Hydrogen, hybrid propulsion and biofuels: greening the future of aviation

When will we be able to board a plane with a clear conscience about the environmental impact of our journey? Aviation is responsible for 2.8% of global carbon emissions. According to the CNN article, many airlines have already vowed to create a future of carbon-neutral aviation, and the first electric planes have already been built, if only in the short term.

Clearly, one of the industry’s key goals is to drastically reduce or eliminate emissions, and the task is not small: it is estimated that by 2050 the industry will have to serve 10 billion passengers a year. Based on today’s emissions standards, this would mean 21.1 gigatonnes of carbon dioxide over three decades.

One possible solution is to replace 65% of fuel with sustainable types, while the use of new propulsion technologies could improve the situation by 13% and efficiency improvements by 3%. The remaining carbon emissions will have to be replaced somehow by airlines.

Sustainable fuels. Major improvements are underway in this area, with British Airways’ parent company aiming for 10 per cent of its fuels to be sustainable by 2030. Etihad Airways, in partnership with Khalifa University and Boeing, has developed a biofuel that will be available at Heathrow next year. Between 5-10 short-haul flights will be stored in London. Sustainable aviation fuel will reduce greenhouse gas emissions by up to 80 per cent compared to fossil fuel use.This is why its introduction is crucial to achieving the 2050 targets. But there is a downside: the price. Sustainable jet fuel costs around three times as much as its fossil-based counterpart and is in short supply. In addition to the rising cost of flying due to the Crown virus, green aviation will be even more expensive, which is why it is arriving more slowly.

Until less harmful fuels become commonplace, air travellers can try to mitigate the impact of their journey with compensation schemes. These schemes compensate for carbon emissions by funding projects that reduce the negative impact of humans on the environment by planting trees, creating wind farms or capturing methane. Several airlines operate their own similar schemes: the offsets provide social benefits and help to mitigate the problem, but do not actually reduce carbon emissions.

While biofuels are expected to be the main driver of the green revolution in aviation, the development of alternative technologies is also progressing rapidly, especially in the market for flights of less than 1,000 miles. Europe’s largest aircraft manufacturer, Airbus, is betting on hydrogen. In a high-profile turnaround last year, the company switched from developing small electric aircraft to new initiatives exploring the potential of hydrogen: Under the name ZEROe, it unveiled a trio of hydrogen-powered, zero-emission passenger concepts, which could be in service by 2035.

But there are still many obstacles to the widespread uptake of hydrogen. For example, airports lack the infrastructure to store and use it. A Caliphonian start-up, Universal Hydrogen, aims to address this by delivering hydrogen in modular capsules directly to the aircraft, and by converting existing aircraft to hydrogen power with its conversion kits.

Ampaire Inc, another California company, converts 9-19 seat aircraft to hybrid propulsion. There are tens of thousands of planes in the world that could do this, transforming the world of short-haul aviation. All-electric aircraft are already available in series production, with a cargo version. The nine-seat, all-electric Alice aircraft from Washington-based Eviation Aircraft produces zero carbon dioxide. The 440-mile range aircraft is intended for shorter, so-called “on-demand” routes and is also available in a cargo version – DHL Express has ordered 12 for 2024.

The aircraft, from UK-based Faradair Aerospace, can carry 18 people, has a payload of five tonnes and a range of 1,850 kilometres, and is built from lightweight composite materials. The aim is to use whatever fuel it is refuelled with in the most efficient way possible, thanks to the aircraft’s design. There will be no need for major modifications to the vehicle for a possible fuel change, thus greatly extending its lifetime compared to many of its peers. At best, the first aircraft could take off in 2024, with commercial flights in 2027.

Source: CNN