CO₂ capture from waste-to-energy plants: Techno-economic assessment of novel integration concepts of calcium looping technology

In Waste-to-Energy (WtE) plants, municipal solid waste (MSW) is combusted while power and/or heat are produced. This approach will largely remain as a promising option to handle the MSW capacities in the future. Due to the organic waste fractions present in MSW, net negative CO₂ emissions are feasible when integrating carbon capture and storage (CCS) processes into WtE plants. The calcium looping (CaL) process represents one option to capture CO₂ from WtE plant exhaust gases. Hereby, CO₂ is separated by a circulating limestone-based sorbent being exposed to cyclic carbonation-calcination reaction regimes. Within this study, a techno-economic analysis of a CaL retrofit on a generic 60 MWth WtE plant is conducted. The analysis considerers three different types of supplementary fuel for the CaL process, namely coal, natural gas (NG) and solid recovered fuel (SRF). Based on a detailed process model, economic key performance indicators were calculated by means of a bottom-up approach. Additionally, different heat integration concepts were proposed and assessed. The techno-economic results are discussed in comparison to a benchmark MEA scrubbing process. It was found that levelized cost of electricity increases quite significantly, which leads to cost of CO₂ avoidance in the range of 119 EUR/tCO2,av (CaL-SRF) up to 288 EUR/tCO2,av (MEA). It is important to note, that the supply of negative CO₂ emissions from a CCS equipped WtE plant enables a cost-efficient solution to at the same time treat MSW in a carbon neutral way while clean heat and/or power as well as negative CO₂ emissions are delivered. © 2020 Elsevier B.V.