Institution of Gas Engineers & Managers

In this podcast David Ledesma talks with Rahmat Poudineh Senior Research Fellow and Aliaksei Patonia Research Fellow on issues and options with respect to long distance transportation of the hydrogen.

Hydrogen currently is mainly a local or regional commodity. If hydrogen is to become a truly global-traded commodity it needs to be transported over long transoceanic distances in an economical way. However unlike natural gas shipping compressed or liquefied hydrogen over long distances is very inefficient and expensive. At the same time hydrogen can be converted into multiple carriers with a higher energy density and higher transport capacity such as liquid ammonia toluene/methylcyclohexane (MCH) or methanol. These chemicals have their own advantages and drawbacks and their techno-economic characteristics in terms of boil-off gas and thermodynamic and conversion losses play a key role in the efficiency of transoceanic transportation of the hydrogen.

On the other hand apart from techno-economic features there are other factors to consider for long distance transportation of the hydrogen via its careers. Here such issues as safety public acceptance as well as legal and regulatory constraints may come into play. Another factor is the availability of the industries and infrastructures already developed around any of possible hydrogen carriers as well as their potential industrial applicability beyond hydrogen. Finally technological progress in other decarbonization applications and most importantly full commercialization of CCUS solutions is likely to dramatically change the approach towards long distance hydrogen transportation.

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On today’s episode of Everything About Hydrogen we are speaking with Dan Sadler Vice President for UK Low Carbon Solutions at Equinor. Equinor is of course a giant in the global energy sector and is taking a prominent role in the development of the international hydrogen economy with high-profile investments in a number of large-scale production projects in major markets such as the UK. Dan has spent the better part of a decade focused on how to leverage hydrogen’s potential as a fuel for the energy transition and we are excited to have him with us to discuss how Equinor is deploying hydrogen technologies and how he and Equinor expect hydrogen to play a role in a decarbonized energy future.

The podcast can be found on their website.

Countries such as China are facing a bottleneck in their paths to carbon neutrality: abating emissions in heavy industries and heavy-duty transport. There are few in-depth studies of the prospective role for clean hydrogen in these ‘hard-to-abate’ (HTA) sectors. Here we carry out an integrated dynamic least-cost modelling analysis. Results show that first clean hydrogen can be both a major energy carrier and feedstock that can significantly reduce carbon emissions of heavy industry. It can also fuel up to 50% of China’s heavy-duty truck and bus fleets by 2060 and significant shares of shipping. Second a realistic clean hydrogen scenario that reaches 65.7 Mt of production in 2060 could avoid US$1.72 trillion of new investment compared with a no-hydrogen scenario. This study provides evidence of the value of clean hydrogen in HTA sectors for China and countries facing similar challenges in reducing emissions to achieve net-zero goals.

Background: Naval trafc is highly dependent on depleting fossil resources and causes signifcant greenhouse gas emissions. At the same time marine transportation is a major backbone of world trade. Thus alternative fuel concepts are highly needed. Diferent fuels such as ammonia methanol liquefed natural gas and hydrogen have been proposed. For some of them frst prototype vessels have been in operation. However practical experience is still limited. Most studies so far focus on aspects such as efciency and economics. However particularly in marine applications reliability of propulsion systems is of utmost importance because failures on essential ship components at sea pose a huge safety risk. If the respective components lose their functionality repair can be much more challenging due to large distances to dockyards and the complicated transport of spare parts to the ship. Consequently evaluation of reliability should be a core element of system analysis for new marine fuels. Results: In this study reliability was studied for four potential fuels. The analysis involved several steps: estimation of overall failure rates identifcation of most vulnerable components and assessment of criticality by including severity of fault events. On the level of overall failure rate ammonia is shown to be very promising. Extending the view over a pure failure rate-based evaluation shows that other approaches such as LOHC or methanol can be competitive in terms of reliability and risk. As diferent scenarios require diferent weightings of the diferent reliability criteria the conclusion on the best technology can difer. Relevant aspects for this decision can be the availability of technical staf high-sea or coastal operation the presence of non-naval personnel onboard and other factors. Conclusions: The analysis allowed to compare diferent alternative marine fuel concepts regarding reliability. However the analysis is not limited to assessment of overall failure rates but can also help to identify critical elements that deserve attention to avoid fault events. As a last step severity of the individual failure modes was included. For the example of ammonia it is shown that the decomposition unit and the fuel cell should be subject to measures for increasing safety and reducing failure rates.

Renewable energies such as the wind energy and solar energy generate low-carbon electricity which can directly charge battery electric vehicles (BEVs). Meanwhile the surplus electricity can be used to produce the “green hydrogen” which provides zero-emission hydrogen fuels to those fuel cell electric vehicles (FCEVs). In order to charge/refuel multi-energy vehicles we propose a novel scheme of hybrid hydrogen/electricity supply using cryogenic and superconducting technologies. In this scheme the green hydrogen is further liquefied into the high-density and low-pressure liquid hydrogen (LH2) for bulk energy storage and transmission. Taking the advantage of the cryogenic environment of LH2 (20 K) it can also be used as the cryogen to cool down super conducting cables to realize the virtually zero-loss power transmission from 100 % renewable sources to vehicle charging stations. This hybrid LH2/electricity energy pipeline can realize long-distance large-capacity and high efficiency clean energy transmission to fulfil the hybrid energy supply demand for BEVs and FCEVs. For the case of a 100 MW-class hybrid hydrogen/electricity supply station the system principle and energy management strategy are analyzed through 9 different operating sub-modes. The corresponding static and dynamic economic modeling are performed and the economic feasibility of the hybrid hydrogen/electricity supply is verified using life-cycle analysis. Taking an example of wind power capacity 1898 MWh and solar power capacity 1619 MWh per day the dynamic payback period is 15.06 years the profitability index is 1.17 the internal rate of return is 7.956 % and the accumulative NPV is 187.92 M$. The system design and techno-economic analysis can potentially offer a technically/economically superior solution for future multi-energy vehicle charging/refueling systems.

Hydrogen can be key in the energy system transition. We investigate the role of offshore hydrogen generation in a future integrated energy system. By performing energy system optimisation in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050 we find that offshore hydrogen generation may likely only play a limited role and that offshore wind energy has higher value when sent to shore in the form of electricity. Forcing all hydrogen generation offshore would lead to increased energy system costs. Under the assumed scenario conditions which result in deep decarbonisation of the energy system towards 2050 hydrogen generation – both onshore and offshore – follows solar PV generation patterns. Combined with hydrogen storage this is the most cost-effective solution to satisfy future hydrogen demand. Overall we find that the role of future offshore hydrogen generation should not simply be derived from minimising costs for the offshore sub-system but by also considering the economic value that such generation would create for the whole integrated energy system. We find as a no-regret option to enable and promote the integration of offshore wind in onshore energy markets via electrical connections.

The increasing energy demand and the subsequent climate change consequences are supporting the search for sustainable alternatives to fossil fuels. In this scenario the link between hydrogen and renewable energy is playing a key role and unitized hydrogen-chlorine (H2-Cl2) regenerative cells (RFCs) have become promising candidates for renewable energy storage. Described herein are the recent advances in cell configurations and catalysts for the different reactions that may take place in these systems that work in both modes: electrolysis and fuel cell. It has been found that platinum (Pt)-based catalysts are the best choice for the electrode where hydrogen is involved whereas for the case of chlorine ruthenium (Ru)-based catalysts are the best candidates. Only a few studies were found where the catalysts had been tested in both modes and recent advances are focused on decreasing the amount of precious metals contained in the catalysts. Moreover the durability of the catalysts tested under realistic conditions has not been thoroughly assessed becoming a key and mandatory step to evaluate the commercial viability of the H2-Cl2 RFC technology.

Blending hydrogen with natural gas is emerging as a pivotal strategy in the transition to low-carbon energy systems. However the exploitation of the natural gas infrastructure to distribute natural gas and hydrogen blends (and 100% hydrogen in the long-term) introduces several technical economic and safety issues. These latter are paramount especially in urban distribution networks that supply residential buildings and dwellings since the quality and safety of the living environment can also be significantly affected. In this scenario the reliability of odorant concentration measurements according to the best practices currently in use for natural gas becomes crucial. This study is aimed at assessing the accuracy of odorant measurements at different concentration levels (i.e. low medium and high) in 100% methane methane–hydrogen blend and 100% hydrogen. The obtained results show the tendency to overestimate the odorant concentration up to 2.3% in methane–hydrogen blends at medium and high concentrations of THT as well as the underestimation of −3.4% in 100% hydrogen at low concentration of TBM. These results are consistent with those of natural gas from the city distribution network with hydrogen content of 5% and 20%.

The current research on green hydrogen can focus from the perspective of production but understanding the demand side is equally important to the initial creation of a hydrogen ecosystem in countries with low industrial activities that can utilise large amounts of hydrogen in the short term. Early movers in these countries must create a demand market in parallel with the green hydrogen plant commissioning. This paper presents research that explores the heavy-duty transport sector as a market-of-interest for early deployment of green hydrogen in Ireland. Conducting a survey-based market research amongst this sector indicate significant interest in hydrogen on the island of Ireland and the barriers the participants presented have been overcome in other jurisdictions. The study develops a model to estimate 1.) the annual hydrogen demand and 2.) the corresponding delivery cost to potential hydrogen consumers either directly or to central hydrogen fuelling hubs.

An investigation was conducted to determine the effects of operating parameters for various electrode types on hydrogen gas production through electrolysis as well as to evaluate the efficiency of the polymer electrolyte membrane (PEM) electrolyzer. Deionized (DI) water was fed to a single-cell PEM electrolyzer with an active area of 36 cm2 . Parameters such as power supply (50–500 mA/cm2 ) feed water flow rate (0.5–5 mL/min) water temperature (25−80 ◦C) and type of anode electrocatalyst (0.5 mg/cm2 PtC [60%] 1.5 mg/cm2 IrRuOx with 1.5 mg/cm2 PtB 3.0 mg/cm2 IrRuOx and 3.0 mg/cm2 PtB) were varied. The effects of these parameter changes were then analyzed in terms of the polarization curve hydrogen flowrate power consumption voltaic efficiency and energy efficiency. The best electrolysis performance was observed at a DI water feed flowrate of 2 mL/min and a cell temperature of 70 ◦C using a membrane electrode assembly that has a 3.0 mg/cm2 IrRuOx catalyst at the anode side. This improved performance of the PEM electrolyzer is due to the reduction in activation as well as ohmic losses. Furthermore the energy consumption was optimal when the current density was about 200 mA/cm2 with voltaic and energy efficiencies of 85% and 67.5% respectively. This result indicates low electrical energy consumption which can lower the operating cost and increase the performance of PEM electrolyzers. Therefore the optimal operating parameters are crucial to ensure the ideal performance and durability of the PEM electrolyzer as well as lower its operating costs.