Publications

Replacement of fossil fuels with clean hydrogen has been recognized as the most feasible approach of implementing CO2-free hydrogen economy globally. However large-scale storage of hydrogen is a critical component of hydrogen economy value chain because hydrogen is the lightest molecule and has moderately low volumetric energy content. To achieve successful storage of buoyant hydrogen at the subsurface and convenient withdrawal during the period of critical energy demand the integrity of the underground storage rock and overlying seal (caprock) must be assured. Presently there is paucity of information on hydrogen wettability of shale and the interfacial properties of H2/brine system. In this research contact angles of shale/H2/brine system and hydrogen/brine interfacial tension (IFT) were measured using Krüss drop shape analyzer (DSA 100) at 50 ◦C and varying pressure (14.7–1000 psi). A modified form of sessile drop approach was used for the contact angles measurement whereas the H2- brine IFT was measured through the pendant drop method. H2-brine IFT values decreased slightly with increasing pressure ranging between 63.68◦ at 14.7 psia and 51.29◦ at 1000 psia. The Eagle-ford shale with moderate total organic carbon (TOC) of 3.83% attained fully hydrogen-wet (contact angle of 99.9◦ ) and intermediate-wet condition (contact angle of 89.7◦ ) at 14.7 psi and 200 psi respectively. Likewise the Wolf-camp shale with low TOC (0.30%) attained weakly water-wet conditions with contact angles of 58.8◦ and 62.9◦ at 14.7 psi and 200 psi respectively. The maximum height of hydrogen that can be securely trapped by the Wolf-camp shale was approximately 325 meters whereas the value was merely 100 meters for the Eagle-ford shale. Results of this study will aid in assessment of hydrogen storage capacity of organic-rich shale (adsorption trapping) as well as evaluation of the sealing potentials of low TOC shale (caprock) during underground hydrogen storage.

Due to its much lower air pollution and potential greenhouse gas (GHG) emissions benefits liquefied natural gas (LNG) is frequently discussed as a fuel pathway towards greener maritime transport. While LNG’s air quality improvements are undeniable there is debate within the sector as to what extent LNG may be able to contribute to decarbonizing shipping. This report “The Role of LNG in the Transition Toward Low- and Zero-Carbon Shipping” considers the potential of LNG to play either a transitional role in which existing LNG infrastructure and vessels could continue to be used with compatible zero-carbon bunker fuels after 2030 or a temporary one in which LNG would be rapidly supplanted by zero-carbon alternatives from 2030. Over concerns about methane leakage which could diminish or even offset any GHG benefits associated with LNG and additional capital expenditures the risk of stranded assets as well as a technology lock-in the report concludes that LNG is unlikely to play a significant role in decarbonizing maritime transport. Instead the research finds that LNG is likely to only be used in niche shipping applications or in its non-liquefied form as a feedstock to kickstart the production of zero-carbon bunker fuels when used in conjunction with carbon capture and storage technology. The research further suggests that new public policy in support of LNG as a bunker fuel should be avoided existing policy support should be reconsidered and methane emissions should be regulated.

H2 Green Steel was founded in 2020 with the aim to build a large-scale green steel production in northern Sweden. H2 Green Steel is on a mission to undertake the global steel industry’s greatest ever technological shift. By 2024 H2 Green Steel will be in production at their Boden site and by 2030 will produce five million tonnes of green steel annually. Vargas co-founder and a major shareholder in Northvolt is also H2 Green Steel’s founder and largest shareholder. The EAH team speaks with Kajsa Ryttberg-Wallgren head of the Hydrogen Business Unit at H2 Green Steel.

The podcast can be found on their website

During the 13th Five-Year Plan China's natural gas industry developed rapidly and a diversified supply and marketing pattern was formed including domestic conventional gas unconventional gas (shale gas tight sandstone gas coalbed methane etc.) coal-based synthetic natural gas imported LNG and imported pipeline gas. The gross calorific value of gas sources ranged from 34 MJ/m3 to 43 MJ/m3 and the maximum difference of calorific value between different gas sources exceeded 20%. On May 24th 2019 the National Development and Reform Commission and other three ministries/commissions jointly issued the Supervision Regulation on the Fair Access of Oil and Gas Pipeline Network Facilities and required that a natural gas energy measuring and pricing system shall be established within 24 months from the implementation date of this Regulation. In order to speed up the construction of China's natural gas energy measuring system this paper summarizes domestic achievements in the construction of natural gas energy measuring system from the aspects of value traceability and energy measurement standard and analyzes natural gas flowrate measurement technology calorific value determination technology value traceability localization intelligentization and application technology of key energy measurement equipment natural gas pipeline network energy balancing technology based on big data analysis multi-source quality tracking and monitoring technology and energy measurement standard system the need of new energy detection and measurement technology and put forward strategy for the development of natural gas measuring in China. And the following research results are obtained. First China's natural gas energy measuring system can basically meet the requirements of implementing natural gas energy measurement but it still falls behind the international leading level in terms of calibration and application of high-level flowmeter (such as 0.5 class) high-accuracy gas reference material level of calorific value reference equipment and measurement standard system and needs to be further improved. Second it is necessary for China to speed up the research and application of the localization and intelligentization technologies of key energy measurement equipment. Third natural gas pipeline network shall be equipped with measurement check method energy balancing system based on big data analysis and multi-source quality tracking and monitoring system so that the energy transmission loss index of natural gas pipeline network can be superior to the international leading level (0.10%). Fourth to realize the large-scale application of hydrogen energy and bio-energy and the mixed transportation of hydrogen bio-methane and natural gas it is necessary to carry out research on new technology and standardization of hydrogen/bio-methane blended natural gas detection and measurement.

This paper describes two models for analysing and simulating the physical effects of explosive phase transition of liquid hydrogen (LH2) also known as cold BLEVE. The present work is based on theoretical and experimental work for liquefied CO2. A Rankine Hugoniot analysis for evaporation waves that was previously developed for CO2 is now extended to LH2. A CFD-method for simulating two-phase flow with mass transfer between the phases is presented and compared with the Rankine Hugoniot analysis results. The Rankine Hugoniot method uses real fluid equations of state suited for LH2 while the CFD method uses linear equations of state suited for shock capturing methods. The results show that there will be a blast from a catastrophic rupture of an LH2 vessel and that the blast waves will experience a slow decay due to the large positive pressure phase.

This episode is a whistle-stop tour of the hydrogen world. The team explore why hydrogen is making a resurgence as an energy carrier how decarbonising the existing hydrogen market is a huge opportunity and how fuel cells fit into the story.

The podcast can be found on their website

Political and scientific discussions on changing German energy supply mix and challenges of such energy transition are already well established. At the supply level energy storage seems to be the biggest challenge ahead for such transition. Hydrogen could be one of the solutions for future energy transition if it is produced using renewable energy resources. In order to analyze the future role of hydrogen its economic performance analysis is inevitable. This has been done in this research for a case study site in Cologne. The potential of hydrogen production with the use of solar electricity powered electrolyzers (alkaline and proton exchange membrane (PEM)) has been analyzed. Both grid connected and off grid modes of solar hydrogen production are considered. Economic performance results are presented for six scenarios. Hydrogen produced with the grid connected solar photovoltaics system coupled with alkaline electrolyzers was found the cheapest with the levelized cost of hydrogen (LCOH) at 6.23 V/kg. These costs are comparable with the current hydrogen price at commercial refueling station in Cologne. On the other hand the LCOH of off grid systems with both alkaline and PEM electrolyzers is expensive as expected the most expensive LCOH among six scenarios reached to 57.61 V/kg.

The spinning process will lead to changes in the micro-structure and mechanical properties of the materials in different positions of the high-pressure hydrogen storage cylinder which will show different hydrogen embrittlement resistance in the high-pressure hydrogen environment. In order to fully study the safety of hydrogen storage in large-volume seamless steel cylinders this chapter associates the influence of the forming process with the deterioration of a high-pressure hydrogen cylinder (≥100 MPa). The anti-hydrogen embrittlement of SA-372 grade J steel at different locations of the formed cylinders was studied experimentally in three cylinders. The hydrogen embrittlement experiments were carried out according to method A of ISO 11114-4:2005. The relationship between tensile strength microstructure and hydrogen embrittlement is analyzed which provides comprehensive and reliable data for the safety of hydrogen storage and transmission.

Characterizing the wettability of hydrogen (H2 )–methane (CH4 ) mixtures in subsurface reservoirs is the first step towards understanding containment and transport properties for underground hydrogen storage (UHS). In this study we investigate the static contact angles of H2 –CH4 mixtures in contact with brine and Bentheimer sandstone rock using a captive-bubble cell device at different pressures temperatures and brine salinity values. It is found that under the studied conditions H2 and CH4 show comparable wettability behaviour with contact angles ranging between [25◦–45◦ ]; and consequently their mixtures behave similar to the pure gas systems independent of composition pressure temperature and salinity. For the system at rest the acting buoyancy and surface forces allow for theoretical sensitivity analysis for the captive-bubble cell approach to characterize the wettability. Moreover it is theoretically validated that under similar Bond numbers and similar bubble sizes the contact angles of H2 and CH4 bubbles and their mixtures are indeed comparable. Consequently in large-scale subsurface storage systems where buoyancy and capillary are the main acting forces H2 CH4 and their mixtures will have similar wettability characteristics.

The transition of residential communities to renewable energy sources is one of the first steps for the decarbonization of the energy sector the reduction of CO2 emissions and the mitigation of global climate change. This study provides information for the development of a microgrid supplied by wind and solar energy which meets the hourly energy demand of a community of 10000 houses in the North Texas region; hydrogen is used as the energy storage medium. The results are presented for two cases: (a) when the renewable energy sources supply only the electricity demand of the community and (b) when these sources provide the electricity as well as the heating needs (for space heating and hot water) of the community. The results show that such a community can be decarbonized with combinations of wind and solar installations. The energy storage requirements are between 2.7 m3 per household and 2.2 m3 per household. There is significant dissipation in the storage–regeneration processes—close to 30% of the current annual electricity demand. The entire decarbonization (electricity and heat) of this community will result in approximately 87500 tons of CO2 emissions avoidance.