» Roadmap Decarbonisation » Scope 1 - Fuels and Process-CO₂ » Project 8 - CCS - Carbon Storage

Project

CCS - Storage of CO₂ (CCS)

  • Start

    prospectively from 2030 onwards

  • possible CO₂ savings

    captured CO2 quantities

Storage of CO₂ (CCS)

For permanent storage, the captured CO₂ must be transported to suitable storage sites and injected there for long-term containment.

CO₂ transport

The transported CO₂ must have a high purity level of over 99% to ensure that 
impurities do not damage the transport infrastructure or impair the efficiency of storage processes.
For transport, the CO₂ must be cooled, liquefied, and compressed, which requires additional equipment and energy.

Pipeline transport of CO₂ is the preferred method, especially for large quantities over long distances. Once the infrastructure is in place, pipelines offer a 
cost-efficient and long-term stable solution, particularly when there is a 
continuous and high CO₂ output. However, constructing new CO₂ pipelines 
requires significant investment, since — unlike hydrogen (H₂) — existing pipelines cannot be repurposed.

For smaller quantities, CO₂ can be transported by truck or rail. Truck transport is still in the testing phase but offers a flexible option. However, the costs per tonne of transported CO₂ is two to three times higher than for pipelines, making this method economically viable only for limited applications.
In regions with existing rail or inland shipping infrastructure but no pipelines, trains or ships could represent a practical alternative.

Storage options

The captured CO₂ can be stored in deep geological formations to prevent it from entering the atmosphere. Common storage options include:

  • Salt domes or deep saline aquifers: Here, CO₂ is pumped into porous rock layers deep underground that are filled with salt water. These formations are typically located more than 800 metres below the Earth's surface.
  • Depleted oil and gas fields: These reservoirs have already held large amounts of oil or gas, making them safe places for long-term CO₂ storage.
  • Mineral storage: In this case, CO₂ reacts with certain minerals in the rock to form stable, solid carbonates. This takes place over long periods of time, but can contribute to permanent storage. More effective and faster implementation of this process is being investigated in research projects. 

From Vision to Reality - Our Milestones

We have begun implementing initial projects on our path to climate neutrality. 
Initial successes are measurable and concrete further steps are planned. 
However, future approaches must also be further developed and specified. 
We are working intensively on this, together with associations, research institutions, partner companies and service providers.

Glossary

FAQ

  • The use of lime is at the beginning of a large number of industrial value chains in Germany and Europe.
  • Regional lime production with high quality standards secures our customers' supply chains and contributes to local value creation.  
  • Supplying our plants with raw materials from our own quarries and our regional proximity to our customers are also important factors in reducing emissions. This avoids long-distance truck transports and reduces CO2 emissions.
    Where possible, we deliver large quantities by rail.

  • In a few applications, lime can be replaced by other less CO2-intensive products, while in others, the amount of lime required can be reduced through process optimisation. Customers are already working on these issues.
  • However, many customers cannot do without lime. That is why we are working to gradually reduce CO2 emissions.

  • The production of quicklime is an energy-intensive process in which, in addition to emissions from the fuels required for this purpose, CO2 is also released from the conversion of natural limestone into quicklime. These process emissions are chemically induced and cannot be reduced at this stage.
  • The production of one tonne of lime emits around one tonne of CO2. Around 30% of this comes from the combustion of fuels and around 70% is released during the conversion of limestone (CaCO3) to quicklime (CaO).  

  • The process CO₂ arised during lime production must be captured and transported for reuse or storage, which requires pipelines and storage facilities. The necessary legal framework must also be created for this purpose.
  • Decarbonisation increases the demand for renewable energy, especially green electricity, but also biomass. A competitive and secure supply of green electricity is crucial for the transformation.
  • In the long term, green hydrogen could be a solution for emissions from fossil fuels. This requires, on the one hand, that sufficient green hydrogen is available at economic conditions and, on the other hand, that a transport infrastructure is established by means of pipelines.
  • The necessary technical renewal requires high investments in new technologies and leads to higher operating costs for companies. These additional costs exceed the savings achieved through reduced emissions, which is why support programmes for investment and research are necessary to maintain the competitiveness of the industry.

This roadmap contains both, concrete projects that can be implemented in the near future and projects that are further in the future for which no concrete plans are yet available. Particularly for future projects, the calculations presented are based in part on initial 
estimates and still contain considerable uncertainties. Assumptions regarding energy and CO₂ costs were made on the basis of current values, which may change significantly in future. Possible projects to promote investment or financing have also not yet been taken into account.

This roadmap therefore initially represents a rough concept that serves as a guideline for the ongoing decarbonisation process. We will regularly review the assumptions and adapt them to new findings. We will further develop and, if necessary, adapt technically feasible projects.

However, the roadmap shows in its initial approach that the decarbonisation of our processes is fundamentally possible. 
A key prerequisite for this will be the provision of sufficient green electricity and the creation of the necessary infrastructure for CO₂ transport and storage – factors over which we have no direct influence.

The energy requirements of each household vary depending on the size of the household, the type of heating and the 
electrical appliances.
However, an average value helps to classify other energy requirements, e.g. in the lime industry.

Energy is used in a household for electricity, heating and hot water.
In a single-family home (approx. 150 m², gas heating, 4 people), this amounts to approx. 30,000-40,000 kWh per year.
In the comparative examples in our roadmap, we have calculated 30,000 kWh per year.