Modeling hydrogen – rock – brine interactions for the Jurassic reservoir and cap rocks from Polish Lowlands

Hydrogen offers an opportunity to move away from fossil fuels, it may help to alleviate major drawbacks of intermittent renewable energy generation. The results of geochemical modeling of hydrogen-rock-brine interactions for sandstones, mudstones and claystones from the geological structures from Polish Lowland are presented. The pH of the pore water is a critical parameter that controls the extent of the reaction. Several dominant reaction schemes were distinguished, and goethite was indicated as responsible for the consumption of stored hydrogen. It was found that the changes in rock porosity in sandstones were much smaller than in mudstones and claystones. The Zaosie sandstones are more favorable for UHS than those from Chabowo. The degradation of cap rock integrity, requires each time further experimental research. The findings of this study can help for better understanding of the behavior of hydrogen, in terms of gas-rock-brine interactions, in conditions of its underground storage.     

Effect of under-floor water storage on the thermal performance of a room

The thermal performance of a room coupled to an evaporatively cooled water storage tank below its floor has been evaluated in terms of the discomfort index for the hot-dry climate of Jodhpur. For a given depth of the storage tank, the effect on the room air temperature of the flow rate with which water is cooled evaporatively has been analysed. It is seen that the storage coupling reduces the mean room temperature but does not affect the swing in the room temperature.     

Assessment of feasible strategies for seasonal underground hydrogen storage in a saline aquifer

Renewable energies fluctuate, resulting in temporary mismatches between demand and supply. The conversion of surplus energy to hydrogen and its storage in geological formations is one option to counteract this energy imbalance. This study evaluates the feasibility of seasonal storage of hydrogen produced from wind power in Castilla-León region (northern Spain). A 3D multiphase numerical model is used to test different extraction well configurations during three annual injection-production cycles in a saline aquifer. Results demonstrate that underground hydrogen storage in saline aquifers can be operated with reasonable recovery ratios. A maximum hydrogen recovery ratio of 78%, which represents a global energy efficiency of 30%, has been estimated. Hydrogen upconing emerges as the major risk on saline aquifer storage without using other cushion gases. However, shallow extraction wells can minimize its effects. Steeply dipping geological structures are key for an efficient hydrogen storage.     

Review on effective parameters in electrochemical hydrogen storage

Today, energy has become one of the most important concerns of developing countries. The use of non-renewable energy sources, as well as the production of pollution, has led to growing efforts to replace fossil fuels, which are the most important energy sources in the modern world. Hydrogen as a clean fuel has attracted a lot of attention in recent years. Various methods have been reported for the production and storage of hydrogen. According to their advantages and disadvantages, it can be said that electrochemical hydrogen storage method is superior to other methods in terms of cost, safety, and optimum condition. The electrochemical hydrogen storage is done in a variety of techniques, and in recent years, the chronopotentiometry method has become one of the most popular methods for scientists. In chronopotentiometry technique, several parameters such as the reference electrode, the counter electrode, the working electrode, electrolyte, and current density are important. In this review, we investigated the articles that have been done in this regard from 2000 to 2020. This review can help scientists to better understand the electrochemical hydrogen storage system.     

Seasonal hydrogen storage in a depleted oil and gas field

Hydrogen storage is essential in hydrogen value chains and subsurface storage may be the most suitable large-scale option. This paper reports numerical simulations of seasonal hydrogen storage in the Norne hydrocarbon field, offshore Norway. Three different storage schemes are examined by injecting pure hydrogen into the gas-, oil-, and water zones. Implementation of four annual withdrawal-injection cycles followed by one prolonged withdrawal period show that the thin gas zone is a preferred target with a final hydrogen recovery factor of 87%. The hydrogen distribution in the subsurface follow the geological structures and is restricted by fluid saturation and displacement efficiencies. Case studies show that the pre-injection of formation gas as a cushion gas efficiently increases the ultimate hydrogen recovery, but at the cost of hydrogen purity. The injection of 30% hydrogen-formation gas mixture results in a varying hydrogen fraction in the withdrawn gas. An alternative well placement down the dipping structure shows lower storage efficiency.     

Large-vscale hydrogen production and storage technologies: Current status and future directions

Over the past years, hydrogen has been identified as the most promising carrier of clean energy. In a world that aims to replace fossil fuels to mitigate greenhouse emissions and address other environmental concerns, hydrogen generation technologies have become a main player in the energy mix. Since hydrogen is the main working medium in fuel cells and hydrogen-based energy storage systems, integrating these systems with other renewable energy systems is becoming very feasible. For example, the coupling of wind or solar systems hydrogen fuel cells as secondary energy sources is proven to enhance grid stability and secure the reliable energy supply for all times. The current demand for clean energy is unprecedented, and it seems that hydrogen can meet such demand only when produced and stored in large quantities. This paper presents an overview of the main hydrogen production and storage technologies, along with their challenges. They are presented to help identify technologies that have sufficient potential for large-scale energy applications that rely on hydrogen. Producing hydrogen from water and fossil fuels and storing it in underground formations are the best large-scale production and storage technologies. However, the local conditions of a specific region play a key role in determining the most suited production and storage methods, and there might be a need to combine multiple strategies together to allow a significant large-scale production and storage of hydrogen.     

Hydrogen underground storage in Romania,potential directions of development,stakeholders and general aspects

Romania is a country with relatively good opportunities to manage the transition from the dependence on fossil energy to an energy industry based on renewable energy sources (RES), supported by hydrogen as an energy carrier. In order to ensure Romania's energy security in the next decades, it will be necessary to consider a fresh approach incorporating a global long-term perspective based on the latest trends in energy systems. The present article focuses on an analysis of the potential use of salt caverns for hydrogen underground storage in Romania. Romanian industry has a long technical and geological tradition in salt exploitation and therefore is believed to have the potential to use the salt structures also in the future for gas and specifically hydrogen underground storage. This paper indicates that more analysis works needs to be undertaken in order to value this potential, based on which macroeconomic decisions then can be taken. The present work examines the structures of today's energy system in Romania and features an analysis of Romania's current potential of hydrogen underground storage as well as, reports on the potential use of this hydrogen in chemical industry, the transport sector and salt industry in Romania and highlighting issues implied by a possible introduction and use of hydrogen and fuel cell technologies.