APA Issue 3, 2021
GREEN ENERGY Anaerobic digestion can help airports become more environmentally friendly and reduce their carbon footprint, writes Jocelyne Bia.
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efore the coronavirus outbreak stole the headlines, the main concern for people and governments around the world was the climate emergency and the need for urgent action.
Like many other industries, the aviation sector was under pressure to reduce its carbon footprint. Airlines were asked to abide by the ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation (Corsia), whilst on the ground, airports sought to make their operations more sustainable. The UK aviation industry had set the tone by establishing a Net Zero by 2050 target for itself. Then COVID-19 hit, and most global air travel all but stopped overnight, dealing the aviation industry a devastating economic blow. As countries prepare for a post COVID-19 recovery, two schools of thought are emerging. On one side are those who want to deliver immediate stimulus packages to put businesses back on their feet, irrespective of the climate change agenda. On the other are those who want to seize the opportunity to ‘build back better’, creating a greener global economy. Indeed, the UN, EU, International Energy Agency, leading economists such as Joseph Stiglitz and Lord Nicholas Stern, and even businesses have been calling for world
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governments to embed decarbonisation and renewables into their plans to kick-start the economy whilst still fulfilling their Paris Agreement commitments. For the aviation sector, and particularly airports, getting back to business while delivering sustainability is not incompatible. There are pre-pandemic examples of airports successfully adapting their operations to implement good sustainability practice. One technology that helps them achieve their greening ambition is anaerobic digestion (AD). By treating food and other organic waste and transforming it into biogas, AD can help establish a low carbon circular economy within the airport, saving both money and greenhouse gases emissions. HOW ANAEROBIC DIGESTION WORKS Anaerobic digestion is the natural breakdown of organic matter, in the absence of oxygen, which takes place in a plant called a digester. This process generates biogas and a bio-fertiliser called digestate. The ‘green gas’ generated by the AD process can be used for electricity and power or upgraded into biomethane, sometimes called renewable natural gas (see gaphic). Biomethane is a direct replacement for fossil natural gas, so it is already injected into the gas grid for heat or used
