Auswahl der wissenschaftlichen Literatur zum Thema „Natural hydrogen accumulation“

The article discusses the features of hydrogen accumulation in various geological, geochemical and tectonic conditions, the nature of hydrogen as a gas component of the Earth, the ratio of hydrogen in gas mixtures with other gases, the importance of hydrogen generation sources, its consumption for geological processes of various specifics. Separate criteria for assessing territories on the prospects of detecting hydrogen accumulations are proposed. The author's personal point of view is expressed regarding the directions of the search for natural hydrogen, taking into account the peculiarities of its further use as a chemical and energy resource. Keywords: natural hydrogen; serpentinization; radiolysis of water; methanogenesis; acetogenesis; sulfate reduction.

Much has been learned about natural hydrogen (H2) seepages and accumulation, but present knowledge of hydrogen behavior in the crust is so limited that it is not yet possible to consider exploitation of this resources. Hydrogen targeting requires a shift in the long-standing paradigms that drive oil and gas exploration. This paper describes the foundation of an integrated source-to-sink view of the hydrogen cycle, and propose preliminary practical guidelines for hydrogen exploration.

The quest for natural or white hydrogen exploration and production emanates from the growing interest in clean, carbon-free hydrogen energy. Countries all over the world are beginning to formulate legislation to promote hydrogen production as a way of combating global warming occasioned by climate change. Currently, all avenues for producing hydrogen are either very expensive or environmentally unsustainable. White hydrogen in commercial accumulations might produce cheaper and more environmentally sustainable hydrogen energy, thus providing a viable alternative to other forms of renewable energy. Despite its potential to become the cheapest hydrogen source, published literature on its occurrence, sources, accumulation, generation processes, and recovery methods are scarce. Consequently, little is known regarding white hydrogen sources, accumulation, and extraction. This study reviewed the various sources and forms in which white hydrogen can exist in nature. The various processes by which white hydrogen is produced and extracted have also been presented. This work aimed to offer new perspectives and direction for future research on white hydrogen exploration and production. Furthermore, the current challenges of white hydrogen exploration and production, and its future outlook, were also presented.

The film photoanodes based on CdSe and NT-TiO2/CdSe have been formed by the electrochemical and painting methods. It is shown that the introduction of graphene oxide into the structure of the semiconductor CdSe film promotes absorption of light and leads to improvement in their characteristics by 25-30 %. The compatibility of the cathode based on composite of hydrogen-sorbing intermetallic alloys LaNi4.5Mn0.5 + LaNi3.5Al0.7Mn0.8 with current-conductive additives in pair with the CdSe photoanode is shown. It was found that 95 – 98 % of the total current generated under the influence of sunlight at the anodes was used on the formation and accumulation of hydrogen by cathodes.

Due to the depletion of natural fossil energy carriers, hydrogen is becoming a promising alternative fuel, the advantages of which are inexhaustible reserves and its high energy and environmental indicators. The undeveloped infrastructure for the supply of hydrogen fuel to consumers, the problems of storage/accumulation of hydrogen hinder the development of hydrogen energy. (Research purpose) The research purpose is in considering modern methods of storage and accumulation of hydrogen, comparing their advantages and disadvantages. (Materials and methods) The article presents the state of the issue on scientific and information sources and patent information published in the open press. Authors considered storage methods for a number of parameters, the main of which are: volume and mass content of hydrogen; storage conditions and hydrogenation-dehydrogenation processes; cyclic stability and cost. The article presents a patent search in the information search system of the database of the Federal Institute of Industrial Property by keywords. Authors studied the abstracts and applications of Russian inventions, formulas of Russian utility models. Mechanical stresses in capillaries were determined using the moment-free theory of shells. (Results and discussion) The article presents the results of studies on the storage of gaseous and liquid hydrogen, in inorganic and organic carriers, carriers based on nanomaterials, in microspheres and adsorbents, capillary structures and energy storage substances. The hydrides do not require maintaining a low temperature and provide a volume density of 100-150 grams per liter, comparable to liquid hydrogen. A cost-effective method of storing hydrogen in microspheres and adsorbents is one of the promising methods for storing hydrogen gas under pressure in capillary or multicapillary structures made of glass, quartz, basalt and other materials. The density of hydrogen exceeds the density of liquid at a pressure of 200 megapascals. (Conclusions) Depending on the scale, purposes of storage and accumulation, it is possible to give preference to the method of storing hydrogen in liquid form, in multicapillary structures and various types of hydrogen carriers.

Possibilities and prospects of accumulation of the electric power generated on objects of renewable energy sources - solar and wind power plants, with use of cryogenic liquids are considered. A comparison of the three most common ways of accumulating electricity: using lithium-ion batteries, hydrogen, liquid air. According to the proposed technology, the efficiency of recovery of electricity from liquid air is from 54 to 70%. The developed technology is based on cryogenic and thermal accumulation and has a high accumulation coefficient. It is shown that energy storage in cryogenic storage devices is the cheapest today. The proposed technology can also be used to generate electricity from liquefied natural gas using standard equipment developed by industry. The technological scheme of the cryoaccumulating station is offered. Bibl. 10, Fig. 1, Table 1.

Natural hydrogen’s viability as a sustainable energy source will be enhanced through comprehensive geological modelling. This paper integrates existing open-source data to delve into the geological aspects of natural hydrogen exploration and proposes possible workflows. Geological and geophysical modelling entails characterising subsurface formations conducive to natural hydrogen generation and trapping. Utilising geological surveys, field observation, geophysical seismic and gravity data, alongside existing well logs, this analysis looks to identify regions with favourable geological conditions for the generation, migration and structures for accumulation of natural hydrogen. Furthermore, understanding the subsurface geology aids in the development of safe and efficient extraction techniques. By incorporating geological modelling into the evaluation of natural hydrogen, this paper provides a comprehensive overview of its potential as a sustainable energy solution. Leveraging existing open-source data alongside geological insights ensures a robust foundation for decision-making in exploration, production, storage, and utilisation strategies. This integrated approach empowers stakeholders to make informed choices in shaping a greener, more sustainable energy landscape.

The former Vaux-en-Bugey field, first French methane production from early 20th century, is revisited as a case study to address the present generation and accumulation theories for gases like hydrogen and helium. The volume of the initial gas in place is estimated to be 22 million m3. Based on a composition of 5% of hydrogen and 0.096% of helium, the volumes of these gases in the field were respectively around 1.1 million m3 for hydrogen and 24 000 m3 for helium. The different hypotheses of hydrogen sources are reviewed: serpentinization, hydro-oxidation of siderite, water radiolysis, bio-fermentation, mechanical generation, degassing from depth trough faults, steel corrosion. For helium generation, the different sources of radioactive minerals and intermediate accumulations are examined. The most probable scenario is the hydrogen production by water radiolysis and helium production by radioactive decay in or near the basement, migrating trough deep faults, stored and concentrating in an aquifer with thermogenic methane, then flushed by methane into the gas field, during Jura thrusting. New measurements with portable gas detector, incomplete but including hydrogen, on a former exploration well with accessible flux of gas, give the opportunity to comment gas saturation evolution more than a century after the 1906 discovery. The decreasing of hydrogen content since the discovery of the field is probably due to Sulphate-Reducing Bacteria activity.

Helium is a scarce strategic resource. Currently, all economically valuable helium resources are found in natural gas reservoirs. Owing to helium’s different formation and migration processes compared to natural gas’s, the traditional method of collecting wellhead gas to detect helium concentration may miss helium-rich layers in the vertical direction, which will not only cause the waste of helium resources, but also restrict the study of helium migration and accumulation mechanisms. To solve this problem, we designed a helium detector based on a quadrupole mass spectrometer. Through the combination of different inlet valves, we avoided gas mixing between different vertical layers during the inlet process and realized high-spatial-resolution helium concentration detection. We applied the helium detector to the Dongsheng gas field in the northern Ordos Basin, and the instrumental detection results were consistent with the laboratory analysis results of the wellhead gas, which demonstrated the stability of the helium detector in the field environment and the reliability of the data. Meanwhile, the results showed that the distribution of helium in the plane is highly heterogeneous, and the natural gas dessert layers and the helium dessert layers do not coincide in the vertical direction. In addition, we found a good correlation between helium and hydrogen concentrations. Combining our results with previous data, we propose a hydrogen–helium migration and accumulation model, which enriches the understanding of helium accumulation mechanisms and provides a basis for future helium resource exploration.

Dans la course pour trouver des moyens de production d'hydrogène propre et bon marché, les puits d'hydrogène naturel de Bourakèbougou offrent une solution prometteuse. Non seulement l'un d'entre eux a pu être exploité avec succès pour produire de l'électricité pour le village local, mais ses vingt-quatre puits actuels offrent également une occasion unique aux géo-scientifiques de déterminer les caractéristiques des réservoirs d'hydrogène naturel, la nature des roches couvertures et les différents processus qui interviennent dans son accumulation, migration et piégeage dans les roches. Ce travail de recherche présente les études de carottage, diagraphie, géophysique et géochimie qui ont été réalisées pour mieux caractériser la nature des réservoirs d’H2 de Bourakèbougou. L’étude de la géologie régionale et de l’ensemble de la zone sur la base de l’interprétation des données de forages et des données bibliographiques a dans un premier temps été réalisée. Cela a permis de fournir une nouvelle carte géologique de la zone ainsi qu’une coupe Nord-Sud de l’ensemble du bassin. L’analyse des faciès ainsi que les données de forages ont permis de montrer qu’il existait une corrélation entre les puits stratigraphiques F1 et F2 forés en 2011 à 100 km au nord de Bourakèbougou et les puits dans la zone d’étude située plus au sud. Une structure antiforme a également été identifiée autour de Bourakèbougou. L’ensemble de ces données ont permis de valider et de fournir un modèle sédimentaire cohérent de l’ensemble de la zone. Afin d’améliorer le cadre géochronologique entre les différents événements de la zone et caractériser la succession chronologique entre les sédiments et les intrusions, des datations U/Pb ont été réalisées sur les carbonates sur Bougou-6, le puits le plus profond, et sur le puits F2. Les âges obtenus sur certains carbonates ont été largement influencés par l’intrusion de méga-sills de dolérites entre 150 et 210 Ma. Ceci est confirmé par la datation de veines issues des carbonates du réservoir principal de Bougou-6 et du puits F2. Les veines datées, notamment celle dans le réservoir principal contenant de l’H2 (Bougou-6) a donné un âge d’environ 210 Ma, ce qui correspond à la période de magmatisme dit de la Central Atlantic Magmatic Province (CAMP). Seule la datation d’un carbonate situé à 890m a donné un âge manifestement synchrone du dépôt (620 ±100 Ma). Cet âge a permis de confirmer l’âge néoprotérozoïque des sédiments et d’établir un lien avec l’événement glaciaire néoprotérozoïque survenu entre 635-710 Ma (Sturtien + Marinoen). Les analyses de carottes, imageries de puits, diagraphie, rock Eval et calcimétrie ont permis de mettre en évidence que les carbonates supérieurs dans lesquels le maximum d’H2 est accumulé correspondent majoritairement à des carbonates dolomitiques de type cap carbonates, et que l’ensemble des accumulation d’H2 se trouvaient dans des cavités karstiques (thermo-karst). Différents faciès classiques du Néoprotérozoïque ont été identifiés le long de la série, notamment des stromatolithes, des microbialites, et des diamictites. Les roches situées au-dessus du réservoir principal qui font office de couverture, principalement une dolérite, ont été caractérisées afin de savoir quel rôle elles jouaient dans le piégeage de l’H2. Non seulement les dolérites jouent un rôle important dans le piégeage par leur épaisseur cumulée, mais, plus en profondeur, la présence d’aquifères pouvait également atténuer la migration de l’H2 en le ralentissant dans sa migration vers la surface. Les analyses diagraphiques couplées aux données de production ont permis de mettre en évidence que le système hydrogène est un système dynamique qui se recharge de manière spontanée pendant la production, contrairement aux systèmes de réservoir de pétrole et de gaz. Enfin, l’analyse des données géophysiques a permis d’apporter une compréhension sur la structure globale de la zone et la signature géophysique de la phase gaz
In the race to find clean and inexpensive ways to produce hydrogen, the natural hydrogen wells of Bourakèbougou offer a promising solution. Not only has one of them been successfully exploited to generate electricity for the local village, but its current twenty-four wells also provide a unique opportunity for geoscientists to determine the key characteristics of natural hydrogen reservoirs, the nature of the cap rocks, and the various processes involved in its accumulation, migration, and trapping in the rocks. This scientific research presents core, logging, geophysical, and geochemical studies that have been conducted to better characterize the nature of Bourakèbougou's H2 reservoirs. The study of regional geology and the entire area based on drilling data interpretation and bibliographic information was initially carried out. This resulted in a new geological map of the area and a North-South cross-section of the entire basin. Facies analysis and drilling data showed a correlation between stratigraphic wells F1 and F2 drilled in 2011, 100 km north of Bourakèbougou, and the wells in the study area located further to the south. An antiform structure was also identified around Bourakèbougou. All of these data helped validate and provide a coherent sedimentary model for the entire area. To improve the geochronological framework between different events in the area and to characterize the chronological sequence between sediments and intrusions, U/Pb dating was performed on carbonates from Bougou-6, the deepest well, and well F2. The ages obtained for some carbonates were largely influenced by the intrusion of mega-sills of dolerites between 150 and 210 million years ago (Ma). This was confirmed through dating veins derived from the carbonates of the main Bougou-6 reservoir and well F2. The dated veins, especially the one in the main reservoir containing H2, provided an age of approximately 210 Ma, corresponding to the period of magmatism known as the Central Atlantic Magmatic Province (CAMP). Only the dating of a carbonate located at 890m yielded an age that was clearly synchronous with the deposition (620 ± 100 Ma). This age confirmed the Neoproterozoic age of the sediments and established a connection with the Neoproterozoic glaciation event that occurred between 635-710 Ma (Sturtian + Marinoan). Core analyses, well imaging, logging, Rock Eval, and calcimetry revealed that the upper carbonates in which the highest amount of H2 is accumulated mainly consist of dolomitic cap carbonates, and all H2 accumulations are found in karstic cavities (thermokarst). Different Neoproterozoic facies were identified along the sequence, including stromatolites, microbialites, sandstones, and diamictites. The rocks located above the main reservoir, primarily dolerite, were characterized to understand their role in trapping H2. It was found that not only do the dolerites play a significant role in trapping due to their cumulative thickness, but the presence of aquifers can also attenuate H2 migration by slowing it down in its migration towards the surface. The diagraphic analyses, coupled with production data, have revealed that the hydrogen system is a dynamic system that is spontaneously recharged in H2-rich gas at the production timescale, unlike oil and gas reservoir systems. Finally, the analysis of geophysical data provided an understanding of the overall structure of the area and the gas phase geophysical signature

AbstractThis chapter analyzes EU-Brazil relations and joint initiatives to tackle the climate crisis, particularly the optimism surrounding green hydrogen as a possible new source of “sustainable connectivity” between them, through the prism of the psychoanalytical concept of disavowal. The chapter makes a distinction between climate denial, when climate change is deliberately denied, and climate disavowal, when climate change is acknowledged, but ineffective responses to mitigate it keep being repeated, in spite of contrary evidence and recurring failures. It argues that mainstream responses to climate change, centered on the conference of the parties (COP), which include net-zero pledges, carbon markets, and natural or artificial carbon sinks, constitute an international circuit of disavowal, in which the EU and Brazil are also caught up. This chapter presents some of the “solutions” being advanced to tackle climate change, presents the ample and readily available evidence that they do not work fast enough or on a scale needed to keep global warming below 1.5 °C, and investigates some of the reasons why they keep being offered despite all the evidence. It proposes that while climate denialism is obviously very dangerous, climate disavowal, which is in operation in the international climate regime, and in EU-Brazil relations and initiatives, including cooperation on green hydrogen, is much more insidious and constitutes a relation of cruel optimism, i.e., “when something you desire is actually an obstacle to your flourishing” (Berlant, 2011, p. 1). It may not work to mitigate the climate crisis, but it works in other spheres: it allows capitalist accumulation to continue unabated; it presents new market niches, new investment opportunities, and new activities in which one can feel useful, productive, creative, and virtuous. There are many benefits, material, symbolic, and psychic, being distributed by this international circuit of disavowal, which explains its durability and expansion despite, or because of, all the evidence that shows that we are heading for catastrophe.

In this chapter, the importance, fundamental mechanisms and benefits of energy storage techniques and applications of the different storage methods are represented in detail. It is expected to make the energy ready to use whenever and wherever it is requested. Energy storage is defined as the accumulation of energy for further usage when the demand arises. Energy can be stored one of the following forms mechanical, chemical, electrical, electrochemical or thermal. Energy storage is an advanced energy technology application that provides a significant potential for not only securing the reliability of the energy supply but also the operation of the energy transportation systems and their components more effectively, efficiently and economically. While underground storage of natural gas can provide the reliability of the energy supply, the storage of high-pressure hydrogen can help to put in practice new generation clean transportation options. The sensible and/or latent heat thermal energy storage applications are used to store the solar energy in space heating/cooling and hot water supply systems. The battery technology and electric to heat/heat to electric storage techniques are used to resolve the intermittency of the wind farms and maintain sustainable energy production. Supplying reliable energy to the end-users throughout the year is a complex mission that includes the management of the seasonal variations in energy supply, daily fluctuations in energy production and demand. On the other hand, it is critical to guarantee a continuous power supply without any interruption for industrial and household usage. That is the storage of energy has an essential and critical role in maintaining a balance between the demand and the supply.

Modern agricultural practices have contributed to the accumulation of herbicides, pesticides and their decomposition products in the soil. These pollutants are known to interact with soil organic matter to form covalent and/or noncovalent bonding associations. The covalent bonds are thought to result from addition or oxidative coupling reactions, some of which may be catalyzed by oxidoreductive enzymes. Noncovalent associations include such interactions as ion exchange, hydrogen bonding, protonation, charge transfer, ligand exchange, coordination through metal ions, van der Waals forces, and hydrophobic bonding. The association of pollutants with soil organic matter is an area of study that is of extreme interest for two reasons. First, dissolved organic matter present in lakes and streams is known to enhance the solubility of pollutants, which poses a real threat to the quality of fresh water supplies. Therefore, if we are to predict the movement of pollutants in the water table we need to have a mechanistic understanding of their interactions with dissolved humic materials. Second, early studies had indicated that some pollutants chemically bind to humic materials, thus reducing the risk of further transport and dispersion. If this chemical binding of the pollutants is irreversible, then this process may serve as a natural means for their detoxification. Regardless of the type of association, the first task in any mechanistic study is to characterize the reaction products structurally. In the case of noncovalent binding mechanisms, studies have focused on the physical characteristics of the process and not on the structure of the associated pollutant. Association studies are used to determine the sorption kinetics and transport of pollutants as well as their association constants. These types of studies utilize various techniques such as batch sorption, gas-purge desorption, column adsorption, and miscible displacement. All of these techniques are only capable of providing quantitative information on the amount of pollutant sorbed by a substrate. The study of the covalent binding of pollutants to humic substances has utilized 14C labeling in addition to various spectrometric techniques such as ultraviolet (UV) difference, fluorescence polarization and infrared (IR) spectroscopy.

Hydrogels crosslinked by homopolymerization of single component acrylate/methacrylate terminated polymers (e.g., poly(ethylene glycol) diacrylate, or PEGDA) were once the dominant biomaterials in biomedical applications, including the encapsulation of therapeutic agents and biological molecules. However, accumulating evidence has revealed many disadvantages of homopolymerized hydrogels, including heterogeneity of the crosslinking that adversely impacted the bioactivity of the encapsulated molecules. As such, recent years have witnessed the expansive use of modular click chemistry for the crosslinking of multicomponent hydrogels, typically consisting of two or more functionally distinct macromolecular building blocks. This chapter provides an overview of the crosslinking and applications of multicomponent hydrogels, focusing on those crosslinked by strain-promoted alkyne–azide cycloaddition (SPAAC), Michael-type addition, Diels–Alder (DA) reactions, inverse electron-demand Diels–Alder (iEDDA), thiol–ene polymerizations, and imine/hydrazone/oxime click reactions. This chapter also summarizes information regarding the characteristics, advantages, and limitations of commonly used synthetic (e.g., PEG, poly(acrylate), poly(vinyl alcohol), etc.) and naturally-derived macromers (e.g., gelatin, hyaluronic acid, etc.) for forming multicomponent hydrogels. Finally, an overview is given on the applications of multicomponent hydrogels in drug delivery, biofabrication, and 3D/4D cell culture.

Abstract In the context of global efforts to achieve carbon neutrality, Hydrogen (H2) has emerged as a key solution for reducing greenhouse gases emission. However, current methods of hydrogen production, such as thermochemical and electrochemical processes like electrolysis, methane reforming and pyrolysis, are generally expensive and suffer from issues including intensive carbon dioxide emission and high electricity consumption etc. (Ishaq et al. 2022; Younas et al. 2022). In fact, hydrogen gas can naturally occur in the subsurface which has been manifested by numerous hydrogen seepages found across the world (cf. Zgonnik 2020 and the references therein). Notably, a significant discovery of natural hydrogen was made accidently during drilling a water well (Bougou-1) in Mali in 1987. Subsequent exploration in the vicinity of Bougou-1 confirmed the existence of an active hydrogen system in the area (Prinzhofer et al. 2018), highlighting the possibility of commercial hydrogen accumulation in the subsurface. Moreover, there is a growing consensus that natural hydrogen could be an important alternative for hydrogen production (Zgonnik 2020). In recent years, extensive exploration activities and scientific research focusing on natural hydrogen occurrences, generation mechanisms, and accumulation processes have been conducted, particularly, in Africa (Moretti et al. 2022; Prinzhofer et al. 2018), Australia (Boreham et al. 2021; Frery et al. 2021; Leila eta al. 2022; Rezaee, 2021), Europe (Combaudon et al. 2022; Larin et al. 2015; Lefeuvre et al. 2022; Leila et al. 2021), Brazil (Moretti et al. 2021; Prinzhofer et al. 2019), and the USA (Guélard et al. 2017; Zgonnik et al. 2015). Geological investigations indicate that natural hydrogen is dominantly found on Precambrian cratons, ophiolite belts and mid-oceanic ridges (Rigollet and Prinzhofer, 2022). It occurs as gas leakages on the surface or is associated with other gases in the conventional and unconventional gas plays (Milkov 2022).

In the context of global carbon neutrality, using hydrogen as an energy source is becoming one of the key solutions to reduce greenhouse gas emissions. At present, hydrogen is mainly generated through a variety of thermochemical and electrochemical processes such as electrolysis, methane reforming and pyrolysis (Ishaq et al., 2022). However, these methods are generally expensive and suffer from serious issues such as intensive carbon dioxide emission and high electricity consumption (Younas et al., 2022). In fact, hydrogen gas can naturally occur in the subsurface, as evidenced by numerous hydrogen seepages found worldwide (cf. Zgonnik 2020 and the references therein). Furthermore, a significant amount of natural hydrogen was accidentally found during the drilling of a water well (Bougou-1) in Mali in 1987. The latest exploration in the vicinity of the Bougou-1 has indicated that an active hydrogen system exists in the area (Prinzhofer et al., 2018). A variety of scientific research and exploration activities have been conducted across the world to understand the occurrences, generation, and accumulation mechanisms of natural hydrogen (Tian et al., 2022). Natural hydrogen exploration is on the verge of becoming a full-fledged business, resembling hydrocarbon exploration that we are familiar with. Seismic is one of the most crucial geophysical data that is widely used to acquire a structural and stratigraphical description of the earth's subsurface and to understand complex geologic features. In addition to structural interpretation, seismic data is often used for reservoir characterization by quantitatively extracting both rock and fluid properties from the data through the solution of an inverse problem (Dvorkin et. Al., 2014). The discipline of rock physics plays an important role in seismic reservoir characterization by providing an accurate relationship between fluid and rock reservoir properties, elastic properties, and seismic responses. However, most seismic work is done for hydrocarbon exploration, and there are very few publications that demonstrate the utilization of geophysical seismic forward modeling and inversion for natural hydrogen exploration. Hydrogen accumulation in the subsurface relies on an effective "hydrogen system" in place, which shares some basic elements with a "hydrocarbon system," such as a reservoir and seal (Prinzhofer et al., 2018). Therefore, seismic exploration is assumed to be useful for hydrogen play detection and evaluation. One of the key aspects of natural hydrogen exploration is to understand the rock physical properties of hydrogen-bearing reservoir rocks in order to perform seismic-based reservoir characterization and potential hydrogen prospect evaluation. Currently, very few, if any, research works have been conducted regarding this topic. In comparison with hydrocarbon gases, hydrogen is characterized by ultra-light density and small molecular size. There is a significant knowledge gap in our routine rock physics analysis regarding how ultra-light gases like hydrogen affect the elastic properties of gas-bearing reservoir rocks. Questions such as whether it is possible to distinguish hydrogen gas with seismic data from other reservoir fluids (e.g., hydrocarbons, CO2, and brine) still need to be answered before conducting any seismic surveys targeting hydrogen plays.

The technology of large scale hydrogen transmission from central production facilities to refueling stations and stationary power sites is at present undeveloped. Among the problems which confront the implementation of this technology is the deleterious effect of hydrogen on structural material properties, in particular at gas pressure of 1000 psi which is the desirable transmission pressure suggested by economic studies for efficient transport. In this paper, a hydrogen transport methodology for the calculation of hydrogen accumulation ahead of a crack tip in a pipeline steel is outlined. The approach accounts for stress-driven transient diffusion of hydrogen and trapping at microstructural defects whose density may evolve dynamically with deformation. The results are used to discuss a lifetime prediction methodology for failure of materials used for pipelines and welds exposed to high-pressure hydrogen. Development of such predictive capability and strategies is of paramount importance to the rapid assessment of using the natural-gas pipeline distribution system for hydrogen transport and of the susceptibility of new alloys tailored for use in the new hydrogen economy.

A three-dimensional mathematical model of unsteady heat and mass transfer in porous hydrogen-absorbing media, accounting for presence of “passive” gas admixtures, is developed. New technique for evaluation of effective thermal conductivity of porous medium, which consists of microparticles, is suggested. Effect of “passive” gas admixtures on heat and mass transfer and sorption rate in metal hydride reactor is analyzed. It is shown that decrease of effective thermal conductivity and partial hydrogen pressure under decrease of hydrogen concentration effect on the hydrogen sorption rate considerably. It is disclosed that an intensive 3D natural convection takes place in a gas volume of reactor under certain conditions. Numerical analysis of heat and mass transfer in metal-hydride reactor of hydrogen accumulation systems was done. Sorption of hydrogen in cylindrical reactors with external cooling and central supply of hydrogen are analyzed including reactors with finned active volume and tube-shell reactor with external and internal cooling cartridge matrix. Unsteady three dimensional temperature and concentration fields in solid phase are presented. Integral curves representing the dynamic of sorption and desorption are calculated. Data on efficiency of considered reactors are presented and compared.

Anaerobic digesters are capable of producing methane-rich biogas from animal manure and also offer the advantages of controlling odors, reducing pathogens, and minimizing the environmental impact of the waste. Unfortunately, biogas is contaminated with hydrogen sulfide (H2S), a highly corrosive gas that is not compatible with many stock engine component materials. As a result, conventional engines can fail after several months of exposure to raw biogas. No small or medium piston engine-generators (<100 kWe) are currently available that can use this fuel without pretreatment to remove the H2S — a process that adds complexity, cost, consumables, and maintenance. As a result, many smaller digester installations simply flare the biogas rather than extracting any useful work from the fuel. Mainstream Engineering is developing a biogas-tolerant engine-generator (BTEG) that can use raw biogas without pretreatment to remove H2S. The development program involved a combination of approaches — materials replacement, coatings, engine control strategy changes, lubrication system changes, and additional sensors. A prototype 25 kW BTEG has been developed using a Ford DSG 2.3 L natural gas engine as the demonstration platform. In this paper, we report on performance testing of the baseline unmodified engine-generator and the BTEG. Measurements of fuel consumption, exhaust temperature, in-cylinder pressure, and exhaust gaseous emissions were made using several synthetic biogas mixtures (60–80% CH4/balance CO2) and pure methane. Because the methane fraction in biogas can change with digester conditions and weather — a method of estimating the biogas composition on the fly and adjusting the spark timing to compensate for the variability has been demonstrated. We also report on limited (100 hr) durability testing of the modified engine using fuel containing 3,000 ppmv of H2S. During this test, the oil was analyzed to track acidification of the engine oil and monitor the accumulation of sulfur or any wear metals.