Hydrogen can be stored in a number of different ways, including as a gas, a liquid, and in solid form. Each of these methods has its own advantages and disadvantages, and the most appropriate method of storage will depend on the specific application and the requirements for the system.
Compressed Hydrogen Gas
This is the most common method of storing hydrogen. It involves compressing the hydrogen gas to a high pressure in order to reduce its volume, allowing it to be stored in a tank or cylinder. The main advantage of this method is that it is relatively simple and inexpensive, but it has a relatively low energy density compared to other methods of storage.
Hydrogen can be cooled and condensed into a liquid at very low temperatures (-253°C). This allows it to be stored in a liquid form, which has a much higher energy density than compressed gas. However, liquid hydrogen requires expensive and complex cryogenic storage systems, and it is also highly flammable.
Metal hydrides are solid materials that can store hydrogen in their crystal structure. The hydrogen can be released from the metal hydride by heating it, allowing it to be used as a fuel. Metal hydrides have a high energy density and are relatively safe, but they can be expensive and difficult to work with.
Chemical hydrides are chemical compounds that can store hydrogen in their chemical bonds. They can be used to store hydrogen in a solid or liquid form, and they can be relatively safe and stable. However, they often have a low energy density and can be expensive to produce.
Carbon-based materials, such as graphene and carbon nanotubes, can be used to store hydrogen in a solid form. These materials have a high surface area, allowing them to store large amounts of hydrogen. However, they are still being developed and are not yet widely available.
Gas and liquid hydrogen is stored in many ways depending on demand and customer geography.
Gas hydrogen can be stored and supplied from high pressure cylinders.
Gas hydrogen tube trailers can be deliveredto customer locations and left to supply gas hydrogen.
Gas hydrogen can be stored in high pressure receivers that are part of a permanent supply system that provides gas hydrogen to the customer.
Liquid hydrogen can be stored in a vacuum-insulated cryogenic hydrogen storage tank as part of a permanent supply system. This system can supply either gas or liquid hydrogen to the customer. This type of supply system will have additional equipment such as vaporizers, pumps, regulators, and valves.
Storing Gas & Liquid Hydrogen
Hydrogen supply systems must meet all the appropriate good practices, such as minimizing leaks and directing vents to properly designed vent stacks.
In addition, hydrogen supply systems must be located away from exposures, either people, equipment, or buildings to protect them from potential hydrogen leaks, and fires. Because of hydrogen’s flammability, these setback distances are larger than setbacks used for other cryogenic fluids such as liquid nitrogen.
CGA Standards for Hydrogen Storage
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