The exhibit below highlights one of the more significant constraints for green hydrogen, which is that the abundant low-cost power opportunities (strong wind and lots of sunshine) are often not where demand for hydrogen exists and the challenge is how to transport it. The problem with reacting it to make something else and then recovering it at the point of use or a distribution hub is that hydrogen is very light and you end up moving a lot of something else to get a little hydrogen. Air Products is looking at making ammonia in Saudi Arabia and shipping the liquid ammonia and the project below is looking at using toluene as a carrier in what appears to be a closed-loop with toluene moving one way and methylcyclohexane moving the other way. The liquid shipping would be cheap, but with the MCH route, only 5% of what you would be moving to Japan would be the green hydrogen. Using ammonia the green hydrogen content is slightly less than 18%, but you have to make the nitrogen on-site. The cost of making the nitrogen would be a function of the local cost of power and these remote locations should have very low-cost renewable power. In the example below, the opportunity is likely unique to the refinery structure and shipping opportunity and we doubt that it is easily replicated in a way that would be more economic than shipping ammonia or shipping compressed hydrogen itself.
Source: H2 Bulletin, August 2021