Startup Amogy raises $46M to fuel cargo ships with green ammonia

Ben Warner climbs into the cab of a John Deere tractor, guiding the hulking machine down a narrow path. He makes a gentle right turn, and the squat white tank and jumble of slender pipes mounted to the tractor’s rear come into view. An early-summer heat radiates from the concrete parking lot in Brooklyn, New York.

Warner is an engineer-turned-tractor-driver for Amogy, a fast-growing startup led by CEO Seonghoon Woo. The company is working to help solve a particularly vexing puzzle facing the global transportation sector: how to reduce greenhouse gas emissions from heavy-duty and long-distance vehicles that — unlike passenger cars — probably can’t run on battery power alone.

The tractor on display today is fueled by ammonia, not diesel. The rear ammonia tank connects to a power system in the vehicle’s front compartment, which drives the tractor without spewing black smoke or rumbling loudly as an engine would. After field-testing the 100-kilowatt system on an upstate farm this month, the startup is looking to tackle bigger, more polluting modes of transportation.

On Thursday, Amogy announced that it raised $46 million in additional capital, an amount Woo says will help ​“accelerate scaling up this technology so that we can demonstrate it on an 18-wheeler and a cargo ship at the beginning of next year.”

The South Korean energy conglomerate SK Innovation led the funding round, which also includes the venture capital arm of Saudi Aramco — the world’s largest oil producer — and e-commerce giant Amazon. In December, Amazon led a separate $22.3 million investment in Amogy through the retailer’s $2 billion Climate Pledge Fund, as part of Amazon’s broader effort to clean up cargo shipping.

The investments reflect the growing global interest in ammonia as a zero-carbon transportation fuel, particularly within the maritime industry.

Cargo shipping contributes nearly 3 percent of global greenhouse gas emissions every year — a percentage that’s expected to climb over time as a rising number of diesel ships make more voyages to shuffle T-shirts, grains, Lego bricks and metals across the world’s waterways.

The International Maritime Organization, the industry’s main regulatory body, aims to reduce ships’ emissions to 50 percent below 2008 levels by 2050. Shipowners and logistics giants are already taking steps to cut carbon from existing vessels. Wind-blown devices such as towing kites and automatically unfurling sails can trim ships’ fuel use. Artificial-intelligence programs help companies chart more energy-efficient voyages. Many vessels can now tap into shoreside electricity supplies to run their lights and equipment while idling at ports.

Yet when it comes to replacing diesel fuel, the industry is just starting to figure out which alternative fuels might work best.

Ammonia should be safe and ​“green,” experts say

Oceangoing vessels must sail for days or weeks between stops, and they often carry many thousands of tons of cargo on or below deck. That massive energy demand limits the types of alternatives that can adequately replace polluting diesel fuel.

Hydrogen, methanol and battery power are gaining favor for certain kinds of ships, while fossil-fuel-derived products like liquefied natural gas and liquefied petroleum gas are catching on — albeit controversially — as lower-carbon alternatives to current oil-based fuels. Ammonia is considered to be among the most promising zero-carbon fuels for deep-sea, long-distance freighters.

Ammonia (NH₃) is mainly used today to make fertilizer, plastics and cleaning products. But companies are interested in using ammonia in transportation for a few key reasons. Because ammonia doesn’t contain carbon atoms, it doesn’t produce carbon dioxide when used as fuel. The chemical is relatively energy-dense, meaning it requires far less space to store on board than an equivalent amount of liquid hydrogen or battery power.

“We expect broader adoption of ammonia [in shipping] to get underway in the early 2030s,” says Hendrik Brinks, a principal researcher for zero-carbon fuels at DNV, a Norwegian firm that classifies and certifies ships. Since 2020, about a dozen projects have been launched to develop ammonia ship technologies for larger vessels.

Still, he adds, many hurdles will have to be overcome before ammonia can be used widely and safely on a global scale. To start, there are various technical challenges to getting it to work as fuel. Ammonia is also pungent, corrosive and potentially fatal in high concentrations. Regulators, companies and consultancy firms like DNV are starting to develop safety guidelines and risk-reduction measures to protect people and ecosystems wherever the toxic fuel is being stored or handled.

Only with such standards ​“can ammonia reach its full potential as one of the most promising green fuels,” Brinks says.

Whether ammonia actually is a ​“green fuel” depends on how it’s made. Of the 185 million metric tons of ammonia produced worldwide in 2020, virtually all of it was made using fossil fuels in highly energy- and carbon-intensive processes.

“Green” ammonia production starts by making hydrogen and nitrogen. Electricity generated from wind, solar and other renewable sources is used to split water molecules into hydrogen and oxygen through the process of electrolysis. The electricity also powers air separation plants that pull nitrogen from the sky. Additional steps combine the hydrogen and nitrogen atoms to produce ammonia.

The global shipping fleet currently consumes about 330 million metric tons of marine fuel every year — almost double today’s ammonia output. To make enough green ammonia to supply the world’s cargo ships, countries will need to install potentially thousands of gigawatts’ worth of wind, solar and other renewables in the coming decades, Brinks and other experts say.

Amogy splits ammonia to power tractors and ships

As manufacturers and engineering firms work on designing engines and fuel cells that can use ammonia directly, Amogy is taking a different tack.

The startup is developing a chemical reactor that splits ammonia back into its constituent parts of hydrogen and nitrogen. Although ammonia is more energy-dense, hydrogen is better suited for the most common and widely manufactured type of fuel cell: polymer electrolyte membrane, or PEM. Amogy’s idea is to take advantage of ammonia’s density and hydrogen’s compatibility by using both compounds in its power system.

At a laboratory in the Brooklyn Navy Yard’s Newlab tech center, Woo holds up a small glass vial containing tiny metallic beads. The substance is used as a catalyst — the heart of Amogy’s design.

On the tractor, the chemical reactor appears as a sturdy black box near the vehicle’s windshield. Inside the box, liquid ammonia flows over a ​“bed” of various catalysts, which spur a chemical reaction that breaks the bonds between atoms and produces hydrogen gas; the gas then flows through the PEM fuel cell. That device converts chemical energy into electricity to drive the tractor’s electric motors. A smaller set of batteries rounds out the system’s power needs.

Meanwhile, as the system uses the hydrogen, the leftover nitrogen is released back into the air, while other chemical remnants are captured in an array of silver tubes nestled between the tractor’s cab and front left tire.

Woo says that, despite the dizzying number of steps involved, ​“It’s much easier this way for us to bring the product to the market.”

Woo co-founded Amogy in late 2020 with three fellow doctoral graduates from the Massachusetts Institute of Technology. Last summer, the small team demonstrated a 5-kilowatt fuel-cell system on a 50-pound personal drone. With the Amazon-led investment, the startup scaled the technology twentyfold to drive the John Deere tractor, which it first demonstrated at nearby Stony Brook University in late May.

The $46 million funding round should allow Amogy to nearly double its 55-person team and develop systems of several hundred kilowatts to retrofit on an existing cargo ship, likely somewhere around Brooklyn. The company is also opening an office in the Nordic region, where government agencies and maritime companies are investing heavily in green ammonia and other types of zero-emissions ship technologies.

“We’re well on our way to further scaling our technology to decarbonize industries that are the highest emitters of greenhouse gases,” Woo says.