How A Nitrogen Gas Generator Is Used In The Marine Industry?
Nitrogen generators have become indispensable helpers in the marine industry today.
Nitrogen gas generators are typically used in combination with compressed air systems. They ensure safe and leak-free handling and transportation of flammable and sensitive cargo.
In this blog, we will dig deep in the nitrogen gas usage in marine vessels. We will also understand the difference between PSA Vs. membrane nitrogen generator and address most FAQs about nitrogen generators.
How Nitrogen Gas Used In the Marine?
Inerting
Elimination of atmospheric air from cargo tanks and ships is called inerting.
Inert gas is the gas that contains extremely low content of oxygen (usually less than 8 %) to diminish the ignition of inflammable hydrocarbon gases.
It is used to remove oxygen from cargo tanks and ships during storage.
The inert process is also commonly used as a purging process and can also be used to purge out contaminants, such as bio-toxins, oil, and other environmental pollutants.
Due to its low flammability index and low toxicity, nitrogen gas is considered a safe and effective alternative in offshore and marine applications. The usage of nitrogen gas as an inert medium prevents explosions that lead to cargo damage, marine pollution and loss of marine as well as human lives.
Purging
Removal of Hydrocarbon vapors from cargo tank is called as purging.
Do not confuse purging with inerting. Purging, by definition, ensures that a combination of hazardous gases isn’t formed in the marine vessels. Inerting makes this combination safe by introducing inert gas into the capacity.
Purging in the marine industry is primarily done through nitrogen. Nitrogen gas generators are utilized by the marine industry to purge the unwanted atmosphere and contaminants in closed vessels, pipelines, containers and other spaces. It also prevents moisture-related equipment damage or even combustion.
Padding/Blanketing
The safety of the crew and environment is the number one priority in marine vessels. Nitrogen gas padding or blanketing ensures just that!
This method creates a dense blanket of nitrogen around the ports, displacing hazardous gases that may be present on the cargo ships, and preventing any chances of fire.
Nitrogen blanketing is a common practice in the marine industry, especially amongst the cargo ships that carry highly flammable chemicals and gases. To mitigate the risks, these ships blanket both wet and dry cargo using inert gases – most likely nitrogen. The blanketing pressure is typically very low, less than 1 pound per square inch (PSIG)
Using a nitrogen generator on chemical tankers is a cost-effective way to stay compliant and safe, and it also reduces third-party dependencies.
Stripping
Chemical cargoes, which create threat to the marine environment, must be discharged until there is virtually no residue left on board. This is where the nitrogen stripping process comes into action!
This process involves the removal of unwanted cargo oil from chemical tankers through the usage of nitrogen gas. The nitrogen gas strips off hazardous cargo oil to shore.
Modern chemical tankers, built these days, are designed with efficient stripping methods in mind. In order to keep cargo safe and off-gas free, they are designed with pumps that run below the cargo level, to prevent any fumes from coming in contact with the cargo.
Fuel Or Cargo Line Inerting
Cargo line inerting is the process where nitrogen gas is used as an inerting agent and introduced into the cargo tanks containing combustible cargoes.
The oxygen content before the insertion of nitrogen is around 8 percent. This percentage is brought down to less than 5% to prevent hazardous accidents.
How Does A Nitrogen Generator Work?
Nitrogen gas generators are storage systems that compress and store nitrogen. They are capable of separating nitrogen from air. The nitrogen or N2 generation system provides a clean environment for samples, scientific equipment and other sensitive applications in the marine industry. Nitrogen generators also protect against corrosion, oxidation and thermal damage.
There are two types of nitrogen generators: PSA systems and Membrane systems, and both are used to produce nitrogen on marine vessels.
PSA VS. Membrane Nitrogen Generator: What's The Difference?
Nitrogen membrane generator uses polymer fibers that separate the nitrogen molecules from other gases. Air is compressed, then pushed through a set of polymer fibers that separate the nitrogen molecules from other gases. This purified air is pumped into a chamber where it is used as an inert buffer for oil and gas, but can also be applied to assist in a variety of other marine applications.
PSA nitrogen generators, on the contrary, involve Pressure Swing Adsorption (PSA) technology which is used to discrete some gas species from a mixture of gases under pressure based on the characteristics and affinity of the nature of the molecules.
The choice of nitrogen generator is largely influenced by the nitrogen needs of every industry. For instance, applications such as fire prevention need nitrogen of 95-98 percent purity. In this scenario, membrane nitrogen generators are the right pick.
We recommend you do your research and decide on the best nitrogen generator that works well on all your ships and marine vessels.