Cement Energy Environment

56 I nn o vative Technogies (Excluding CCUS) While at a considerably earlier stage of development than CCUS, electrification of cement production could also help reduce emissions by using low-emissions electricity and by facilitating the capture of process CO 2 emissions (i.e. emissions from limestone decomposition during clinker production). In Sweden, cement producer Cementa (a subsidiary of Heidelberg Cement) and energy producer Vattenfall are working together on the CemZero project to electrify cement production. The feasibility study, completed in early 2019, showed that electrified cement production is technically possible and likely cost-competitive with other options to substantially reduce emissions. The next step will be an in depth study on how to construct a pilot plant and is still under roll out. Another great potential to reduce CO 2 comes from the usage of Alternate Raw Materials., In this context an example of greenfield plant at Novotroizk Russia can be discussed where a Clinkerisation plant was conceptualised with usage of 30% of blast furnace Alternative binding materials could also be key to reduce cement production emissions, particularly process emissions. They rely on raw materials or mixes different from those of ordinary Portland cement clinker and are currently at various stages of development. Several alternative binding materials are already commercially available, although their use so far has been relatively limited to niche applications. Recent innovation on an alternative binding material developed by Solidia Technologies with potential for very low emissions – carbonation of calcium silicates – led to the announcement of a first commercial venture in 2019. However, application is limited to precast products. steel slag as main raw material, natural gas as fuel and lower power consumption in grinding of raw material was ensured by usage of Roller Press as grinding machine, Total Clinkerisation plant was supplied by KHD Humboldt Wedag Germany where major thrust was to save heat & power energy and subsequently CO 2 emission in Clinkerisation process, Usage of 30% slag in raw material replaced a large portion of CaCO 3 Hence a great reduction by 30-33% CO 2 emission in cement manufacturing (Figure 2) (Reduction in CO 2 by 170g/kg cl out of 530 g/kg clinker CO 2 emission contributed from raw materials when carbonates of Calcium and magnesium used as raw material). At the same plant due to lower specific heat consumption (596 kcal/kg cl) the CO 2 contribution from fuel (Natural gas) also reduced by 30 g/kg cl. When total reduction in CO 2 emission is added as above it comes as 0.2 kg CO 2 / kg cl or 0.2 mt CO 2 /mt clinker which accounts to total savings in CO 2 emission as 400000 t/ annum for 2x3000 tpd clinker unit. Continued innovation could further develop and advance opportunities to deploy various alternative binding materials. Calcined Clay based Cements , LC3 are examples of such cements where clinker is replaced by Calcined clay and limestone up to 50% which not only reduces CO 2 emission but also it is at par with cement strength and quality. The typical composition of LCS cement remains Clinker 50%,Calcined clay 30%,Limestone 15%, Gypsum 5%.