As the global energy sector races to decarbonize, innovative hybrid approaches that repurpose existing technologies are emerging as practical, scalable solutions. This weeklong series explores one such pathway—blending geothermal energy, waste methane, hydrogen production, and synthetic fuels into a circular, low-emissions system. Each article breaks down a different piece of the puzzle, inviting leaders across cleantech, utilities, and policy to weigh in on what’s possible.
Today’s article dives into the chemistry: of how methane is converted into e-fuels for sectors like aviation and shipping — helping close the loop on clean fuel production.
What’s Next in the Series
This article is Part 3 of our 5-part series on a novel clean fuels strategy. Here’s where we are:
- Posted Monday: A Novel Clean Fuel Strategy: Where Geothermal Meets Waste Methane
- Posted Tuesday: Can Waste Methane Be the Hero? Navigating Classification and Compliance
- Today (Wednesday): Geothermal-Powered Hydrogen: Rethinking Steam Methane Reforming
- Coming Thursday: Closing the Loop: From Green Hydrogen to Carbon-Neutral E-Fuels
- Coming Friday: A Circular Pathway to Truly Clean Fuels: What It’ll Take
When people in the energy sector hear “Steam Methane Reforming” (SMR), they often think of fossil-heavy industrial processes—not to clean hydrogen. But it doesn’t have to be that way. Pair SMR with geothermal power and stranded methane, and suddenly it becomes part of a cleaner, modular, and scalable hydrogen production pathway.
This concept may feel counterintuitive at first. After all, conventional SMR relies on high-temperature steam to extract hydrogen from methane, releasing CO₂ in the process. But if that heat comes from clean geothermal energy—and the methane is from previously wasted sources—then the lifecycle emissions equation changes dramatically.
Let’s walk through how.
The Case for Geothermal-SMR
Steam Methane Reforming remains one of the most cost-effective and technically mature methods of hydrogen production. But critics point out that it still emits CO₂, making it a questionable player in the clean fuels conversation. This is where geothermal enters the picture.
Geothermal energy offers a constant, zero-carbon heat source. Unlike solar or wind, it doesn’t fluctuate with the weather. That makes it ideal for SMR, where process reliability and high temperatures are essential. In this model, geothermal heat can displace fossil fuel combustion traditionally used to power the reforming process.
Now consider the feedstock. In many geothermal-rich regions, methane surfaces alongside geothermal fluids. Today, this methane is often flared or vented—wasting its chemical energy and contributing to GHG emissions. But by routing it through an SMR unit co-located with the geothermal plant, we can put it to good use.
Modular, Distributed Production
One of the most promising aspects of this approach is its scalability. Geothermal-SMR doesn’t have to be deployed as a mega-plant. Modular designs allow for smaller installations in remote or resource-rich regions—particularly where geothermal energy and stranded methane coincide.
These compact systems could unlock hydrogen production closer to demand centers or feed directly into clean fuel synthesis facilities. This shortens supply chains, reduces transport-related emissions, and opens doors for smaller energy developers—not just big players.
And the modular model isn’t speculative. Compact SMR units are already being piloted for localized hydrogen generation. Pairing these with proven binary-cycle geothermal tech creates a real-world opportunity to innovate at the intersection of two mature technologies.
Carbon Considerations
Yes, SMR produces CO₂. But when the methane source is considered “waste” or “renewable”—and when CO₂ is either captured or recycled into synthetic fuels—the total carbon footprint improves dramatically.
In this system, CO₂ is not the end of the line. As we’ll explore in tomorrow’s article, it can be combined with green hydrogen to form e-methanol, e-kerosene, or other carbon-neutral fuels. That’s the loop we aim to close.
Even without full capture, this hybrid geothermal-SMR approach can dramatically reduce lifecycle emissions compared to fossil-powered SMR or coal-based hydrogen production (sometimes called “brown hydrogen”). Add carbon capture or utilization—and the equation improves again.
The Process
Steam Methane Reforming (SMR) is a process that converts methane, a primary component of natural gas, into a mixture of hydrogen and carbon monoxide (syngas) using steam and a catalyst. This process is widely used for producing hydrogen and is considered a key technology for various industries, including fuel cells and chemical synthesis.
Here’s a more detailed breakdown:
Steps:
- Feedstock: Wate Methane (CH4) as discussed above is combined with steam (H2O).
- Catalyst: A nickel-based catalyst is used to facilitate the reaction.
- Reforming Reaction: Methane reacts with steam under high temperatures and pressure, typically around 800-900 °C and 20-30 bar, producing hydrogen (H2) and carbon monoxide (CO).
- Water-Gas Shift Reaction: The carbon monoxide produced is further reacted with steam, using another catalyst, to produce more hydrogen and carbon dioxide (CO2).
- Separation: The resulting gas mixture (syngas) containing hydrogen, carbon dioxide, unreacted methane, and other trace compounds is then separated and purified to obtain high-purity hydrogen.
Why It Matters
There’s increasing urgency to decarbonize industrial processes—and that includes hydrogen. While electrolyzers powered by renewables get the most press, they’re not the only solution. Geothermal-SMR offers a near-term pathway that’s cost-effective, location-flexible, and rooted in proven technologies.
It’s also an approach that could be deployed in countries or regions where electrolyzer infrastructure lags, but geothermal and methane are abundant. In other words, it’s a bridge—not a compromise.
What’s Next
So far in this series, we’ve explored why geothermal wells that also produce waste methane offer a powerful — and profitable — foundation for clean fuel projects. We’ve also looked at how tax credits and compliance pathways can strengthen the economics.
Now, we turn to the chemistry.
Tomorrow’s article will unpack how methane gets transformed — through water-gas shift reactions and carbon capture — into carbon-neutral e-fuels ready to power aviation and shipping.
Let’s Build It
If you’re an engineer, geothermal developer, or clean hydrogen strategist—how are you thinking about the intersection of heat, hydrogen, and methane? Let’s connect and explore what’s possible when we rethink what SMR can be.