Use of Hydrogen energy in the commercial airline industry
Due to several environmental problems related to carbon emissions from the use of fossil fuels, researchers are looking for more efficient and environmentally friendly fuels that can minimize pollution. For this purpose, after conducting several types of research, scientists discovered hydrogen and other carbon-neutral fuels. The reason is that these types of fuels emit almost no carbons and can serve energy needs greatly.
What kind of fuel do airplanes use now?
There are two types of fuels currently being used in the commercial airline industry.
Jet Fuel
As the name shows, jet fuels are used to power jet engines that need the powerful thrust of expelled air to take the plane in a forwarding direction. It is a colorless or sometimes a straw-colored liquefied gas categorized in Jet A and Jet A-1 types of fuels. One of the main differences between Jet A and Jet A-1 fuel is their different freezing points. The Jet A type of fuel is commonly used in the US, developed in the 1950s having a freezing point of -40ºC or sometimes below (source).
The Jet A-1 fuel has freezing point (-47ºC) lower than Jet A and is commonly used all over the world. The manufacturing process of both fuels varies however, they can be used interchangeably. The main difference among them is the amount and nature of additives used in the manufacturing of fuels like Jet A uses dissipater additives while Jet A-1 does not.
Avgas
Avgas is also known as aviation gasoline that is commonly used to power piston engines airplanes. It is used in aircraft that are used to run by the rotation of their propellers to generate thrust. The modern turboprop aircraft can also be run on Jet Fuel instead of Avgas because they have engines installed with a gas turbine that powers the propellers for thrust.
The standard type of Avgas is the high-octane Avgas used to power piston engines. This aviation gasoline has a high lead proportion and is dyed green in color. The Avgas 100LL is similar makeup blue in color with a lower lead proportion (source).
Other Types of Fuel
The following are some more common types of aviation fuels used in most airplanes. Some fuels are dedicated to military aviation and are used in extreme climate conditions.
TS-1
It is a primary jet fuel mostly used in Russia. It is a kerosene-based fuel that is volatile with a low freezing point of -50ºC which is important for its working in extremely cold climates.
Jet B
Jet B is used in cold climates in north Canada with a relatively low freezing point of -60ºC. This fuel is a mixture of kerosene and gasoline and is categorized as “wide-cut” fuel. The composition of Jet B fuel makes it a more flammable fuel than Jet A this is why it is more carefully handled. It also includes anti-icing additives and corrosion inhibitors.
JP-8
It is a military-type jet fuel that is commonly used by NATO air forces.
JP-5
It is a high flash point jet fuel based on kerosene that is commonly used in military aircraft carriers.
What is the environmental impact of the airline industry?
The fuels used in the airline industry are responsible for carbon emission and other toxic gasses like sulfur dioxide that can pollute the air badly.
Some of the common environmental impacts of the airline industry are discussed below.
Aviation Emissions
Aircraft works on the combustion of fuel that results in carbon dioxide including nitrogen oxides, sulfur, and carbon monoxide in small proportions. Most aircraft burn fossil fuels as a result they produce carbon content emissions that impact the environment badly.
Environmental Effects
The gasses emitted from the combustion of jet fuels transform into other toxic gasses when entered the atmosphere. The pollutants released from the airline industry normally transform into three different forms.
- Immediate pollutants released from the combustion of fuels within the engine
- Emitting from the hot exhaust plume of the aircraft
- Emitted, cooled, and mixed into the atmosphere
The pollutants emitted from aircraft affect air quality badly and can change the global climate. The airline industry is not a major contributor to global warming and carbon emissions as compared to maritime and general transport, still, it is affecting the environment negatively. The most significant impact of airline emissions is that the pollutants are emitted in the upper troposphere and lower stratosphere that are more climatically sensitive regions. Moreover, due to reasons, they are emitted at higher altitudes so there is a high chance of spreading over a wide area in the atmosphere.
In short, airline emissions do have negative effects mainly depending on the quantity and characteristics of emissions and how humans and sensitive environments get exposed to them.
Despite that, the airline industry is a comparatively small contributor to global warming but it is also the fastest-growing industry. According to reports, there was a 5% rise in flights annually between 2000 and 2019 accountable for 2.5% of the overall world’s CO2 emissions (source).
What are the alternatives for airplane fuels?
Today, almost every jet fuel is produced from fossil fuels (petroleum). Only a few types are manufactured using oil sands. Natural gas, shale oil, and coal are also used to manufacture jet fuel. The production of fuel depends on the large reserves of these fossil fuels. As the use of fuel increased in the past decades, the reserves are getting deserted resulting in the need to switch to alternative fuels for the transport industry like airline or maritime.
The following are some of the alternatives for airplane fuels.
Biofuels
Raw materials like biomass are considered as potential alternative airline fuels. Ethanol and biodiesel extracted from biomass have been used by blending gasoline and diesel to be used as fuel. The reason for the usage of biofuels is to diversify energy sources and expand the production of fuels.
Electrofuels
Electrofuels are also referred to as synthetic fuels that have more potential to be used as aviation fuel but there isn’t much production or acceptance of these fuels yet. These fuels truly emit low-carbon emissions hence strict sustainability criteria are required to manage them. The first-ever flight took place recently using sustainable e-kerosene which only used 5% of kerosene in its fuel mix. The CEO of the Air Transport Economics consultancy, Chris Lyle said that the big problem is that at the moment, it’s about three times the cost of conventional fuels (source).
Cryogenic Fuels
Cryogenic fuels are the normal gasses that have been cooled to the point where they can be stored as low-temperature liquids like hydrogen and liquid methane. Such fuels require storage at extremely low temperatures to keep them in a liquid state.
Liquid methane and hydrogen possess high gravimetric energy content, however, they have low density resulting in low volumetric energy content. Cryogenic fuels are different from traditional jet fuels and there’s a need to introduce a whole new fueling infrastructure for the aviation industry.
Hydrogen fuel lies in the cryogenic fuels category and is considered as the fuel of the future extracted from renewable resources. Hydrogen is present in abundance in our nature and can be produced using natural gas and methane. Before introducing such fuels to the transport industry an efficient and economical infrastructure is needed so that hydrogen fuel can replace fossil fuels as a major source of energy. Hydrogen fuels can be generated from water and several other renewable sources like solar, biomass, and recycling of waste using the LTC process. These fuels can replace fossil fuels in commercial aviation but it can take some time.
Is hydrogen a viable option for airplanes to use as fuel?
Aviation companies are currently researching to introduce and explore hydrogen (the world’s most abundant element) as a fuel. It has the potential to power electric as well as combustion engines along with its eco-friendly nature with zero-carbon emission. The aviation industry is determined to achieve the zero-carbon emission mission by 2050 (source). Hydrogen can be a source of clean energy used in fuels cells, hybrid engines, and combustible fuel.
The aviation industry can be a potential area for the application of hydrogen as a fuel. However, exploration and several kinds of research are carried out in this area. Hydrogen can be a viable option for aviation fuels as it has some unique properties including global availability, safety, minimum pollution, and lightweight which makes it an ideal fuel.
White Hydrogen Coalition (WH2C) — Introducing new technologies for a cleaner future
White Hydrogen Coalition is an international community that supports renewable energy to reduce global warming and decarbonization of industry and transport. They are focused on producing and using White Hydrogen as a source of energy in almost every industrial sector to purify the world.
The goal of this technology-based coalition is to produce white hydrogen with the help of cleantech solutions like Low-Temperature Conversion (LTC) and reduce the overall carbon content of the world. The white coalition projects are based on blockchain and anyone can participate in this worthy program as a token holder and get benefits in return.
Are hydrogen planes a better alternative than electric planes and why?
The aviation industry burns a lot of carbon-emitting jet fuel making it a major greenhouse gas emitter in the world. Therefore, it becomes important to come up with more clean ways to power airplanes.
Clean energy sources including hydrogen, biomass, and solar are some of the cleanest forms of energy that can be used in the aviation industry due to their low-carbon emission nature. Among them, hydrogen gets more attention as it is present in abundance naturally and can be generated through several techniques. The approach of using and storing pure hydrogen as a liquid fuel and burning it with water as a byproduct is proven a more realistic solution for reducing the overall emissions from airplanes.
The liquified form of hydrogen is dense and carries more energy content than the most exotic battery, which is the reason it can be easily burnt. Given its potentials of efficiency and eco-friendly nature, hydrogen can be a fuel of the future for the aviation industry, however, one of the humongous challenges faced by the industry is to develop hydrogen-based infrastructure as it is expensive at the moment. The production of hydrogen is not yet common and the industry would be needing a constant supply of hydrogen just like it is consuming huge quantities of jet fuel now.
