Cement Industry

Cementing a Lower-carbon Future

Cement is everywhere - in our buildings, roads, bridges and dams - yet its production is responsible for around 7% of global carbon dioxide (CO₂) emissions. Many cement producers are keen to decarbonize their operations.

There are two main sources of carbon emissions in cement production. The first is calcination, where the feedstock limestone decomposes into calcium oxide (CaO) and CO₂ (to form clinker) in a cement kiln at temperatures of around 1,450°C (2,642°F). This reaction is essential to produce clinker, making this a hard-to-abate process. This shifts the decarbonization focus to capture rather than avoidance. The second source of carbon emissions is related to the combustion of fossil fuels to generate the high temperatures needed in the kiln. These emissions can be reduced by using green hydrogen as the combustion fuel. And there are other ways to mitigate combustion-related emissions.

Post-combustion capture (PCC), for instance, is an effective way to reduce the CO₂ emitted by the cement kiln during the production of clinker. In other words, the CO₂ is captured after the combustion process. The flue gas is treated to separate and purify the CO₂ stream. This can be achieved by means of advanced technologies such as carbon absorption using amine solutions. Alternatively, adsorptive technologies can be combined with cryogenic technologies to shrink carbon footprints further at lower cost. The effectiveness of PCC methods can be enhanced by using oxygen-enriched air or pure oxygen instead of air for the combustion process. This oxyfuel process results in a higher flame temperature and more efficient fuel burning.

Additionally, the reduction in nitrogen content increases the concentration of CO₂ in the flue gases, making it easier to capture and purify.

Extending along the wider CO₂ value chain, the captured and treated gas can then be used as a feedstock for other industrial processes or stored in special reservoirs. This captured gas can also be a welcome new source of CO₂ to help secure supplies for the merchant market.

HISOLV^TM Solvent-based Carbon Capture Solution

This post-combustion capture (PCC) approach is a mature, field-proven technology to capture CO₂ from flue gas streams. The gas is removed from the flue gas through chemical scrubbing with an aqueous amine-based solvent. This advanced amine wash technology allows for CO₂ capture rates in excess of 95% with CO₂ purities of 99.9 vol% (dry). An all-in-one offering combines our strength and proven track record in the design and delivery of turnkey industrial plants with the high-performance gas treatment technologies delivered by our license partners. This gives you an optimal interplay spanning solvent, process design, equipment and plant integration. Amine wash solutions can be implemented downstream of existing assets without interfering with upstream processes. For new assets, we develop sophisticated plant integration concepts offering optimized total costs of ownership. HISOLV is a popular choice for flue gas streams with low CO₂ concentrations and in regions where fossil-fired energy is relatively affordable.

HITREAT^TM CO₂ Treatment Solutions

The CO₂ off-gas from cement kilns captured by our HISOLV^TM advanced amine wash technology may require post-processing to make it suitable for downstream use. Our HITREAT CO₂ processing units (CPUs) are the ideal way to achieve this.

HITREAT spans all steps in the processing chain - from compression and purification to dehydration and even liquefaction - making it ideal for onward transport by road, rail or ship. Our HITREAT offering is like a toolbox. In other words, we combine the steps you need to meet your CO₂ specifications. This could include the removal of trace components such as sulfur- or nitrogen-containing compounds, water, hydrocarbons, heavy metals and air gases. This toolbox approach includes all delivery options - you get CO₂ in the purity and phase you need, whether that be gaseous, supercritical or liquefied.