It’s well known that Japanese automakers have long been reluctant to fully commit to battery electric vehicles. Toyota has been the most vocal about this stance, with chairman Akio Toyoda claiming that EVs will never exceed a 30 percent market share. Instead, companies from the Land of the Rising Sun see biofuels as a potential savior of the internal combustion engine. Even hydrogen-burning ICEs can play a role in decoration.
Mazda, though a much smaller company, shares a similar philosophy. It is not ready to give up on combustion engines, believing they can still be made significantly cleaner. Unveiled at the Japan Mobility Show, the Vision X Coupe made headlines for its sleek design and rotary engine, but there was more to it than that.
The swoopy show car was engineered to accommodate Mazda’s so-called “mobile carbon capture” system, a device that literally neutralizes 20 percent of exhaust gases. While it may seem like Mazda is grasping at straws to save the combustion engine, the company insists it’s more than just a pipe dream.
‘Although challenges remain, we have already established the technology at the demonstration test level. We are now moving into full-scale validation towards practical implementation. We have experimentally verified that Co₂ can be separated from exhaust gases using Co₂ adsorbents. We will begin testing the demonstration of this coupe technology at the final round of this year’s Super Taikyu Series, said Kazu Ichikawa, an expert at Mazda’s next-generation environmental technology research department.
Ichikawa admits that “there are still some issues to be resolved,” but his goal is clear: to put the carbon capture device into production cars. The captured exhaust gases are dried, and the carbon is bound to a crystalline zeolite substrate. The ₂ stored in a small tank can then serve as a raw material, potentially for the production of recycled plastics.
The rotary engine we mentioned earlier does not run on gasoline, but on plant-derived biofuel made from nanochloroplasts. It is a type of microalgae with high lipid production efficiency, yielding oil with diesel-like properties. During its growth, algae absorb CO₂ through photosynthesis.
Mazda believes that producing this microalgae-based fuel at “relatively low cost” could reduce CO₂ emissions by up to 90 percent compared to fossil fuels. When combined with a carbon capture system that recovers 20 percent of the car’s own emissions, Chief Technology Officer Ryuichi Amishita says a vehicle like the Vision X Coupe can achieve a carbon-negative result of about 10 percent.
In theory, Mazda says, “the more you drive, the less ₂ you emit.” But scaling up biofuel production is a huge challenge. Currently it takes about two weeks to refine just over one liter of fuel from a 1,000 liter culture tank. Ideally, widespread biofuel production could make a carbon-negative scenario a reality.
The catch can also be reused to grow more microalgae, meaning the car will help clean the air as it moves. Mazda is serious about making this vision a reality, but while R&D makes sense, such a future depends heavily on scaling biofuel production to a viable level. There will need to be an infrastructure in place to collect and properly dispose of or reuse captured co.2.
Nonetheless, we should appreciate Mazda’s continued willingness to think outside the box. Only time will tell if this latest approach leads to any dead ends. Even if it does, the combustion engine isn’t going anywhere: the new Skytec-Z is coming.
