EDITOR/BAIHUAHUA
A loud bang on a winter night in 1943 scared the inhabitants of Oregon into dissipation.
It was during the Second World War, and many people thought it was a bomb.
However, the most panicked were the workers of the shipyard, their eyes widening in disbelief at the scene before them, the first Liberty Ship that had been so hard to build had been split in half!
This scene shocked everyone present, and they could not imagine what terrible force could break an oil tanker in half so easily.
They couldn't find the cause of the break. At a loss, some people put forward the hypothesis of aliens, believing that it was an alien mysterious force that split the ship in two.
The media even carefully investigated whether anyone had seen the paranormal that day, but there were no reports of any UFO sightings that day. I believe such an unreliable statement, it's really a rush to the doctor.
Even if the cause of the fracture is not identified. They continued to build the Liberty Ship, but two months later, the other Liberty Ship cracked as soon as it reached New York.
The cost of a freeship is $2 million. There are 18 shipyards, and countless billionaires and business magnates, all counting on the Liberty Wheel to make a fortune. Now that the ship is cracked, what to do?
You must know that the United States is a country that started out by making war money. Transporting soldiers and supplies to battlefields around the world is a big business. Not only these capitalists, but also the US government is reluctant to give up.
At that time, the United States had fallen into a frenzy for money, building a cruise ship in 5 days, 18 factories started work at the same time, and the ship was nailed with steel plates when it cracked, and it was in full swing.
Therefore, knowing that the technology is not up to par, the United States has built 2,710 free ships, and nearly 1,500 of them have cracks in the end. More than 100 ships can be sunk in a month.
After a crazy patch, 20 ships had to sink in a month, and such an expensive cruise ship turned out to be a disposable chopstick, thrown away when it ran out.
Of the more than 2,000 ships that have been preserved today, only four have survived, and the survival rate of 2 per 1,000 is more than the American soldiers. This picture is one of the survivors, the USS John Brown.
After the war, physicists at the U.S. Naval Research Laboratory discovered that the problem was the welding process.
At that time, electric welding technology injected a dangerous element into the hull of a ship during the welding process, and that was hydrogen.
Hydrogen embrittlement is so fierce?
Hydrogen has been found in hydrogen embrittlement for a long time. As early as 1874, scientists from the Royal Society of England discovered that iron wire, after being soaked in an acidic solution for a period of time, becomes extremely fragile and can be broken with a slight break.
He speculated that it could be a chemical reaction between iron and acid, and the resulting hydrogen invaded the iron's interior, making it brittle. This phenomenon is called hydrogen embrittlement.
Hydrogen embrittlement, a word that sounds very unfamiliar, has invisibly become a metal killer. This seemingly insignificant element can cause the metal material to become fragile and vulnerable to external stresses or loads, and even form small cracks inside.
Hydrogen embrittlement is not unique, and it has had serious consequences in a number of areas.
In 2019, at a hydrogen refueling station in Norway, a high-pressure hydrogen storage cylinder assembly sequence went wrong, resulting in a hydrogen leak, which directly caused an explosion and fire.
These accidents have fully exposed the dangers of hydrogen embrittlement. Therefore, we must pay great attention to it and take effective measures to prevent and control the occurrence of hydrogen embrittlement to ensure the safety of our lives and property.
How humans conquer dangerous hydrogen
The development of hydrogen storage and transportation technology is relatively lagging behind, and this problem has always been one of the important bottlenecks in the promotion of hydrogen energy. But human ingenuity will eventually tame them.
In terms of storage methods, high-pressure gaseous hydrogen storage is currently the most commonly used method. This method involves compressing hydrogen to a high-pressure state and then enclosing it in specially treated cylinders or cylinders for storage.
Due to the extremely high diffusion rate of hydrogen, which can have a corrosive and embrittlement effect on hydrogen storage vessels and metal materials, hydrogen storage tanks need to use specially treated metal and have a high thickness to ensure safety.
In recent years, in order to improve the safety of hydrogen storage, R&D personnel are also exploring hydrogen storage tanks made of new materials to meet this challenge.
The transportation of hydrogen also presents some technical challenges. At present, common modes of transportation include pipeline transportation, storage and transportation vehicle transportation, and liquid hydrogen ship and hydrogen tanker transportation.
Pipeline transport is considered to be the most cost-effective way to transport hydrogen over long distances. However, pipeline transportation requires significant upfront investment and can be limited in terms of environmental and social acceptance.
Storage and transport vehicles are suitable for short-distance transportation, but have high requirements for tightness to avoid hydrogen leakage. The requirements for thermal insulation performance are also very high, and a series of thermal insulation measures need to be taken.
As for hydrogen-fired power generation technology, current gas-fired generators cannot yet use pure hydrogen as fuel, but use hydrogen-blended natural gas. However, with the continuous advancement of research and technology on hydrogen energy, the prospects for hydrogen-fired power generation are still very broad.
The latest gas-fired generator technology can burn natural gas mixtures with up to 50% hydrogen content, which somewhat reduces the reliance on pure hydrogen.
In the future, how to overcome the storage and transportation problems of hydrogen and ensure a safe and reliable supply will be the key to the development of the hydrogen energy industry.
Since hydrogen is so dangerous, what is the level of hydrogen energy vehicles at the Winter Olympics in China, and how advanced is it?
It's green, but it's not completely green
In a country like China, which is rich in coal resources and relies on hydrogen production from by-products of coal chemical industry, the development of the hydrogen energy industry is facing many challenges.
Although China has become the world's largest hydrogen producer, the vast majority of hydrogen still comes from chemical by-products, the so-called "grey hydrogen". In order to produce gray hydrogen, there will also be a lot of carbon emissions, let alone environmental protection.
In contrast, "green hydrogen" is produced through renewable energy, water electrolysis and other methods to achieve zero carbon emissions and zero pollution, but it currently accounts for less than 1% of the Chinese market.
In terms of cost, the production cost of green hydrogen is much higher than that of grey hydrogen, mainly due to electricity consumption and the cost of setting up electrolyzers. At present, the average cost of hydrogen production by electrolysis of water is 38 yuan/kg.
The average cost of hydrogen production using industrial by-products is only 8-14 yuan/kg. For green hydrogen to be competitive in the market, industrial electricity prices need to fall below 0.3 kW·h from the current 0.6 kW·h.
Faced with this dilemma, some Chinese companies have begun to invest heavily in R&D and production of green hydrogen. Most of the midstream and downstream enterprises are still producing gray hydrogen, and how to guide these enterprises to the development of the green hydrogen industry will be an important task in the coming period.
Only if hydrogen comes entirely from zero-carbon electricity can hydrogen fuel cell vehicles be truly environmentally friendly.
In the current environment dominated by thermal power generation, hydrogen-powered vehicles are likely to generate more carbon emissions, making them a diversion of pollution rather than a real solution.
China's hydrogen industry is at an important turning point, with the need to address the environmental problems caused by grey hydrogen on the one hand, and the need to reduce the production cost of green hydrogen on the other.
This requires the joint efforts of the government, enterprises and all sectors of society to promote innovation and cooperation in technology research and development, policy support, market cultivation and other aspects to achieve the green transformation and high-quality development of the hydrogen energy industry.