Ever since the Industrial Revolution, the world has been inventing and optimizing new methods of energy production. As we look towards hydrogen generation, especially green hydrogen made from renewable resources, the topic of intermittency needs to be addressed. Fortunately, just like there’s various methods to transport hydrogen, there’s a variety of ways to store hydrogen.
Storing efficiently and effectively is the topic of my article in the Autumn issue of Global Hydrogen Review with the descriptive title, Precious Cargo. Whether you are producing energy or chemicals, a reliable supply of hydrogen is essential.
Using hydrogen to provide base load power supply is important for the electrical distribution grid, but it is also important to maintain a consistent supply for chemical processes, like ammonia synthesis, that have low plant-turndown ratios. These chemical processes are best when they are running 24/7 at a consistent production rate, with the most complicated and dangerous parts of production being startup and shutdown.
The article discusses common concerns and multiple storage strategies to overcome intermittency and ensure a stable and constant distribution of hydrogen:
- Compressed hydrogen using cylinders for mobile or flexible on-site storage.
- Pipeline storage utilizing line packing, where the injection rate into the pipeline is greater than the withdrawal rate, increasing the mass of hydrogen in the pipeline.
- Liquification is energy intensive, but the most efficient for longer term storage.
- Salt caverns within salt domes, where Earth’s natural geography can store immense amounts of hydrogen.
- Hydrogen carrier molecules, such as ammonia and hydrogen hydrides, with more favorable properties and existing value chains.
- Material considerations and when they are most important to minimize permeation and embrittlement.
The growing importance of hydrogen as an energy storage mechanism is driving the need for more storage in more places. Techniques depending on brute compression may be reaching the limits of materials, but other options are adding flexibility and improved capabilities for increasing energy density.
Making this happen calls for a wide variety of instrumentation designed for the challenges of hydrogen fuel production and distribution. Performance and accuracy are especially important as hydrogen moves in and out of storage, to verify totals for internal inventory or custody transfer purposes. Custody transfer sites for compressed hydrogen generally use a group of instruments to provide a highly accurate picture of a batch or continuous flow:
- Micro Motion Elite Coriolis Mass flow meter as an undisputed standard for custody transfer.
- Rosemount 3051S Pressure Transmitter able to handle required pressures.
- Rosemount 700XA Gas Chromatograph to verify compositional quality.
- Rosemount X-well Technology Temperature Transmitter to monitor temperature without a process penetration.
Just as hydrogen infrastructure is calling for new strategies and hardware, those providing it must also develop new expertise and the know-how needed for this evolving industry. Companies wanting to create hydrogen infrastructure find that reliable experts and partners are critical to success.
Wherever there is hydrogen storage, there should also be hydrogen safety measures such as leak detectors and infrared flame detectors. A leak in a hydrogen storage vessel needs to be identified and fixed with urgency to minimize product loss and to ensure employee safety. Hydrogen leaks can quickly turn into hydrogen flames which are invisible to the naked eye.
- Rosemount Incus Ultrasonic Gas Leak Detector continuously monitors for leaks, regardless of weather conditions.
- Rosemount 975HR Hydrogen Flame Detector has a high resistance to false alarms and ensures hydrogen flames are detected as soon as they happen.
For more information, visit Emerson’s Renewable Fuels pages at Emerson.com. You can also connect and interact with other engineers in the Sustainable Energy and Chemical Processing Groups at the Emerson Exchange 365 community.
