The core technology - Direct Separation

The LEILAC project is based on a technology called Direct Separation, which aims to enable the efficient capture of the unavoidable process emissions from lime and cement production.


Calix’s technology re-engineers the existing process flows of a traditional calciner, indirectly heating the limestone via a special steel vessel. This unique system enables pure CO2 to be captured as it is released from the limestone, as the furnace exhaust gases are kept separate. It is also a solution which requires no additional chemicals or processes, and requires minimal changes to the conventional processes for cement as it simply replaces the calciner.

As two-thirds of CO2 emission from cement production is generated from the limestone itself, this technology offers a unique opportunity as it can capture these emissions without significant energy or capital penalty. The energy losses associated with Direct Separation technology are primarily heat losses in the equipment, and CO2 compression (for transport and storage). 

It also enables the use of carbon capture techniques, which have been already developed by the power sector to be applied to the heating emissions.


This innovation requires minimal changes to the conventional processes for cement, replacing the calciner in the Preheater-Calciner Tower. For lime there is no product contamination from the combustion gas. The technology has the potential to be used with alternative fuels and other capture technologies to reach the targeted 80% emission reduction in 2050. 

The Direct Separation Reactor

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This project has received € 12m of funding from Horizon 2020 program for research and innovation of the European Union under the grant agreement No 654465.