Poland

This is article presents the results of the testing of the addition of a hydrogen-to-nitrogen-rich natural gas of the Lw group and its influence on the operation of selected gas-fired domestic appliances. The tests were performed on appliances used for the preparation of meals and hot water production for hygienic and heating purposes. The characteristics of the tested gas appliances are also presented. The burners and their controllers with which the tested appliances were equipped were adapted for the combustion of Lw natural gas. The tested appliances reflected the most popular designs for domestic gas appliances in their group used both in Poland and in other European countries. The tested appliances were supplied with nitrogen-rich natural gas of the Lw group and a mixture of this gas with hydrogen at 13.2% content. The article presents the approximate percentage compositions of the gases used during the tests and their energy parameters. The research was focused on checking the following operating parameters and the safety of the tested appliances: the rated heat input thermal efficiency combustion quality ignition flame stability and transfer. The article contains an analysis of the test results referring in detail to the issue of decreasing the heat input of the appliances by lowering the energy parameters of the nitrogen-rich natural gas of the Lw group mixture with a hydrogen addition and how it influenced the thermal efficiency achieved by the appliances. The conclusions contain an explanation regarding among other things how the design of an appliance influences the thermal efficiency achieved by it in relation to the heat input decrease. In the conclusions on the basis of the research results answers have been provided to the following questions: (1) Whether the hydrogen addition to the nitrogen-rich natural gas of the Lw group will influence the safe and proper operation of domestic gas appliances; (2) What hydrogen percentage can be added to the nitrogen-rich natural gas of the Lw group in order for the appliances adapted for combusting it to operate safely and effectively without the need for modifying them?

Underground hydrogen storage in geological structures is considered appropriate for storing large amounts of hydrogen. Using the geological Konary structure in the deep saline aquifers an analysis of the influence of depth on hydrogen storage was carried out. Hydrogen injection and withdrawal modeling was performed using TOUGH2 software assuming different structure depths. Changes in the relevant parameters for the operation of an underground hydrogen storage facility including the amount of H2 injected in the initial filling period cushion gas working gas and average amount of extracted water are presented. The results showed that increasing the depth to approximately 1500 m positively affects hydrogen storage (flow rate of injected hydrogen total capacity and working gas). Below this depth the trend was reversed. The cushion gas-to-working gas ratio did not significantly change with increasing depth. Its magnitude depends on the length of the initial hydrogen filling period. An increase in the depth of hydrogen storage is associated with a greater amount of extracted water. Increasing the duration of the initial hydrogen filling period will reduce the water production but increase the cushion gas volume.

Green hydrogen supply chain includes supply sources production and distribution of hydrogen produced from renewable energy sources (RES). It is a promising scientific and application area as it is related to the problem of instability of power grids supplied with RES. The article presents the conceptual assumptions of the research on the design of a functional multi-criteria model of the stabilization model architecture of energy distribution networks based on a hydrogen energy buffer taking into account the applicable use of hydrogen. The aim of the research was to identify the variables contributing to the stabilization of the operation of distribution networks. The method used to obtain this result was a systematic review of the literature using the technique of in-depth analysis of full-text articles and expert consultations. The concept of a functional model was described as a matrix in two dimensions in which the identified variables were embedded. The first dimension covers the phases of the supply chain: procurement and production along with storage and distribution. The second dimension divides the separate factors into technical economic and logistic. The research was conducted in the context of system optimization from the point of view of the operator of the energy distribution system. As a result of the research several benefits resulting from stabilization using a hydrogen buffer were identified. Furthermore the model may be used in designing solutions stabilizing the operation of power grids in which there are surpluses of electricity produced from RES. Due to the applied multidimensional approach the developed model is recommended for use as it enables the design of solutions in a systemic manner. Due to the growing level of energy obtained from renewable energy sources the issue of stabilizing the energy network is becoming increasingly important for energy network distributors.

The study focuses on the aspect of using the structure of gasars i.e. materials with directed open porosity as a potential hydrogen storage. The structure of the tested gasar is composed of a large number of thin open tubular pores running through the entire longitudinal section of the sample. This allows hydrogen to easily penetrate into the entire sample volume. The analysis of pore distribution showed that the longest diffusion path needed for full penetration of the metal structure with hydrogen is about L = 50–70 μm regardless of the external dimensions of the sample. Attempts to hydrogenate the magnesium gasar structure have shown its ability to accumulate hydrogen at a level of 1 wt%. The obtained results were compared with the best result was obtained for the ZK60 alloy after equal channel angular pressing (ECAP) and crushed to a powder form. The result obtained exceeded 4 wt% of hydrogen accumulated in the metal structure at theoretical 6.9 wt% maximum capacity. A model analysis of the theoretic absorption capacity of pure magnesium was also carried out based on the concentration of vacancies in the metal structure. The theoretical results obtained correlate well with experimental data.

An experimental study of flame propagation acceleration and transition to detonation in hydrogen-air mixture in 2 m long rectangular cross section channel filled with obstacles located at the bottom wall was performed. The initial conditions of the hydrogen-air mixture were 0.1 MPa and 293 K. Three different cases of obstacle height (blockage ratio 0.25 0.5 and 0.75) and four cases of obstacle density were studied with the channel height equal to 0.08 m. The channel width was 0.11 m in all experiments. The propagation of flame and pressure waves was monitored by four pressure transducers and four in house ion probes. The pairs of transducers and probes were placed at various locations along the channel in order to get information about the progress of the phenomena along the channel. To examine the influence of mixture composition on flame propagation and DDT the experiments were performed for the compositions of 20% 25% and 29.6% of H2 in air by volume. As a result of the experiments the deflagration and detonation regimes and velocities of flame propagation in the obstructed channel were determined.

Hydrogen vehicles may emerge as a leading contender to replace today’s internal combustion engine powered vehicles. A Phenomena Identification and Ranking Table exercise conducted as part of the European Network of Excellence on Hydrogen Safety (HySafe) identified the use of hydrogen vehicles in road tunnels as a topic of important concern. An internal project called HyTunnel was duly established within HySafe to review identify and analyse the issues involved and to contribute to the wider activity to establish the true nature of the hazards posed by hydrogen vehicles in the confined space of a tunnel and their relative severity compared to those posed by vehicles powered by conventional fuels including compressed natural gas (CNG). In addition to reviewing current hydrogen vehicle designs tunnel design practice and previous research a programme of experiments and CFD modelling activities was performed for selected scenarios to examine the dispersion and explosion hazards potentially posed by hydrogen vehicles. Releases from compressed gaseous hydrogen (CGH2) and liquid hydrogen (LH2) powered vehicles have been studied under various tunnel geometries and ventilation regimes. The findings drawn from the limited work done so far indicate that under normal circumstances hydrogen powered vehicles do not pose a significantly higher risk than those powered by petrol diesel or CNG but this needs to be confirmed by further research. In particular obstructions at tunnel ceiling level have been identified as a potential hazard in respect to fast deflagration or even detonation in some circumstances which warrants further investigation. The shape of the tunnel tunnel ventilation and vehicle pressure relief device (PRD) operation are potentially important parameters in determining explosion risks and the appropriate mitigation measures.

This work is aimed at solving the problem of converting diesel power drives to diesel– hydrogen fuels which are more environmentally friendly and less expensive alternatives to diesel fuel. The method of increasing the energy efficiency of diesel fuels has been improved. The thermochemical essence of using methanol as an alternative fuel to increase energy efficiency based on the provisions of thermotechnics is considered. Alternative methanol fuel has been chosen as the initial product for the hydrogen conversion process and its energy value cost and temperature conditions have been taken into account. Calculations showed that the caloric effect from the combustion of the converted mixture of hydrogen H2 and carbon monoxide CO exceeds the effect from the combustion of the same amount of methanol fuel. Engine power and fuel energy were increased due to the thermochemical regeneration of engine exhaust gas heat. An experimental setup was created to study the operation of a converted diesel engine on diesel–hydrogen products. Experimental studies of power and environmental parameters of a diesel engine converted for diesel–hydrogen products were performed. The studies showed that the conversion of diesel engines to operate using diesel– hydrogen products is technically feasible. A reduction in energy consumption was accompanied by an improvement in the environmental performance of the diesel–hydrogen engine working together with a chemical methanol conversion thermoreactor. The formation of carbon monoxide occurred in the range of 52–62%; nitrogen oxides in the exhaust gases decreased by 53–60% according to the crankshaft speed and loading on the experimental engine. In addition soot emissions were reduced by 17% for the engine fueled with the diesel–hydrogen fuel. The conversion of diesel engines for diesel–hydrogen products is very profitable because the price of methanol is on average 10–20% of the cost of petroleum fuel.

The article discusses issues related to the operation of fuel cells stack fed with hydrogen at low temperature. The test object was a Toyota Mirai passenger car equipped with this type of powertrain. Tests were carried out in a thermoclimatic chamber at the Cracow University of Technology. They had an initial character and their aim was to evaluate the work of individual subassemblies of the propulsion system including the hydrogen supply system in terms of operational safety.

The energy approach for determining the durability of structural elements at high temperature creep and hydrogen activity was proposed. It has been shown that the approach significantly simplifies research compared with the known ones. Approbation of the approach was carried out on the example of determining the indicators of durability of the Bridgman sample under conditions of creep and different levels of hydrogenation of the metal. It was shown that with an increase of hydrogen concentration in the metal from 2 to 10 ppm the durability of the test sample decreased from 22 to 58%.

With regard to the goals of the European HySafe Network research facilities are essential for the experimental investigation of relevant phenomena for testing devices and safety concepts as well as for the generation of validation data for the various numerical codes and models. The integrating activity ‘Integration of Experimental Facilities (IEF)’ has provided basic support for jointly performed experimental work within HySafe. Even beyond the funding period of the NoE HySafe in the 6th Framework Programme IEF represents a long lasting effort for reaching sustainable integration of the experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners emphasis was put on the know-how transfer between the partners. The strategy for reaching the objectives consisted of two parts. On the one hand a documentation of the experimental capacities has been prepared and analysed. On the other hand a communication base has been established by means of biannual workshops on experimental issues. A total of 8 well received workshops has been organised covering topics from measurement technologies to safety issues. Based on the information presented by the partners a working document on best practice including the joint experimental knowledge of all partners with regard to experiments and instrumentation was created. Preserving the character of a working document it was implemented in the IEF wiki website which was set up in order to provide a central communication platform. The paper gives an overview of the IEF network activities over the last 5 years.

Hydrogen-yielding fermentation conducted in bioreactors is an alternative method of hydrogen production. However unfavourable processes can seriously inhibit bio-hydrogen generation during the acidogenic step of anaerobic digestion. Here ascomycetous yeasts were identified as a major factor inhibiting the production of bio-hydrogen by fermentation. Changes in the performance of hydrogen-producing bioreactors including metabolic shift quantitative changes in the fermentation products decreased pH instability of the microbial community and consequently a dramatic drop in bio-hydrogen yield were observed following yeast infection. Ascomycetous yeasts from the genera Candida Kazachstania and Geotrichum were isolated from hydrogen-producing bioreactors. Yeast metabolites secreted into the growth medium showed antibacterial activity. Our studies indicate that yeast infection of hydrogen-producing microbial communities is one of the serious obstacles to use dark fermentation as an alternative method of bio-hydrogen production. It also explains why studies on hydrogen fermentation are still limited to the laboratory or pilot-scale systems.

The recent advances on the effects of microstructural refinement and various nano-catalytic additives on the hydrogen storage properties of metal and complex hydrides obtained in the last few years in the allied laboratories at the University of Waterloo (Canada) and Military University of Technology (Warsaw Poland) are critically reviewed in this paper. The research results indicate that microstructural refinement (particle and grain size) induced by ball milling influences quite modestly the hydrogen storage properties of simple metal and complex metal hydrides. On the other hand the addition of nanometric elemental metals acting as potent catalysts and/or metal halide catalytic precursors brings about profound improvements in the hydrogen absorption/desorption kinetics for simple metal and complex metal hydrides alike. In general catalytic precursors react with the hydride matrix forming a metal salt and free nanometric or amorphous elemental metals/intermetallics which in turn act catalytically. However these catalysts change only kinetic properties i.e. the hydrogen absorption/desorption rate but they do not change thermodynamics (e.g. enthalpy change of hydrogen sorption reactions). It is shown that a complex metal hydride LiAlH4 after high energy ball milling with a nanometric Ni metal catalyst and/or MnCl2 catalytic precursor is able to desorb relatively large quantities of hydrogen at RT 40 and 80 °C. This kind of behavior is very encouraging for the future development of solid state hydrogen systems.

Power-to-gas technology plays a key role in the success of the energy transformation. This paper addresses issues related to the legal and technical regulations specifying the rules for adding hydrogen to the natural gas network. The main issue reviewed is the effects of the addition of hydrogen to natural gas on the durability of diaphragm gas meters. The possibility of adding hydrogen to the gas network requires confirmation of whether within the expected hydrogen concentrations long-term operation of gas meters will be ensured without compromising their metrological properties and operational safety. Methods for testing the durability of gas meters applied at test benches and sample results of durability tests of gas meters are presented. Based on these results a metrological and statistical analysis was carried out to establish whether the addition of hydrogen affects the durability of gas meters over time. The most important conclusion resulting from the conducted study indicates that for the tested gas meter specimens there was no significant metrological difference between the obtained changes of errors of indications after testing the durability of gas meters with varying hydrogen content (from 0% to 15%).

An experimental investigation was performed to determine critical semi-open channel height (h*) and two-sided open channel width (w*) in which hydrogen-air detonation may propagate. Three types of gaseous mixture composition were used: 25% 29.6% and 40% of hydrogen in air. Experimental setup was based on rectangular (0.11 × 0.11 × 2 m) test channel equipped with acceleration section (0.11 × 0.11 × 1 m). Different channel heights h in range of 15–40 mm and widths w in range of 30–50 mm were used in the test channel. The critical height h* and width w* were defined for each investigated configuration. To determine representative detonation cell sizes λ and to calculate their relationship to h* and w* the sooted plate technique was used. The results showed that detonation in stoichiometric H2-air mixture may propagate in semi-open channel only when the channel height is very close to or higher than approximately 3λ. For less reactive mixtures critical relation h*/λ reaches 3.1 or 3.6 for mixtures with 25% and 40% of hydrogen in air respectively. For two-sided open channel similar relations w*/λ were close to 4.9 and 5.5 for 29.6%H2 and 40%H2 in air respectively.

The paper presents an overview of the main achievements of the internal project InsHyde of the HySafe NoE. The scope of InsHyde was to investigate realistic small-medium indoor hydrogen leaks and provide recommendations for the safe use/storage of indoor hydrogen systems. Additionally InsHyde served to integrate proposals from HySafe work packages and existing external research projects towards a common effort. Following a state of the art review InsHyde activities expanded into experimental and simulation work. Dispersion experiments were performed using hydrogen and helium at the INERIS gallery facility to evaluate short and long term dispersion patterns in garage like settings. A new facility (GARAGE) was built at CEA and dispersion experiments were performed there using helium to evaluate hydrogen dispersion under highly controlled conditions. In parallel combustion experiments were performed by FZK to evaluate the maximum amount of hydrogen that could be safely ignited indoors. The combustion experiments were extended later on by KI at their test site by considering the ignition of larger amounts of hydrogen in obstructed environments outdoors. An evaluation of the performance of commercial hydrogen detectors as well as inter-lab calibration work was jointly performed by JRC INERIS and BAM. Simulation work was as intensive as the experimental work with participation from most of the partners. It included pre-test simulations validation of the available CFD codes against previously performed experiments with significant CFD code inter-comparisons as well as CFD application to investigate specific realistic scenarios. Additionally an evaluation of permeation issues was performed by VOLVO CEA NCSRD and UU by combining theoretical computational and experimental approaches with the results being presented to key automotive regulations and standards groups. Finally the InsHyde project concluded with a public document providing initial guidance on the use of hydrogen in confined spaces.

The paper presents the results of the CFD inter-comparison exercise SBEP-V3 performed within the activity InsHyde internal project of the HYSAFE network of excellence in the framework of evaluating the capability of various CFD tools and modelling approaches in predicting the physical phenomena associated to the short and long term mixing and distribution of hydrogen releases in confined spaces. The experiment simulated was INERIS-TEST-6C performed within the InsHyde project by INERIS consisting of a 1 g/s vertical hydrogen release for 240 s from an orifice of 20 mm diameter into a rectangular room (garage) of dimensions 3.78x7.2x2.88 m in width length and height respectively. Two small openings at the front and bottom side of the room assured constant pressure conditions. During the test hydrogen concentration time histories were measured at 12 positions in the room for a period up to 5160 s after the end of release covering both the release and the subsequent diffusion phases. The benchmark was organized in two phases. The first phase consisted of blind simulations performed prior to the execution of the tests. The second phase consisted of post calculations performed after the tests were concluded and the experimental results made available. The participation in the benchmark was high: 12 different organizations (2 non-HYSAFE partners) 10 different CFD codes and 8 different turbulence models. Large variation in predicted results was found in the first phase of the benchmark between the various modelling approaches. This was attributed mainly to differences in turbulence models and numerical accuracy options (time/space resolution and discretization schemes). During the second phase of the benchmark the variation between predicted results was reduced.

In this article the solution based on hydrogen generation to increase the flexibility of energy storage systems is proposed. Operating characteristics of a hydrogen generator with integrated electrical energy storage and a photovoltaic installation were determined. The key role of the electricity storage in the proposed system was to maintain the highest operating efficiency related to the nominal parameters of the hydrogen generator. The hydrogen generators achieved the highest energy efficiency for the nominal operating point at the highest power output. Lead-acid batteries were used to ensure the optimal operating conditions for the hydrogen generator supplied with renewable energy throughout the day. The proposed system reduces significantly the hydrogen generator nominal power and devices in system operate in such a way to improve their efficiency and durability. The relations between individual components and their constraints were determined. The proposed solution is fully in-line with previously investigated technologies for improving grid stability and can help incorporate renewable energy sources to increase the sustainability of the energy sector and green hydrogen production.

The global policy solution seeks to reduce the usage of fossil fuels and greenhouse gas (GHG) emissions and biogas (BG) represents a solutions to these problems. The use of biogas could help cope with increased amounts of waste and reduce usage of fossil fuels. Biogas could be used in compressed natural gas (CNG) engines but the engine electronic control unit (ECU) needs to be modified. In this research a spark ignition (SI) engine was tested for mixtures of biogas and hydrogen (volumetric hydrogen concentration of 0 14 24 33 and 43%). In all experiments two cases of spark timing (ST) were used: the first for an optimal mixture and the second for CNG. The results show that hydrogen increases combustion quality and reduces incomplete combustion products. Because of BG’s lower burning speed the advanced ST increased brake thermal efficiency (BTE) by 4.3% when the engine was running on biogas. Adding 14 vol% of hydrogen (H2 ) increases the burning speed of the mixture and enhances BTE by 2.6% at spark timing optimal for CNG (CNG ST) and 0.6% at the optimal mixture ST (mixture ST). Analyses of the rate of heat release (ROHR) temperature and pressure increase in the cylinder were carried out using utility BURN in AVL BOOST software.

To have a uniform distribution of reactants is an advantage to a fuel cell. We report results for such a distributor with tree-like flow field plates (FFP). Numerical simulations have shown that the width scaling parameters of tree-like patterns in FFPs used in polymer electrolyte membrane fuel cells (PEMFC) reduces the viscous dissipation in the channels. In this study experimental investigations were conducted on a 2-layer FF plate possessing a tree-like FF pattern which was CNC milled on high-quality graphite. Three FF designs of different width scaling parameters were employed. I–V curves power curves and impedance spectra were generated at 70% 60% and 50% relative humidity (25 cm² active area) and compared to those obtained from a conventional 1-channel serpentine FF. It was found that the FF design with a width scaling factor of 0.917 in the inlet and 0.925 in the outlet pattern exhibited the best peak power out of the three designs (only 11% - 0.08 W/cm² lower than reference serpentine FF). Results showed that a reduction of the viscous dissipation in the flow pattern was not directly linked to a PEMFC performance increase. It was found that water accumulation together with a slight increase in single PEMFC resistance were the main reasons for the reduced power density. As further improvements a reduction of the number of branching generation levels and width scaling factor were recommended.

In Poland lignocellulose wastes constitute about 43% of municipal waste (∼4 417 Gg). Anaerobic and/or dark fermentation are sustainable methods of lignocellulosic waste-management and contribute greatly to ever increasing demand for energy and products. This paper presents the results of the theoretical potential of methane and hydrogen yields from lignocellulosic wastes. Also state-of-the-art methods in the field of lignocellulose fermentation as well as its development and pretreatment are discussed. The main reason for applying pretreatment is the decomposition (decrystallization) of cellulose and hemicellulose and cleavage of polymers into monomers which may be more easily digested by bacteria in DF and AD fermentation processes. At current price levels the cheapest methods are basic and acidic pretreatments. Acidic pretreatment is very efficient (especially using sulfuric acids) solubilizing up to 80% of lignocellulose but strong acids produce inhibitors and are highly corrosive. Alkaline pretreatment is a competitive and even more efficient (>80%) method to acidic pretreatment especially for some rigid materials that acid cannot solubilize. Oxidative pretreatment is usually expensive but can support the sacharisation process by either alkaline or acidic methods; in the case of NMMO efficiency reaching 82%. Ion-liquid pretreatment is selective (almost 100% sacharisation) but very costly and is too expensive for hydrogen production. The last methods can be profitable if some valuable by-products results. An efficient chemical pretreatment should be preceded by physical comminution e.g. mechanical which is the cheapest one.

This paper summarizes a series of the authors’ research in the field of assessing the operational degradation of oil and gas transit pipeline steels. Both mechanical and electrochemical properties of steels are deteriorated after operation as is their resistance to environmentally-assisted cracking. The characteristics of resistance to brittle fracture and stress corrosion cracking decrease most intensively which is associated with a development of in-bulk dissipated microdamages of the material. The most sensitive indicators of changes in the material’s state caused by degradation are impact toughness and fracture toughness by the J-integral method. The degradation degree of pipeline steels can also be evaluated nondestructively based on in-service changes in their polarization resistance and potential of the fracture surface. Attention is drawn to hydrogenation of a pipe wall from inside as a result of the electrochemical interaction of pipe metal with condensed moisture which facilitates operational degradation of steel due to the combined action of operating stresses and hydrogen. The development of microdamages along steel texture was evidenced metallographically as a trend to the selective etching of boundaries between adjacent bands of ferrite and pearlite and fractographically by revealing brittle fracture elements on the fracture surfaces namely delamination and cleavage indicating the sites of cohesion weakening between ferrite and pearlite bands. The state of the X52 steel in its initial state and after use for 30 years was assessed based on the numerical simulation method.

The paper presents the conceptual assumptions of research concerning the design of a theoretical multi-criteria model of a system architecture to stabilize the operation of power distribution networks based on a hydrogen energy buffer taking into account the utility application of hydrogen. The basis of the research process was a systematic literature review using the technique of in-depth analysis of full-text articles and expert consultations. The structural model concept was described in two dimensions in which the identified variables were embedded. The first dimension includes the supply chain phases: procurement and production with warehousing and distribution. The second dimension takes into account a comprehensive and interdisciplinary approach and includes the following factors: technical economic–logistical locational and formal–legal.

One of the options to reduce the dependence on fossil fuels is to produce gas with the quality of natural gas but based on renewable energy sources. It can encompass among other biogas generation from various types of biomass and its subsequent upgrading. The main aim of this study is to analyze under a combined technical economic and environmental perspective three of the most representative technologies for the production of biomethane (bio-based natural gas): (i) manure fermentation and its subsequent upgrading by CO₂ removal (ii) manure fermentation and biogas methanation using renewable hydrogen from electrolysis and (iii) biomass gasification in the atmosphere of oxygen and methanation of the resulted gas. Thermodynamic economic and environmental analyses are conducted to thoroughly compare the three cases. For these purposes detailed models in Aspen Plus software were built while environmental analysis was performed using the Life Cycle Assessment methodology. The results show that the highest efficiency (66.80%) and the lowest break-even price of biomethane (19.2 €/GJ) are reached for the technology involving fermentation and CO₂ capture. Concerning environmental assessment the system with the best environmental performance varies depending on the impact category analyzed being the system with biomass gasification and methanation a suitable trade-off solution for biomethane production.

Nanoporous carbons remain the most promising candidates for effective hydrogen storage by physisorption in currently foreseen hydrogen-based scenarios of the world’s energy future. An optimal sorbent meeting the current technological requirement has not been developed yet. Here we first review the storage limitations of currently available nanoporous carbons then we discuss possible ways to improve their storage performance. We focus on two fundamental parameters determining the storage (the surface accessible for adsorption and hydrogen adsorption energy). We define numerically the values nanoporous carbons have to show to satisfy mobile application requirements at pressures lower than 120 bar. Possible necessary modifications of the topology and chemical compositions of carbon nanostructures are proposed and discussed. We indicate that pore wall fragmentation (nano-size graphene scaffolds) is a partial solution only and chemical modifications of the carbon pore walls are required. The positive effects (and their limits) of the carbon substitutions by B and Be atoms are described. The experimental ‘proof of concept’ of the proposed strategies is also presented. We show that boron substituted nanoporous carbons prepared by a simple arc-discharge technique show a hydrogen adsorption energy twice as high as their pure carbon analogs. These preliminary results justify the continuation of the joint experimental and numerical research effort in this field.

This article discusses the technology for doping hydrogen into the fermenter to increase methane production and the amount of energy in the mixture. Hydrogen doping is anticipated to enable more carbon to be applied to produce methane. Hydrogen is proposed to be produced by using excess electricity from for example off-peak electricity hours at night. The possibilities of using a mixture of hydrogen and biogas for combustion in boilers and internal combustion engines have been determined. It has been proven that the volumetric addition of hydrogen reduces the heat of combustion of the mixture. Problems arising from hydrogen doping during the methane fermentation process have been identified.