Here are some new trends in electrolyser tech to catalyse green hydrogen production

Subject : Science and Technology

Context:

Green hydrogen, one of the major fuels to propel India’s clean energy transition, is produced by electrolysis of water done using clean electricity from renewable sources (wind, solar, etc).

Green hydrogen:

Green hydrogen is the name given to hydrogen gas that has been produced using renewable energy, such as wind or solar power, which create no greenhouse gas emissions.

Green hydrogen production technologies:

Green Hydrogen is produced by breaking the hydrogen and oxygen from water molecule via the electrolysis process.
Alkaline and Polymer Electrolyte Membrane (PEM) electrolysers are the most widely used commercial technologies.
In Alkaline, a liquid alkaline electrolyte of sodium or potassium hydroxide is used.
For PEM, a solid polymer membrane acts as a separator between the anode and the cathode compartments.
Solid oxide electrolysers use solid oxide or ceramic as an electrolyte to produce hydrogen (or carbon monoxide) and oxygen.
Newer technologies, such as electrochemical (thermally activated chemical water-splitting process) use time cycles to separate the hydrogen and oxygen generation.
Anion exchange membrane electrolysis has positively charged functioning bodies that use a semi-permeable membrane to conduct the anions and reject the cations.

How is hydrogen used as a fuel?

In a fuel cell – a device that converts the energy of a chemical into electricity – hydrogen gas reacts with oxygen to produce electricity and water vapour.
Because of hydrogen’s capacity to generate energy without releasing greenhouse emissions, it is a potential clean alternative to fossil fuels.

Electrolysis using solar power:

The photoelectrolysis process using semiconductor photoelectrodes is a clean and green way of producing hydrogen.
The source of energy for splitting water in a photoelectrochemical cell is sunlight.
This type of electrolysis generates dihydrogen, which can be used in fuel cells to produce energy and heat as well as to generate electricity.
In a report by the International Renewable Energy Agency, an intergovernmental organisation for renewable energy research and adoption, the following methods have been identified for photoelectrolysis:

Another option is positioning the electrolyser close to offshore wind turbines for an offshore mode of operation.
This would provide an opportunity for reducing losses and all-around costs and eliminate the requirement for alternating current rectifiers.
Offshore hydrogen would address environmental concerns through the creation of a zero-emission fleet.
The offshore wind farms would benefit from becoming hydrogen refuelling stations for transportation in the future.

Issue in the production of green hydrogen:

The cost of electrolysers and electricity make up the largest share of the production cost.
Apart from such costs, the other included costs are operating costs, transmission & distribution costs, wheeling costs for electricity, and the local duties and taxes in India.