Using LCA/TEA to Characterize Technological Transitions in Integrated Models: The Case of Cement

Cement manufacturing is responsible for 8% of global anthropogenic CO2 emissions and the industry lacks clear paths toward decarbonization. A number of emergent technologies could cut the emissions from feedstock calcination or process heat but the role of these various approaches on global scale decarbonization efforts remain unclear. Here, life-cycle analysis was paired with a technoeconomic analysis to characterize the performance of a range of emergent cement technologies, and these were then input into the Global Change Analysis Model, a US-based IPCC-class integrated model. The six technologies modeled here are: a high efficiency kiln system (HEKS); fuel switching (FS); the use of supplemental cementitious materials (SCMs); alternative cements limestone calcined clay cement (LC3) and carbonateable calcium silicate cements (CCSC); and the adoption of carbon capture and storage (CCS) on the cement plant. LCA/TEA results suggest that CCS offers emissions reductions of 572 kg CO2 but at substantial costs increases to the industry of $46.02 per t-cement. In contrast, alternative formulations like LC3 cut emissions by a more modest 250 kg CO2 per t-cement but are already cost-competitive with conventional cements. Incorporating all these findings into GCAM enables a projection of cement industry composition over the coming years. With alternative cements LC3 and CCSC available, there is near term reduction of emissions, but the emission plateau and the industry remains a major source of emissions, responsible for 200-300 MtCO2/year by end of century. CCS is not nearly as important of an enabling technology as existing integrated modeling runs would suggest but these results are very sensitive to price. These results suggest that the cement industry needs significant innovation over the coming decades, or it needs the prices of CCS to drop considerably in order for the industry to meet decarbonization goals.