Hydrogen Delivery and Fueling (Text Alternative Version)
This is the text alternative transcript for the U.S. Hydrogen Program podcast titled: Hydrogen Delivery and Fueling. The media files can be accessed on the DOE Hydrogen Program Media Files page.
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Welcome to The Hydrogen Report. I'm Mike Weiner.
In this episode, we're going to talk about hydrogen delivery and fueling.
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As we've noted, hydrogen is not new — it's been used for decades for petroleum refining, ammonia production, and in other industries. But because its use has been primarily for industrial purposes, we don't have a national delivery infrastructure suitable for widespread consumer use of hydrogen like we do for gasoline.
Hydrogen can be produced in a distributed fashion, at the point of use - say, at a refueling station. Using technologies like distributed natural gas reforming or water electrolysis to generate hydrogen on-site eliminates the need for (and cost of) delivery. But hydrogen is — and will be — produced at large, central plants, as well as semi-centrally, anywhere from 25 to 100 miles from the point of end use. Producing hydrogen in larger quantities at a big plant allows for reduced cost through economies of scale. But it must be delivered to the point of use. So how does it happen today, and how might it be delivered in the future to drivers needing to refuel their hydrogen vehicles and other consumers who need it?
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Pipelines are the cheapest way to deliver large quantities of hydrogen — but the current pipeline infrastructure is not sufficient to support widespread consumer use. Mark Paster of the U.S. Department of Energy explains:
"There are about 700 miles of hydrogen pipelines operating in the U.S. — located near large petroleum refineries and chemical plants in Illinois, California, and the Gulf Coast region. But compare this to the more than 1 million miles of natural gas pipeline in the U.S. and our large gasoline delivery infrastructure, and you can see that the existing hydrogen infrastructure is not nearly adequate to meet the needs of a mainstream commercial market."
The time and money needed to expand our Nation's pipeline infrastructure presents a major challenge to delivering hydrogen in an inexpensive and efficient way. That's why a wide range of possible delivery methods are under investigation. Mark Paster says:
"When we really started to look at the options for expanding the hydrogen pipeline infrastructure, people drew comparisons between hydrogen, a gaseous fuel, and natural gas. But it's not that easy. The properties of hydrogen are different. It might be possible to use existing natural gas pipelines to transport a blend of hydrogen and natural gas — up to about 10% hydrogen — without significant modifications. But hydrogen can embrittle pipeline steel and welds, and it can permeate and leak from certain containment materials. So we can't simply use the same pipeline and switch one fuel for the other. Pipelines are an excellent option for hydrogen delivery, though, and we're looking at new materials for lower cost pipelines and analyzing the options."
Aside from pipelines, how else can we get hydrogen from point A to point B?
Today, hydrogen is commonly delivered using tube trailers or cryogenic liquid tankers, and for special purposes, it could be transported by barge. For short distances — less than 200 miles — it can be transported as a compressed gas in high-pressure tube trailers. It's cost-prohibitive, though, to transport this way for greater distances. That's because although hydrogen has a high energy content by weight, it does not have a high energy content by volume, so it is difficult to package, so to speak, for delivery. We delve into the issues and complexities of hydrogen storage in another episode of The Hydrogen Report, but it's worth noting here that with today's technology, the storage and delivery of hydrogen to the point of end use are costly and result in some of the energy inefficiencies with using it as a fuel or energy carrier.
About 9 million tons of hydrogen are produced annually in the U.S. If it's not by pipeline or as a compressed gas, then what are the other options for hydrogen delivery? Well, liquid hydrogen is one. It's denser and has a higher energy content — so you can hold more hydrogen in a given volume of liquid on a tanker truck, for example, than you can with a gas. Mark Paster explains:
"For delivery in trucks over longer distances, hydrogen is typically transported as a cool liquid. It's cooled to -423 degrees Fahrenheit, and then transported in super-insulated trucks. You've probably seen them on the highway and not even noticed. Now when the truck reaches the point of use, if the hydrogen is not intended to be used as a liquid, it's vaporized for dispensing and use as a gaseous fuel. It's still costly — it takes energy to liquefy hydrogen and there are issues with keeping it cooled to liquid temperatures — but given the energy content advantages over hydrogen gas, hydrogen is often transported this way — at the current time."
Researchers are also looking at what are called "novel liquid and solid carriers" for hydrogen delivery. By using a carrier like ethanol, or some novel hydrogen-containing compound, it can be easily transported using existing infrastructure, through pipelines, or on trucks in a liquid or possibly solid form. On delivery to the final destination, the hydrogen can be released from the carrier for dispensing.
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Once the hydrogen is delivered, how it is dispensed depends on the application for which it will be used. As we know, as an energy carrier, hydrogen can serve nearly every end-use need, from vehicles to stationary fuel cells providing back up or remote power to small portable devices like video cameras or laptops.
Portable devices can use hydrogen storage cartridges that may be refilled using specialty refueling equipment or delivered pre-fueled, just like batteries. Stationary fuel cells can use hydrogen canisters delivered by a fuel provider or they can use hydrogen generated at the site by tapping into existing natural gas lines for distributed reforming or by taking advantage of available renewable resources to produce hydrogen by water electrolysis.
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Building a national hydrogen delivery infrastructure is a big challenge. It will take time to develop and will likely include combinations of various technologies that depend on the local market needs and method of hydrogen production.
Thanks for listening. If you'd like to learn more about hydrogen — and increase your H2IQ — visit hydrogen.energy.gov. And be sure to listen for future episodes of The Hydrogen Report.