Low-CO2 emission strategies to achieve net zero target in cement sector.

Cement industry is one of the largest contributors to greenhouse gas emissions accounting for about 7% of global CO 2 emission. As global cement demand continues to rise exponentially, the industry is taking numerous effective steps to meet net-zero emission targets by limiting global warming to 1.5 °C by the end of the century and improve the ecological system. Worldwide, about 2.9 billion tons of CO 2 were emitted in 2021 from cement production and the industries are expected to achieve the net-zero target by 2050. The reduction of CO 2 emission remains a major challenge for the cement industry as the manufacturing processes and the current infrastructure allow little margin for the reduction in CO 2 emission, considering the age-old and conventional Portland cement chemistry. To achieve a net-zero emission target, several effective measures are being explored to mitigate CO 2 emissions from cement industries, viz., use of alternative fuels, reducing clinker-to-cement ratio, improving energy efficiency, carbon capture, utilization, and storage (CCUS) techniques etc. Apart from these, production of low-carbon cement different from Portland clinker chemistry has the potential to make a big difference in mitigating CO 2 emission. Carbonatable calcium silicate-based cement, is found to be a promising alternative to OPC and reduces about 70% of total CO 2 emission from cement production. This paper thoroughly reviews the different low-carbon emission approaches (both direct and indirect) such as reducing clinker factor, lowering the clinkerization temperature by using fluxes and mineralizers (such as CaF 2 , BaO, SnO 2 , P 2 O 5 , Na 2 O, NiO, ZnO etc), producing low temperature clinker, use of supplementary cementitious materials (SCMs) in concrete and capturing the emitted CO 2 through mineral carbonation, direct air capture (DAC) etc for future alternative low-carbon cements. Various commercialized technologies for reducing CO 2 emissions (CarbonCure, Solidia, Heidelberg, Novacem, Carbicrete and CO 2 -SUICOM) with their technology readiness levels (TRLs) are also discussed. [Display omitted] • Focus on reviewing major strategies to mitigate the carbon footprint of cement industry. • The CO 2 reduction potential of various low-carbon cements are discussed. • The status of various commercialized CO 2 utilization technologies are further discussed. [ABSTRACT FROM AUTHOR]