Assessment of Different Carbon Capture and Electrification Configurations for Low-Carbon Cement

Abstract

This study explores the potential for decarbonising the cement sector through calciner electrification combined with amine-based carbon capture for rotary kiln emissions. A techno-economic analysis, based on process simulation, was conducted for two alternative configurations, differing in the calciner technology – entrainment (Ent) vs. drop tube (DT) – and in the heat recovery strategy for the hot CO2 produced. The heat content of the CO2-rich stream can either be used to preheat the raw materials (RMP case) or transferred to a fraction of the vent air from the clinker cooler via a gas-gas heat exchanger (GGHX case). The two alternative configurations, labelled Ent-RMP and DT-GGHX, were benchmarked against a reference plant without mitigation measures and an oxyfuel cement plant.

Across different energy mix scenarios, DT-GGHX demonstrates better energy efficiency than Ent-RMP, although their environmental performances are similar. Under an EU-27 energy mix, the specific primary energy consumption for CO2 avoided (SPECCA) ranges between 5.14-5.72 MJLHV/kgCO2, with a CO2 avoidance rate of 70-72%, making these options less competitive compared to oxyfuel cement plants. However, when powered by renewable energy, both configurations showed significant performance improvements making them competitive with oxyfuel technology. Ent-RMP emerges as the most economically favourable configuration with a cost of avoided CO2 of 217.4 €/tCO2, while this is equal to 233.6 €/tCO2 for DT-GGHX.

Keywords: cement industry, decarbonisation, carbon capture, electrification, techno-economic analysis