I’ve subscribed to the theory that “hydrogen is the fuel of the future (and always will be)” for most of my 30 years on this beat, but a confluence of recent developments suggests maybe we’re nearing a tipping point for the universe’s smallest known molecule.
Accelerated development of fuel cells for use in heavy-duty trucking promises to boost infrastructure and bring the economies of scale needed to hasten light-duty fuel cell electric vehicle (FCEV) adoption. Proliferation of renewable energy is increasing demand for ways to store surplus grid power, which can be done using hydrogen, and a novel means of inexpensively producing green hydrogen is emerging.
National Renewable Energy Laboratory senior research fellow and fuel cell group manager Bryan Pivovar tipped me off to this tipping point during a recent panel discussion on Autoline Detroit. His lab has teamed with five other national labs on the HyBlend project to investigate blending up to 20 percent hydrogen into the natural gas infrastructure. With said hydrogen being produced by electrolysis from surplus solar and wind energy, the project could lower the carbon footprint of the natural gas infrastructure.
The HyBlend project will spend two years assessing the safety and efficiency of such hydrogen/methane blends, as hydrogen has lower energy density and is more explosive than methane. It will also study the effect these smaller H2 molecules, which are also three times “more permeable,” have on the pipelines themselves. Such blending would create a market for clean hydrogen accessible via the nation’s $1 trillion natural gas infrastructure while we work to expand our currently meager 1,600-mile hydrogen pipeline network.
Toyota, Hyundai, Daimler, and Volvo all have heavy-duty fuel cell trucks in the works. Initial applications will concentrate on local delivery and port drayage utilizing central fleet refueling, but long-haul hydrogen trucking will follow. During an expected million-mile service life, a long-haul diesel truck typically burns fuel costing three times the tractor’s purchase price. Because FCEV tractors promise far greater efficiency, the powertrain can be considerably more expensive than a diesel engine and still make economic sense over that life cycle. For light-duty vehicles, the lifetime ratio of fuel cost to vehicle purchase price ratio is closer to 1:1, so economies of scale from heavy applications are needed to help lower the powertrain cost. But fleet refueling and shared ownership models could also hasten adoption of light-duty FCEVs.
Meanwhile, Proton Technologies of Calgary, Canada, has developed an “ox-injection” means of extracting pure hydrogen from abandoned oil and gas wells in a process that leaves harmful CO2 and syngas safely sequestered in the ground. It starts by cryogenically separating liquid oxygen from the air. This oxygen then flash-evaporates at sufficient pressure to force it down into the well, where it bubbles up through the water at the bottom of most wells. At the water/oil (or gas) interface, it oxidizes, creating heat and steam that powers the gasification, pyrolysis, aquathermolysis, and water-gas shift reactions that liberate the hydrogen. Such underground combustion has assisted oil production for years, with the hydrogen being vented or flared. Now, a palladium alloy catalyst/chemical filter allows only hydrogen to flow to the surface, trapping everything else underground.
Powering the ox-injection operation entirely with hydrogen produced on site keeps things greener and the costs low. Production costs are estimated to be less than $0.20 per kilogram—well below the $2.00 to $3.00 per-kilogram cost of producing hydrogen via steam-methane reformation and way below the $16.70 per kilo we recently paid to “gas up” a Toyota Mirai. Ox-injection-generated hydrogen is also drastically cheaper than gas and diesel. (Remember, we didn’t switch from whale oil to crude oil to save the whales.)
Of 50,000 global oil fields, more than half are depleted and/or abandoned, most with half or more of their original oil or gas in place. Best of all: Many of these potential ox-injection sites are close to population centers and energy infrastructure, which simplifies transportation.
Hydrogen may not yet make economic sense as a transportation fuel on its own. Establishing a hydrogen infrastructure capable of storing surplus green energy may not make sense on its own, either. But add them together and tap a network of abandoned oil wells to produce clean, cheap hydrogen, and the fuel of the future’s future starts looking nearer than ever.