Ammonia vs. Liquid Hydrogen
With the Moon Jae-in administration focusing on the growth of the domestic hydrogen economy, South Korean enterprises are being divided into ammonia- and liquid hydrogen-based hydrogen production and procurement.
The South Korean government announced its clean hydrogen introduction plan on Oct. 7. According to the plan, ammonia, that is, a compound of nitrogen and hydrogen will be imported from Australia, Russia and the Middle East, the ammonia will be decomposed in South Korea, and the resultant hydrogen will be distributed in the domestic market.
POSCO is one of those that have opted for ammonia-based hydrogen storage and transport. According to the company, it is the hydrogen transport technique that can be commercialized within the shortest time. Korea Shipbuilding & Offshore Engineering and HMM are also working on an ammonia-based hydrogen ecosystem.
Ammonia is an essential component of chemical fertilizers, and a lot of ammonia production facilities are already in operation. It is a liquid at room temperature, production and transport do not cost a lot, and a lot of hydrogen can be stored per unit volume. According to the International Energy Agency, ammonia is likely to be the most optimal way of hydrogen storage and transport more economical than liquid hydrogen. Ammonia, however, is a toxic substance.
The South Korean government’s plan includes liquid hydrogen as well. Hyosung Heavy Industries is building a liquid hydrogen plant with an annual capacity of 13,000 tons in Ulsan City with Linde. SK E&S is going to build the same plant in Incheon City. GS Caltex is aiming to initiate commercial liquid hydrogen production in 2024.
According to those companies, it is not ammonia but liquid hydrogen that will become the standard hydrogen carrier. Liquid hydrogen is small in volume, its pressure rises during vaporization, and thus liquid hydrogen-based charging can be done more quickly than that based on gaseous hydrogen already in distribution. In addition, liquid hydrogen is not toxic.
The weak point is that it entails a high level of technological difficulty along with high production costs. Specifically, liquid hydrogen must be kept at a temperature of 253 degrees Celsius below zero and requires a dedicated high-pressure tank. At present, no South Korean company is capable of liquefying hydrogen. This is why Hyosung is building the plant with Linde.