Toyota’s newest EV alternative is an engine that sucks carbon from the air

TOKYO — In the age of electric vehicles, Toyota's critics have pulled no punches in calling the Japanese carmaker's tenacious commitment to internal combustion backward, even ecologically unsound.

But what if there was a technology that could make tomorrow's engines not only carbon neutral, but even carbon negative? Engines that suck carbon dioxide from the sky as they drive.

Now, Toyota Motor Corp. is demonstrating just such a technology — a carbon capture engine.

The world's biggest automaker began testing the system last year in a GR Corolla race car.

The car's hydrogen-burning engine emits only trace amounts of carbon dioxide, making it carbon neutral. And a new filtering device removes the greenhouse gas from the atmosphere with every lap.

"This type of technology to capture carbon dioxide in the atmosphere is advancing rapidly in the infrastructure industry," said Naoaki Ito, project general manager of GR vehicle development. "But as far as we know, Toyota is the first company to test this technology in a vehicle."

Still, there are many hurdles to commercializing the technology, which in tests removes only small amounts of carbon dioxide from the air.

The Japanese carmaker's gambit is part of its effort to explore new takes on old tech.

Toyota says internal combustion still has potential to help win the war against carbon emissions while also saving jobs and preserving the smell, sound and feel that dyed-in-the-wool car fans crave. As part of the carmaker's multipath approach to greener vehicles, Toyota announced in January a new round of advanced internal combustion engine development.

Toyota's diversified approach, championed by Chairman Akio Toyoda, was once derided by investors, environmentalists and EV enthusiasts pushing for a faster shift to full electrics.

But more recently, Toyota has won support as it racks record profits and sales on the back of its hybrid vehicles and as optimism for a rapid market transition to EVs cools. Investors have pumped up its stock price 80 per cent over the last year and some 30 per cent since Jan. 1.

The carmaker's market capitalization topped the symbolic ¥50 trillion (US $333 billion) mark this month, making it the first Japanese company to pass the milestone.

Toyota's renewed focus on engines is expected to first center on cleaner power plants for its trademark hybrids. Global sales of Toyota's standard hybrids soared 31 per cent to 3.4 million vehicles in 2023. They accounted for 33 per cent of worldwide deliveries, from 27 per cent in 2022.

But hydrogen combustion and carbon capture offer glimpses of possible directions.

The carbon capture technology debuted last summer in the GR Corolla that Toyota's Rookie Racing motorsports team fielded at a five-hour endurance race in southwestern Japan.

The company's Gazoo Racing motorsports and performance unit has competed with the experimental cars to test hydrogen combustion and other new technologies.

The carbon capture system consists of two circular filters that trap carbon dioxide from the air and a receptacle of fluid that absorbs and stores the carbon dioxide from the filters.

Critically, the system requires no additional energy to remove the carbon dioxide. The filters clean carbon from the air. Then, the engine's own heat releases carbon from the filters into the liquid. There, it is absorbed and bound to an alkyl amine solution that can be disposed of.

The key is a ceramic catalyst in the filters coated with a carbon dioxide absorbent developed by Kawasaki Heavy Industries. The technology is similar to that used in typical exhaust pipes.

There are two filters. One is mounted in the inlet to the air cleaner, which sucks up 60 liters of outside air every second. The other filter sits at the front of the engine bay, along the path engine oil takes as it circulates to lubricate the engine. The heat of the engine releases the carbon.

The technology can be applied to any vehicle with an engine, even gasoline-powered ones.

If the idea seems far-out, so is commercialization.

The test car captured only 20 grams of carbon dioxide every 20 laps. A traditional gasoline engine spits out 8,887 grams of carbon dioxide, on average, for every gallon it consumes, according to the EPA.

Furthermore, in Toyota's race car, the filters needed to be changed manually at every pit stop. And the best method of safely disposing of the absorbent fluid is still a matter of debate.

Toyota's experiment may never make it to passenger cars and could end up being a pilot program geared toward securing patents, said Koji Endo, senior auto analyst at SBI Securities Co. in Tokyo. Even if it is commercialized, the carbon capture technology may be better suited to heavy-duty trucks or industrial-scale land movers that can accommodate bigger filters, he said.

Nevertheless, the idea shows Toyota's focus on cleaning up combustion in the fight for carbon neutrality.

"They still need some kind of engine as a bridge to pure EVs," Endo said. "They should keep developing the efficiency of internal combustion so that when combined with a hybrid system it might even match EVs in terms of overall life cycle assessement of emissions."

Bigger filters would no doubt capture more carbon, but they also cost more and take up space. And filter swapping must also somehow be automated, Toyota's Ito said.

The attempt might be likened to when Toyota first installed solar panels on its Prius plug-in hybrid. At first, the technology seemed gimmicky. But later, after continued development and improvement, it began to add value.

"The amount of carbon dioxide recovered is small compared to the amount of carbon dioxide generated in the world," Ito conceded. But every new idea starts off small, he noted.

"It is still very early in the development of this carbon dioxide capture technology, but we are utilizing motorsports to speed up development," he said.

"We think there is potential and will continue to develop the technology."