Ammonia, a compound consisting of three hydrogen atoms and one nitrogen atom, has emerged as a promising alternative fuel for a clean and sustainable future. As the world grapples with the challenges of energy security and seeks to reduce its dependence on fossil fuels (more on this on our podcast #BDE), ammonia offers a remarkable solution. Its abundance, ease of production, and capacity to store and transport hydrogen make it an ideal candidate for large-scale clean energy applications. In this blog, we will explore the practical challenges and opportunities with this fuel.
Ammonia Could Be the Wave of the Future
As a fuel source, ammonia has a lot going for it. First, it’s super efficient relative to other sources, and a large-scale distribution network is already in place globally. Also, it’s got a high-octane rating (110-130) and a narrow flammability range, so it’s not likely to explode. Even better, it’s totally carbon-neutral since it’s a combination of nitrogen and hydrogen. Without carbon, it’s hard to burn any off into the atmosphere.
Ammonia may be the most hard-core natural chemical compound there is. It’s manufactured with solar, wind, or biomass energy—all clean and renewable.
But ammonia ain’t all sunshine and unicorns, and transporting ammonia is tricky. It’s toxic as hell, for starters. Just because it’s carbon neutral doesn’t mean there aren’t other problems. To wit: if ammonia does ignite, it emits fairly significant pollutants. And the traditional method for ammonia production, Haber-Bosch, uses heat as a transformation catalyst, which typically produces carbon emissions.
But here’s the really good news. Ammonia-as-fuel startups are working in many areas of ammonia production and storage, and some have had solid test results. The company Amogy is the flavor of the month, converting tractors and trucks into ammonia-powered vehicles. Now they’re working on tugboats. It’s possible that ammonia is really happening as something besides a household cleaning product.
Large-scale ammonia as a renewable energy source would be a huge step forward in the fight against carbon emissions, but that will also drive up the demand. So expect to see ammonia tankers and rail cars crossing your path. The downside? More opportunity for chemical threats.
Managing the Toxicity of Ammonia
There is one serious issue that ammonia on a large scale faces—how do you safely get a tanker of the stuff from point A to point B? If you’ve ever wondered why you’re supposed to open the windows if you’re using a cleaner with a lot of ammonia in it, it’s because the vapors can kill you. If there are children around, it’s even more toxic for them. Compromised respiratory systems are at huge risk from ammonia fumes.
Let’s discuss some of the more terrifying side effects of ammonia exposure. I’m talking now about industrial ammonia. But any ammonia manufactured for fuel will have a higher concentration level than a bottle of Windex.
Anhydrous ammonia is hygroscopic—it basically sucks up the water in your body when you come in contact with it. Now you know why your hands are so dry after you’ve cleaned the bathroom. It’s also caustic and corrosive enough to damage that dried-out tissue, so much that people who have inhaled a lot of ammonia can suffocate when the throat literally swells shut.
Then, there’s the possibility of severe chemical burns and frostbite to your eyes and skin (and respiratory tract if you inhale it). With all this sturm and drang, there’s no wonder that transporting ammonia is a serious obstacle to deploying ammonia at scale. Unlike mishaps involving a tractor full of fuel oil or chickens, ammonia accidents can cause serious environmental and human (including pets here) problems.
How Ammonia Is Regulated and Shipped
The US Department of Transportation (DOT) regulates anhydrous ammonia under CFR Title 49, the regulations that govern federal motor carriers and transporting hazardous materials. Title 49 covers safety and labeling precautions for ammonia, from glow-in-the-dark signage to hazmat suits. The DOT also labels ammonia as a lethal concentration, a Hazard Zone D material—poisonous if inhaled.
International shipping norms consider ammonia a toxic gas. But it’s a non-flammable gas domestically. Okay, whatever. It’s listed as an inhalation hazard in shipping documentation and has to have hazard labeling on shipping packaging. These regulations for transporting ammonia apply to all kinds of commercial transportation—like railroad cars and cargo or portable highway tanks. If you’re playing Dr. Strangelove in the garage, don’t try to store your ammonia in an airtight tank and stick it in the back of your truck unless you’re game for a world of hurt.
PPE and Hazmat Suits
I’m not kidding about the seriousness of transporting ammonia. Anybody who works around anhydrous ammonia suits up in stylish personal protective equipment—ventless goggles or a face shield about the size of a salad bar, long-cuff ammonia-proof rubber gloves that you can roll up to catch drips, and long sleeves—generally from chemical-resistant threads. Also, bring your glasses. Wearing contacts is highly discouraged around highly toxic gases.
Ammonia Road and Truck Warriors
Notice that there’s no airplane mentioned here. Aviation is a singularly bad way choice for transporting ammonia. If there’s a leak in the tank, no matter how airtight the cargo hold, you’re trapped at 35,000 feet over the Pacific on your way to New Zealand… So, it’s a really bad idea.
Anyway, ammonia pairs well with pipelines, barges, rail, and highways for commercial transportation. The current use is industrial and agricultural; there isn’t any large-scale transport for ammonia-based energy yet.
NuStar Energy is currently running about 2,000 miles of ammonia pipeline in the Midwest: Kansas, Iowa, Minnesota, Nebraska, and the Dakotas, to be exact. The ammonia gets converted to a pressurized liquified gas for transport. Companies can also convert natural gas and petroleum pipelines for transporting ammonia when it’s ready for prime time.
There’s another pipeline in Russia that runs from the city of Togliatti to the port city of Odessa and is about 1,360 miles long.
The DOT has a pretty good safety record in transporting ammonia—over 1.7 million bulk shipments every year, with an accident rate of 0.04%. That’s a really solid track record… unless you live in an area where there was a leak or derailment (see East Palestine, Ohio).
The truth is, a leak is fairly rare. The tanker cars carrying ammonia are pressurized, but they have additional safety features. The valves and fittings have protection against shearing off and releasing the ammonia into the environment. There’s also a pressure release valve on top of the car that prevents a rupture in the vehicle if there’s a fire. These tank cars can hold over 33,000 gallons of PNG ammonia.
Those big tanks you see on the road are extremely specialized for transporting any hazardous materials. Like the rail tanker, these are heavily insulated and reinforced against bumps and bruises. The capacity on the road is a lot less than by rail—only 11,500 gallons.
The Mississippi River is ground zero, so to speak, for river barges to move ammonia along the river and its tributaries. Those secondary waterways—the Ohio, Arkansas, Illinois, Tennessee, and Red Rivers—allow the barges to deliver ammonia to farms, factories, and chemical plants all over the Midwest.
Amogy is partnering with Southern Devall, a Louisiana chemical towing company, to retrofit their barges with ammonia power. The test barge is already on site near Amogy’s Brooklyn headquarters.
There is already one ammonia tug barge in the Pacific Northwest waters: the Harvest. This barge is pretty cool—literally—because it carries an onboard reliquefaction plant that keeps the cargo cooled to -27° F.
TSA and the Chemical Security Analysis Center (CSAC) started a collaboration in 2010 to determine national vulnerability to toxic gas spills and leaks—primarily chlorine and ammonia. They ran the tests at the Dugway Proving Ground, an Army installation built for testing biological and chemical weapons in the Utah desert. The idea was to see what the damage could be in the large population areas. I imagine the people of East Palestine would say that they need to think about small towns, too, but I digress.
They called it the Jack Rabbit program, and it’s now in its third iteration—Jack Rabbit III—and researching how ammonia behaves during a leak or spill so that they can develop safety and planning procedures for the country. With any luck, JRIII can predict chemical dispersion habits and hazardous behaviors so that communities can implement emergency preparedness procedures. The study is also trying to determine how ammonia reacts with first responder equipment, building materials, and local vegetation. Ammonia looks a lot like your basic garden variety fog when it goes into the atmosphere. But unlike fog, it doesn’t disperse in the air. Instead, it is initially so cold that it just sinks to the ground and stays there.
Here’s a contradiction for you. Ammonia in the soil is a bad thing. Rain releases hydrogen, increasing the affected soil’s acidity, which can exacerbate erosion and result in lower crop yields. On the other hand, fertilizer has a lot of ammonia, which is good for the soil. I guess, as with everything else in life and in chemistry, the details do matter.