At least for First Automotive Works, the notion of using hydrogen as a gasoline alternative is beginning to appeal in China (FAW).
One of China’s oldest manufacturers is collaborating with experts from the Beijing Institute of Technology (BIT) to develop a hydrogen-powered internal combustion engine. It’s not going to be an easy task.
Extremely pure hydrogen is required for fuel cells, however, this is not necessary for “burning” it. Thermal efficiency is critical not only for reducing hydrogen waste – getting it already took a lot of energy – but also for reducing any polluting combustion products as much as feasible.
As a consequence of the study, a direct-injection four-cylinder engine with a displacement of 2 liters and a turbocharger has been developed. It has a maximum power of 120 kW/163 CV at 4,400 RPM and a maximum torque of 340 Nm at 2,000 RPM, which is comparable to diesel. It is less efficient as a technological solution than a fuel cell, but it is far less expensive to build.
According to the authors of the research in the journal Fuel, Bao et al, a thermal braking efficiency of 42.6 percent was achieved at 2,000 revolutions with an extra air mixture, lambda 1.91. With even more surplus air, lambda 2.47 (*), efficiency declines to 40.4 percent at 3,000 RPM, similar to the best gasoline engines in production.
In terms of emissions, there are some nitrogen oxides (NO x) in addition to water vapor, not to mention the unavoidable combustion of oil. In most cases, NO x stays below 20 parts per million (PPM) owing to a urea injection system in the exhaust, which is common in current diesel. NO x is neutralized to 99.5 percent below 2,000 RPM, then lowered to 90 percent above 4,400 RPM.
In other words, this engine can produce strong power, large peak torque, great thermodynamic efficiency, and almost zero emissions for a fraction of the cost of fuel cells and without the need for nearly pure hydrogen. However, no matter how efficient it is, there is still a loss of energy from well to wheel.
