One of the solutions for fighting climate change is using Hydrogen and more precisely Green Hydrogen. The reason is, Hydrogen provides enormous power generation with zero emissions.
The use of Hydrogen is mostly relevant when looking at decarbonizing the following sectors – Heavy Industry, Railways, Aviation and Shipping. These are the biggest CO2 emitters and the hardest to decarbonize.
Hydrogen presents many challenges when it comes to shipping and storage. Hydrogen is easily flammable and has very low volume at ambient temperature/pressure which requires compressing it for transportation. Hydrogen shipping and storage is done today mainly in compressed form at 700 bar and −253 °C which makes it challenging at a commercial scale.
One solution being reviewed is converting Hydrogen to Ammonia and back to Hydrogen. Air products has already committed to such a project in Saudi Arabia.
Another solution being researched is the idea of Liquid Organic Hydrogen Carrier (LOHC). The idea is to chemically bind hydrogen liquid molecules (usually organic liquid material), ship it and then dehydrogenate it at the point of use, thus enabling a safe, easy, economic way for transport. Think about it as two cycles – hydrogenation and then dehydrogenation. To overly simplify the process one can describe it as loading and unloading organic liquid with hydrogen.
One of the biggest challenges with Hydrogen has been solved. Click To TweetThe liquid before hydrogenation (unloaded) looks like water and once hydrogenated becomes thicker (like honey). One of the biggest benefits of the process aside from making the Hydrogen easily transportable is the fact it is flame retardant. Storing a LOHC is safe and can be for long-term use at ambient temperature and pressure. The organic liquid material can be loaded, unloaded and reloaded few hundred times and is available from multiple suppliers. Hydrogen purity is being maintained during the process.
Taken one step forward, the Hydrogen bound compound can be used in Fuel Cells. Currently, Fuel Cells (independent of their technology) are converting Hydrogen to electricity with zero-emission generating only water in the process. LOHC-FC can use the hydrogenated liquid and in the same device doing both, dehydrogenation and electricity generation.
The concept of LOHC is still at the early stages of development with ongoing projects in Japan, Finland, US and Germany.