Measurements of hydrogen solubility in various nitrobenzene-aniline mixtures were conducted in an autoclave reactor with a stirrer and control of temperature. The solubility of hydrogen was measured at 7 different values of temperature (30 °C, 40 °C, 50 °C, 90 °C, 130 °C, 170 °C, 210 °C, respectively), 3 values of stirrer rotation speed (1200 rpm, 1600 rpm, 2000 rpm, respectively) and a range of pressure of 20 ‒ 30 bar. Moreover, pure aniline, pure nitrobenzene and their mixtures with different concentrations were used. In the next step, values of Henry’s constant were calculated. Based on experimental data a dependence of Henry’s constant on temperature for pure aniline and pure nitrobenzene was proposed. Additionally, for each temperature correlations between Henry’s constant and aniline’s concentration in mixture of nitrobenzene-aniline were found.

On 14 January 2021, the Polish Ministry of Climate and the Environment submitted for public consultation the draft Polish Hydrogen Strategy until 2030 with a perspective until 2040. The project defines goals and activities related to developing national competencies and technologies for building a low-emission hydrogen economy. The draft announces the preparation of the “Hydrogen Law”, which is to be a package of changes to currently existing acts, particularly the Polish Energy Law. However, the proposals presented in the strategy do not seem to be fully consistent with the vision of the development of the future regulation of the hydrogen market presented by the European Commission. The article presents the Polish Hydrogen Strategy’s most important assumptions regarding the proposed legislative changes and discusses them in the context of the European strategy. The main focus is on two aspects related to the planned legislative changes that seem to be the most important at this stage in order to stimulate the development of the hydrogen market: the definition of hydrogen and the decision upon which production methods will be supported, and the future regulation of the hydrogen market.

In the era of the fight against global warming and in light of the search for energy with the least possible impact on the environment, interest in hydrogen has become a natural direction of development. Striving for a zero-emission Europe by 2050, the EU promotes low-emission and ultimately emission-free hydrogen for the widest possible use in the economy. Poland has developed a strategic document specifying the necessary activities for the use of hydrogen in the economy, which should at the same time maintain its competitiveness. Poland is currently the third producer of hydrogen in the European Union, which enables strategic thinking about maintaining Poland as a leading player on the hydrogen market in the long term. Currently, hydrogen in Poland is produced by (usually large) state-owned enterprises for their own needs with only a small margin of its resale. This is conventional hydrogen that is mainly obtained from natural gas. Therefore, it is difficult to talk about the hydrogen market, which must develop so that this raw material can be widely used in many branches of the modern economy. However, this requires taking a number of legislative, research and development and investment activities, as well as directing the national energy transformation to renewable energy sources, which may ultimately reduce the costs of pure hydrogen production. A number of actions have been taken, but the delay in legislative actions is slowing down the creation of the hydrogen market and is limiting the interest of private businesses in engaging in transformation activities.

Strategies and roadmaps are essential in areas that require long-term planning, such as the energy transition. Strategic plans can play an important role in developing visions for reducing CO2 emissions, developing renewable energy sources (RES) and hydrogen technologies. Hydrogen can be included in value chains in various sectors of the economy as raw material, emission-free fuel, or as an energy carrier and storage. The analysis of the future of hydrogen energy, which is an essential component of transforming the economy into an environmentally neutral one, is an integral part of the strategies of the European Union (EU) Member States.
This article reviews the strategic documents of the EU countries in the field of a hydrogen economy. Currently, six EU Member States have approved the hydrogen strategy (Germany, France, the Netherlands, Portugal, Hungary, Czech Republic), and two of them have roadmaps (Spain, Finland). The others are working on their completion in 2021. EU countries have the possibility of energy transformation based on a hydrogen policy, including green hydrogen, within the framework of the European Green Deal, i.e. aiming for climate neutrality and creating a modern and environmentally friendly economy.
By 2030, some of the countries plan to become a leader not only in the field of hydrogen production or RES development aimed at this process but also in the areas of research and development (R&D), sales of new technologies, and international cooperation. Member countries are focused on the production of clean hydrogen using electrolysis, creating incentives to stimulate demand, developing a hydrogen market, and implementing hydrogen infrastructure.

One of the problems limiting the use of vanadium as hydrogen permeable membranes is its high dilatation upon hydrogen dissolution in it. The information available for the dilatation coefficient value (Δυ/Ω) is contradictory, experimental information on the hydrogen solubility in vanadium within 100-1000 kPa at from 250 to 700°С is very limited. It does not enable to calculate the membrane dilatation. The article contains the measuring results for dilatation of strips made of vanadium foil 100 μm thick in a hydrogen atmosphere in the pressure range from 75 to 1000 kPa, temperatures from 250 to 700°С. The dilatation coefficient (Δυ/Ω) of polycrystalline vanadium was calculated based on the data obtained for dilatation and data previously published for the hydrogen concentration in the α-solid solution at 400°С. It is 0.165. Isobars for the temperature dependence of the hydrogen concentration in vanadium are calculated and constructed using the dilatation measuring results and the dilatation coefficient values. These data are agreed with theoretical and experimental data published previously. The limiting change in concentration and linear dimensions over the cross section of a hydrogen-permeable membrane from V was estimated at various temperatures and operating pressures at the membrane outlet based on the isobars plotted for temperature dependences of the CH/V. The conclusions are made on the optimal working conditions of Pd/V/Pd membranes when hydrogen is released from hydrogen-containing gas mixtures in accordance with Fick’s 1st law and data published previously for hydrogen concentration value at which solid hydrogen solutions in vanadium become brittle.

The paper presents the results of laboratory-scale tests of Polish hard coal steam gasification process combined with CO2 capture by absorption on CaO in a single step. Polish coal mine Piast was selected as a coal samples supplier based on the coal resources, quality, price and reactivity which makes it a potential supplier for a future full-scale gasification system. Steam gasification tests were conducted in a vertical fixed bed reactor at the temperature range of948-I I 73K in three series: with addition of CaO layered on a coal sample (II), mixed with a coal sample (111) and without adding CaO (I). The CaO increased both the hydrogen yield and content in gaseous products mixture in comparison with series l. As expected, mixing of CaO with coal sample improved the effects in terms of hydrogen yield and concentration in outlet gas when compared with CaO layered on a coal sample. An effective CO2 absorption was observed in tests with CaO mixed with a coal sample and at relatively low temperatures. At higher temperatures a reaction resulting in CO2 concentration increase in the produced gas mixture was observed.

Is hydrogen the answer, and if so, which technologies? Here we present an overview of “everything you need to know” about this promising new global energy source.

A series of steps taken to determine a kinetic equation that describes hydrogenation of propene on nickel catalyst is presented in this study. Mixed factorial design approach, belongs to designing of experiments methods was used to plane experiments. The investigations showed that the method applied makes possible determination of the kinetic equation in a relatively fast and cheap manner since only a few measurement points is required. The equation obtained was verified experimentally and statistically. Both tests showed satisfactory precision of anticipated values of the process rate.

The hydrogen embrittlement of metals is caused by the penetration and accumulation of hydrogen atoms inside the metal. The failure of the product due to hydrogen embrittlement is delayed in time and does not occur immediately after its manufacture, but several hours, days, or even weeks later. Therefore, the chances of detecting hydrogen embrittlement when checking the quality of the finished product are very slim. The use of high-strength bolts in industry is associated with the risk of hydrogen embrittlement. This phenomenon poses a threat to the safe use of devices by limiting or completely losing the functionality of the bolt joint. Even a low influence of moisture can trigger failure mechanisms.
The article proposes a method for assessing the risk of hydrogen embrittlement for high-strength bolts in class12.9. For this purpose, bolts made of material grade 32CrB4 were prepared and in a controlled manner the grain flow inconsistency was made, leading in extreme cases to the production of the forging lap. To perform the study, the device proposed by the European Assessment Document (EAD) was adapted to the testing of hydrogen embrittlement of threaded fasteners in concrete. The concrete substrate was replaced with metal spacers that were preloaded with a bolt. The use of the wedge distance under the bolt head led to the generation of two stress states – tensile and compressive, which translated into an increased risk of hydrogen embrittlement. After being tested, the bolts were visually and microscopically inspected to assess potential locations for cracks and hydrogen propagation. As a result of the conducted tests, it was found that the prepared test method allows to assess the resistance or susceptibility of the bolt to threats related to hydrogen embrittlement.

Many modern processes for the production and casting of metals and their alloys are carried out in protective gas atmospheres, which protect them, for example, from oxygen pollution. This applies, for example, to titanium, magnesium or aluminum alloys. Most liquid alloys are comprised of constituents that differ in vapor pressures, resulting in harmful phenomenon during melting due to evaporation of some of its components. This harmful process may be limited by the selection of a suitable gas atmosphere in which the liquid metal treatment process is carried out. In the paper, results of study on the impact of the type of gas atmosphere on the rate of evaporation of zinc in argon – hydrogen mixtures are presented. It should be noted that such mixtures are used, for example, in metal welding processes, in which it is also possible to evaporate a component of the so-called liquid metal pool. The research results showed that the rate of zinc evaporation increases with the increase of hydrogen content in the gas atmosphere.

The advancement of contemporary internal combustion engine technologies necessitates not only design enhancements but also the exploration of alternative fuels or fuel catalysts. These endeavors are integral to curbing the emission of hazardous substances in exhaust gases. Most contemporary catalyst additives are of complex chemical origins, introduced into the fuel during the fuel preparation stage. Nonetheless, none of these additives yield a significant reduction in fuel consumption. The research endeavors to develop the fuel system of a primary marine diesel engine to facilitate the incorporation of pure hydrogen additives into diesel fuel. Notably, this study introduces a pioneering approach, employing compressed gaseous hydrogen up to 5 MPa as an additive to the principal diesel fuel. This method obviates the need for extensive modifications to the ship engine fuel equipment and is adaptable to modern marine power plants. With the introduction of modest quantities of hydrogen into the primary fuel, observable shifts in the behavior of the fuel equipment become apparent, aligning with the calculations outlined in the methodology. The innovative outcomes of the experimental study affirm that the mass consumption of hydrogen is contingent upon the hydrogen supply pressure, the settings of the fuel equipment, and the structural attributes of the fuel delivery system. The modulation of engine load exerts a particularly pronounced influence on the mass admixture of hydrogen. The proportion of mass addition of hydrogen in relation to the pressure of supply (ranging from 4–12 MPa) adheres to a geometric progression (within the range of 0.04–0.1%). The application of this technology allows for a reduction in the specific fuel consumption of the engine by 2–5%, contingent upon the type of fuel system in use, and concurrently permits an augmentation in engine power by up to 5%. The resultant economic benefits are estimated at 1.5–4.2% of the total fuel expenses. This technology is applicable across marine, automotive, tractor, and stationary diesel engines. Its implementation necessitates no intricate modifications to the engine design, and its utilization demands no specialized skills. It is worth noting that, in addition to hydrogen, other combustible gases can be employed.

Current efforts are taken to increase resource efficiency, close material loops, and improve sustainable waste and by-products management. Thus, networking agro-food by-products andc onverting them into valuable products completely exhausting the potential of the raw material becomes significant. Model lignocellulosic and starch based biomass were subjected to pre-treatment with the application of acidic compounds, i.e. sulphuric (SA) and acetic (AA) acids. The response, i.e. total sugar content and derivatives content is investigated depending on variables changed during hydrolysis: concentration of acid, process duration, temperature and the size of the biomass particles. After saccharification, the hydrolysates were analysed via HPLC. Total reducing sugars concentration was in the range of 0.1 – 15.53 g/LAmong the substances present in the hydrolysates, protein, peptides, hydroxybenzyl acid (HA), 5-HMF, furfural (FF), vanillin (V), vanillic acid (VA), formic acid (FA) and levulinic acid (LA) were found in the range of 0.44 – 9.05 g/L and determined as total derivatives concentration. The aim of the study was to evaluate the measurable effects of the research and deliver information about the statistically important parameters for the process course and relations between the variables.

The production of biohydrogen from food waste (FW) by dark fermentation (DF) is a promising technology for commercialisation, as it is both a clean fuel and a suitable means of sustainable waste management. The described experiments compared the biohydrogen production yields obtained after the use of inoculum from two different sources: digested sludge from the wastewater treatment plant (WWTP) in Lodz and sludge from the anaerobic treatment of dairy industry wastewater (DIW) (unconcentrated and double-concentrated). In addition, the effect of different temperatures (70, 90 and 121°C) of inoculum pretreatment on the biohydrogen production in DF was tested. The process was carried out batchwise at 37°C. The highest yield of hydrogen production was obtained after the inoculum pretreatment at 70°C. In addition, a higher amount of hydrogen could be obtained by using sludge from the WWTP as the inoculum (96 cm3 H2/gTVSFW) than unthickened sludge from the DIW (85 cm ³ H ₂/g _TVSFW). However, after thickening the sludge from the dairy industry, and at the same time balancing the dry matter of both sludges, the hydrogen production potential was comparable for bothsludges (for the WWTP sludge – 96 and for the DIW sludge – 93 cm ³ H ₂/g _TVSFW). The kinetics of hydrogen production was described by modified Gompertz equation, which showed a good fit (determination coefficient R2 between 0.909 and 0.999) to the experimental data.

Hydrogen-based power engineering has great potential for upgrading present and future structures of heat and electricity generation and for decarbonizing industrial technologies. The production of hydrogen and its optimal utilization in the economy and transport for the achievement of ecological and economic goals requires a wide discussion of many technological and operational – related issues as well as intensive scientific research. The introductory section of the paper indicates the main functions of hydrogen in the decarbonization of power energy generation and industrial processes, and discusses selected assumptions and conditions for the implementation of development scenarios outlined by the Hydrogen Council, 2017 and IEA, 2019. The first scenario assumes an 18% share of hydrogen in final energy consumption in 2050 and the elimination 6 Gt of carbon dioxide emissions per year. The second document was prepared in connection with the G20 summit in Japan. It presents the current state of hydrogen technology development and outlines the scenario of their development and significance, in particular until 2030. The second part of the paper presents a description of main hybrid Power-to-Power, Power-to-Gas and Power-to-Liquid technological structures with the electrolytic production of hydrogen from renewable sources. General technological diagrams of the use of water and carbon dioxide coelectrolysis in the production of fuels using F-T synthesis and the methanol production scheme are presented. Methods of integration of renewable energy with electrolytic hydrogen production technologies are indicated, and reliability indicators used in the selection of the principal modules of hybrid systems are discussed. A more detailed description is presented of the optimal method of obtaining a direct coupling of photovoltaic (PV) panels with electrolyzers.

Nowadays, hydrogen is considered a potential successor to the current fossil-fuel-based energy. Within a few years, it will be an essential energy carrier, and an economy based on hydrogen will require appropriate hydrogen storage systems. Due to their large capacity, underground geological structures (deep aquifers, depleted hydrocarbon fields, salt caverns) are being considered for hydrogen storage. Their use for this purpose requires an understanding of geological and reservoir conditions, including an analysis of the preparation and operation of underground hydrogen storage. The results of hydrogen injection and withdrawal modeling in relation to the deep Lower Jurassic, saline aquifer of the Konary geological structure (trap) are presented in this paper. A geological model of the considered structure was built, allowable pressures were estimated, the time period of the initial hydrogen filling of the underground storage was determined and thirty cycles of underground storage operations (gas injection and withdrawal) were simulated. The simulations made it possible to determine the essential parameters affecting underground hydrogen storage operation: maximum flow rate of injected hydrogen, total capacity, working gas and cushion gas capacity. The best option for hydrogen storage is a two-year period of initial filling, using the least amount of cushion gas. Extracted water will pose a problem in relation to its disposal. The obtained results are essential for the analysis of underground hydrogen storage operations and affect the economic aspects of UHS in deep aquifers.

The aim of this work is to examine the impact of the hydrogen blended natural gas on the linepack energy under emergency scenarios of the pipeline operation. Production of hydrogen from renewable energy sources through electrolysis and subsequently injecting it into the natural gas network, gives flexibility in power grid regulation and the energy storage. In this context, knowledge about the hydrogen percentage content, which can safely effect on materials in a long time steel pipeline service during transport of the hydrogen-natural gas mixture, is essential for operators of a transmission network. This paper first reviews the allowable content of hydrogen that can be blended with natural gas in existing pipeline systems, and then investigates the impact on linepack energy with both startup and shutdown of the compressors scenarios. In the latter case, an unsteady gas flow model is used. To avoid spurious oscillations in the solution domain, a flux limiter is applied for the numerical approximation. The GERG-2008 equation of state is used to calculate the physical properties. For the case study, a tree-topological high pressure gas network, which have been inservice for many years, is selected. The outcomes are valuable for pipeline operators to assess the security of supply.

This study explores the hydrogen embrittlement behaviour of two Ni-based superalloys using electrochemical hydrogen charging. Two types of tensile specimens with different geometry for the Haynes 617 and Hastelloy X alloys were electrochemically hydrogen-charged, and then a slow strain rate test was conducted to investigate the hydrogen embrittlement behaviour. Unlike the ASTM standard specimens, two-step dog-bone specimens with a higher surface-area-to-volume ratio showed higher sensitivity to hydrogen embrittlement because hydrogen atoms are distributed mostly on the surface area. On the other hand, the Haynes 617 alloy had a lower hydrogen embrittlement resistance than that of the Hastelloy X alloy due to its relatively large grain size and the presence of precipitates at grain boundaries. The Haynes 617 alloy primarily showed an intergranular fracture mode with cracks from the slip band, whereas the Hastelloy X alloy exhibited a combination of transgranular and intergranular fracture behavior under hydrogen-charged conditions.

This study describes how microstructural constituents affected the hydrogen embrittlement resistance of high-strength pipeline steels. The American Petroleum Institute (API) X60, X70, and X80 pipeline steels demonstrated complicated microstructure comprising polygonal ferrite (PF), acicular ferrite, granular bainite (GB), bainitic ferrite (BF), and secondary phases, e.g., the martensite-austenite (MA) constituent, and the volume fraction of the microstructures was dependent on alloying elements and processing conditions. To evaluate the hydrogen embrittlement resistance, a slow strain rate test (SSRT) was performed after electrochemical hydrogen charging. The SSRT results indicated that the X80 steel with the highest volume fraction of the MA constituent demonstrated relatively high yield strength but exhibited the lowest hydrogen embrittlement resistance because the MA constituent acted as a reversible hydrogen trap site.

Hydrogen as a raw material finds its main use and application on the Polish market in the chemical industry. Its potential applications for the production of energy in fuel cell systems or as a fuel for automobiles are widely analyzed and commented upon ever more frequently. At present, hydrogen is produced worldwide mainly from natural gas, using the SMR technology or via the electrolysis of water. Countries with high levels of coal resources are exceptional in that respect, as there the production of hydrogen is increasingly based on gasification processes. China is such an example. There some 68% of hydrogen is generated from coal. The paper discusses the economic efficiency of hydrogen production technologies employing lignite gasification, comparing it with steam reforming of natural gas technology (SMR). In present Polish conditions, this technology seems to be the most probable alternative for natural gas substitution.

For the purpose of evaluating the economic efficiency, a model has been developed, in which a sensitivity analysis has been carried out. An example of the technological process of energy-chemical processing of lignite has been presented, based on the gasification process rooted in disperse systems, characteristics of the fuel has been discussed, as well as carbon dioxide emission issues. Subsequently, the assumed methodology of economic assessment has been described in detail, together with its key assumptions. Successively, based on the method of discounted cash flows, the unit of hydrogen generation has been determined, which was followed by a detailed sensitivity analysis, taking the main risk factors connected with lignite/coal and natural gas price relations, as well as the price of carbon credits (allowances for emission of CO2) into account.

Looking for alternative sources of energy to generate electricity has been a hot topic for society for a very long time. The need to replace current energy resources such as fuel, oil, and gas is increasing, and the replacement comes from energy obtained from the wind, sun, and sea waves. In many cases, valuable raw materials can be obtained in addition to energy production, while having a significant environmental effect simultaneously.
The shortage of energy and raw material resources in many countries stimulates the growth of interest in all potential sources of energy – solar, wind, wave, tidal – has lead to accelerating the demand for oil and gas, shale gas, as well as the expansion of the areas for the cultivation of technical crops for biofuels. Classical energy resources like oil, gas and coal are serious polluters of the natural environment. Especially harmful is the release of carbon dioxide and sulfur oxides during the exploitation of these resources.
A significant energy raw material potential of non-traditional resources lies in the waters and bottom of the Black Sea, which is a natural geobiotechnological reactor, capable of producing a variety of energy raw resources.
This paper discusses the use of hydrogen sulfide available in the Black Sea waters to produce energy and useful industrial products and proposes the respective. The technology also has an ecological effect in terms of the purification of the hydrogen sulfide pool. The paper also discusses some technologies for the separation of hydrogen sulfide to hydrogen and sulfur. An estimation of the heat value of hydrogen sulfide in the water of the Black Sea is also presented.

The rational management of underground space, especially when used for various purposes, requires a comprehensive approach to the subject. The possibility of using the same geological structures (aquifers, hydrocarbon reservoirs, and salt caverns) for the storage of CH4, H2 and CO2 may result in conflicts of interest, especially in Poland. These conflicts are related to the use of the rock mass, spatial planning, nature protection, and social acceptance.
The experience in the field of natural gas storage can be transferred to other gases. The geological and reservoir conditions are crucial when selecting geological structures for gas storage, as storage safety and the absence of undesirable geochemical and microbiological interactions with reservoir fluids and the rock matrix are essential. Economic aspects, which are associated with the storage efficiency, should also be taken into account.
The lack of regulations setting priorities of rock mass development may result in the use of the same geological structures for the storage of various gases. The introduction of appropriate provisions to the legal regulations concerning spatial development will facilitate the process of granting licenses for underground gas storage. The provisions on area based nature protection should take other methods of developing the rock mass than the exploitation of deposits into account. Failure to do so may hinder the establishment of underground storage facilities in protected areas. Knowledge of the technology and ensuring the safety of underground gas storage should translate into growing social acceptance for CO2 and H2storage.

The introduction highlights the technologies of converting the chemical energy of biomass and municipal waste into various forms of final energy (electricity, heat, cooling, new fuels) as important in the pursuit of a low-carbon economy, especially for energy and transport sector. The work continues to focus mainly on gasification as a process of energy valorization of the initial form of biomass or waste, which does not imply that other methods of biomass energy use are not considered or used. Furthermore, the article presents a general technological flowchart of gasification with a gas purification process developed by Investeko S.A. in the framework of Lifecogeneration.pl. In addition, selected properties of the municipal waste residual fraction are described, which are of key importance when selecting the technology for its energy recovery. Significant quality parameters were identified, which have a significant impact on the production and quality of syngas, hydrogen production and electricity generation capacity in SOFC cells. On the basis of the research on the waste stream, a preliminary qualitative assessment was made in the context of the possibility of using the waste gasification technology, syngas production with a significant share of hydrogen and in combination with the technology of energy production in oxide-ceramic SOFC cells. The article presents configurations of energy systems with a fuel cell, with particular emphasis on oxide fuel cells and their integration with waste gasification process. An important part of the content of the article is also the environmental protection requirements for the proposed solution.

Humanity is being forced to alter how we use energy sources, to move away from fossil fuels and focus instead on renewable, especially solar energy. This transformation may prove to be the long sought-after “holy grail” of energy.

Entrapped gases, solidification shrinkage and non-metallic compound formation are main sources of porosity in aluminium alloy castings. Porosity is detrimental to the mechanical properties of these castings; therefore, its reduction is pursued. Rotary degassing is the method mostly employed in industry to remove dissolved gases from aluminium melts, reducing porosity formation during solidification of the cast part. Recently, ultrasonic degassing has emerged as a promising alternative thanks to a lower dross formation and higher energy efficiency. This work aims to evaluate the efficiency of the ultrasonic degasser and compare it to a conventional rotary degassing technique applied to an AlSi10Mg alloy. Degassing efficiency was evaluated employing the reduced pressure test (RPT), where samples solidified under reduced pressure conditions are analysed. Factors affecting RPT were considered and temperature parameters for the test were established. The influence of ultrasonic degassing process parameters, such as degassing treatment duration and purging gas flow rate were studied, as well as treated aluminium volume and oxide content. Finally, ultrasonic degassing process was contrasted to a conventional rotary degassing technique, comparing their efficiency.