TTCT – If international trade is a living organism, then sea transportation must be the lifeblood. But how can the 55,000 merchant ships out there survive the era of fossil fuel eradication?
In the middle of a sweltering June day, a ship filled with sci-fi film color docked in Saigon - a stark contrast to the floating restaurant with the "one thousand nine hundred" shark that was parked nearby. With two parallel floating hulls, connected by a single deck, and two sets of long rectangular wings pointing straight up into the sky, it looks more like a giant (and expensive) toy than a boat. .
More than 200m2 solar panels cover the ship, sneezes hot all over the writer's body during the tour. But the Energy Observer (EO) is not a photovoltaic vessel, which is famous here and there as the “first zero-emission hydrogen ship”. Around the world since 2017, EO wants to prove that the widespread use of hydrogen fuel – the piece of “another future for energy” – is possible.
The keyword here is “widely used”. The idea of hydrogen fuel has been around since the early 19th century, but 200 years later, hydrogen still plays an insignificant role in the clean energy era. The world is still figuring out how to balance the pros and cons of this completely carbon-free fuel.
Hydrogen colors
Hydrogen is the most abundant chemical element in the universe, but on Earth it very rarely exists in pure form. So want to use H gas2, we must first separate the hydrogen from the compounds, i.e. input is required and energy will be expended.
The number 1 candidate is the country (surname)2O). If we use 100% renewable energy to electrolyze water into hydrogen and oxygen, we will have a clean source of hydrogen, named "green hydrogen", because the whole process does not emit greenhouse gases. At that time, THEY2 can be burned to release energy (similar to kerosene or gas), or passed through a fuel cell to generate electricity. Either way, the only waste is harmless steam.
However, like many other clean technologies, the hydrogen solution also has complex nuances, especially when it comes to how “clean” it is. A major drawback of green hydrogen is the high cost of production. In fact, less than 0.1% of dedicated hydrogen production globally is in the "green" category, according to the International Energy Agency (IEA) report The Future of Hydrogen in June 2019.
In contrast to blue hydrogen, "gray hydrogen" is the dirtiest because it comes from fossil fuels. Unfortunately, it is also the most common and cheapest hydrogen available today, emitting 830 million tons of CO .2 per year, equal to the total carbon footprints of the UK and Indonesia combined.
Recently, technological advancements and rising prices of fossil fuels have increased competition for green hydrogen. In the Hydrogen Forecast to 2050, the latest forecast for hydrogen through 2050, energy testing and consulting firm DNV says that by 2050, 72% of hydrogen gas and its energy-carrying derivatives will be produced based on electricity.
One possible way
Even with "green" production, hydrogen fuel is expensive and less efficient when compared to using electricity directly. The reason is because the process of generating H2 often "swallows" more input energy than the output energy that we can use (similar to the loss of electric car batteries: the amount of electricity discharged is less than the amount of electricity charged in. ).
Using more electricity to generate less electricity, so should hydrogen be the last resort? Youth Weekend asked that question to the EO crew. “We produce hydrogen with excess electricity when the battery is fully charged,” says engineer Luc Bourserie. This extra electricity you don't use anyway, so you don't mind."
The type of battery Bourserie mentioned is a Li-Ion battery, used to store 100 KWh of solar electricity in the short term. When the battery is full but sunlight is still abundant, the ship will switch to electrolysis of H2O in seawater to collect H2, is long-term stored in compressed air in 8 tanks. A total of 62kg of hydrogen gas, when running through Toyota's fuel cells, can provide up to 1 MWh of electricity (10 times more than Li-Ion batteries) to keep the ship operating at night or on sunny days. then it was 1 MWh of thermal energy for heating and hot water.
In other words, although it cannot "turn off the sun" or "tie the wind" like Xuan Dieu, the EO ship can save a large amount of renewable energy in the form of hydrogen fuel. Therefore, hydrogen and its derivatives, including ammonia (SM3), can become a clean fuel source for the shipping sector, where direct electricity use is not feasible. The other two potential areas are aeronautics and high-temperature industrial processes such as metallurgy.
Compressed air storage tank (Left) and Engine (Right) of the Energy Observe ship.
New fate of the maritime industry?
Today, our 80% goods, in terms of volume, are transported by sea, from clothing to cars to food. To demonstrate a solution to reduce CO2 in maritime traffic, the concept of "zero-emission cargo ship" Energy Observer 2 was launched in February 2022.
Unlike the first model that used gaseous hydrogen, EO2 uses liquid hydrogen, which is also produced from renewable energy. In terms of energy, each kilogram of liquid hydrogen is equivalent to 3 kilograms of oil. The EO2's tanks can store up to 70 tons of liquid hydrogen (1,000m3).
However, the application of hydrogen fuel at the scale of cargo ships exposes two other disadvantages. The first is the storage barrier, because 1kg of liquid hydrogen takes up more space than 1kg of marine diesel (about 4.3 times). And space for cargo ships is money.
But the biggest challenge is keeping liquid hydrogen at minus 253oC, while trying to protect the ship's components from damage. To “feel” the difficulty of the problem, we need to know that absolute zero – the coldest possible temperature is minus 273.15oC.
But there is some very positive news. In March 2022, Reuters reported that a $364 million project jointly by the Australian and Japanese governments had demonstrated that the use of liquefied hydrogen gas tankers (such as oil tankers) was technically feasible. Kawasaki Heavy Industries' Suiso Frontier left Victoria on January 25, carrying 75 tons of liquid hydrogen made from Australian brown coal, and docked at Kobe a month later. The cargo - maintained at minus 253oC throughout the voyage - was successfully unloaded at the end of February.
“The stages from production and transportation to transport and storage illustrated in this project show that there is already a technological foundation for the future use of hydrogen as an energy source like liquefied natural gas. (LNG)” – Motohiko Nishimura, managing director of Kawasaki Heavy Industries, announced to the press.
In addition, industry is also optimistic about using ammonia - a compound of hydrogen and nitrogen - as a fuel with zero or low emissions. Although not very fragrant and quite toxic, NH3 is highly liquefied, has been transported across oceans on a large scale, and has an energy density nearly twice that of liquid hydrogen.
According to DNV, in general, "hydrogen is likely to meet only 5% of global energy demand by 2050", which is only a third of what is needed. It is clear that the world needs stronger policies to promote hydrogen fuel to meet the goals of the Paris Agreement on climate change.
At the same time, hydrogen production itself must be 100% green, before it can contribute to the removal of carbon from the energy system. Anyone who finds a way to produce hydrogen cleaner, at a larger scale and at a lower cost will likely lead the way in the global renewable energy race.
-Source of Tuoi Tre Newspaper-
