Is burning, blindness, and death. Is it safe to transport ammonia gas around the world?

Xintang Maritime Network Gao Longyan

Amino fuel is about to become the first choice for zero carbon shipping, and it is also a cost -effective carrier for long -distance transportation of hydrogen. While we are paying attention to the potential of ammonia fuel as green energy, some experts are uneasy about the large -scale transportation of ammonia. In an interview with the media, "if it is leaked, the ocean may lose vitality."

Photo source: C-Job Naval Architects

A recent report from Irena (Irena) states that in the case of still maintaining 1.5 ° C climate target, a quarter of the world in the world in 2050 will undergo international trade, of which 45%are in the form of ammonia. Transportation, accounting for about 69 million tons of hydrogen. In the report, Irena also pointed out that under its 1.5 ° C climate target, the demand for ammonia in the middle of this century will increase four times to 688 million tons. Among them, 197 million tons were used for shipping fuels and 127 million tons were used as hydrogen energy carriers.

Is there a problem of maritime safety in ammonia fuel transportation?

One of the issues that significantly expand the scale of ammonia gas transportation are that as more and more ships sail on the public sea, the possibility of serious accidents is also increasing.

David Cebon, a professor of mechanical engineering at Cambridge University, said in an interview that compared with 2018, shipping casualties and accidents in 2019 increased by 5%to 2815. 40%of all cargo transported goods are fossil fuels. If you use fossil fuel as a way to transmit energy, 40%of ships carry ammonia. About 20 ships sink each year, and a large number of ammonia will eventually enter the ocean.

Ammonia is moderate toxic, but it has strong corrosiveness. Even if the concentration in the air is very low, it is only 30 % (PPM), which may come from very small leaks, and sometimes even conventional operations. If a person comes into contact with it for more than 15 minutes, it will cause breathing difficulties. At 100ppm, the stimulation of the eyes and throats will appear. At 500-700 ppm, any contact will become dangerous. The risk of burning throat, skin, lungs, and eyes may cause blindness. At a higher concentration, the risk of death has increased greatly. The severity of the damage depends on the exact concentration of ammonia and the length of contact time, but in the worst case, it can cause the respiratory tract to be burned and suffocate the victim.

This is not over yet. When the ammonia is overflowing. For example, a collision occurs at sea, causing the tank to rupture, especially if it encounters water, it will react with the condensation in the air to form a heavy toxic mist and will not dissipate.

George MalloupPas, a scientist at Cyprus Ocean and Maritime Institute (CMMI), explained that "ammonia clouds are very difficult to deal with. It's almost impossible. "

Although the combustibleness of ammonia is significantly lower than the LNG (LNG), it is still combustible, so any offshore leak will be accompanied by the risk of explosion or fire. Severe ammonia leaks will also be devastating under the action of waves. After ammonia dissolved in water, ammonium hydroxide is formed, which is toxic for marine life.

Paul Martin, co -founder of the Hydrogen Science Alliance, said that "ammonia with a concentration of 1ppm in water is enough to kill many marine creatures. After a ship with ammonia sank, it may cause the ocean of the square to lose its vitality dozens of kilometers."

Ammonia is considered to be one of the most common causes of fish death in aquatic ecosystems. The impact of ammonia qi leakage at ports, estuaries and semi -closed bays will be the most serious.

Is it a good security record so far?

On land, several ammonia accidents have occurred, especially in 1976, a destructive road accident in Texas, a crashing ammonia tank cars died of 5 people and 178 people were injured. Just last month, Carlsberg was fined 3 million pounds ($ 3.6 million) by the British regulatory agency due to the ammonia leakage of its beer factory, causing one person to die and the other were seriously injured.

However, it is worth noting that although a large amount of ammonia has been transported through maritime for many years, it accounts for about 8%of the total output, so far, there are relatively few accidents related to ammonia at sea.

IHS Markit's shipping accident database report said that as of 2021, there were only four accidents related to ammonia, and only one of them was related to the ammonia leakage of the cargo transportation. This incident did not cause casualties or environmental damage. However, the remaining three were fatal accidents, which occurred on the fishing boat. The ammonia of the refrigerant on the boat either leaked or exploded.

However, David Cebon, a professor of mechanical engineering at Cambridge University, warned that due to lack of effective maritime supervision, the expansion of ammonia transportation is expected to lead to more accidents.

According to Together in Safeth, 75-96%of the maritime accidents are caused by man-made errors, because time on board and away from loved ones will weaken the efficiency of the crew. For the mastery and training of the crew's professional knowledge on the treatment of ammonia gas, it takes time and money. Some shipping companies may not be able to spend money to buy these knowledge, which will also lead to further risks.

Maritin even further said that the tankers mooring near the densely populated area will be more dangerous and may cause catastrophic casualties. The risk increases when using ammonia as shipping fuel

Another reason for the "relatively clean" safety record of ammonia is that it is relatively new as fuel, without testing, but it is more risky in nature.

Unlike the ammonia gas, the ammonia gas is installed in a sealed jar, and the ammonia of the fuel will be integrated into the operation of the ship. This means that the pipeline is transported from the fuel from the fuel tank to the fuel preparation room (including the space of pumps, compressors, etc.), and then to the engine to maximize the surface area that may be leaked or damaged. This means that ammonia is burned in the engine and may leak or explode.

There are crew members in the machine room, and the escape ammonia emissions in the engine will be relieved from the exhaust pipe, and they may all be exposed to the leaked fuel.

The good news is that LNG has relatively safely completed the transformation from cargo to fuel, so other liquefied gases have a model to learn from. The bad news is that, as the car -grade community DNV clearly states in its recent "ammonia gas as a ship's fuel safety manual" that ship design with liquefied natural gas as fuel is not suitable for ammonia fuels, so a new method is required, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new method, including a new way, including Design and operation.

Professor Elias Yfantis, a senior scientist at the centers of CMMI and offshore science, technology, and engineering centers, explained: "Relevant crew must have appropriate skills, improve skills or re -learning, to meet the specific requirements of a new fuel, physical physical physical physical physical physical physics. The chemical characteristics and behavior are significantly different from the existing ship's liquid fuel. "

DNV recommends taking some relief measures to safe loading, transportation and combustion of ammonia on the maritime.

First of all, it is recommended to put the ammonia tank away from the operation of ships and goods, and carefully consider its position to minimize the risk of external events, such as stranding or collision. The report is also recommended to set up a secondary barrier around the tank, pipeline and engine to curb any potential leakage and prevent them from penetrating into the area where the crew may be operating.

In addition, air lock exports should be set in the closed space of ammonia and people coexist, so that crew can quickly escape and capture any escape ammonia. Complete personal protection equipment (PPE) is inevitable, and there is an effective management system to deal with the so -called "boiling gas".

At the port, the loading and uninstallation of ammonia should be carried out as remote as possible, and professional staff should be carried out to reduce the risk of leakage. DNV added that the fuel loading hose should be brushed with an inert gas to remove any residual ammonia gas.

What if any one in these systems fails? George MalloupPas, a scientist at Cyprus Ocean and Maritime Institute (CMMI), believes that the current leakage detection system on the market can remind crew members to pay attention to potential leakage so that they can intervene before the situation upgrade. He said: "There are commercial and mature sensors and systems available for business, which can quickly detect leaks. The reaction time will be as fast as other systems that leaks. There are also some new systems need to be approved."

In general, CMMI believes that although ammonia is indeed a dangerous transportation substance, the combination of supervision and innovation will be enough to reduce risks. CMMI believes that ammonia is an effective energy carrier, provided that the technical mature, applicable, safe, and cost -effective solutions will be completely available and obtained appropriate verification and approval by the carriers.

When asked about the possibility of effective supervision, Martin was not so optimistic. "I believe we can do this, but I also believe that we will not do this until there are major losses for forcing us to implement supervision. "

It's hard not to compare it with nuclear power. Like ammonia, nuclear power may cause large -scale energy systems to decapy and have relatively good safety records, but this is very small for the anxiety of possible catastrophic consequences. Like nuclear power, synthetic ammonia has no room for safety. It will require shipping companies, engine manufacturers and shipyards, and supervisors to make huge efforts and large investment to avoid even a devastating accident.

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