Never mind Net Zero, lime producers aim for Net Negative

Net Negative for lime

The Minerals Products Association's group of lime companies, together known as MPA Lime, are aiming to be Net Negative by 2040.

The Mineral Products Association's lime producers have launch an ambitious plan to deliver ‘Net Negative’ carbon emissions by 2040.

Spearheaded by the industry’s trade body, MPA Lime, the Net Negative 2040 Roadmap explains how the sector can go beyond Net Zero a decade ahead of the UK government's 2050 target by deploying technologies such as fuel switching and carbon capture, as well as employing lime’s natural carbon-absorbing properties.

The sector’s two main products – high-calcium quicklime and dolomitic lime (dolime) – are versatile and vital to numerous everyday essentials from the manufacture of metals, glass, plastics and building materials to the purification of drinking water, treatment of sewage, control of air pollution, animal welfare and production of many food staples including eggs, sugar, and dairy products. Lime mortars and putties are also produced.

Used around the world for millennia, lime is made by heating quarried limestone or chalk to above 900°C to trigger a chemical reaction known as calcination. Around two-thirds of the industry’s carbon dioxide emissions arise from calcination, with most of the remainder resulting from fuel combustion.

Since 2005, action and investment by British lime producers has already resulted in a reduction in absolute carbon emissions of around 25%. Now the industry’s Net Negative roadmap identifies further technologies and infrastructure to enable it to fully decarbonise, as well as outlining the enabling actions required by government and other industries in the supply chain.

In addition, research by the European Lime Association confirms that around one-third of the carbon dioxide from lime production is naturally re-absorbed from the atmosphere back into lime products – a process known as carbonation – although this has yet to be recognised in carbon accounting methodologies.

Combining the industry proposed developments with the enabling action by government and the natural effects of carbonation, means the production of British lime could become Net Negative by 2040 and make a positive and ongoing contribution to addressing climate change.

Richard Stansfield, chair of the MPA Lime management committee, says: "The British lime and dolime industry has already achieved remarkable progress in both business commitment and tangible actions to decarbonise and play its part in tackling climate change.

"The publication of our Net Negative 2040 Roadmap is a milestone on the journey and serves to communicate, as well as incentivise, the changes that are essential for the future. The pace of change must accelerate, and we are jointly committed to ensuring that it does. Importantly, we can’t achieve this alone. Reaching and exceeding net zero will also require some key enabling action by government and others."

Net Negative Road Map

MPA Lime Net Negative 2040 Roadmap: This ‘waterfall’ chart shows the contribution of each of the decarbonisation levers from historic baseline emissions in 2005 to a reference point in 2018, with each of the levers expressed as a percentage reduction of the 2018 reference. Some of the levers are happening now and are not yet accounted for (eg carbonation), some are relevant to early action (indirect emissions) and others cannot be deployed to their full potential right now due to the need for enabling action (fuel switching and CCUS). This is just one of the possible scenarios to deliver Net Zero production and a Net Negative outcome.

The MPA Lime Net Negative 2040 Roadmap shows how lime production could be decarbonised by 2040 through the deployment of five key levers:

  1. Product carbonation – whereby exposure of lime products to the atmosphere can permanently absorb a third of the calcination-related carbon emissions
  2. Fuel switching – away from fossil fuels to low- or zero-carbon alternatives like hydrogen or waste biomass could achieve a 22% carbon reduction for quicklime and 37% for dolime
  3. Carbon capture, utilisation and storage (CCUS) – a fundamental requirement that will account for more than half of emissions from lime production
  4. Reduction of the indirect emissions from electricity use
  5. Reduction of emissions from transport of materials.

Mike Haynes, director of MPA Lime, says: "Each lever will contribute to decarbonisation – many initiatives are happening already or will come on stream this decade – and in combination they will deliver a dramatic carbon reduction to reach Zero by 2040.

"In addition, the combination of using biomass fuels with carbon capture and lime product carbonation will result in the removal of 250,000 tonnes of atmospheric carbon dioxide every year, making the sector net negative overall. Other levers, especially indirect emissions and transportation, require broader collaboration and enabling action by government and other industries."

Ruth Herbert, chief executive of The Carbon Capture & Storage Association, says: "It’s fantastic to see such a vital industry as lime setting out its own net-zero roadmap. The roadmap is clear that there is no option to decarbonise the lime industry without the installation of carbon capture, utilisation and storage (CCUS).

"It’s clear that demand for CCUS from UK industries is very high – with this roadmap alone planning for all five sites to access CCUS clusters by 2038. This reinforces our message to the Government that they need to urgently set out a national deployment plan for CCUS, indicating how and when sites like these can have access to CO2 infrastructure."

Examples of enabling action by government and other industries in the supply chain could include:

  • Carbon accounting to ensure that net zero is not met by simply closing British manufacturing sites and importing goods instead
  • Regulation that provides long-term visibility on decarbonisation policies and delivers cost-competitive clean electricity
  • Infrastructure that supplies green hydrogen to lime production sites and can transport captured carbon dioxide to storage or use
  • Financial support that attracts investment to UK sites for the deployment of decarbonisation technologies
  • Maintaining competitiveness to ensure British lime producers can continue to supply the UK and compete in international markets.

Mike Haynes: "Getting this enabling action right will allow the British lime industry to provide the whole of the UK, and beyond, with net-zero products that are essential to our everyday lives while removing more carbon dioxide from the atmosphere than it emits. The British lime industry is committed to addressing the challenges of climate change and we now have a credible roadmap to get us there."