strategy of hydrogen electricity conversion are proposed to solve the problem of deep application of hydrogen energy. Finally the effectiveness of the proposed multi-station integrated system is verified by using three simulation models.
Progress and Prospect of the Novel Integrated SOFC-ICE Hybrid Power System: System Design, Mass and Heat Integration, System Optimization and Techno-economic Analysis
Jan 2023
Publication
This paper presents a review of system design and analysis control strategy optimization and heat and mass integration of integrated solid oxide fuel cell (SOFC) and reciprocating internal combustion engine (ICE) system. Facing the future power-fuel-power path both SOFC and ICE can adapt to a variety of fuels which is one evidence that ICE is amenable to integration with SOFC while SOFC is more efficient cleaner and quieter than ICE. Different system topologies are classified whose dynamic performances are also analyzed. In addition the heat and mass integration of system is discussed. Moreover the combustion modes of ICE which can be applied to steady combustion high efficiency and low emissions are analyzed and compared. Meanwhile the potential and methods of system waste heat recovery are discussed. The exergy analysis energy density and techno-economy are discussed. Finally the results are discussed in the last section with the final conclusion that SOFC-ICE systems are very suitable for long-distance transportation such as maritime and aviation which can also solve problems of the carbon and pollutant emissions with the background of engine cannot be replaced in maritime while the system can adapt a variety of alternative fuels.
Investment Estimation in the Energy and Power Sector towards Carbon Neutrality Target: A Case Study of China
Mar 2023
Publication
The transition towards low-carbon energy and power has been extensively studied by research institutions and scholars. However the investment demand during the transition process has received insufficient attention. To address this gap an energy investment estimation method is proposed in this paper which takes the unit construction costs and potential development of major technology in the energy and power sector as input. The proposed estimation method can comprehensively assess the investment demand for various energy sources in different years including coal oil natural gas biomass power and hydrogen energy. Specifically we applied this method to estimate the investment demand of China’s energy and power sector from 2020 to 2060 at five year intervals. The results indicate that China’s cumulative energy investment demand over this period is approximately 127 trillion CNY with the power sector accounting for the largest proportion at 92.35% or approximately 117 trillion CNY. The calculated cumulative investment demand is consistent with the findings of several influential research institutions providing validation for the proposed method.
Low-carbon Economic Dispatch of Power Systems Based on Mobile Hydrogen Storage
Mar 2022
Publication
To alleviate the global warming crisis carbon reduction is an inevitable trend of sustainable development. The energy carrier with Hydrogen (H2) is considered to be one of the promising choices for realizing a low-carbon economy. With the increasing penetration level of wind power generation and for well-balancing wind generation fluctuations this paper proposes a low-carbon economic dispatch method for power systems based on mobile hydrogen storage(MHS). The wind power surplus during off-peak load periods is first utilized to generate green H2. Afterward the green H2 is optimally transported to multiple hydrogen storage(HS) stations for generating power electricity by flexibly controlling the electrolysis(EL) methanation(ME) carbon capture(CCS) and H2 power generation processes in such a way the wind power is coordinated with the hydrogen production transport and utilization to reduce the total carbon emission and minimize the operation cost of power systems. Finally the proposed power system low-carbon economic dispatch model is verified by case studies.
Research on Multi-market Strategies for Virtual Power Plants with Hydrogen Energy Storage
Oct 2023
Publication
As the main body of resource aggregation Virtual Power Plant (VPP) not only needs to participate in the external energy market but also needs to optimize the management of internal resources. Different from other energy storage hydrogen energy storage systems can participate in the hydrogen market in addition to assuming the backup supplementary function of electric energy. For the Virtual Power Plant Operator (VPPO) it needs to optimize the scheduling of internal resources and formulate bidding strategies for the electric-hydrogen market based on external market information. In this study a two-stage model is constructed considering the internal and external interaction mechanism. The first stage model optimizes the operation of renewable energy flexible load extraction storage and hydrogen energy storage system based on the complementary characteristics of internal resources; the second stage model optimizes the bidding strategy to maximize the total revenue of the electricity energy market auxiliary service market and hydrogen market. Finally a typical scenario is constructed and the rationality and effectiveness of the strategy are verified. The results show that the hybrid VPP with hydrogen storage has better economic benefits resource benefits and reliability.
Advantages and Technological Progress of Hydrogen Fuel Cell Vehicles
Jun 2023
Publication
The automotive industry is undergoing a profound transformation driven by the need for sustainable and environmentally friendly transportation solutions [1]. In this context fuel cell technology has emerged as a promising alternative offering clean efficient and high-performance power sources for vehicles [2]. Fuel cell vehicles are electric vehicles that use fuel cell systems as a single power source or as a hybrid power source in combination with rechargeable energy storage systems. A typical fuel cell system for electric vehicle is exhibited in Figure 1 which provides a comprehensive demonstration of this kind of complex system. Hydrogen energy is a crucial field in the new energy revolution and will become a key pillar in building a green efficient and secure new energy system. As a critical field for hydrogen utilization fuel cell vehicles will play an important role in the transformation and development of the automotive industry. The development of fuel cell vehicles offers numerous advantages such as strong power outputs safety reliability and economic energy savings [3]. However improvements must urgently be made in existing technologies such as fuel cell stacks (including proton exchange membranes catalysts gas diffusion layers and bipolar plates) compressors and onboard hydrogen storage systems [4]. The advantages and current technological status are analyzed here.
Can Africa Serve Europe with Hydrogen Energy from Its Renewables?—Assessing the Economics of Shipping Hydrogen and Hydrogen Carriers to Europe from Different Parts of the Continent
Apr 2023
Publication
There exists no single optimal way for transporting hydrogen and other hydrogen carriers from one port to the other globally. Its delivery depends on several factors such as the quantity distance economics and the availability of the required infrastructure for its transportation. Europe has a strategy to invest in the production of green hydrogen in Africa to meet its needs. This study assessed the economic viability of shipping liquefied hydrogen (LH2 ) and hydrogen carriers to Germany from six African countries that have been identified as countries with great potential in the production of hydrogen. The results obtained suggest that the shipping of LH2 to Europe (Germany) will cost between 0.47 and 1.55 USD/kg H2 depending on the distance of travel for the ship. Similarly the transportation of hydrogen carriers could range from 0.19 to 0.55 USD/kg H2 for ammonia 0.25 to 0.77 USD/kg H2 for LNG 0.24 to 0.73 USD/kg H2 for methanol and 0.43 to 1.28 USD/kg H2 for liquid organic hydrogen carriers (LOHCs). Ammonia was found to be the ideal hydrogen carrier since it recorded the least transportation cost. A sensitivity analysis conducted indicates that an increase in the economic life by 5 years could averagely decrease the cost of LNG by some 13.9% NH3 by 13.2% methanol by 7.9% LOHC by 8.03% and LH2 by 12.41% under a constant distance of 6470 nautical miles. The study concludes with a suggestion that if both foreign and local participation in the development of the hydrogen market is increased in Africa the continent could supply LH2 and other hydrogen carriers to Europe at a cheaper price using clean fuel.
Design Strategies for Large Current Density Hydrogen Evolution Reaction
Apr 2022
Publication
Hydrogen energy is considered one of the cleanest and most promising alternatives to fossil fuel because the only combustion product is water. The development of water splitting electrocatalysts with Earth abundance cost-efficiency and high performance for large current density industrial applications is vital for H2 production. However most of the reported catalysts are usually tested within relatively small current densities (< 100 mA cm−2 ) which is far from satisfactory for industrial applications. In this minireview we summarize the latest progress of effective non-noble electrocatalysts for large current density hydrogen evolution reaction (HER) whose performance is comparable to that of noble metal-based catalysts. Then the design strategy of intrinsic activities and architecture design are discussed including self-supporting electrodes to avoid the detachment of active materials the superaerophobicity and superhydrophilicity to release H2 bubble in time and the mechanical properties to resist destructive stress. Finally some views on the further development of high current density HER electrocatalysts are proposed such as scale up of the synthesis process in situ characterization to reveal the micro mechanism and the implementation of catalysts into practical electrolyzers for the commercial application of as-developed catalysts. This review aimed to guide HER catalyst design and make large-scale hydrogen production one step further.
Aluminum-Based Fuels as Energy Carriers for Controllable Power and Hydrogen Generation—A Review
Dec 2022
Publication
Metallic aluminum is widely used in propellants energy-containing materials and batteries due to its high energy density. In addition to burning in the air aluminum can react with water to generate hydrogen. Aluminum is carbon-free and the solid-phase products can be recycled easily after the reaction. Micron aluminum powder is stable in the air and enables global trade. Aluminum metal is considered to be a viable recyclable carrier for clean energy. Based on the reaction characteristics of aluminum fuel in air and water this work summarizes the energy conversion system of aluminum fuel the combustion characteristics of aluminum and the recycling of aluminum. The conversion path and application direction of electric energy and chemistry in the aluminum energy conversion system are described. The reaction properties of aluminum in the air are described as well as the mode of activation and the effects of the aluminum-water reaction. In situ hydrogen production is achievable through the aluminum-water reaction. The development of low-carbon and energy-saving electrolytic aluminum technology is introduced. The work also analyzes the current difficulties and development directions for the large-scale application of aluminum fuel energy storage technology. The development of energy storage technology based on aluminum is conducive to transforming the energy structure.
Study Progress on the Pipeline Transportation Safety of Hydrogen-blended Natural Gas
Oct 2023
Publication
The core of carbon neutrality is the energy structure adjustment and economic structure transformation. Hydrogen energy as a kind of clean energy with great potential has provided important support for the implementation of the carbon peaking and carbon neutrality goals of China. How to achieve the large-range safe and reliable transportation of hydrogen energy with good economic benefits remains the key to limiting the development of hydrogen energy. Using the existing natural gas pipeline network can save many infrastructure construction costs to transport hydrogen-blended natural gas. However due to great differences in the physical and chemical properties of hydrogen and natural gas the transportation of hydrogen-blended natural gas will bring safety risks to the pipeline network operation to a certain extent. In this paper the influences of pipeline transportation of hydrogen-blended natural gas on existing pipelines and parts along the pipelines are analyzed from two aspects of pipe compatibility and hydrogen blending ratio and the safety of pipeline transportation of hydrogen-blended natural gas is summarized from two aspects of leakage and accumulation as well as combustion and explosion. In addition the integrity management of hydrogen-blended natural gas pipelines and the existing relevant standards and specifications are reviewed. This paper points out the shortcomings of current hydrogen-blended natural gas pipeline transportation and gives some relevant suggestions. Hopefully this work can provide a useful reference for developing a hydrogen-blended natural gas pipeline transportation system.
A Theoretical Study on the Hydrogen Filling Process of the On-board Storage Cylinder in Hydrogen Refueling Station
May 2023
Publication
With the development of the hydrogen fuel automobile industry higher requirements are put forward for the construction of hydrogen energy infrastructure the matching of parameters and the control strategy of hydrogen filling rate in the hydrogen charging process of hydrogen refueling stations. At present the technological difficulty of hydrogen fueling is mainly reflected in the balanced treatment of reducing the temperature rise of hydrogen and shortening the filling time during the fast filling process. Vehicle hydrogen storage cylinder (VHSC) is one of the important components of hydrogen fuel cell vehicles. This study proposed a theoretical model for calculating the temperature rise in the VHSC during the high pressure refueling process and revealed the hydrogen temperature rise during refueling. A hydrogen temperature rise prediction model was constructed to elucidate the relationship between filling parameters and temperature rise. The filling process of VHSC was analyzed from the theoretical method. The theoretical analysis results were consistent with the simulation and experimental analysis results which provided a theoretical basis for the current hydrogen temperature control algorithm of the gas source in the hydrogen refueling station and then reduced the energy consumption required for hydrogen cooling in the hydrogen refueling station.
Recent Advances of Metal Borohydrides for Hydrogen Storage
Aug 2022
Publication
Hydrogen energy is an excellent carrier for connecting various renewable energy sources and has many advantages. However hydrogen is flammable and explosive and its density is low and easy to escape which brings inconvenience to the storage and transportation of hydrogen. Therefore hydrogen storage technology has become one of the key steps in the application of hydrogen energy. Solid-state hydrogen storage method has a very high volumetric hydrogen density compared to the traditional compressed hydrogen method. The main issue of solid-state hydrogen storage method is the development of advanced hydrogen storage materials. Metal borohydrides have very high hydrogen density and have received much attention over the past two decades. However high hydrogen sorption temperature slow kinetics and poor reversibility still severely restrict its practical applications. This paper mainly discusses the research progress and problems to be solved of metal borohydride hydrogen storage materials for solid-state hydrogen storage.
Energy Management Strategy Based on Dynamic Programming with Durability Extension for Fuel Cell Hybrid Tramway
Sep 2021
Publication
This paper proposes an energy management strategy for a fuel cell (FC) hybrid power system based on dynamic programming and state machine strategy which takes into account the durability of the FC and the hydrogen consumption of the system. The strategy first uses the principle of dynamic programming to solve the optimal power distribution between the FC and supercapacitor (SC) and then uses the optimization results of dynamic programming to update the threshold values in each state of the finite state machine to realize real-time management of the output power of the FC and SC. An FC/SC hybrid tramway simulation platform is established based on RTLAB real-time simulator. The compared results verify that the proposed EMS can improve the durability of the FC increase its working time in the high-efficiency range effectively reduce the hydrogen consumption and keep the state of charge in an ideal range.
Integrated Energy System Optimal Operation in Coal District With Hydrogen Heavy Trucks
Sep 2021
Publication
The coal industry contributes significantly to the social economy but the emission of greenhouse gases puts huge pressure on the environment in the process of mining transportation and power generation. In the integrated energy system (IES) the current research about the power-to-gas (P2G) technology mainly focuses on the injection of hydrogen generated from renewable energy electrolyzed water into natural gas pipelines which may cause hydrogen embrittlement of the pipeline and cannot be repaired. In this paper sufficient hydrogen energy can be produced through P2G technology and coal-to-hydrogen (C2H) of coal gasification considering the typical scenario of coal district is rich in coal and renewable energy. In order to transport the mined coal to the destination hydrogen heavy trucks have a broad space for development which can absorb hydrogen energy in time and avoid potentially dangerous hydrogen injection into pipelines and relatively expensive hydrogen storage. An optimized scheduling model of electric-gas IES is proposed based on second-order cone programming (SOCP). In the model proposed above the closed industrial loop (including coal mining hydrogen production truck transportation of coal and integrated energy systems) has been innovatively studied to consume renewable energy and coordinate multi-energy. Finally an electric-gas IES study case constructed by IEEE 30-node power system and Belgium 24-node natural gas network was used to analyze. The results show that by introducing the proposed hydrogen production technology typical daily operating costs are effectively reduced by 7.7%. Under China’s carbon emissions trading system the operating costs of hydrogen heavy trucks have been reduced by 0.95 and 4.68% respectively compared with electric vehicles and diesel trucks. Under Europe’s stricter carbon emissions trading system the percentages of cost reduction are 2.56 and 9.12% respectively. The above technical results verify the feasibility economy low carbon and effectiveness of the proposed mechanism.
Study on the Effects of the Hydrogen Substitution Rate on the Performance of a Hydrogen–Diesel Dual-Fuel Engine under Different Loads
Aug 2023
Publication
Due to having zero carbon emissions and renewable advantages hydrogen has great prospects as a renewable form of alternate energy. Engine load and hydrogen substitution rate have a considerable influence on a hydrogen–diesel dual-fuel engine’s efficiency. This experiment’s objective is to study the influence of hydrogen substitution rate on engine combustion and emission under different loads and to study the impact of exhaust gas recirculation (EGR) technology or main injection timing on the engine’s capability under high load and high hydrogen substitution rate. The range of the maximum hydrogen substitution rate was determined under different loads (30%~90%) at 1800 rpm and then the effects of the EGR rate (0%~15%) and main injection timing (−8 ◦CA ATDC~0 ◦CA ATDC) on the engine performance under 90% high load were studied. The research results show that the larger the load the smaller the maximum hydrogen substitution rate that can be added to the dual-fuel engine. Under each load with the increase of the hydrogen substitution rate the cylinder pressure and the peak heat release rate (HRR) increase the equivalent brake-specific fuel consumption (BSFCequ) decreases the thermal efficiency increases the maximum thermal efficiency is 43.1% the carbon dioxide (CO2 ) emission is effectively reduced by 35.2% and the nitrogen oxide (NOx) emission decreases at medium and low loads and the maximum increase rate is 20.1% at 90% load. Under high load with the increase of EGR rate or the delay of main injection timing the problem of NOx emission increases after hydrogen doping can be effectively solved. As the EGR rate rises from 0% to 15% the maximum reduction of NOx is 63.1% and with the delay of main injection timing from −8 ◦CA ATDC to 0 ◦CA ATDC the maximum reduction of NOx is 44.5%.
Optimal Configuration and Scheduling Model of a Multi-Park Integrated Energy System Based on Sustainable Development
Mar 2023
Publication
To maximize the utilization of renewable energy (RE) as much as possible in cold areas while reducing traditional energy use and carbon dioxide emissions a three-layer configuration optimization and scheduling model considering a multi-park integrated energy system (MPIES) a shared energy storage power station (SESPS) and a hydrogen refueling station (HRS) cooperation based on the Wasserstein generative adversarial networks the simultaneous backward reduction technique and the Quantity-Contour (WGAN-SBR_QC) method is proposed. Firstly the WGAN-SBR_QC method is used to generate typical scenarios of RE output. Secondly a three-layer configuration and schedule optimization model is constructed using MPIES SESPS and HRS. Finally the model’s validity is investigated by selecting a multi-park in Eastern Mongolia. The results show that: (1) the typical scenario of RE output improved the overall robustness of the system. (2) The profits of the MPIES and HRS increased by 1.84% and 52.68% respectively and the SESPS profit increased considerably. (3) The proposed approach increased RE utilization to 99.47% while reducing carbon emissions by 32.67%. Thus this model is a reference for complex energy system configuration and scheduling as well as a means of encouraging RE use.
Location Optimization of Hydrogen Refueling Stations in Hydrogen Expressway Based on Hydrogen Supply Chain Cost
Jan 2021
Publication
Hydrogen energy is regarded as an important way to achieve carbon emission reduction. This paper focuses on the combination of the design of the hydrogen supply chain network and the location of hydrogen refueling stations on the expressway. Based on the cost analysis of the hydrogen supply chain a multi-objective model is developed to determine the optimal scale and location of hydrogen refueling stations on the hydrogen expressway. The proposed model considers the hydrogen demand forecast hydrogen source selection hydrogen production and storage and transportation hydrogen station refueling mode etc. Taking Dalian City China as an example with offshore wind power as a reliable green hydrogen supply to select the location and capacity of hydrogen refueling stations for the hydrogen energy demonstration section of a certain expressway under multiple scenarios. The results of the case show that 4 and 5 stations are optimized on the expressway section respectively and the unit hydrogen cost is $14.3 /kg H2 and $11.8 /kg H2 respectively which are equal to the average hydrogen price in the international range. The optimization results verify the feasibility and effectiveness of the model.
Research Progress of Hydrogen Production Technology and Related Catalysts by Electrolysis of Water
Jun 2023
Publication
As a clean and renewable energy source for sustainable development hydrogen energy has gained a lot of attention from the general public and researchers. Hydrogen production by electrolysis of water is the most important approach to producing hydrogen and it is also the main way to realize carbon neutrality. In this paper the main technologies of hydrogen production by electrolysis of water are discussed in detail; their characteristics advantages and disadvantages are analyzed; and the selection criteria and design criteria of catalysts are presented. The catalysts used in various hydrogen production technologies and their characteristics are emphatically expounded aiming at optimizing the existing catalyst system and developing new high-performance high-stability and low-cost catalysts. Finally the problems and solutions in the practical design of catalysts are discussed and explored.
Potential of Salt Caverns for Hydrogen Storage in Southern Ontario, Canada
Jul 2023
Publication
Salt caverns produced by solution mining in Southern Ontario provide ideal spaces for gas storage due to their low permeability. Underground hydrogen storage (UHS) is an important part of the future renewable energy market in Ontario in order to achieve global carbon neutrality and to fill the gap left by retiring nuclear power plants. However large-scale hydrogen storage is still restricted by limited storage space on the ground’s surface. In this study hydrogen’s physical and chemical properties are first introduced and characterized by low molecular weight high diffusivity low solubility and low density. Then the geological conditions of the underground reservoirs are analyzed especially salt caverns. Salt caverns with their inert cavity environments and stable physical properties offer the most promising options for future hydrogen storage. The scales heights and thicknesses of the roof and floor salt layers and the internal temperatures and pressures conditions of salt caverns can affect stabilities and storage capacities. Finally several potential problems that may affect the safe storage of hydrogen in salt caverns are discussed. Through the comprehensive analysis of the influencing factors of hydrogen storage in salt caverns this study puts forward the most appropriate development strategy for salt caverns which provides theoretical guidance for UHS in the future and helps to reduce the risk of large-scale storage design.
An Analysis of Renewable Energy Sources for Developing a Sustainable and Low-Carbon Hydrogen Economy in China
Apr 2023
Publication
A significant effort is required to reduce China’s dependency on fossil fuels while also supporting worldwide efforts to reduce climate change and develop hydrogen energy systems. A hydrogen economy must include renewable energy sources (RESs) which can offer a clean and sustainable energy source for producing hydrogen. This study uses an integrated fuzzy AHP–fuzzy TOPSIS method to evaluate and rank renewable energy sources for developing a hydrogen economy in China. This is a novel approach because it can capture the uncertainty and vagueness in the decision-making process and provide a comprehensive and robust evaluation of the alternatives. Moreover it considers multiple criteria and sub-criteria that reflect the environmental economic technical social and political aspects of RESs from the perspective of a hydrogen economy. This study identified five major criteria fifteen sub-criteria and six RES alternatives for hydrogen production. This integrated approach uses fuzzy AHP to evaluate and rank the criteria and sub-criteria and fuzzy TOPSIS to identify the most suitable and feasible RES. The results show that environmental economic and technical criteria are the most important criteria. Solar wind and hydropower are the top three RES alternatives that are most suitable and feasible. Furthermore biomass geo-thermal and tidal energy were ranked lower which might be due to the limitations and challenges in their adoption and performance in the context of the criteria and sub-criteria used for the analysis. This study’s findings add to the literature on guidelines to strategize for renewable energy adoption for the hydrogen economy in China.
The Necessity and Feasibility of Hydrogen Storage for Large-Scale, Long-Term Energy Storage in the New Power System in China
Jun 2023
Publication
In the process of building a new power system with new energy sources as the mainstay wind power and photovoltaic energy enter the multiplication stage with randomness and uncertainty and the foundation and support role of large-scale long-time energy storage is highlighted. Considering the advantages of hydrogen energy storage in large-scale cross-seasonal and cross-regional aspects the necessity feasibility and economy of hydrogen energy participation in long-time energy storage under the new power system are discussed. Firstly power supply and demand production simulations were carried out based on the characteristics of new energy generation in China. When the penetration of new energy sources in the new power system reaches 45% long-term energy storage becomes an essential regulation tool. Secondly by comparing the storage duration storage scale and application scenarios of various energy storage technologies it was determined that hydrogen storage is the most preferable choice to participate in large-scale and long-term energy storage. Three long-time hydrogen storage methods are screened out from numerous hydrogen storage technologies including salt-cavern hydrogen storage natural gas blending and solid-state hydrogen storage. Finally by analyzing the development status and economy of the above three types of hydrogen storage technologies and based on the geographical characteristics and resource endowment of China it is pointed out that China will form a hydrogen storage system of “solid state hydrogen storage above ground and salt cavern storage underground” in the future.
Research of the Impact of Hydrogen Metallurgy Technology on the Reduction of the Chinese Steel Industry’s Carbon Dioxide Emissions
Feb 2024
Publication
The steel industry which relies heavily on primary energy is one of the industries with the highest CO2 emissions in China. It is urgent for the industry to identify ways to embark on the path to “green steel”. Hydrogen metallurgy technology uses hydrogen as a reducing agent and its use is an important way to reduce CO2 emissions from long-term steelmaking and ensure the green and sustainable development of the steel industry. Previous research has demonstrated the feasibility and emission reduction effects of hydrogen metallurgy technology; however further research is needed to dynamically analyze the overall impact of the large-scale development of hydrogen metallurgy technology on future CO2 emissions from the steel industry. This article selects the integrated MARKAL-EFOM system (TIMES) model as its analysis model constructs a China steel industry hydrogen metallurgy model (TIMES-CSHM) and analyzes the resulting impact of hydrogen metallurgy technology on CO2 emissions. The results indicate that in the business-as-usual scenario (BAU scenario) applying hydrogen metallurgy technology in the period from 2020 to 2050 is expected to reduce emissions by 203 million tons and make an average 39.85% contribution to reducing the steel industry’s CO2 emissions. In the carbon emission reduction scenario applying hydrogen metallurgy technology in the period from 2020 to 2050 is expected to reduce emissions by 353 million tons contributing an average of 41.32% to steel industry CO2 reduction. This study provides an assessment of how hydrogen metallurgy can reduce CO2 emissions in the steel industry and also provides a reference for the development of hydrogen metallurgy technology.
Storage Integrity During Underground Hydrogen Storage in Depleted Gas Reservoirs
Nov 2023
Publication
The transition from fossil fuels to renewable energy sources particularly hydrogen has emerged as a central strategy for decarbonization and the pursuit of net-zero carbon emissions. Meeting the demand for large-scale hydrogen storage a crucial component of the hydrogen supply chain has led to the exploration of underground hydrogen storage as an economically viable solution to global energy needs. In contrast to other subsurface storage options such as salt caverns and aquifers which are geographically limited depleted gas reservoirs have garnered increasing attention due to their broader distribution and higher storage capacity. However the safe storage and cycling of hydrogen in depleted gas reservoirs require the preservation of high stability and integrity in the caprock reservoir and wellbore. Nevertheless there exists a significant gap in the current research concerning storage integrity in underground hydrogen storage within depleted gas reservoirs and a systematic approach is lacking. This paper aims to address this gap by reviewing the primary challenges associated with storage integrity including geochemical reactions microbial activities faults and fractures and perspectives on hydrogen cycling. The study comprehensively reviews the processes and impacts such as abiotic and biotic mineral dissolution/precipitation reactivation and propagation of faults and fractures in caprock and host-rock wellbore instability due to cement degradation and casing corrosion and stress changes during hydrogen cycling. To provide a practical solution a technical screening tool has been developed considering controlling variables risks and consequences affecting storage integrity. Finally this paper highlights knowledge gaps and suggests feasible methods and pathways to mitigate these risks facilitating the development of large-scale underground hydrogen storage in depleted gas reservoirs.
Low-Carbon Optimal Scheduling Model for Peak Shaving Resources in Multi-Energy Power Systems Considering Large-Scale Access for Electric Vehicles
May 2023
Publication
Aiming at the synergy between a system’s carbon emission reduction demand and the economy of peak shaving operation in the process of optimizing the flexible resource peaking unit portfolio of a multi-energy power system containing large-scale electric vehicles this paper proposes a low-carbon optimal scheduling model for peak shaving resources in multi-energy power systems considering large-scale access for electric vehicles. Firstly the charging and discharging characteristics of electric vehicles were studied and a comprehensive cost model for electric vehicles heat storage and hydrogen storage was established. At the same time the carbon emission characteristics of multienergy power systems and their emission cost models under specific carbon trading mechanisms were established. Secondly the change characteristics of the system’s carbon emissions were studied and a carbon emission cost model of multi-energy power was established considering the carbon emission reduction demand of the system. Then taking the carbon emission of the system and the peak regulating operation costs of traditional units energy storage and new energy unit as optimization objectives the multi-energy power system peak regulation multi-objective optimization scheduling model was established and NSGA-II was used to solve the scheduling model. Finally based on a regional power grid data in Northeast China the improved IEEE 30 node multi-energy power system peak shaving simulation model was built and the simulation analysis verified the feasibility of the optimal scheduling model proposed in this paper.
How a Grid Company Could Enter the Hydrogen Industry through a New Business Model: A Case Study in China
Mar 2023
Publication
The increasing penetration of renewable and distributed resources signals a global boom in energy transition but traditional grid utilities have yet to share in much of the triumph at the current stage. Higher grid management costs lower electricity prices fewer customers and other challenges have emerged along the path toward renewable energy but many more opportunities await to be seized. Most importantly there are insufficient studies on how grid utilities can thrive within the hydrogen economy. Through a case study on the State Grid Corporation of China we identify the strengths weaknesses opportunities and threats (SWOT) of grid utilities within the hydrogen economy. Based on these factors we recommend that grids integrate hydrogen into the energy-as-a-service model and deliver it to industrial customers who are under decarbonization pressure. We also recommend that grid utilities fund a joint venture with pipeline companies to optimize electricity and hydrogen transmissions simultaneously.
The Origin and Occurrence of Natural Hydrogen
Mar 2023
Publication
Hydrogen is an attractive clean sustainable energy source primarily produced via industry. At present most reviews on hydrogen mainly focus on the preparation and storage of hydrogen while the development and utilization of natural hydrogen will greatly reduce its cost. Natural hydrogen has been discovered in many geological environments. Therefore based on extensive literature research in this study the distribution and sources of natural hydrogen were systematically sorted and the identification method and occurrence state of natural hydrogen were examined and summarized. The results of this research show that hydrogen has been discovered in oceanic spreading centers transform faults passive margins convergent margins and intraplate settings. The primary sources of the hydrogen include alterations in Fe(II)-containing rocks the radiolysis of water degassed magma and the reaction of water- and silica-containing rocks during the mechanical fracturing. Hydrogen can appear in free gas it can be adsorbed and trapped in inclusions. Currently natural hydrogen exploration is in its infancy. This systematic review helps to understand the origin distribution and occurrence pattern of natural hydrogen. In addition it facilitates the exploration and development of natural hydrogen deposits thus enabling the production of low-cost hydrogen.
Equivalent Minimum Hydrogen Consumption of Fuzzy Control-Based Fuel Cells: Exploration of Energy Management Strategies for Ships
Feb 2024
Publication
Aiming to solve the problems of insufficient dynamic responses the large loss of energy storage life of a single power cell and the large fluctuation in DC (direct current) bus voltage in fuel cell vessels this study takes a certain type of fuel cell ferry as the research object and proposes an improved equivalent minimum hydrogen consumption energy management strategy based on fuzzy logic control. First a hybrid power system including a fuel cell a lithium–iron–phosphate battery and a supercapacitor is proposed with the simulation of the power system of the modified mother ship. Second a power system simulation model and a double-closed-loop PI (proportion integration) control model are established in MATLAB/Simulink to design the equivalent hydrogen consumption model and fuzzy logic control strategy. The simulation results show that under the premise of meeting the load requirements the control strategy designed in this paper improves the Li-ion battery’s power the Li-ion battery’s SOC (state of charge) the bus voltage stability and the equivalent hydrogen consumption significantly compared with those before optimization which improves the stability and economy of the power system and has certain practical engineering value.
A Review of the Research Progress and Application of Key Components in the Hydrogen Fuel Cell System
Jan 2024
Publication
The hydrogen cycle system one of the main systems used for hydrogen fuel cells has many advantages. It can improve the efficiency the water capacity and the management of thermal fuel cells. It can also enhance the safety of the system. Therefore it is widely used in hydrogen fuel cell vehicles. We introduce the structure and principles of hydrogen cycle pumps ejectors and steam separators and analyze and summarize the advantages of the components as well as reviewing the latest research progress and industrialization status of hydrogen cycle pumps and ejectors. The technical challenges in hydrogen circulation systems and the development direction of key technologies in the future are discussed. This paper aims to provide a reference for research concerning hydrogen energy storage application technology in hydrogen fuel cell systems.
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