Study of Energy Use and CO 2 Emissions in the Manufacturing of Clinker and Cement

Cement is one of the most widely used materials in construction. This study presents a process-wise evaluation of energy use and CO 2 emissions for clinker, Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC) using the principles of life-cycle assessment. Two cement plants located in India are considered as typical case studies. The gate-to-gate system boundary condition is considered. The energy use for clinker is found to be 3990 and 3626 MJ/ton for case studies 1 and 2, respectively. The associated CO 2 emissions for clinker are 849 and 868 kg CO 2 /ton. The energy use for OPC is 4015 and 3821 MJ/ton for case studies 1 and 2, respectively. The related CO 2 emissions are 802 and 855 kg CO 2 /ton. The energy use for PPC is 3077 and 2733 MJ/ton for case studies 1 and 2, respectively. The associated CO 2 emissions are 606 and 595 kg CO 2 /ton. It is observed that the energy use and CO 2 emission of PPC are at least 20% less compared to OPC. The results are compared with five geographical regions across the world.