The Basics

The past 2 decades were about transitioning electricity production away from fossil fuels (i.e. coal and POL) to renewable (RE) and clean sources like solar and wind. Though the success of this transition varies from country to country, overall remarkable success has been achieved . This success has created a new problem. RE sources are intermittent sources of electricity and thus necessarily require storage. Energy in the form of electricity can not be stored. Various options have been tried but with limited success. The latest effort (which shows promise) is to use Hydrogen

The other big trend has been replacing fossil fuel from transportation system. This has had little traction (pun unintended!) in the past two decades and is now becoming an increased focus. While EVs address the problem, they (i) are only as clean as electricity and (ii) face technical challenges in many non passenger applications. Hence a push for transitioning to alternate fuels which are produced using clean electricity.

For both the above, Green Hydrogen (and hence Green Ammonia) are seen as the key component.

Hydrogen, the most abundant element is nature is at the center of this transition. Carbon, upon combustion, produces CO2. Hydrogen, on the other hand, on combustion produces water! This means any process that uses hydrogen as a source of energy, will only have water as a by-product. 

For more on Hydrogen, refer to our post "Its "elementary" my dear Hydrogen!"

Ammonia is a gas (at room temperature) produced by combining Nitrogen and Hydrogen (NH3). Its a colourless gas with a highly pungent odour (the infamous public toilet smell!). Ammonia is expected to play a pivotal role in transitioining to Hydrogen because

• Supply Chain in place: Ammonia being the most widely produced (~180 MT in FY20), traded and transported inorganic compound in the world, its logistics are well established.

• Established demand: While there are emerging uses of Ammonia (e.g. fuel in power plants) there are many well established uses (e.g. fertilizer)

• Established technology: There is no change required to Haber-Bosch process. Only source of hydrogen needs to change from Grey Hydrogen to Blue Hydrogen.

• High Energy Density: Ammonia has a relatively high energy density of 3 kWh / litre

For more information refer to our blogpost "Ammonia - The Hydrogen Carrier"!