With COP26 in its second and final week, a lot has been said about the potential for alternative energy sources and supporting a clean energy transition. One such alternative will be presented by the World Biogas Association (WBA) at the event.

The WBA will be exploring how anaerobic digestion (AD) can help reduce methane emissions and fulfil the Global Methane Pledge (GMP), a collective commitment signed by international Governments to help decrease the amount of methane emitted into the atmosphere.

At its COP26 Blue Zone event, the organisation will showcase the value of AD in reducing global methane emissions, a greenhouse gas (GHG) that is 86 times more potent than carbon dioxide (CO2) in the first 20 years after release into the atmosphere.

Emitted from billions of tonnes of organic waste generated from food, farming, landfill and wastewater treatment each year, methane has been a hot topic at COP26, with over 100 countries signing up to the GMP – a pledge that aims to reduce emissions by 30% from 2020 levels by 2030.

Slated as ‘one of the key technologies that can deliver methane reductions at low cost’ by the UN Environment Programme and Climate and Clean Air Coalition in their joint report, the Global Methane Assessment, AD is considered to play an integral role in slowing the global temperature increase.

Speaking about AD, Drew Shindell, Lead Author, GMA report, said, “AD technologies can provide substantial, low-cost mitigation in these sectors this decade while simultaneously producing useful products such as biogas.”

“Using AD to turn organic food, farm and sewage waste into biogas and biofertilizer that can be sold or used on-site to generate energy, can help reduce methane and create a sustainable source of revenue and job creation.”

Biogas & biomethane in brief

Biogas is produced through the decomposition of an organic waste feedstock in an oxygen-free environment, known as anaerobic digestion.

By filtering the biogas through a membrane, an ‘upgraded’ form is produced, biomethane.

AD works by treating this waste organic matter and transforming it into biogas and bioCO2. The widespread adoption of biogas as a fertiliser and fuel could help decarbonise industries such as transport, agriculture and food and drink, all considered to be hard-to-abate sectors.

Especially hard-to-abate is the trucking industry, with heavy goods vehicles (HGVs) being responsible for around 17% of UK GHG emissions from road transport and around 21% of road transport nitrogen oxide (NOx) emissions.

To reduce emissions and decarbonise the transport sector, industrial gas giant Air Liquide has been exploring the use of biomethane, an upgraded form of biogas which can be used to fuel trucks and can also be fed into the gas grid.

The Gas Vehicles Network in the UK saw a 78% increase in the number of gas-powered HGVs in its fleet between 2019 and 2020, with the primary source of fuel for gas trucks being environmentally friendly biomethane. This signifies an acceptance of the technology, allowing it to receive more funding and subsequently accelerate its development.

“When we at Air Liquide began looking at biomethane around 2014, it was clear that we had to avoid impacting land use,” said David Hurren, UK CEO, Air Liquide Biogas Solutions Europe.

”…we don’t like the term ‘waste’, what we’re actually talking about are resources for the green energy transition.”

“As such, the Air Liquide biomethane solution is based wholly on organic waste streams such as food waste and industrial residuals. Although, I should specify that we don’t like the term ‘waste’, what we’re actually talking about are resources for the green energy transition.”

These high-quality resources are part of the biomethane innovations being explored by Air Liquide as a substitute for natural gas in the UK’s gas grid. The company stated that, with 85% of UK homes connected to the country’s extensive gas grid, replacing even a small percentage of natural gas with biomethane would have a ‘major impact’ on the country’s carbon emissions.

The company is currently finishing its tenth biogas-to-biomethane purification plant, known as a production unit. Initially starting with a focus on down-stream efforts and helping companies feed gas into the grid, Air Liquide has begun to move up-stream to produce biogas by operating digesters.

“This opens up the potential for circular solutions in cases where retailers or industrials create potential feedstock on site,” said Hurren.

With the sale of petrol and diesel trucks between 3.5 and 26 tonnes being banned from 2035, Hurren added that it’s no surprise that Air Liquide’s clients are switching their fleets to biomethane gas trucks, enforced by the fact that biomethane reduces CO2 emissions by around 90%.

Biomethane is just one of innumerable technologies made possible by harnessing the energy produced by organic waste. In addition to AD, biomethane and biogas could play a key role in reducing methane and CO2 emissions.

Commenting on WBA’s showcase on the uses of biogas, Charlotte Morton, Chief Executive, WBA, said, “Recycling the 105bn tonnes of methane-emitting organic wastes we humans produce ever year through anaerobic digestion is an easy win – it is a technology widely used across the world today.”

“We are delighted to be given this opportunity to showcase the value of AD and biogas in reducing methane emissions to the world’s most influential players in the climate change agenda.”

The WBA COP26 event, held in partnership with the Kenya Climate Change Working Group (KCCWG) will take place today (10th Nov) between 4pm and 5:15 pm in Action Room 1, amended from its previously announced location. The event will also be livestreamed, registration is available here.