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Potential of Green Hydrogen as alternative fuel

Context:

  1. IIT-Madras generates hydrogen from seawater using solar energy.

Key Details:

  1. Researchers at IIT-Madras’ Department of Physics have made significant advancements in the field of seawater electrolysis to produce hydrogen.
  2. The team successfully tackled the challenges associated with current alkaline water electrolysis technology, which consumes high energy, relies on expensive oxide-polymer separators, and requires fresh water for the process.
  3. Instead of using pure or fresh water, they developed an electrolysis technique that utilises alkaline seawater.
  4. They employed a carbon-based support material for the electrodes, which greatly minimises the risk of corrosion compared to traditional metal-based electrodes.
  5. Additionally, the researchers created transition metal-based catalysts capable of catalysing both oxygen and hydrogen evolution reactions. These catalysts enhance the production of hydrogen and oxygen, even in the presence of impurities and chemical deposition on the electrodes.
  6. To address the issue of crossover between oxygen and hydrogen, the team devised a cellulose-based separator that is cost-effective.
  7. This separator allows hydroxide ions to pass through while effectively preventing the crossover of oxygen and hydrogen gases.
  8. The novel cellulose-based separator offers an efficient and cost-effective alternative to the commonly used zirconium oxide-based material.
  9. Furthermore, the researchers optimised various parameters, enabling the water electrolysis system to directly utilise photovoltaic-derived voltage for splitting seawater, thereby generating green hydrogen and oxygen. The generated oxygen can be utilised in other applications.

Reactions:

  1. In an alkaline water electrolyser, two half-reactions occur at the anode and cathode.
  2. At the cathode, water dissociates into H+ and hydroxide ions, leading to the conversion of H+ ions into hydrogen.
  3. Meanwhile, the hydroxide ions permeate through the separator, resulting in the generation of oxygen at the anode.
  4. When seawater is used for electrolysis, the hypochlorite formation causes electrode support material corrosion and competes with the oxygen evolution reaction, consequently reducing the amount of oxygen produced.
  5. At the cathode, impurities adsorbed on the electrode surface slow down the hydrogen evolution reaction.
  6. The catalyst employed contains transition bimetals, which exhibit higher selectivity towards the oxygen evolution reaction compared to hypochlorite formation. This resolves the issue of hypochlorite formation reducing the production of oxygen.

What is Green Hydrogen?

  1. Green hydrogen is a type of hydrogen that is produced through the electrolysis of water using renewable energy sources such as solar or wind power.
  2. The electrolysis process splits water into hydrogen and oxygen, and the hydrogen produced can be used as a clean and renewable fuel.

Uses:

  1. Chemical industry: Manufacturing ammonia and fertilisers.
  2. Petrochemical industry: Production of petroleum products.
  3. Furthermore, it is starting to be used in the steel industry, a sector which is under considerable pressure in Europe because of its polluting effect.

What is the Significance of Green Hydrogen?

  1. Achieving Emission Target: Green hydrogen energy is vital for India to meet its Nationally Determined Contribution (NDC) Targets and ensure regional and national energy security, access and availability.
  2. Under the Paris Climate Agreement, India pledged to reduce the emission intensity of its economy by 33-35% from 2005 levels by 2030. Green hydrogen can drive India’s transition to clean energy, combat climate change.
  3. Energy Storage and Mobility: Green Hydrogen can act as an energy storage option, which would be essential to meet intermittencies (of renewable energy) in the future.
  4. In terms of mobility, for long distance mobilizations for either urban freight movement within cities and states or for passengers, Green Hydrogen can be used in railways, large ships, buses or trucks, etc.
  5. Reducing Import Dependence: It will reduce India’s import dependency on fossil fuels. The localisation of electrolyser production and the development of green hydrogen projects can create a new green technologies market in India worth USD 18-20 billion and thousands of jobs.

What are the Challenges Related to Green Hydrogen?

  1. High Production Costs: Currently, the production of green hydrogen is more expensive than hydrogen produced from fossil fuels.
  2. This is because the process of electrolysis, which is used to produce green hydrogen, requires a large amount of electricity, and the cost of renewable electricity is still relatively high in India.
  3. Lack of Infrastructure: There is currently a lack of infrastructure in India for the production, storage, and distribution of green hydrogen.
  4. This includes a lack of hydrogen refuelling stations and pipelines for transporting hydrogen.
  5. Limited Adoption: Despite the potential benefits of green hydrogen, there is currently limited adoption of this technology in India.
  6. This is due to a lack of awareness and understanding of green hydrogen among the general public, as well as a lack of incentives for businesses to switch to this technology.
  7. Economic Sustainability: Extraction of green hydrogen is one of the biggest challenges facing the industry for using hydrogen commercially.
  8. For transportation fuel cells, hydrogen must be cost-competitive with conventional fuels and technologies on a per-mile basis.

What Should be the Way Forward?

  1. Increase the Capacity to Generate Renewable Electricity: In order to reduce the cost of green hydrogen production, it is necessary to increase the capacity to generate renewable electricity in India.
  2. This can be done through the expansion of renewable energy sources such as solar and wind power.
  3. Developing Hydrogen Infrastructure: There is a need to develop infrastructure for the production, storage, and distribution of green hydrogen to make this technology more accessible. This includes building hydrogen refuelling stations and pipelines for transporting hydrogen.
  4. Implement Regulatory Incentives: The government can play a key role in promoting the adoption of green hydrogen by implementing regulatory incentives, such as tax credits and subsidies, to encourage the production and use of this technology.
  5. Raise Awareness and Understanding of Green Hydrogen: It is important to educate the public about the benefits of green hydrogen and the role it can play in helping to reduce greenhouse gas emissions.
  6. This can be done through public awareness campaigns and educational initiatives.