Leilac Low-Emission Cement and Lime Technology

Calix Limited is an Australian environmental technology company founded in 2005 and headquartered in Pymble, New South Wales, with businesses in cement and lime decarbonisation, sustainable mineral processing and magnesia. Its subsidiary Leilac Limited is the exclusive licensee of the Low Emissions Intensity Lime and Cement technology and works with cement and lime producers to cut process emissions, which make up about two-thirds of the industry's CO2.

Leilac heats limestone indirectly inside a modular array of steel tubes, so the CO2 released from the raw material is kept separate from furnace gases and leaves as a high-purity stream above 95%, ready for capture without extra chemicals. The heat source can be electricity, biomass, hydrogen or other alternative fuels. Modules retrofit into existing plants and scale to full plant capacity. Leilac-1 operated in Belgium and Leilac-2 is a retrofit with Heidelberg Materials in Germany targeting about 100,000 tonnes of CO2 a year.

• Indirect calcination: limestone is heated through steel tube walls, keeping process CO2 apart from combustion gases.
• High-purity CO2: the captured stream exceeds 95% purity without added chemicals or processes.
• Fuel and electricity flexibility: runs on electricity, biomass, hydrogen and waste-derived fuels.
• Modular retrofit: modules multiply up to full plant capacity in existing cement or lime plants.
• Reference projects: Leilac-1 in Belgium and Leilac-2 with Heidelberg Materials in Germany.
• Licensing partnership: technology deployed with cement and lime producers in Europe, the Americas and Asia Pacific.

Vietnamese integrated cement plants exporting clinker can retrofit calciner modules to capture process CO2 and reduce exposure to carbon border costs. Lime producers serving steel and chemical industries can produce lower-carbon lime with captured CO2 for utilisation. Cement groups can pair captured CO2 with mineralisation or storage projects to earn carbon credits.

Process CO2 is separated directly as a stream above 95% purity, avoiding costly separation from flue gases. Specific energy use is roughly the same as a conventional calciner, so the energy penalty is minimal. Fuel flexibility lets plants switch to electricity, biomass or hydrogen and use low-cost power for grid balancing. Modular retrofit limits disruption to existing kilns.

Cement and lime account for about 8% of global CO2 emissions, and process emissions from limestone cannot be removed by fuel switching alone. Large Asian producers have begun commercial projects with indirect calcination, and Vietnam, one of the largest cement producers and exporters in the region, faces carbon border adjustments in export markets and a new domestic carbon exchange.

Calix was founded in 2005 and is headquartered in Pymble, NSW, Australia; it holds about 93% of Leilac after Carbon Direct Capital Management bought a 6.98% stake for EUR 15 million in 2021. Heidelberg Materials signed the first global licence in 2022. Partners include CEMEX, Lhoist, ENGIE, Port of Rotterdam and Heirloom.