Introduction: The Hard-to-Abate Challenge
While many sectors can be cleaned up through direct electrification (using batteries and renewable power), certain “heavy” industries present a unique challenge. These sectors require extreme temperatures or specific chemical reactions that electricity alone cannot provide.
Hydrogen is the primary candidate to fill this gap, offering a way to decarbonise industrial processes that currently account for a massive portion of global carbon emissions.
1. Steel: Swapping Coal for Hydrogen
The iron and steel industry is responsible for approximately 7% to 9% of global carbon emissions, primarily due to the massive use of coal.
- The Current Method: Traditional blast furnaces use coal as both a source of high-grade heat and a “reducing agent” to strip oxygen away from iron ore.
- The Hydrogen Solution: Hydrogen can replace coal as the reducing agent in a process called Direct Reduced Iron (DRI).
- Zero-Carbon Steel: When pure green hydrogen is used, the only chemical byproduct of this reaction is water vapor instead of carbon. This can deliver emission reductions of 90% to 95%.
2. High-Temperature Process Heat
Industries like cement, glass, and aluminum manufacturing require temperatures exceeding 1,000°C.
- The Fuel Switch: Hydrogen can be burned to provide this high-grade heat, acting as a low-carbon alternative to natural gas or coal.
- Cement Production: In cement kilns, hydrogen is currently being tested in “blends” (replacing 5% to 20% of fossil fuels) to reduce combustion emissions.
- Challenges: Hydrogen flames have different properties (such as heat dispersion) than traditional fuels, so researchers are developing specialized burners to ensure the quality of materials like clinker remains high.
3. Chemical Feedstocks
In the chemical sector, hydrogen is not just a fuel; it is a raw material.
- Ammonia & Fertilizers: About 55% of global hydrogen is currently used to make ammonia for fertilizers. Switching to green hydrogen feedstocks can eliminate the emissions associated with our global food supply.
- Methanol: Hydrogen is a key ingredient for methanol, which is used to produce plastics, resins, and synthetic fibers.
4. Economic Realities (The Price Gap)
While technically feasible, the switch to hydrogen currently comes with a “green premium”.
- Steel Costs: Replacing coal with green hydrogen could initially increase the price of a ton of steel by about one third.
- Cement Costs: High costs are currently an impediment, with hydrogen blends potentially increasing production costs by up to 16%.
- 2030 Outlook: This gap is expected to narrow significantly by 2030 as carbon pricing rises and the cost of renewable electricity and electrolyzers falls.
Conclusion
For heavy industry, hydrogen is not just a “nice-to-have”—it is a necessity for meeting net-zero goals. By transforming how we make steel, cement, and chemicals, hydrogen addresses the core of our modern industrial footprint.
Next Up: The ocean is next. In Article 13, we explore: What is the potential for hydrogen in the maritime industry?