Engineered Removal of Carbon is Creating Opportunities for the Biogas Sector

To keep global warming below 2°C—ideally 1.5°C—we must do more than just cut emissions; we need to actively remove carbon from the atmosphere.

The Climate Change Committee’s Seventh Carbon Budget released in February 2025 highlights carbon capture storage and engineered removals as key to meeting our carbon commitments under the Paris Agreement and Global Methane Pledge.

The IPCC states that alongside substantial emission reductions, up to 10 gigatonnes of CO₂ needs to be removed from the atmosphere annually to achieve net zero goals.

This presents a major opportunity for the biogas sector, which already captures CO₂ when upgrading biogas to biomethane.

Richard Gueterbock explores how biogas sites and industry can collaborate on long-term CO₂ storage with pioneering companies driving novel carbon removal solutions. 

These processes can achieve the same level of carbon storage in one hour as 50 trees would over a year, offering a scalable and efficient supplement to natural CO₂ storage.

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Technology Development

Engineered carbon capture involves isolating CO₂ from other gases at emission points (e.g. in power plants or industrial processes such as brewing as well as production of biomethane). Once captured, the CO₂ can be compressed and re-used in industrial processes or transported to sites of permanent storage in biological sinks.  

Sequestered carbon needs to remain stored for centuries, to achieve lasting climate benefits, and restore balance to the natural carbon cycle, which is being overwhelmed by emissions from fossil fuels that had been stored safely away for millennia. 

According to the Intergovernmental Panel on Climate Change (IPCC) carbon capture, utilisation and storage is critical for the journey to net-zero and it is suggested that circa 1 Gt CO₂/y of CCS will be needed by 2030, increasing to over 6 Gt CO₂/y by 2050.

The range of systems being developed for carbon removal include direct air capture and carbon storage (DACCS) carbon capture and storage (CCS) and carbon dioxide removal (CDR).  

DACCS removes CO₂ from the atmosphere using chemical processes (adsorbents or solvents) to bind the carbon. Such systems are expensive, requiring significant energy input.

CCS can trap fossil CO₂ produced by industrial emitters, known as point-source emissions. However, the cost of capturing post combustion carbon can be up to 5 times higher than the cost of membrane separation and cryogenic liquefaction on AD sites. 

CDR (also known as negative emissions) involves capture of atmospheric or biogenic CO₂ for storage and elimination.  

While growing plants provide natural means for carbon removal, systems that rely on land management, such as re-forestation may not be permanent, if wood is later felled, or trees die. Also, there are limitations on re-forestation in a world where productive land is required for food and other crops.  

Given the cost concerns and feasibility of DAC and CCS from point source emissions and land use challenges associated with natural CDR, there is a need for cost-effective solutions that offer additional carbon removal capacity.  

The construction industry represents just one such opportunity.  

Carbonisation Technology Options

With concerns about subsequent emissions from long-term storage and unease over the inflationary impact of more sophisticated technologies, there is a need for cost-effective carbon removal solutions that are commercially and technically scalable.

Hence, effort is being put into capturing carbon in existing waste streams and products, such as building materials and aggregates. 

In 2023, the global cement industry emitted 2.4 billion metric tons of carbon dioxide equivalent (GtCO₂e), or 6% of total global emissions. If it were a country, construction would be the world’s fourth-biggest emitter of greenhouse gases.  

The industry must find a way to cut its hard-to-abate emissions while satisfying the world’s increasingly complex urbanisation and construction needs. 

Mineralisation with biogenic CO₂ can revolutionise the construction industry. This process converts CO₂ into stable materials such as carbonates and offers a means of permanent storage.  

CO₂ in the air naturally reacts with the minerals in concrete and rocks, a process known as natural carbonation. By optimising this natural process under pressure, pure CO₂ (99% versus 0.04% as found in the air) is bonded to recycled construction materials broken down to fine aggregates. .   

This method uses existing existing material streams to capture and permanently store CO₂ – both permanently and locally.  

Not only is the CO₂ trapped in the recycled aggregate, but the material properties of the aggregate are not impacted. It can be used in road construction or for fresh recycled concrete. Also, if using carbonated recycled aggregate in the production of concrete, the embodied CO₂ makes it stronger and more durable.  

Recycled construction materials offer a further means of combining mineralised CO₂ into industrial byproducts. Materials such as steel slag, cement kiln dust or bottom ash from power plants are also suited to CO₂ mineralisation.  

Companies like Canary Wharf Group are increasingly using recycled concrete and other sustainable construction practices for new construction projects. ConcreteZero is an industry forum that aims to reduce emissions by using recycled materials.  

They have been working with companies like global building materials supplier Holcim to develop concrete with 20% recycled aggregates. Other aggregate companies, such as Day Aggregates, are increasingly focused on recycled and manufactured aggregates as well as capture of CO₂ in building materials.  

There is scope for long-term carbon capture in materials used across the construction sector, including recycled concrete. Locking biogenic CO₂ in a stable mineral form provides a safe and permanent solution and AD sites can partner with the construction sector to deploy these technologies.   

Long Term Carbon Removal

By working with carbon removal solution providers to supply biogenic CO₂, biogas sites can diversify their revenue streams and enhance the environmental impact of their operations.  

For technologies that embed carbon into construction materials, the biogas sector can become a key supplier. 

Swiss company Neustark, a technology leader in capturing CO₂ in recycled concrete and aggregates, is keen to source biogenic CO₂ from UK biogas production sites. 

These processes can achieve the same level of carbon storage in one hour as 50 trees would over a year, offering a scalable and efficient supplement to natural CO₂ storage.  

Neustark benefits from the carbon credits earnt from carbon removals, while recyclers can secure a premium on ‘greener’ construction products. 

With links between the AD sector and the carbon removal market getting stronger, there are interesting challengers to more established suppliers of fossil CO₂, including UK company Blended Products, that are focused on the biogenic market including supply to the construction sector. Hence, the market is getting more competitive. 

Evolving Marketplace

Companies like Blended, AD Fuels and Neustark are looking to work with the growing number of UK AD sites capturing CO₂. With the construction sector under pressure to curb its environmental footprint, there will be a significant opportunity for biogas sites. 

Neustark’s recent entry into the UK market offers a scalable solution to integrate CO₂ removal into the construction supply chain. The technology requires a continuous supply of liquefied biogenic CO₂.  

Neustark is aiming to secure 4,000 tonnes of CO₂ annually starting in 2025, for projects in the Southeast and Midlands. Ideally, the transport distance between capture and storage site should be less than 50 miles but hopefully much closer. 

The CO₂ supplied from biogas plants upgrading to biomethane is transported to nearby aggregate recycling facilities where it is injected into demolition concrete aggregates in a fully automated process. 

Neustark is building a network of CO₂ suppliers linked to carbon sink partners in the construction sector, with a number of UK projects that require biogenic CO₂ underway.

Building the Biogenic Carbon Market

A range of novel carbon capture solutions is emerging and there is a need to encourage more investment in cost-effective alternatives. This may necessitate support from government to encourage point-source capture from industrial processes, before carbon enters the atmosphere.  

Engineered carbon capture technologies offer commercially viable and scalable means of achieving permanent carbon storage. While the construction and agri-food supply chains need to reduce emissions, biogas plants injecting biomethane into the grid should aim to generate further value from captured CO₂.  

To achieve increased CO₂ use in the construction sector, plus recycling opportunities within the agri-food supply chain, more investment is needed in deployment of cost-effective carbon capture solutions. Perhaps, in future, biogas plants could be built using concrete and aggregates that are storing the CO₂ that has been created in the biogas sector?