Publications

The Poza de la Sal diapir is a closed circular depression with Cretaceous Mesozoic materials formed by gypsum Keuper clays and a large extension of salt in the center with intercalations of ophite. The low seismic activity of the area the reduced permeability and porosity of the salt caverns and the proximity to the Páramo de Poza wind park make it a suitable place for the construction of a facility for underground storage of green hydrogen obtained from surplus wind power. The design of a cavern for hydrogen storage at a depth of 1000 m takes into account the differences in stresses temperatures and confining pressures involved in the salt deformation process. During the 8 months of the injection phase 23.0 GWh can be stored in the form of hydrogen obtained from the wind energy surplus to be used later in the extraction phase. The injection and extraction ratio must be developed under the conditions of geomechanical safety of the cavity so as to minimize the risks to the environment and people by conditioning the gas pressure inside the cavity to remain within a given range.

Clean fuel is advocated to be used for sustainability. The number of liquefied petroleum gas (LPG) and hydrogen vehicles is increasing globally. Explosion hazard is a threat. On the other hand the use of hydrogen is under consideration in Hong Kong. Explosion hazards of these clean fuel (LPG and hydrogen) vehicles were studied and are compared in this paper. The computational fluid dynamics (CFD) software Flame Acceleration Simulator (FLACS) was used. A car garage with a rolling shutter as its entrance was selected for study. Dispersion of LPG from the leakage source with ignition at a higher position was studied. The same garage was used with a typical hydrogen vehicle leaking 3.4 pounds (1.5 kg) of hydrogen in 100 s the mass flow rate being equal to 0.015 kgs−1 . The hydrogen vehicle used in the simulation has two hydrogen tanks with a combined capacity of 5 kg. The entire tank would be completely vented out in about 333 s. Two scenarios of CFD simulation were carried out. In the first scenario the rolling shutter was completely closed and the leaked LPG or hydrogen was ignited at 300 s after leakage. The second scenario was conducted with a gap height of 0.3 m under the rolling shutter. Predicted results of explosion pressure and temperature show that appropriate active fire engineering systems are required when servicing these clean fuel vehicles in garages. An appropriate vent in an enclosed space such as the garage is important in reducing explosion hazards.

The main goal of THyGA’s WP5 is to investigate ways to adapt residential or commercial appliances that have safety or performance issues to different levels of H2 concentrations in natural gas. This first deliverable presents some possible mitigation measures based on a literature study and some calculations.<br/>Acting on gas quality to avoid that hydrogen addition enhance current gas properties variations was explored several times in the past. Designing new appliances that could operate with variable gas composition including hydrogen. Dealing with existing appliances in order to guaranty safety for users and appliances.

Since the 1970s hydrogen has been considered as a possible energy carrier for the storage of renewable energy. The main focus has been on addressing the ultimate challenge: developing an environmentally friendly successor for gasoline. This very ambitious goal has not yet been fully reached as discussed in this review but a range of new lightweight hydrogen-containing materials has been discovered with fascinating properties. State-of-the-art and future perspectives for hydrogen-containing solids will be discussed with a focus on metal borohydrides which reveal significant structural flexibility and may have a range of new interesting properties combined with very high hydrogen densities.

The application of appropriate procedures in the downstream gas industry (defined as any works downstream of the emergency control value) is critical in protecting consumers of gas both domestic and commercial. The two primary standard setting bodies for the downstream gas industry are the British Standard Institution (BSI) and the Institution of Gas Engineers and Managers (IGEM). To ensure only competent engineers carry out works on a gas installation all gas businesses or selfemployed persons must become a member of Gas Safe Register as stipulated by the Gas Safety (Installation and Use) Regulations 1998 1 and each gas operative shall be included on the register and hold a valid license card that covers the areas of gas work they undertake. Membership of the Gas Safe Register is contingent upon demonstration of competency the recognised competency assessments are based on the relevant BSI and IGEM standards. Therefore the primary source of a gas operative’s competency to work on natural gas installations are the associated BSI and IGEM natural gas downstream standards.<br/>Investigation was undertaken to understand the potential implications of introducing 20 mol% hydrogen (H2) within natural gas supplies on the ability of gas operatives to competently carry out works. This investigation took the form of identifying all BSI and IGEM standards that could be applied on natural gas installations and reviewing them within the context of the known effects of introducing a 20 mol% H2 blend. Following review a series of technical questions were generated and responded to by the Health and Safety Executive Science Division. The responses provided were then reviewed and if considered necessary challenged to provide further information. The procedural review was led by Blue Flame Associates a body deemed sufficiently competent in downstream standards training certification and investigation. The report was subsequently reviewed by industry and feedback received. The industry comments were reviewed by the Project Team and where considered necessary the report was updated.

Decentralised renewable energy production in the form of fuels or electricity can have large scale deployment in future energy systems but the feasibility needs to be assessed. The novelty of this paper is in the design and implementation of a mixed integer linear programming optimisation model to minimise the net present cost of decentralised hydrogen production for different energy demands on neighbourhood urban scale while simultaneously adhering to European Union targets on greenhouse gas emission reductions. The energy system configurations optimised were assumed to possibly consist of a variable number or size of wind turbines solar photovoltaics grey grid electricity usage battery storage electrolyser and hydrogen storage. The demands served are hydrogen for heating and mobility and electricity for the households. A hydrogen residential heating project currently being developed in Hoogeveen The Netherlands served as a case study. Six scenarios were compared each taking one or multiple energy demand services into question. For each scenario the levelised cost of hydrogen was calculated. The lowest levelised cost of hydrogen was found for the combined heating and mobility scenario: 8.36 € kg− 1 for heating and 9.83 € kg− 1 for mobility. The results support potential cost reductions of combined demand patterns of different energy services. A sensitivity analysis showed a strong influence of electrolyser efficiency wind turbine parameters and emission reduction factor on levelised cost. Wind energy was strongly preferred because of the lower cost and the low greenhouse gas emissions compared to solar photovoltaics and grid electricity. Increasing electrolyser efficiency and greenhouse gas emission reduction of the used technologies deserve further research.

The main objective of this paper is to select the optimal configuration of a ship’s power system considering the use of fuel cells and batteries that would achieve the lowest CO2 emissions also taking into consideration the number of battery cycles. The ship analyzed in this work is a Platform Supply Vessel (PSV) used to support oil and gas offshore platforms transporting goods equipment and personnel. The proposed scheme considers the ship’s retrofitting. The ship’s original main generators are maintained and the fuel cell and batteries are installed as complementary sources. Moreover a sensitivity analysis is pursued on the ship’s demand curve. The simulations used to calculate the CO2 emissions for each of the new hybrid configurations were developed using HOMER software. The proposed solutions are auxiliary generators three types of batteries and a protonexchange membrane fuel cell (PEMFC) with different sizes of hydrogen tanks. The PEMFC and batteries were sized as containerized solutions and the sizing of the auxiliary engines was based on previous works. Each configuration consists of a combination of these solutions. The selection of the best configuration is one contribution of this paper. The new configurations are classified according to the reduction of CO2 emitted in comparison to the original system. For different demand levels the results indicate that the configuration classification may vary. Another valuable contribution of this work is the sizing of the battery and hydrogen storage systems. They were installed in 20 ft containers since the installation of batteries fuel cells and hydrogen tanks in containers is widely used for ship retrofit. As a result the most significant reduction of CO2 emissions is 10.69%. This is achieved when the configuration includes main generators auxiliary generators a 3119 kW lithium nickel manganese cobalt (LNMC) battery a 250 kW PEMFC and 581 kg of stored hydrogen.

The HyDeploy project has undertaken a programme of work to assess the effect of hydrogen addition on the safety and performance of gas appliances and installations. A representative set of eight appliances have been assessed in laboratory experiments with a range of test gases that explored high and low Wobbe Index and hydrogen concentrations up to 28.4 % mol/mol. These tests have demonstrated that the addition of hydrogen does not affect the key hazard areas of CO production light back flame out or the operation of flame failure devices. It was identified that for some designs of gas fire appliances the operation of the oxygen depletion sensors may be affected by the addition of hydrogen. Testing of the gas fires that are present at Keele University that use oxygen depletion sensors have been shown to operate satisfactorily.<br/>A comprehensive onsite survey programme at Keele University has assessed 95% of the installations (126 of 133) that will receive the hydrogen blended gas during the HyDeploy trial. Where access to properties was not possible then the information obtained revealed that the appliances were annually checked either through British Gas service contracts or as a result of being rental properties. The onsite testing programme assessed installations for gas tightness and appliance combustion safety and operation with normal line gas G20 reference gas and two hydrogen blended gases. The checks identified a small number instances were remedial work was required to correct poor condition or operation. Only one case was found to be immediately dangerous which was capped off until repair work was undertaken. CO and smoke alarms were fitted in approximately half of properties and alarms were provided as required to the occupants. Gas tightness tests identified leaks in three installations. Where installations are gas tight then analysis has shown that no additional leaks would occur with hydrogen blended gas. There were no issues identified with the combustion performance of those appliances that were operating correctly and results were in line with those obtained in the laboratory testing programme.<br/>The findings of the Appliance and Installation testing program have been used to define the input values into the HyDeploy quantified risk assessment (QRA) where Keele University specific operation is different to GB as a whole or where the findings show the addition of hydrogen will change the risk profile.<br/>Click on supplements to see the other documents from this report

Decarbonization plays an important role in future energy systems for reducing greenhouse gas emissions and establishing a zero-carbon society. Hydrogen is believed to be a promising secondary energy source (energy carrier) that can be converted stored and utilized efficiently leading to a broad range of possibilities for future applications. Moreover hydrogen and electricity are mutually converted creating high energy security and broad economic opportunities toward high energy resilience. Hydrogen can be stored in various forms including compressed gas liquid hydrogen hydrides adsorbed hydrogen and reformed fuels. Among these liquid hydrogen has advantages including high gravimetric and volumetric hydrogen densities and hydrogen purity. However liquid hydrogen is garnering increasing attention owing to the demand for long storage periods long transportation distances and economic performance. This paper reviews the characteristics of liquid hydrogen liquefaction technology storage and transportation methods and safety standards to handle liquid hydrogen. The main challenges in utilizing liquid hydrogen are its extremely low temperature and ortho- to para-hydrogen conversion. These two characteristics have led to the urgent development of hydrogen liquefaction storage and transportation. In addition safety standards for handling liquid hydrogen must be updated regularly especially to facilitate massive and large-scale hydrogen liquefaction storage and transportation.

The results of studies of the influence of hydrogen and hydrogen-containing gas additives on the parameters of various types of internal combustion engines are analyzed and summarized. It made possible to identify the features of the effect on the combustion of fuel during internal combustion engine operation at partial loads. The dependences of reducing the toxicity and fuel consumption of internal combustion engine on the amount of addition of hydrogen and a hydrogen-containing gas to the air-fuel mixture were obtained. It allowed to establish quantitative effects of free hydrogen in particular to quantify the region of small hydrogen additives and the conditions under which hydrogen exhibits the qualities of a chemically active component of the mixture.