Hydrogen

Researchers at LLNL couple modeling, characterization, and testing to probe physical limitations in current storage systems and suggest improvement strategies for future system design.

Materials-based storage

Storing hydrogen in solid-state materials or liquids provides a more compact and less expensive alternative to conventional methods. Our team focuses on multiscale modeling of materials and interfaces, aided by experimental characterization, to develop an understanding of two classes of materials-based storage and delivery solutions: metal hydrides and liquid organic hydrogen carriers.

Additionally, our research address challenges in modeling the operation mechanisms of materials for hydrogen storage by developing:

• “Beyond-ideal” models that better approximate real materials and their operating environments
• Methods for integrating atomistic and continuum scales to understand the coupling between chemistry and phase evolution.
• Methods for tightly integrating modeling with atomic- and mesoscale characterization experiments.

Our researchers lead the modeling and simulation efforts within the Hydrogen Materials Advanced Research Consortium (HyMARC), which seeks to develop tools and understanding to accelerate the development of materials for hydrogen storage.

Underground storage

Subsurface storage can provide safe and cost-effective hydrogen storage at very large scales. The Subsurface Hydrogen Assessment, Storage, and Technology Acceleration (SHASTA) project aims to determine the technical feasibility of hydrogen storage in subsurface systems and quantify the operational risks.

A key component of the effort involves studying the safety and efficiency of storing both pure hydrogen gas and blended mixtures of hydrogen and natural gas in subsurface reservoirs. Our research focuses on conducting:

• Subsurface modeling work to understand how hydrogen disperses and potentially reacts inside a reservoir
• Experimental work to investigate how hydrogen-rich environments affect the integrity and compatibility of materials in reservoirs, at relevant pressures and temperatures

Hydrogen researchers are studying a variety of pathways to produce hydrogen using energy from renewable, nuclear, or geothermal resources, with feedstocks that include water, biomass, and fossil fuels. A significant challenge involves improving both the durability and the efficiency of the materials driving the conversion process.

LLNL’s high-performance computing capabilities help us address several technological challenges in this approach. We are developing:

• Novel simulation techniques to determine the interplay and coupling between chemical, physical, and materials processes related to material performance and degradation.
• Methods for integrating atomistic and mesoscale modeling and characterization experiments.
• A fundamental understanding of the physicochemical processes that govern the efficiency and durability of materials for hydrogen production under operating conditions.

This work supports the HydroGEN Advanced Water Splitting Materials and the Hydrogen from Next-generation Electrolyzers of Water (H2NEW) consortia.

To complement modeling techniques, LLNL offers unique platforms used for testing hydrogen systems over a wide range of pressures, temperatures, volumnes, and flow rates. These testing facilities allow researchers to identify issues that may occur when hydrogen interacts with materials under extreme conditions—providing insights for improved hydrogen systems.

In particular, our researchers maintain two testing facilities:

• The Cryogenic Hydrogen Test Facility assesses the performance of hydrogen storage systems and components. It has a 3,000-gallon liquid hydrogen storage tank and a cryo-pump capable of supplying hydrogen at 120 kilograms per hour, 80 grams per liter, and 875 bar. The facility includes a sealed containment vessel capable of cycle and burst testing pressure systems with hydrogen or other flammable gases.
• The Hydrogen Materials Degradation Laboratory (HMDL) can perform pressure-composition-temperature (PCT) measurements on solid materials and porous materials up to 200 bar and at temperatures ranging from cryogenic to 200°C. HDML’s residual gas analyzer tests either gas compositions from loaded materials or preferential absorption of gas mixtures during operation of the PCT. HDML can also analyze pore size and surface area.

Reliable and efficient infrastructure is needed to fully realize hydrogen’s potential. LLNL researchers are developing ways to apply their deep knowledge of materials to the selection of cost-effective and efficient materials to use during hydrogen infrastructure development.

Our cross-scale Systems-to-Atoms (S2A) model framework optimizes the cost-based performance and durability of materials and operations across the full hydrogen supply chain. S2A incorporates information from techno-economic analyses, process design models, and component/material models to assess feasibility at the pre-demonstration or early deployment phase. It also accounts for regionally specific operational constraints to assess the impact of all components of the hydrogen supply chain on net process efficiency and cost.

The framework includes the following features:

• Rapid scenario evaluation for best fit of specific materials and technology in the hydrogen supply chain
• Detection of supply chain vulnerability via sensitivity and uncertainty analyses
• Optimal flexible operation analyses to minimize cost while maximizing efficiency and durability