The production of green hydrogen could offer further options in the transition to net-zero carbon dioxide emissions. These include:

• Energy Storage – Hydrogen can be easily stored in bulk as a liquid at modest pressures (10-15 bar as ammonia) or bound with renewable CO2 from the air to form liquid renewable hydrocarbons (LRH). This makes it an ideal chemical store for renewable energy. There is an existing distribution network, in which ammonia and hydrocarbons are stored in large tanks and transported around the world by pipes, road tankers and ships.

 

• As Net-Zero-carbon fuel – Ammonia and LRH can be used in a fuel cells to produce electricity. When used, ammonia’s only by-products are water and nitrogen, while the CO2 release from the LRH is returned to the air from once it came. The maritime and heavy duty transport industries are likely to be the early adopters, replacing the use of fossil fuel oil.

 

• As a Hydrogen carrier – Current applications where hydrogen gas is used (e.g. in PEM fuel cells), is difficult and expensive to store in bulk (needing cryogenic tanks or high-pressure cylinders). Ammonia and LRH are easier and cheaper to store, and transport and can be readily “cracked” and purified to give hydrogen gas when required.