If you work at or you’re planning to visit industries, including those of oil refineries, steel production, and ammonia & methanol synthesis. There’s always heavy usage of hydrogen gas and ignition sources. You might be left with the question “is hydrogen flammable?” Let’s look at whether hydrogen is flammable.
Is Hydrogen Flammable?
Yes. Hydrogen is a flammable chemical substance that can cause explosions or fire outbreaks if it is not taken care of appropriately. Chemists have ratified hydrogen to be a flammable gas. There are different hydrogen with distinct flammable probabilities.
It is imperative to discern the properties of hydrogen that make it flammable. Besides, you need to know the different hydrogen, their properties, their origin, and how they are created.
This will help you familiarise yourself with the component and take precautions to avoid explosions.
What are the Properties of Hydrogen that make it Flammable?
Whenever there is a hydrogen leak, you might not notice it quickly because the chemical is colorless, odorless, and tasteless, but highly combustible and non-toxic.
Hydrogen comprises 75 percent of all matter and this renders it the most plentiful chemical element on the planet.
Hydrogen exists in molecular forms such as organic compounds and water. A single atom of hydrogen comprises one electron, one proton, and no neutrons. Hydrogen is inherently a nonmetallic element except at drastic high pressures.
The exclusive property of hydrogen that makes it flammable is its combustion. It is a highly combustible chemical that ranks one of its most elementary properties.
When there is combustion of hydrogen with oxygen in the air, it creates explosive mixtures from 4 to 74 percent. Whenever there is heat, spark, or sunlight, the explosive mixtures are kindled and can steer into an explosion.
In short, the combustible nature of hydrogen explains why the chemical is flammable.
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How is Hydrogen Produced?
They can synthesize hydrogen gas using several chemical processes. These major processes include methane reforming, production of coal, production from coke, and electrolytic splitting of water molecules.
- Methane reforming: This method is also known as steam methane reforming. It is a catalytic reaction between methane (natural gas) or other lower-boiling-points hydrocarbons and steam. It is the cheapest and most prominent method used for the production of hydrogen and accounts for approximately 50% of the world’s hydrogen gas.
- Production from coal: This process uses methods such as coal gasification and coal carbonization. The coal gasification method involves breaking up the molecular bonds in coal by using a combination of gases, which include steam and oxygen gas. Coal carbonization uses high temperature and low temperature.
- Production from coke: This process also uses the coal gasification method, since this method is a general means of obtaining hydrogen gas from carbon sources. Hydrogen gas is obtained through this method by passing steam at a very high temperature over a red hot coke.
- Electrolysis of water: Water is a molecule formed from the chemical bonding between oxygen and hydrogen. This hydrogen can be obtained by passing electricity into the water to decompose it and separate oxygen gas from hydrogen gas. Hydrogen gas obtained from this process can be used as fuel or combined with oxygen gas to generate oxyhydrogen gas which is popularly employed in welding operations.
Hydrogen produced from these processes exhibits similar properties and similar flashpoints. The flashpoint of a material is the minimum temperature at which it is ignited when it comes in contact with an ignition source, even after the source is completely separated from it.
However, hydrogen does not have an average flashpoint. It easily ignites when it is mixed with a small amount of air. Therefore, it does not require any ignition source for it to be ignited.
Hydrogen gas has been considered as an alternative to fossil fuels, especially in transportation and electricity generation applications.
Based on the approaches made by the United States Department of energy, the Energy Policy Act of 1992 encourages the use of hydrogen gas as an alternative fuel.
Hydrogen fuel is a unique source of fuel due to it being a renewable and readily produced gas. It does not emit toxic substances into the atmosphere, making it a clean and environment-friendly fuel. There is also a lower maintenance cost that comes with using hydrogen fuel cells.
However, it is a highly flammable gas, and this makes the risk of owning fuel cells that contain it high. Its volatile reactivity with a small amount of air makes its storage an expensive operation.
We can store hydrogen in gaseous form using high-pressure tanks (at a pressure of about 350-700bar) or in liquid form under extremely low temperatures (about 21K under atmospheric pressure).
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Types of hydrogen chemical
1) Gaseous Hydrogen: As the name implies, gaseous hydrogen is in gas form. Gas is part of the basic states of matter. Gaseous hydrogen comprises individual atoms, elemental molecules, and compound molecules.
Mostly, the elemental molecules are composed of one type of atom, oxygen is a good example. The compound molecules comprise a variety of atoms. Carbon dioxide is an example of a compound molecule.
Gaseous hydrogen is not in a liquid or solid form and it is usually the most common type of hydrogen. When you hear of hydrogen, a gas usually comes to your mind.
2) Liquid Hydrogen: Liquid hydrogen is the liquid state of the chemical element. It is simply hydrogen in liquid. It is usually symbolized with H².
Liquid hydrogen is produced when hydrogen is cooled below its critical point, which is 33K. If the cooling procedure is over, the element might not be in liquid. 20.28 K is the critical point that is required for hydrogen to be cooled.
While gaseous hydrogen takes more storage space, liquid hydrogen takes less space when stored. It is used as a full-bodied form to store hydrogen.
The liquid density of liquid hydrogen is low when compared to other common fuels. Lesser amounts of liquid hydrogen can be explosive when combined with air.
3. Metallic Hydrogen: Metallic hydrogen is a stage of hydrogen that functions as an electrical conductor. Metallic hydrogen partially exists as a liquid in some conditions and this is when it is at high temperature and pressure. This kind of hydrogen is not as common as the gaseous and liquid form. There are several theoretical predictions to substantiate its existence.
4. Plasma Hydrogen: Plasma is one of the fundamental states of matter. Plasma hydrogen comprises charged particles; ions and electrons. Plasma hydrogen can be produced artificially by warming up a neutral gas.
The flammability of plasma hydrogen cannot be compared to gaseous and liquid hydrogen with elevated flammability when incorporated with air.
5. Solid Hydrogen: A solid Hydrogen is a hydrogen that is solid. It differs from liquid and gaseous hydrogen because of its solid-state.
It is produced by diminishing the temperature of the gas from the regular hydrogen melting point, which is 14.01 K. Solid hydrogen has the lowest solid density when compared to other solid chemical substances.
All the hydrogen above are flammable because they are highly combustible. Albeit, they differ in properties from one another based on their form and how they are produced. Solid hydrogen might burn slowly compared to gaseous hydrogen. They are all still flammable.
Therefore, it is better to avoid sparks or heat where hydrogen is stored. Since it is flammable, ethical precautions should be heeded to rescind fire outbreak accidents.
Which property of hydrogen fascinates you the most? Do you have access to hydrogen? If yes, which one? You can drop a comment to share your opinions. Also, if you’ve seen hydrogen react to fire, kindly drop a comment and share your insights.