Mazda Motor Corp., a Japanese automotive manufacturer, has planned to shift from fossil fuel to renewable resources through the dual-version of its rotary engine. To reduce the risk of abnormal combustion or detonation, the rotary was sustained with separate chambers for the intake and combustion strokes, making it ideal for hydrogen-fuel use.
The engine went through a test in an experimental RX-8, driven at Mazda's sprawling Hiroshima manufacturing complex. The venue is considered one of the world's largest plants, considering that it sits on 2.2 million square meters. The test has proven the engine to possess decent fuel consumption. The 110 liters of hydrogen stored in two tanks pressurized to 5,000 psi has been consumed in 100 kilometers of driving. And, the 61 liter gasoline tank enables the vehicle to run up to 600 km.
An impressive side of the engine comes from the capability of the gasoline tank to be filled with just about any liquid fuel. That means the RX-8 could be powered with E85, a blend of 85 per cent ethanol and 15 per cent gasoline.
The test has also proven two things. First, the twin hydrogen injectors in each of the two cylinders efficiently worked, creating no deterioration in the operating characteristics. The idle is relatively smooth along with the engine that provides linear pull as the revs build.
Subsequently, there is a massive effect on power output (hydrogen packs approximately half the punch of gasoline) brought up by the energy density difference between gasoline and hydrogen. In the test, the rotary engine's output swooped from 210 hp and 164 pound-feet of torque as it runs on gasoline to 110 hp and 89 pound-feet as it switched to hydrogen.
The use of gasoline requires 7.5 seconds for the RX-8 to run 100 kilometer per hour, considering that the dual-fuel version is heavier than a conventional RX-8 by about 130 kilograms. As the vehicle switch to hydrogen, the elapsed time goes up to 18 seconds. Though it seems to be something to be worried about, it was not actually a problem. The driver could purposely push a button and select the gasoline side of the RX-8's dual personality.
The hydrogen use was proven to be perfect for driving in a tamer pace. Though there are still some NOx emissions from the combustion process, it is significantly regulated by a catalytic converter along with a quality . Thus, the emissions do not contribute to the present growing pollution.
The Japanese automotive has been considering the optimization of the engine. In fact, the RX-8 is currently optimized to run on gasoline, considering that it is the dirtier fuel that needs to be properly burned to keep the emissions at its lowest. When tuned to consume the best of hydrogen, the engine's power output is boosted to up to 35 per cent. Teaming up the hydrogen with E85 could also help in enhancing such power.
At present, Mazda is still looking for other steps that could create a machine potentially capable of providing the demands of the people for environmentally friendly vehicles.
