Hydrogen as fuel in the maritime industry

Hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water. You can produce hydrogen from a variety of domestic resources, such as natural gas, nuclear power, biomass, and renewable power like solar and wind. However, to produce hydrogen You need energy. These qualities make it an attractive fuel option for transportation and electricity generation applications. You can use hydrogen in cars, in houses, for portable power, and Vessels! Propulsion systems are still under constant development, and hydrogen could be a big game changer!

The biggest advantage of hydrogen: it is energy that can be store! You can produce it in one place and move it from one place to another. This allowed the production of hydrogen from windmills and deliver energy produced for the industry region. There are several methods to produce hydrogen, however the most popular is by thermal process from natural has. Other methods required solar factors or biological processes, so in my opinion, the most popular in the next years become the thermal process method.

Thermal process – How to produce hydrogen as fuel?

Thermal processes for hydrogen production typically involve steam reforming, a high-temperature process in which steam reacts with a hydrocarbon fuel to produce hydrogen. Many hydrocarbon fuels can be reformed to produce hydrogen. Including natural gas, diesel, renewable liquid fuels, gasified coal, or gasified biomass. Today, about 95% of all hydrogen production is done from steam reforming of natural gas. How does it work? Natural gas contains methane CH₄. From this we produce hydrogen in one of two methods described below:

Chemical reactions for Steam-Methane

Steam-methane reforming reaction
CH₄ + H₂O (+ heat) → CO + 3H₂

Water-gas shift reaction
CO + H₂O → CO₂ + H₂ (+ small amount of heat)

Chemical reactions for Partial Oxidation

Partial oxidation of methane reaction
CH₄ + ½O₂ → CO + 2H₂ (+ heat)

Water-gas shift reaction
CO + H₂O → CO₂ + H₂ (+ small amount of heat)

Temperature to production is between 700-1000°C. So this is an energy-consuming process. However, that prepared hydrogen is ready to be store and deliver to a vessel as fuel.

Risks of hydrogen as fuel

Hydrogen is not a perfect fuel. It can be store only in high-pressure tanks between 350-700 bar, in compress form. Storage of hydrogen in a liquid form requires extremely low temperature in atmosphere pressure (-252,8°C). A good idea will be to store it in a combined solution as a compressed-cold environment. This allows for the reduction of pressure but requires controlling temperature.

Hydrogen can be store as material based. Like complex hydride, or adsorbent. However this methods are still under challenges.

An analysis was complete of the hazards and risks of hydrogen, compared to the traditional fuel sources of gasoline and natural gas (methane).  The results show that, for flammability hazards, hydrogen has an increased flammability range, lower ignition energy, and a higher deflagration index. For both gasoline and natural gas (methane) the heat of combustion is higher (on a mole basis). Thus, hydrogen has a somewhat higher flammability hazard.

Hydrogen as fuel in current use

There are currently over 25,000 hydrogen fuel cell power forklifts operating. Around the world in shipping fulfillment centers the likes of Amazon, Walmart, FedEx, and more. These systems have been in service for well over a decade and operate 24/7, having completed >16 million refuels. Whether you knew it or not. Your recent purchases were likely moved by a hydrogen fuel cell vehicle! Moreover, these systems are often operated by someone that may or may not have a high school diploma. That is just a matter of time until hydrogen will be implement at sea. Question is, will be this fuel better than other green fuels?

First Hydrogen Vessels

First, a hydrogen-powered ocean going ship will be a ZEUS. The project will be built by Fincantieri.

This will be a pilot vessel. It will be a floating laboratory as Fincatiery officials say. The idea behind this is to find a standardization for hydrogen for Cruise Ships, Yachts, and ferries. However, hydrogen fuels were not installed yet for maritime use at sea. So, this will be the first chance.

The boat is approximately 25-meter long and has a tonnage of around 170 tons. In fact, Zeus is going to be a floating laboratory, aimed at collecting information on fuel cell behavior in the real environment. Such an electrochemical device allows obtaining electricity directly from hydrogen without the thermal combustion process.

What’s more, it will have a 130-kilowatt fuel cell facility, powered by about 50 pounds of hydrogen contained in 8 metal hydride cylinders. Such technologies are already in use by the Navy by submarines! Together with the system of batteries, the facility will allow autonomous work for about 8 hours of sailing with zero emissions at a speed of about 7.5 knots.

The architecture of the propulsion framework, as per the manufacturer’s report, will supply the engines in 4 different ways:
– zero noise, with the use of lithium batteries only, able to guarantee an autonomy of 4 hours of sailing at a speed of 4 knots;
– zero-emission, with the use of the electrical power, supplied by the fuel cell;
– diesel generator navigation with battery charging; 
– diesel generator navigation for transfers, with autonomous work for 60-hour sailing at 9 knots.

In Conclusion about hydrogen in the maritime industry

In my opinion, hydrogen is a very difficult fuel to implement onboard vessels. Conditions of transfer hydrogen in tanks are very costly to achieve. This could a good alternative for coastal vessels, which can do bunkering frequently. However, for ocean-going vessels, this will be really difficult to implement. What do You think about hydrogen? Will this technology be used widely or You have your other type for “green fuel”?