The urgent global commitment to achieve carbon neutrality by 2050 compels a radical shift towards sustainable energy alternatives. Among these, biomethane, produced through anaerobic digestion (AD), is a solution with far-reaching environmental and economic benefits.
Anaerobic digestion is a natural process where microorganisms break down organic materials in the absence of oxygen, yielding biogas. This biogas is then upgraded to biomethane, a renewable natural gas (RNG) that is virtually identical to fossil natural gas, meaning it’s interchangeable and injectable into existing gas grids or usable as a transport fuel.
Environmental benefits of reducing emissions
One of the environmental benefits of anaerobic digestion is its contribution to meeting governmental targets for renewable energy and reducing greenhouse gas (GHG) emissions. Many countries, including Ireland, are actively investing in biomethane production to boost indigenous renewable energy sources and enhance energy security.
This move, along with broader initiatives like the EU’s RePowerEU target of producing 32 billion cubic meters (BCM) of biomethane by 2030, significantly reduces reliance on imported fossil fuels. The European Biogas Association projects that the EU’s biomethane production could reach 151 BCM by 2050, potentially replacing up to 40 per cent of Europe’s total fossil natural gas consumption.
Such a reduction would prevent approximately 730 million metric tonnes of carbon dioxide from entering the atmosphere, equivalent to meeting the annual energy needs of 137 million European households, according to the EBA’s Green Impact Translator.
Why is biomethane considered carbon neutral?
A key reason biomethane is considered carbon neutral, and sometimes carbon negative, lies in the biogenic carbon cycle. Unlike fossil fuels, which release ancient carbon stored underground for millions of years, the carbon emitted when producing biomethane was recently absorbed from the atmosphere by the organic matter used in its production.
Therefore, the carbon released from burning biomethane is part of a natural cycle, not adding new carbon to the atmosphere.
Beyond carbon neutrality, AD plays a crucial role in methane mitigation. Methane is 80 times more effective at trapping heat than CO2 and accounts for about half the net rise in global average temperature since the pre-industrial era.
Reducing CHG by capturing methane emissions
By capturing methane emissions from organic agricultural and food waste, biomethane production directly reduces the amount of this powerful GHG entering the atmosphere. This aligns with the Global Methane Pledge, signed by over 100 countries, aiming to reduce methane emissions by at least 30 per cent from 2020 levels by 2030.
Achieving this goal could prevent a temperature rise of over 0.2 degrees Celsius by 2050 and reduce emissions of over eight gigatons of CO2 equivalent (GtCO2e).
Biomethane replaces fossil fuels
Furthermore, biomethane has a significant role in reducing GHGs by replacing fossil fuels, especially in challenging sectors like heavy-duty and marine transport. While overall EU GHG emissions have decreased, CO2 emissions from fossil-fuel-powered heavy-duty vehicles have risen.
Biomethane offers a viable alternative where electrification is difficult. Projections show that LNG-fuelled heavy-duty transport could increase tenfold to 280,000 vehicles by 2030.
Using a mix of LNG and Bio-LNG could reduce carbon emissions by 50 per cent. Creating 100 per cent Bio-LNG from manure could even make GHG emissions carbon-negative.
In shipping, using a 20% blend of Bio-LNG can reduce GHG emissions by 18%, and 100% Bio-LNG can achieve at least a 93% reduction.
Digestate is a useful byproduct of AD
Finally, the byproduct of AD, known as digestate, contributes significantly to environmental sustainability. This nutrient-rich organic fertilizer can replace carbon-intensive synthetic mineral fertilizers, whose production chain is responsible for a staggering 1.13 Gigatons CO2 equivalent (GtCO2e), or 2.1 per cent of all global GHG emissions.
Scientific studies indicate that replacing synthetic fertilizers with digestate can avoid significant CO2 equivalent emissions per hectare annually. Digestate also improves soil and water quality, as the nitrogen it contains is more readily absorbed by plants, reducing leaching into water bodies.
Contribution to a circular economy
Anaerobic digestion significantly contributes to a circular economy by transforming waste into valuable resources, creating economic opportunities, and fostering local resilience.
Jobs
The European Biogas Association (EBA) reports that the biogas and biomethane industries already support over 210,000 green jobs across the EU, with projections of creating about 420,000 jobs by 2030 and more than 1 million by 2050.
Ireland’s biomethane target alone has the potential to generate up to 1,800 direct jobs and 4,400 indirect jobs across its rural economy, revitalizing communities facing issues like depopulation and limited employment opportunities.
Energy security
Another crucial economic benefit is energy security. By utilizing local organic waste, communities can reduce their reliance on imported fossil fuels, building a more resilient and stable local energy system.
Biomethane’s continuous production from waste makes it a highly stable and predictable energy source, unlike intermittent renewables like solar or wind. This indigenous production also helps shield against price instability and volatility in international energy markets.
Farmers
Farmers who partner with a biomethane producer can supply feedstock to reduce slurry management costs. Plus, the use of digestate as a low-cost, high-quality fertilizer can significantly cut synthetic fertilizer expenses and overall sustainability.
Agi-businesses and farmers can also earn additional revenue through land leases or sales for plant development, with long-term contracts providing consistent income and waste-management solutions. All contribute to making farming more sustainable and bolstering rural economies that depend on agricultural activity.
Real-world benefits of anaerobic digestion
Anaerobic digestion and biomethane production offer a powerful combination of environmental and economic benefits. It can help meet ambitious renewable energy targets and significantly reduce potent greenhouse gas emissions like methane and CO2.
The economic benefits are as attractive as AD plants create local jobs, enhance energy security, and provide substantial economic advantages for farmers. AD plays a pivotal role in transitioning towards a sustainable and circular economy.
AD can transform waste into valuable, carbon-neutral, and even carbon-negative fuels as a cornerstone in the global effort to combat climate change and build a more resilient future.
Cycle0 Your Partner in Renewable Gas Solutions
At Cycle0, we develop, own and operate biogas plants across Europe, working towards our mission to turn waste into renewable natural gas. We are a biogas plant developer that understands the intricacies of anaerobic digestion.
Contact us today to explore how we can partner to turn your waste into a valuable renewable energy resource and contribute to a greener future.