Why liquid hydrogen may make sense for airplanes, replacing jet fuel
If you want to find a major source of transportation-related emissions, just look up.Aviation currently accounts for around 2 percent of global carbon emissions, and many analysts believe its share could triple by the middle of the century if projected growth in air travel occurs.
But finding alternatives to fossil fuels has proven much more difficult for aircraft than it has with ground vehicles.One possibility might be replacing jet fuel with liquid hydrogen.
That's a concept posited by a study of ways to improve energy efficiency across all forms of transportation by physicist and Leiden University professor Jo Hermans, published in the journal MRS Energy & Sustainability.
"Given the severe weight limitations for fuel in aircraft, liquid hydrogen may be a viable alternative in the long run," Hermans says.