Ammonia is a compound that is available in humans and nature. It is formed by hydrogen and nitrogen and its chemical formula is NH3. It is produced in chemical factories for industrial purposes as well. Naturally, it is derived from decomposition, mainly of organic matter that includes wastes from plants as well as animals.
But is ammonia flammable, combustible, or does ammonia explode?
Let’s find out.
Is Ammonia Flammable?
Ammonia is a nonflammable gas but will ignite at a temperature of 1204°F within a vapor concentration of approximately 15% to 28% by volume in air. The National Fire Protection Association (NFPA) rates anhydrous ammonia as a 3–1 on a scale of 4, making it a flammable gas.
Does Ammonia Explode?
Containers of ammonia may explode when exposed to high heat. Pressurized containers that are heated can cause the ammonia to rapidly expand and rupture the containers, releasing a large amount of gas and energy in an explosion.
When ammonia reacts with oxygen, it forms an explosive compound called ammonium nitrate. This can happen when ammonia is mixed with certain chemicals, such as nitric acid, or when it is exposed to high temperatures or pressures.
What Are The Flammable Limits Of Ammonia?
The flammable limits of ammonia are the concentration range of ammonia gas in air that can ignite or explode if exposed to a source of ignition.
According to research, the lower flammable limit (LFL) of ammonia is 15%, and the upper flammable limit (UFL) is 28%. This means that ammonia gas is flammable when its concentration in air is between 15% and 28%. Below 15%, the mixture is too lean to burn, and above 28%, the mixture is too rich to burn.
At What Temperature Does Ammonia Explode?
The temperature at which ammonia explodes depends on several factors, such as the presence of a catalyst, the concentration of ammonia, and the pressure of the system.
Ammonia has an auto-ignition temperature of about 1204 °F (651 °C) when catalyzed, and about 1570 °F (854 °C) when not catalyzed. However, these temperatures may vary depending on the conditions and the purity of the ammonia.
Is Ammonia Flammable In Air?
As I have already mentioned ammonia is not highly flammable. The trouble begins when it gets mixed with oxygen. Now, the fact is a source of ignition can wreak havoc with this working as a catalyst. Again metal ions can act as a catalyst and cause a big explosion.
For this reason alone, people working near ammonia plants are prohibited from smoking, carrying inflammables, or anything that can trigger a fire. It is best to avoid open flames near such factories. Even if you use ammonia, then I would advise you to stay away from such sources.
What Happens When Ammonia Burns In Air?
When it combines with oxygen, it usually burns with a pale yellow-greenish flame. It releases steam or to be precise water vapor while burning. It does not burn freely and cannot sustain combustion.
The moment it gets ignited, chlorine gets passed into this ammonia. This forms hydrogen chloride and nitrogen. Now, if chlorine is present in excess, then it forms nitrogen trichloride, which is again an explosive.
What Are Accidental Release Measures For Ammonia?
In case, ammonia is released, then I will suggest you leave the area immediately. Do not go near to it till the time the severity of the situation gets determined. If you want to more about the steps that you can take to save yourself from such a situation, then you must:
- The first thing is to get and wear an escape-type respirator
- Evacuate the place right away
- Do not let others enter the area
- Use protective gear as available
- Eliminate all sources of ignition
- Ventilate as much as you can
Safely Storing Ammonia
Here are some general guidelines on how to store ammonia safely:
- Store ammonia under pressure in non-corrosive containers, such as steel cylinders or tanks. Do not use containers made of copper, brass, or zinc, as they can react with ammonia.
- Paint the containers in light, reflective colors, such as white or silver, to reduce heat absorption and prevent pressure build-up.
- Keep the containers in a cool, dry, and well-ventilated place, away from sources of heat, sparks, and flames, and from incompatible substances, such as acids, oxidizers, and halogens.
- Inspect the containers and hoses regularly for leaks, cracks, or corrosion, and repair or replace them as needed.
- Use an ammonia gas detector to monitor the concentration of ammonia vapors in the storage area. If the level exceeds the lower flammable limit (15%), evacuate the area and call for emergency assistance.
In case of an explosion, you must use only dry chemical extinguishers. People that try to extinguish the fire should wear proper protective gear along with a self-contained breathing apparatus or SCBA. Those that do not have a PPE must get away or evacuate the place as soon as possible. For this could be a life-threatening situation that you will like to circumvent without delay.
I would like to remind you of the basic safety protocols to be followed. Leave no stones unturned to ensure that everyone is safe, but save yourself first. You can save lives only if you remain safe. Protect others but follow the safety practices, ventilate the area on your way out and then help others. This is the right way to do and there is no other way. Following the right procedures can keep all this under control. Hence, keep a tab on safe working conditions all the time.
The whole point of this discussion on the flammability of ammonia, combustion, and explosive properties of ammonia is to help you remain safe. This means you must manage things in a secure way when working with ammonia gas.
