The role of hydrogen toward a greener future

Blue hydrogen is a viable option in hydrocarbon-rich regions, given its widespread availability across multiple geographical locations. In contrast, green hydrogen is marred with challenges associated with technological advancements and expanding infrastructure, particularly in accessing affordable green power sources, as this requirement continues to grow.

If electrification alone proves insufficient or fails to consolidate a definitive argument for green hydrogen while hydrocarbon-based fuels remain accessible, a blend of green and blue hydrogen may offer a viable solution, as the carbon intensity associated with its production falls to acceptable levels. This approach capitalizes on the strengths of both options, potentially reducing costs while leveraging carbon incentives and responsibly managing CO₂ emissions. In short, it promotes a practical and sustainable transition.

Integrating green hydrogen production with blue hydrogen processes would support a smoother transition, especially as green hydrogen costs are expected to drop by 2050. A cost-effective approach, known as “teal hydrogen” (teal H₂), combines auto-thermal reforming, water electrolysis and carbon capture (with potential carbon utilization). Teal hydrogen can serve as a practical step to advancing the energy sector toward carbon neutrality.

Blue hydrogen is produced by upgrading conventional hydrogen plants with carbon capture technologies to store and utilize the carbon dioxide by-product. In contrast, green hydrogen relies on water electrolysis, biomass gasification (BG) and renewable technologies.

Most hydrogen production (95%+) currently comes from fossil fuels, making blue H₂ a more accessible technology with numerous commercial plants. Blue hydrogen involves a more established production route, with costs ranging from 1.30 to 2.50 USD/kg, which is less than the cost of green H₂, which ranges from 2.70 to 9.00 USD/kg. However, green hydrogen has the potential to be carbon-neutral or even carbon-negative, especially when powered by renewable energy sources.

Green hydrogen is produced from electrolysis, which is a cleaner, more environmentally friendly process. Blue hydrogen, when produced from autothermal reforming (ATR), uses pressurized oxygen and resulting pressurized CO₂, enhancing the efficiency and maturity of well-established technology. Blending green and blue hydrogen creates teal hydrogen, which delivers the benefits of both methods and offers a dynamic approach to hydrogen production.

Teal hydrogen offers significant benefits, particularly with a 30/70 green/blue ratio. This ratio uses all excess oxygen from the electrolyzer and eliminates the need for an air separation unit (ASU) in the ATR process. By removing the need to dispose of excess oxygen, this balanced approach enhances operational efficiency. Moreover, should there be a need to generate more oxygen, increasing the electrolysis can provide flexibility in tailored output adjustments based on specific requirements.

Teal hydrogen also addresses energy input fluctuations and associated costs. Depending on the scenarios, by combining the stable and cost-efficient ATR process with electrolysis, overall production becomes less susceptible to variations in energy prices, compared to relying solely on either ATR or electrolysis. This hybrid approach can be strategically balanced, optimizing both economic and environmental considerations.

The continuous supply of natural gas, which is usually steady for the ATR process, further stabilizes teal hydrogen production. Not only does it help maintain consistent overall production by providing operational reliability, it also works with common infrastructure, making teal hydrogen a viable choice for integration into current energy frameworks.

A case study compares different hydrogen production applications using a simplified approach based on public information sources, establishing a common basis for hydrogen production.

Component costs for 2024 are estimated using typical industry indexes to establish a forecast trend.

Specific applications should be analyzed on a case-by-case basis, considering location, natural gas supply, power supply and available infrastructure.

Once the facility has generated sufficient profits and the cost of green hydrogen production has decreased as expected, the ATR unit can be repurposed for several uses:

• Renewable methane conversion
• CCUS integration and relocation
• Production of industrial heat or steam
• Hydrogen storage using parts of the ATR infrastructure

Teal hydrogen, with its dual reliance on electrolysis and ATR, offers a blend of green and blue hydrogen technologies. This hybrid approach addresses environmental concerns and acceptable carbon intensities (CIs) while providing economic flexibility, adaptability to varying energy input costs and operational stability. It is a strong candidate for advancing the transition to a sustainable and efficient hydrogen economy.