What is Green Ammonia?
- Definition: Ammonia (NH₃) synthesized through a fully renewable‑energy‑based process, resulting in a near‑zero carbon footprint.
- Key Feature: Uses green hydrogen produced by water electrolysis powered by solar, wind or hydro electricity.
Production Process
- Green Hydrogen Production – Renewable electricity powers electrolysis, splitting water (H₂O) into hydrogen (H₂) and oxygen (O₂).
- Nitrogen Extraction – Atmospheric air is processed to obtain nitrogen (N₂).
- Ammonia Synthesis – Hydrogen and nitrogen are combined in a modified Haber‑Bosch reactor under high pressure and temperature, using renewable electricity.
Types of Ammonia – Emission Profile
| Type | Feedstock / Production Method | Carbon Emissions | Key Characteristics |
|---|---|---|---|
| Grey | Fossil fuels (natural gas via SMR or coal gasification) | Highest (≈2‑3 t CO₂ per t NH₃) | Conventional, carbon‑intensive |
| Blue | Fossil fuels with Carbon Capture & Storage (CCS) | Moderate (reduced by CCS) | Transitional low‑carbon option |
| Green | Renewable electricity → electrolysis → green H₂ + N₂ | Near‑zero | Fully decarbonised pathway |
Environmental Significance
- Conventional ammonia production accounts for ~2 % of global CO₂ emissions.
- Emission intensity: 2–3 t CO₂ per tonne of grey ammonia.
- Green ammonia can substantially cut these emissions, aiding India’s Paris Agreement targets.
Applications
- Green Fertiliser: Low‑carbon feedstock for agriculture, reducing the carbon intensity of the food chain.
- Carbon‑Free Fuel: Potential replacement for heavy fuel oil in maritime shipping and for coal co‑firing in power plants (NOx can be controlled via SCR).
- Hydrogen Carrier: Easier storage & transport than H₂ (liquefies at –33 °C vs. –253 °C). Can be “cracked” back to hydrogen at the point of use.
Strategic Interventions for Green Hydrogen Transition (SIGHT) Scheme
- Administered by: Ministry of New and Renewable Energy (MNRE) through SECI.
- Part of: National Green Hydrogen Mission.
- Objectives:
- Promote indigenous electrolyser manufacturing.
- Boost domestic green hydrogen and derivative (green ammonia) production.
- Achieve cost‑competitiveness with fossil‑fuel‑based alternatives.
- Two Key Components:
- Component I – Electrolyser Manufacturing: Performance‑linked incentives based on energy efficiency and localisation.
- Component II – Green Hydrogen Production: Competitive bidding, long‑term offtake agreements (7‑10 years) to de‑risk investments.
Policy & Legal Framework
- National Green Hydrogen Mission (2021) – Provides the overarching policy direction for green hydrogen and its derivatives.
- SIGHT Scheme – Financial incentive mechanism under the Mission, aligned with India’s Energy Security, Decarbonisation, and Make in India objectives.
- International Commitments – Supports India’s Intended Nationally Determined Contributions (INDCs) under the UNFCCC.
Relevance for UPSC
- Illustrates the intersection of environmental science, energy policy, and industrial strategy.
- Demonstrates how government incentives can catalyse emerging clean technologies.
- Provides factual data for Prelims (emission figures, scheme components) and analytical material for Mains (policy evaluation, strategic importance).