Consider the following heavy industries: 1. Fertilizer plants 2. Oil refineries 3. Steel plants Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?

Green hydrogen, produced by electrolyzing water using renewable energy, is a critical technology for decarbonizing various industrial sectors, especially those considered 'hard-to-abate' due to their high energy consumption and reliance on fossil fuels.

1. Fertilizer plants: The production of ammonia, a key component in fertilizers, currently relies heavily on fossil fuels (primarily natural gas) through processes like steam methane reforming, which release significant CO2. Green hydrogen can replace fossil fuels as a feedstock in ammonia synthesis, drastically reducing emissions. Thus, green hydrogen is expected to play a significant role in decarbonizing fertilizer plants.

2. Oil refineries: Refineries use large quantities of hydrogen in processes such as hydrocracking and hydrotreating to refine crude oil and remove impurities. This hydrogen is mostly derived from natural gas (grey hydrogen). Replacing grey hydrogen with green hydrogen can substantially lower the carbon footprint of refinery operations. Thus, green hydrogen is expected to play a significant role in decarbonizing oil refineries.

3. Steel plants: Traditional steel production using blast furnaces and coal is a major emitter of CO2. Green hydrogen can be used as a reducing agent in the direct reduced iron (DRI) method, replacing coal or natural gas. This allows for the production of 'green steel' with significantly reduced or zero emissions. Thus, green hydrogen is expected to play a significant role in decarbonizing steel plants.

Therefore, green hydrogen is expected to play a significant role in decarbonizing all three of these heavy industries.