Hydrogen can be produced from water through a process called electrolysis, driven by renewable power , but this process is currently expensive and requires large amounts of energy. Aviation passenger numbers are projected to double by , meaning many more greenhouse gas emissions unless sustainable alternatives are found Credit: Getty Images.
As things stand, liquid hydrogen is more than four times as expensive as conventional jet fuel. Over the coming decades the price is expected to drop as infrastructure is scaled up and becomes more efficient.
But according to Britain's Royal Society and the management consulting group McKinsey , it is likely to remain at least twice as expensive as fossil fuels for the next few decades. These factors, and others, give pause for some major players in aviation.
Sean Newsum, director of environmental strategy at Boeing Commercial, Airbus's main rival, recently told the Financial Times : "Our belief is that it will take a while for all the technology and elements of hydrogen propulsion to be worked out before we can get to… commercial use. So what are the alternatives? In September , t he Air Transport Action Group, a Geneva-based body that speaks on behalf the global aviation industry, published a set of scenarios which suggest that, even as the volume of air traffic increases, it will be possible for global aviation to reach zero emissions of carbon dioxide — but only a decade or so later than According to these scenarios, the direct use of hydrogen will play only a marginal role, but the game-changer will be what are termed "sustainable aviation fuels", or SAFs.
This catch-all term covers a range of products, such as biofuels, that result in low net emissions of carbon dioxide and other pollutants associated with conventional jet fuel. The advocates of SAFs argue they have a number of clear advantages over pure hydrogen. Because they are chemically identical to existing jet fuel, they can in principle be "dropped in" to existing systems with little or no redesign, without delay, and without the substantial ancillary investments required for hydrogen-powered airframes and their supporting infrastructure.
Paul Stein, chief technology officer at the engine makers Rolls Royce, argues they are the key to a more sustainable future. Biofuels are one alternative to fossil fuels for aviation, but they require large tracts of land to grow Credit: Getty Images. SAFs can be divided into two categories. The first are biofuels made through the chemical or thermal treatment of biomass such as agricultural residues and other wastes.
A second category is electro fuels, or "E fuels". Through these fuels, which are also known as "power to liquid", hydrogen could end up playing a key role in aviation after all.
E fuels are made by reacting hydrogen with carbon dioxide to make "syngas". This is then converted through what is known as Fischer-Tropsch process into "e-crude" — a crude oil substitute that can be refined to jet fuel and other fuels. If the large amount of energy required at each stage of manufacture is sourced from zero carbon sources, then the whole process can be carbon neutral, with no more carbon dioxide in the atmosphere after the flight than before the fuel was made.
Aviation kerosene is the fuel of choice for aircraft across the globe. But why do planes use kerosene over other types of fuel? One of the primary reasons as to why jets rely on kerosene is due to its low freezing point. Planes fly at extremely high altitudes, which means they spend a lot of airtime in sub-zero temperatures.
As a result, planes need to use fuel with a low freezing point — like kerosene - so the fuel functions properly without solidifying during the flight. Kerosene is highly flammable, more so than diesel, which gives it the explosive burning qualities required for take-off. Gasoline is also highly flammable, but its energy pay back is poor and fuel consumption too rapid, which is more inefficient. This means a plane would have to carry a greater volume of fuel for the same journey duration.
Aviation kerosene is less viscous than gasoline when used during flight, making it the preferred choice for jet crafts. Liquids with a high viscosity are thick, sticky and gluey — this is not an ideal property for jet fuel!
Kerosene maintains a low viscosity during flights thanks to its low freezing point. Kerosene is much cheaper than gasoline, making it a more affordable option for airlines. Flights are an expensive operation, so its important for airlines to use a cheaper source of fuel without compromising safety.
Safety is a crucial factor for all airlines, and aviation kerosene is an extremely safe source of fuel. Firstly, kerosene has a higher flash point than gasoline, meaning its unlikely to cause unplanned combustion.
The first time I flew was in Since then, I've been on at least 10 other flights. So, it surprised me then, when it recently occurred to me that I have no idea what powers planes. The first time I sat at a window seat right behind the wing, I wondered how planes worked, how the motion of the lever-like parts of the wing affected the motion, what turbulence was, and especially how safe I was.
I wasted no time in looking all these up as soon as I got out of the airport, but I had never wondered what the fuel energy source is for airplanes. We know what powers cars, we know where that comes from and how renewable and environmentally safe these are for the world. Why do we have no conversations in my experience about aviation fuels? All aviation fuels commonly used today are distilled fractions from crude oil. There are two types of aviation fuels: jet fuels, which are made from and similar to the kerosene fraction obtained from crude oils, and avgas-gasoline used in planes.
Engines that use avgas are different from those that use jet fuels. Jet fuels are used in turbine-based engines whilst avgas is used in piston engines. Monroe is committed to customer satisfaction, we strive for Continuous Improvement in our products and our people.
Read More. Call Us: Skip to content. The Basics of Airplane Fuel With the exception of piston-based airplanes, most airplanes use kerosene fuel.
The Benefits of Kerosene Fuel Airplanes use kerosene fuel for several reasons. More Popular Posts. How is Aluminum Metal Anodized? November 11, Products. November 10, Products.
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