Take another look at the neglected bottle of ammonia under your sink. In addition to being a bathroom cleaner, ammonia is packed with enough energy to fly a jet. Advances in chemistry and cheap renewable energy are making “green” ammonia, manufactured from air and water, commercially viable. Companies like Siemens, ThyssenKrupp and French energy giant Engie are piloting green ammonia projects, with an eye to using it as a fuel, a source of energy-rich hydrogen and long-term energy storage. A new report from Environmental Defense Fund Europe says green ammonia could also be the kind of clean fuel the shipping industry needs (currently a $137B market) to meet its goal of cutting climate pollution by at least 50% by 2050.
New chemistry and cheap renewables make ammonia green
Ammonia (NH3, one nitrogen and three hydrogen atoms) is energy dense and easy to store and transport as a liquid. In the 1960s, X-15 jets set records for altitude and speed using liquid oxygen and ammonia as fuels. When Belgium faced diesel shortages in World War II, the government successfully rigged buses to run on ammonia.
Ammonia never made it big as a fuel because it needs super-high temperatures to combust. Most ammonia is made for fertilizer, and it’s manufactured by stripping hydrogen out of the hydrocarbon chains that make up fossil fuels, in a reaction that also produces carbon dioxide. Ammonia production consumes about 2% of the world’s energy and generates 1% of its CO2. It’s anything but green.
But change is on the horizon. In 2018, chemists discovered a new process that can reduce the amount of energy needed to fire up ammonia as well as suppress the formation of NOx, a polluting byproduct. In addition, the plummeting price of renewable energy is allowing a new, cleaner ammonia manufacturing process to become commercially viable.
Instead of using fossil fuels as a source of ammonia’s hydrogen, manufacturers start with water. Hydrogen can be separated from oxygen in water using electricity supplied by wind or solar power, and then combined with nitrogen in the air to make NH3. There’s no fossil fuel input, and no CO2 released. It’s slower than stripping hydrogen out of fossil fuels, but scientists are finding new ways to speed up the reaction and produce larger amounts of hydrogen.
Major players are piloting green ammonia projects
In the Australian desert, Yara, the world’s biggest ammonia manufacturer, is working with Engie on a pilot plant that uses solar power and water to create green ammonia. In the UK, Siemens is using wind energy to do it. Another green ammonia pilot plant is operating in Japan, and more have been proposed in Australia, the Netherlands and Morocco.
The ammonia produced at these plants is only truly green if the renewable energy used to make it isn’t diverted from the grid and replaced by climate-polluting fossil fuels. If genuinely carbon-free ammonia is used in fertilizer, it would reduce the carbon footprint of industrial agriculture. It could provide a less expensive, easily transportable source of hydrogen for clean vehicles that run on hydrogen fuel cells. It could be burned directly in dedicated power plants, or used to store excess renewable energy from the grid. It could also, using existing technology, be used to power tens of thousands of ocean-going vessels that currently use some of the dirtiest fuel on the planet.
A green fuel to power world trade
Shipping fuel today is a chunky porridge of unrefined petroleum, almost raw from the well. It produces 350 times as much sulfur as the gas we put in cars, along with smog-forming nitrogen oxides, lung-clogging particulates and climate-polluting black carbon. Yet 90,000 ships use this fuel to ply the world’s oceans, carrying everything from grain to toys to car parts all over the globe.
“There’s no way we would have something that polluting on our streets,” says Aoife O’Leary, an international shipping expert for Environmental Defense Fund Europe. “But because it’s on the ocean people don’t pay attention.”
As the International Maritime Organization seeks ways to clean up its air and climate pollution, green ammonia could provide a solution as a carbon-free fuel that can be burned in ship’s engines with minimal modifications. Green ammonia manufacturing could also benefit developing nations, which are concerned about the cost of meeting the IMO’s climate directive.
EDF looked at Morocco, a country with massive renewable energy potential that’s also a crossroads for international shipping and a major manufacturer of fertilizer. Just 0.6% of Morocco’s excess or untapped wind and solar energy could produce enough green ammonia to refuel every container and dry bulk ship (vessels carrying solid cargo like grains or iron ore) that passes through Morocco’s ports.
“You don’t need a strong grid to develop renewables for shipping,” says O’Leary. “With a proper carbon pricing system in place, you can drive a lot of investment into developing countries to build out a supply chain for clean shipping fuel. We want more countries to see this as an economic opportunity, not a challenge.”
The article was originally published in Medium