Analysis of integrated calcium looping alternatives in a cement plant

Abstract

Calcium looping is a promising post-combustion CO₂ capturing technology, highly compatible with the cement industry, one of the major industrial sources of CO₂ emissions. Limestone, a raw material for clinker, forms lime, a calcium looping adsorbent. Thus, it is possible to maximize the synergies between a cement plant and a calcium looping unit by establishing an integrated configuration. Nevertheless, the integration of calcium looping in cement plants has not yet been thoroughly studied. This study examines different integration alternatives, developing models for the preheater and calciner using Aspen Plus, validated with operational data, alongside an entrained-flow carbonator model considering adsorbent deactivation. By combining these models, six integrated configurations are proposed and compared with the tail–end calcium looping configuration. The integrated configurations show a reduction in fuel consumption and net energy consumption for the same CO₂ avoided emissions. The most promising configuration was identified and a comparative techno-economic analysis was conducted.