At minus 253 degrees Celsius, hydrogen becomes a liquid, and its volume falls to one-eighth of its original size. Because hydrogen is too heavy to transport as a gas, liquidizing it is being considered.
However, there is a problem: liquid hydrogen boils away at a rate of 2% to 3% per day under typical storage. By the time it reaches Korean coastlines, up to 20-30% of the tank will be depleted.
The evaporation issue is particularly important for South Korea, which expects to import the majority of its hydrogen. The country’s demand for carbon-neutral hydrogen would more than double to 27 million tons by 2050, while only 5 million tons will be generated domestically. The remaining 22 million tons will need to be imported from other countries. Hydrogen can be produced by passing electricity through water or converting natural gas, but Korea lacks a local supply of natural gas and is unable to create enough renewable energy to rely on electrolysis due to its location.
The leaking problem of liquid hydrogen presents a technological dilemma, according to Yoo Byeong-yong, vice president of Korea Shipbuilding & Offshore Engineering, a shipbuilding arm of Korea’s eighth-largest conglomerate Hyundai Heavy Industries Group.
“Like a pressure cooker, containing liquid hydrogen inside a thick tank can apply pressure and prevent leaks,” the 47-year-old CEO explained, “but it would increase the ship’s weight and push up the expenses.”
When liquid hydrogen is placed within a narrow tank, it boils away fiercely, according to Yoo, who earned bachelor’s, master’s, and doctoral degrees in naval architectural engineering from Seoul National University. Hydrogen must be discharged through microscopic holes to keep it from exploding.
“To capture lost hydrogen and transform it back into liquid, helium gas is required, which is costly. Furthermore, the entire procedure requires an excessive amount of power. “It’s just not possible,” Yoo explained.
“Rather than recapturing the hydrogen, KSOE is investigating a method that utilizes the lost hydrogen as a fuel to power hydrogen fuel cells.”
KSOE is now working on a fuel cell-powered liquid hydrogen transporter. By 2027, it hopes to have the world’s first large-scale liquid hydrogen transporter on the market. The Korean Register of Shipping gave the company the world’s first approval for the design of a commercial LNG carrier in October of last year.
The liquid hydrogen carrier industry is projected to take off in 2030, according to DNV, a global classification agency. Liquid hydrogen carrier orders are predicted to increase from nine in 2030 to 51 in 2040.
To seize the lead, KSOE plans to finish standardizing liquid hydrogen carriers with the KRS by the end of next year and submit it to the International Maritime Organization.
European firms, such as Air Liquide of France, control the technology for capturing and liquidating spilled hydrogen. KSOE expects to save hundreds of millions of dollars in royalties by inventing a liquid hydrogen transporter that does not require such technology.
Despite controlling more than 72% of the worldwide liquefied natural gas carrier market last year, Korean shipbuilders acquired important technology from a French company, GTT, and owing it enormous payments. GTT normally obtains a 5% royalty cut on LNG carriers, which cost around 200 billion won ($167.8 million).
“Recovering and liquidating leaking LNG with GTT’s technology is truly lucrative, but only when LNG is liquidated at minus 163 degrees Celsius. It won’t work with liquid hydrogen, which transforms into a liquid at negative 253 degrees Celsius, barely 20 degrees above absolute zero of minus 273 degrees Celsius, according to Yoo.
KSOE appears to have it all worked out, but infrastructure remains a major concern. Even if KSOE’s liquid hydrogen carrier successfully transports the cargo, terrestrial infrastructure, such as subsurface liquid hydrogen pipes, is required.
It won’t be a problem, according to Yoo, even in areas where liquid hydrogen infrastructure isn’t yet in place.
“If you look closely at our liquid hydrogen carrier’s concept illustration, you’ll notice five fuel pumps. We added two extra pumps to the original design, which had three. The two pumps will turn liquid hydrogen into gas and deliver it to hydrogen tube trailers immediately.”