Institution of Gas Engineers & Managers

Renewable Energy Community (REC) is a new paradigm in European Union to produce transform share and sell renewables at a local consumer level also via e-fuel (i.e. hydrogen). This work investigates the economic feasibility of a hydrogen Power-to-Gas (PtG) system realized inside a REC using only excess renewable electricity not consumed by REC itself. A single centralized photovoltaic (PV) plant is directly connected to an electrolyser; a hydrogen compressor and two hydrogen storages at low and high pressure complete the PtG system. A scenario of a REC composed by 450 residential electric users (around 1000 people) has been analysed coupled with described PtG considering eight different sizes of PV plant. In the study Italian subsidies to REC shared energy are evaluated as incentives to hydrogen production. An optimal size of PtG components for each PV size is investigated at the limit of economical sustainability evaluating net present value (NPV) positive and near zero. Results show that for the considered REC it is possible to produce and sell up to around 3 tons per year of green hydrogen at most to the same lowest selling price declared currently in the Italian market (5 €/kg).

Hydrogen a green energy carrier is one of the most promising energy sources. However，it is currently mainly produced from depleting fossil fuels with high carbon emissions which has serious negative effects on the economy and environment. To address this issue sustainable hydrogen production from bio-energy with carbon capture and storage (HyBECCS) is an ideal technology to reduce global carbon emissions while meeting energy demand. This review presents an overview of the latest progress in alkaline thermal treatment (ATT) of biomass for hydrogen production with carbon storage especially focusing on the technical characteristics and related challenges from an industrial application perspective. Additionally the roles of alkali and catalyst in the ATT process are critically discussed and several aspects that have great influences on the ATT process such as biomass types reaction parameters and reactors are expounded. Finally the potential solutions to the general challenges and obstacles to the future industrial-scale application of ATT of biomass for hydrogen production are proposed.

China is by far the world’s largest producer and consumer of hydrogen mostly from coal and other fossil fuels and the country has an ambitious hydrogen strategy. In this podcast we dive into the provincial strategies on hydrogen in China and specifically discuss a recent paper published by the Institute entitled China’s hydrogen development: A tale of three cities. The paper looks at the experiences and plans of the pilot hydrogen clusters located in Datong Shanxi province Chengdu in Sichuan province and Zhangjiakou in the northern part of Hebei province which surrounds Beijing. In this podcast we are speaking with the paper’s author Arabella Miller-Wang recently an Aramco fellow at the Institute and also a Research Assistant at the Smith School of Enterprise and the Environment of The University of Oxford as well as with Michal Meidan director of the China Energy Programme at OIES and with Martin Lambert who heads hydrogen research at the OIES.

The podcast can be found on their website.

H2 production via membrane-assisted steam methane reforming (MA-SMR) can ensure higher energy efficiency and lower emissions compared to conventional reforming processes (SMR). Ceramic-supported Pd–Ag membranes have been extensively investigated for membrane-assisted steam methane reforming applications with outstanding performance. However costs sealings for integration in the reactor structure and resistance to solicitations remain challenging issues. In this work the surface quality of a low-cost porous Hastelloy-X filter is improved by asymmetric filling with α-Al2O3 of decreasing size and deposition of γ-Al2O3 as an interdiffusion barrier. On the modified support a thin Pd–Ag layer was deposited via electroless plating (ELP) resulting in a membrane with H2/N2 selectivity >10000. The permeation characteristics of the membrane were studied followed by testing for membrane-assisted methane steam reforming. The results showed the ability of the membrane reactor to overcome thermodynamic conversion of the conventional process for all explored operating conditions as well as ensuring 99.3% H2 purity in the permeate stream at 500 ◦C and 4 bar.

Grid-scale underground hydrogen storage (UHS) is essential for the decarbonization of energy supply systems on the path towards a zero-emissions future. This study presents the feasibility of UHS in an actual saline aquifer with a typical dome-shaped anticline structure to balance the potential seasonal mismatches between energy supply and demand in the UK domestic heating sector. As a main requirement for UHS in saline aquifers we investigate the role of well configuration design in enhancing storage performance in the selected site via numerical simulation. The results demonstrate that the efficiency of cyclic hydrogen recovery can reach around 70% in the short term without the need for upfront cushion gas injection. Storage capacity and deliverability increase in successive storage cycles for all scenarios with the co-production of water from the aquifer having a minimal impact on the efficiency of hydrogen recovery. Storage capacity and deliverability also increase when additional wells are added to the storage site; however the distance between wells can strongly influence this effect. For optimum well spacing in a multi-well storage scenario within a dome-shaped anticline structure it is essential to attain an efficient balance between well pressure interference effects at short well distances and the gas uprising phenomenon at large distances. Overall the findings obtained and the approach described can provide effective technical guidelines pertaining to the design and optimization of hydrogen storage operations in deep saline aquifers.

Global supply chains must be decarbonised as part of meeting climate targets set by the United Nations and world leaders. Rail networks are vital infrastructure in passenger and freight transport however have not received the same push for decarbonisation as road transport. In this investigation we used real world data from locomotives operating on seven rail corridors to identify optimal battery capacity and hydrogen fuel cell (HFC) power in hybrid systems. We found that the required battery capacity is dependent on both the available regenerative braking energy and on the capacity required to buffer surpluses and deficits from the HFC. The optimal system for each corridor was identified however it was found that one 3.6 MWh battery and 860 kW HFC system could service six of the seven corridors. The optimal systems presented in this work suggest an average of around 5 h of battery storage for the HFC power which is larger than the 2 h previously reported in literature. This may indicate a gap between purely theoretical works that use only route topography and speed and those that employ real world locomotive data.

The Green Deal Industrial Plan aims to boost the competitiveness of Europe’s net-zero industry and to accelerate the transition to climate neutrality. The Plan is based on four pillars: (1) a predictable and simplified regulatory environment; (2) faster access to funding; (3) developing skills for net-zero industry; and (4) open trade for resilient supply chains.

A direct drive wave power generation system (DDWPGS) has the advantages of a simple structure and easy deployment and is the first choice to provide electricity for islands and operation platforms in the deep sea. However due to the off-grid the source and load cannot be matched so accommodation is an important issue. Hydrogen storage is the optimal choice for offshore wave energy accommodation. Therefore aiming at the source-load mismatch problem of the DDWPGS an electric-hydrogen hybrid energy storage system (HESS) for the DDWPGS is designed in this paper. Based on the characteristics of the devices in the electric-hydrogen HESS a new dynamic power allocation strategy and its control strategy are proposed. Firstly empirical mode decomposition (EMD) is utilized to allocate the power fluctuations that need to be stabilized. Secondly with the state of charge (SOC) of the battery and the operating characteristics of the alkaline electrolyzer being considered the power assignments of the battery and the electrolyzer are determined using the rule-based method. In addition model predictive control (MPC) with good tracking performance is used to adjust the output power of the battery and electrolyzer. Finally the supercapacitor (SC) is controlled to maintain the DC bus voltage while also balancing the system’s power. A simulation was established to verify the feasibility of the designed system. The results show that the electric-hydrogen HESS can stabilize the power fluctuations dynamically when the DDWPGS captures instantaneous power. Moreover its control strategy can not only reduce the start-stop times of the alkaline electrolyzer but also help the energy storage devices to maintain a good state and extend the service life.

Tropical countries can approach their natural resources to produce low-carbon H2 from solar wind hydro and biomass resources to satisfy their domestic demand and to export it. To do so Colombia published the National Hydrogen Roadmap in which green H2 was prioritized. This study estimates Colombia's potential to produce green H2 and a timeline of scenarios displaying the required installed capacity capital investment and environmental analysis related to water utilization and CO2 capture. Accordingly Colombia can produce H2 at a rate of 9 Mt/a by 2050 by installing 121 GW renewables while processing 303 Mt/a of residual biomass. In this scenario Colombia's share of the H2 international market can reach 1.2% with a cumulative investment of over 244 billion USD by 2050. This study provides insights into potential global resources for low-carbon H2 generation.

Liquid hydrogen is one of the high-quality energy carriers but a large leak of liquid hydrogen can pose significant safety risks. Understanding its diffusion law after accidental leakage is an important issue for the safe utilization of hydrogen energy. In this paper a series of open-space large-volume liquid hydrogen release experiments are performed to observe the evolution of visible clouds during the release and an array of hydrogen concentration sensors is set up to monitor the fluctuation in hydrogen concentration at different locations. Based on the experimental conditions the diffusion of hydrogen clouds in the atmosphere under different release hole diameters and different ground materials is compared. The results show that with the release of liquid hydrogen the white visible cloud formed by air condensation or solidification is generated rapidly and spread widely and the visible cloud is most obvious near the ground. With the termination of liquid hydrogen release solid air is deposited on the ground and the visible clouds gradually shrink from the far field to the release source. Hydrogen concentration fluctuations in the far field in the case of the cobblestone ground are more dependent on spontaneous diffusion by the hydrogen concentration gradient. In addition compared with the concrete ground the cobblestone ground has greater resistance to liquid hydrogen extension; the diffusion of hydrogen clouds to the far field lags. The rapid increase stage of hydrogen concentration at N8 in Test 7 lags about 3 s behind N12 in Test 6 N3 lags about 7.5 s behind N1 and N16 lags about 8.25 s behind N14. The near-source space is prone to high-concentration hydrogen clouds. The duration of the high-concentration hydrogen cloud at N12 is about 15 s which is twice as long as the duration at N8 increasing the safety risk of the near-source space.