November 04, 2024
Announcement
“World’s First! Successful Stable Operation of a Small Rotary Engine with Hydrogen and Multi-Fuel Compatibility”
We are pleased to announce the successful hydrogen adaptation of an 80cc gasoline-fueled Wankel-type rotary engine (hereafter referred to as RE). This adaptation achieved stable, continuous operation for over 3 hours and 30 minutes, including successful use as a generator.
Our hydrogen fuel supply methods include an Electronic Control Unit (ECU) controlled “pre-mix injection method” (where fuel is introduced into the intake manifold in advance) and “direct injection method” (where fuel is injected directly into the engine), both of which enabled stable, long-duration operation. (At 3600 RPM, we achieved operation output exceeding 1.5 kW.)
Additionally, leveraging the RE’s structural advantages, we succeeded in stable operation using a “mixer type” mechanical pre-mix method for hydrogen fuel, without ECU control. This setup also allowed for continuous stable operation over 3 hours and 30 minutes.


▲80cc RE operating on hydrogen. There is a generator for the generator at the tip of the RE. Attach a pump etc. and use it as a prime mover.
▲Attach a generator to RE80cc.
Comparison of RE and 4-Stroke Engines


▲ Wankel-Type Rotary Engine
▲ 4-Stroke Engine
The RE has a simpler design than a 4-stroke engine as it lacks intake and exhaust valves, which enhances maintenance efficiency. Furthermore, the RE’s design separates the intake from the combustion chamber (spark plug), reducing the occurrence of pre-ignition or backfire. The hydrogen-fueled small Wankel-type RE developed by our company demonstrated compatibility with varying output demands across low and high speeds, utilizing either the injector or mixer method for fuel supply.
Currently, the RE operates on various fuels, including hydrogen, gasoline, kerosene, and canister fuel used for portable stoves. In emergency situations, we envision this RE serving as a generator that runs on accessible fuels such as LPG, kerosene, and canister fuel. Moving forward, we aim to expand testing for stable operation across a broader range of fuel types.