世界银行-使用清洁氢气对氨和氮肥进行脱碳处理（英）-2025.2_11页_834kb

Decarbonizing Ammonia and Nitrogen Fertilizers with Clean Hydrogen

Introduction

Synthetic fertilizers are vital for food security and agricultural productivity, but their production contributes 1.8-2.4% of global greenhouse gas (GHG) emissions. This report explores the role of clean hydrogen in reducing emissions on a large scale. Fertilizer production relies heavily on natural gas, making decarbonization crucial.

Key Solution: Clean Hydrogen Use

Clean hydrogen enables decarbonization in ammonia synthesis, which is a core step in producing fertilizers like urea, ammonium nitrate, and ammonium phosphate. Traditional Haber-Bosch synthesis uses fossil fuels; replacing them with clean hydrogen, from renewable sources or carbon capture (CCS), lowers the carbon intensity. For instance, renewable hydrogen generated from solar and wind can be used to produce surrogate ammonia, but costs are high ($794–$1,543 per ton) compared to grey ammonia ($121–$518 per ton). Process improvements like autothermal reforming (ATR) could reduce costs, capturing more emissions efficiently than steam methane reforming (SMR).

Economic and Policy Considerations

Adoption faces challenges due to higher costs. Governments and international donors should promote subsidies, tax incentives, and off-take agreements to ensure market stability. Subsidies will likely need to range from $500–$1,200 per metric ton in some cases to compete with conventional fertilizers. Addressing financing gaps through green bonds or concessional loans can help bridge the investment barrier. Switching to low-carbon fertilizers may require adjustments in subsidy schemes and agricultural practices.

Case Studies

• India: Large-scale projects, like the AM Green complex in Kakinada, aim to produce services (1 MMT) using renewable energy and electrolyzers by 2026. India's National Hydrogen Mission targets 5 MMT of renewable hydrogen by 2030.
• Morocco: The Tarfaya project leverages solar and wind to produce renewable ammonia, supporting sustainable fertilizer imports and decarbonization.
• Brazil: Using natural gas with CCS, projects target 1 MMT/year, boosting agricultural sectors.
• Emerging markets like Kenya, Nigeria, and Brazil show potential for local production and exports, despite access challenges.

Policy Recommendations and Benefits

Governments should develop supportive frameworks, including carbon pricing and clear regulations for clean hydrogen use, to foster investment and innovation. Projects can enhance food security, reduce emissions, and make agriculture resilient. Clean hydrogen is an enabler for sustainable nitrogen fertilizers, promoting global climate goals.

Conclusion

Decarbonizing fertilizer production with clean hydrogen addresses environmental and food security needs. Despite initial costs, strategic policies and technology advancements can ensure widespread use, contributing to a sustainable agriculture future.