China has snatched the "three pearls" in the crown of shipbuilding (aircraft carriers, large cruise ships, LNG carriers) and put them in its pocket. There is more than one kind of LNG carrier, including the transportation of various gaseous chemical products, such as liquid hydrogen, liquid oxygen, liquid nitrogen, liquid ammonia (NH3), liquid carbon dioxide, liquefied petroleum gas, etc. The common feature of them is that they can only be liquefied at very low temperatures, so they must be transported in tanks made of low-temperature and seawater corrosion resistant materials. Aluminum is the most suitable material.
There are about 4 or 5 large tanks on each ship. Each tank has a volume of more than 30,000 m3, and there are spherical and square tanks. This LNG storage tank is generally welded from 6,000 "watermelon skin" aluminum plates, with the thinnest part about 30mm, the thickest part about 170mm at the "equator", the diameter of the spherical tank is about 41m, and the mass is about 900t. The amount of aluminum used for such a single tank is mostly higher than 400t.
In addition, the transportation of liquefied chemical gas must also have loading base and unloading base. Taking LNG loading and unloading base as an example, the aluminum consumption of above-ground storage tank is about 1300t/tank, and the aluminum consumption of underground storage tank is about 120t/tank. The aluminum and workpieces used are plates, profiles, castings, forgings, pipes, etc.
Application of Aluminum Materials in CO2 Transportation
With the deepening of the concept of decarbonization, the CCS technology of recovering CO2 and storing it underground will be applied to production practice as soon as possible. China is currently the largest country in terms of coal-fired power generation, and the country with the largest emissions of CO2 from power plants. If the emissions of CO2 are captured and liquefied, it is a formidable task to transport them to the storage site. The liquefaction of CO2 is more difficult than that of natural gas, because CO2 will freeze (pressure 416.5 kN/m2) at minus 21.1°C and turn into dry ice. The state of CO2 at this pressure and temperature is the three-phase point. Under the temperature and pressure of the three-phase point, CO2 cannot exist in a completely liquid form. When transported by pipeline, there is a risk of blocking the pipeline, so a certain pressure must be maintained during transportation. But it is quite difficult to maintain the pressure of large storage tanks, and only aluminum storage tanks can be qualified.
Japan has developed a small liquefied carrier in 2021, and a large carrier is being developed by Mitsubishi Shipbuilding and Imachi Shipbuilding. It is reported that the first large liquefied CO2 carrier can be operated in 2027. This is a new technology that recycles CO2 emissions from power plants and sequesters them deep underground. The Japanese government has proposed a goal of sequestering 120 million to 240 million tons of CO2 annually by 2025. According to relevant institutions, the global CCS market is expected to grow at a compound annual growth rate of 15.1%, from $2.4 billion in 2022 to $4.9 billion in 2027.
Therefore, CCS technology and market are potential large markets for expanding aluminum application, which should be developed on a larger scale.
Japan plans to sequester a total of 16 billion tons of CO2 in 11 locations, but some locations are difficult to implement. Japan's Kawasaki Steamship Co., Ltd., which participated in the Northern Lights CCS project, the largest CCS project in Europe, promoted aluminum alloy CO2 carriers, and will be responsible for the management and transportation of liquefied CO2 carriers after 2024. Japan's Mitsui Merchant Marine Co., Ltd. and Kansai Electric Power Co., Ltd. will also promote the investigation and discussion of shipping liquefied CO2 to sequestration candidatesJapan plans to sequester a total of 16 billion tons of CO2 in 11 locations, but some locations are difficult to implement. Japan's Kawasaki Steamship Co., Ltd., which participated in the Northern Lights CCS project, the largest CCS project in Europe, promoted aluminum alloy CO2 carriers, and will be responsible for the management and transportation of liquefied CO2 carriers after 2024. Japan's Mitsui Merchant Marine Co., Ltd. and Kansai Electric Power Co., Ltd. will also promote the investigation and discussion of shipping liquefied CO2 to sequestration candidates by sea. In March this year, Japan had a small vessel capable of transporting 1450m3 liquefied CO2. Currently, there are only four such small vessels in the world. Now, the construction of large vessels with a capacity of more than 12,000m3 is also on the agenda in the industry.
China's first offshore 1,000,000-ton-class CO2 storage project was put into operation in April this year, with an estimated 35% of the superstructure made of aluminum.
Without aluminum, there would be no large-scale hydrogen industry.
Low-carbon development makes the use of fossil fuels less and less, while the use of H2 will be more and more, will play a more and more important role, used in aerospace, cars, trains, welding, metallurgical reducing agent, ammonia production and other fields.
Hydrogen is the first chemical element in the periodic table, a colorless, odorless, tasteless gas composed of diatomic molecules (H2). Hydrogen atoms, symbol H, consist of a unit positively charged nucleus and a single electron. It has an atomic number of 1 and an atomic weight of 1.00797. It is the main component of water and organic matter, and is widely distributed not only on Earth but also in the universe. Hydrogen has three isotopes: deuterium, mass number 1, which makes up 99.98% of the natural element; tritium, mass number 2, which makes up 0.02% of the natural element; and tritium, mass number 3, which is found in very small amounts in nature but can be produced artificially by various nuclear reactions.
Hydrogen in its condensed form makes up 0.76% of the mass of the Earth's crust, and 13.5% of the atoms in the crust are hydrogen, surpassed only by oxygen and silicon. Most of this hydrogen is in seawater, accounting for about 10.82%. Many metals can absorb hydrogen, but palladium is especially good at this, dissolving about 1,000 times its own weight in hydrogen.
Hydrogen is a rather inert substance at room temperature, but at high temperatures it is highly reactive. It reacts with oxygen to form water, 2H2+O2→2H2O, with a heat of reaction of 57.6 kCal/mol. At room temperature the reaction does not actually take place, but at about 300°C it occurs slightly and at greater than 500°C it occurs rapidly.
There are many processes for the preparation of H2, depending on the amount of H2 required, the purity required, the utilization rate and price of raw materials and other factors. The commonly used ones are the reaction of metals with water or acid, the electrolysis of water, the reaction of steam with hydrocarbons or other organic compounds, and the thermal decomposition of hydrocarbons.
H2 is transported in liquid form and on all-aluminum ships. The so-called all-aluminum ship does not mean that the ship itself and all equipment on board are made of aluminum, but that all equipment that can be made of aluminum under existing technical conditions is processed with aluminum, or most of it.