LOHC
The LOHC (liquid organic hydrogen carrier) concept is a capable technology [1] for supplying hydrogen refuelling stations due to its high hydrogen storage densities (57 $kg_{H2} m_{LOHC}^{-3}$) and easy handling (liquid, low toxicity, low flammability). ...
The LOHC technology is based on the chemical bonding of hydrogen to liquid organic carriers, which are mostly aromatic hydrocarbons or heterocyclic substances. ...
There are three different types of organic carriers: methyl cyclohexane-toluene, NEC (N-ethyl carbazole), and DBT (dibenzyl toluene).
In contrast to some other chemical hydrogen storage processes, these reactions are reversible. The carrier molecule is cycled between a loaded and unloaded state. ... The most technically advanced concept, which is pursued by Hydrogenious Technologies, is based on the use of the common heat transfer oil dibenzyltoluene, which is available in large quantities and is not classified as a dangerous good.
Compared to other technologies that store hydrogen at temperatures of -253 °C or at pressures up to 500 bar, using LOHC technology greatly reduces the cost of handling hydrogen.
The hydrogen-rich or loaded LOHC (LOHC+) can be transported via standard tank trucks to the hydrogen refueling stations, which are equipped with a dehydrogenation system. There, the hydrogen can be produced as needed and then integrated into the existing hydrogen refueling station technology. The German Climate Action Plan of 2050 acknowledges that LOHC technology has considerable potential for establishing hydrogen as a fuel.
The question of just how hydrogen will get around the world, and what it will cost, is key to putting in place global hydrogen infrastructure [3]. A report.. from Rethink Energy, part of Rethink Technology Research, shows that the bulk of the effort will be split between pipelines and liquid organic hydrogen carriers (LOHC), often transported in ships – and points to the limiting cost factors which shall define each transport use case.
One VLCC ship [3] can carry up to 350,000 DWT which would be equivalent to 17,000 tons H2. One train in Europe can pull up to 35 wagons which would be equivalent to 59 tons of H2. A quick calculation shows the amount of energy that can be carried across Atlantic by a fleet of 20 ships using LOHC techology,
one_trip = 17000*1000*33.6 / (365*24*1e3)
print ("One trip, single ship %0.1f MW" % (one_trip))
print ("Fleet %0.1f GW" % (one_trip*12*20 / 1e3))
One trip, single ship 65.2 MW
Fleet 15.6 GW
The Guardian, ABC, Manufacturers' Monthly
In March, the Queensland University of Technology [QUT] made history when it achieved the first export of a small quantity of clean, green hydrogen produced in Australia from renewable energy, to Japanese energy giant JXTG – proving that it was in fact possible.
The actors involved; JXTG, is Japan’s largest petroleum conglomerate. QUT provided solar panels that can work with salt water. The second link above also says:
"[H2] was created by adding water and acid to a chemical called toluene in an electrochemical process using solar energy. The toluene was converted into a substance called methyl cyclohexane (MCH) using JXTG’s process powered by QUT’s solar arrays".
Methyl cyclohexane is a convenient carrier for H2, as liquid and at normal temparatures.
"Methyl cyclohexane is a clear colorless liquid with a petroleum-like odor. Flash point 25°F. Less dense than water and insoluble in water. Vapors heavier than air".
On the receiving end.. "once shipped to Japan, the MCH was converted back to toluene and the hydrogen extracted for use in a suitable fuel cell or vehicle. The toluene is then available for re-use in the transportation cycle."
Australia has the sunshine, ports, expertise and logistics in transportation. The process described above uses a proprietry tech developed by JXTG. If I was a country with lots of sunshine, I'd invite them to set up shop in my country, let them produce, export H2 (to themselves in Japan) from sunshine, tax their ass, and use the money for whatever. U'd literally be making money out of thin air.
Reference
[1] Hydrogenious Presentation - 1
[1] Hydrogenious Presentation - 2
[2] Rethink Energy