Hydrogen is the most abundant element in the universe, making up over 90% of all atoms. Through this article, let us take a look at the three major types of Hydrogen– Green, Blue and Grey.
Hydrogen makes up over 90% of all the atoms and is therefore rightly called the most abundant element in the universe. It is also a promising source of clean energy on our planet. Lately, Hydrogen energy has been gaining a lot of momentum as the world is advancing towards achieving net-zero targets. Against this backdrop, let us take a look at Hydrogen and the differences between three major types of Hydrogen– Green, Blue and Grey.
What is Hydrogen?
The term Hydrogen is named after Greek words ‘Hydro’ meaning water and ‘Genes’ meaning forming. Hydrogen, denoted by H, is a colourless, odourless, tasteless, flammable gaseous substance that makes up around 0.14% of Earth’s crust by weight. It can be produced through fossil fuels, nuclear energy, biomass, renewable energy sources, amongst others. Hydrogen, when burnt, produces water.
Discovery of Hydrogen
While experimenting with iron rods and acids, Robert Boyle produced Hydrogen gas in 1671 but it wasn’t until 1766 when Henry Cavendish acknowledged it as a distinct element. This distinct element was named by French chemist Antoine Lavoisier.
Facts about Hydrogen
1- Atomic number- 1
2- Atomic symbol- H
3- Atomic weight- 1.00794
4- Density- 0.00008988 grams per cubic centimetre
5- Phase at room temperature- Gas
6- Melting point- minus 434.7°F
7- Boiling point- minus 423.2°F
8- Number of isotopes – 3 common isotopes, including 2 stable ones
9- Most common isotope- 1H, natural abundance 99.9885%
Difference between Green, Blue and Grey Hydrogen
Hydrogen has many colours, each depending on the way it is generated. Green Hydrogen is the only form that is generated in a climate-neutral manner and can help the world reach the goal of net-zero emissions by 2050.
Green Hydrogen
Referred to as ‘Clean Hydrogen’, Green Hydrogen is generated using renewable sources of energy such as solar or wind power through electrolysis.
Electrolysis
It is the process through which water is split into two Hydrogen atoms and one oxygen atom. The by-products are water and water vapour.
Grey Hydrogen
It is the most common form of Hydrogen and is produced using fossil fuels through a process called Steam Methane Reforming.
Steam Methane Reforming
It is the process through which hydrogen is generated from natural gas. High-temperature steam ranging between 700°C–1,000°C is used to produce hydrogen from a methane source, such as natural gas.
It is to be noted that the process is endothermic, i.e., heat must be supplied for the initiation of the reaction.
Blue Hydrogen
When Hydrogen is produced through the steam reforming process but the carbon generated is captured and stored, it is known as Blue Hydrogen.
Carbon Capture and Storage (CCS)
It is the process of capturing and storing carbon dioxide (CO2) before it is released into the atmosphere. Through this process, 99% of the CO2 which is released by burning fossil fuels is captured.
Other colours of Hydrogen
Black/Brown Hydrogen: Most environmentally damaging form of Hydrogen as CO2 and Carbon Monoxide produced during the process are not captured. It is formed through coal gasification.
Turquoise Hydrogen: It is generated through methane pyrolysis, a process that generates solid carbon. In this process, the carbon generated can be used in other applications such as tyre manufacturing/soil improvement.
Pink Hydrogen: It is created using electrolysis, but is powered by nuclear energy. The extreme temperatures from nuclear reactors can be used to produce other forms of Hydrogen.
Yellow Hydrogen: It is a relatively new term and is used for the Hydrogen produced through electrolysis using solar power.
White Hydrogen: It is a naturally occurring hydrogen found in underground deposits and created through fracking.
Some of the aforementioned Hydrogen colours may fade, while others may play a significant role in reaching the net-zero emissions goal by 2050 as the world is switching to greener and cleaner alternatives.
Source: jagranjosh
