Technoeconomic evaluation of combined rich and lean vapour compression configuration for CO₂ capture from a cement plant

A combined rich and lean vapour compression configuration was investigated for CO₂ capture from a cement plant. This was to assess its performance in energy consumption, actual CO₂ emission reduction, and cost reduction potentials compared with the conventional process and the simple rich vapour compression and lean vapour compression configurations. Two electricity supply scenarios were considered: from natural gas combined cycle power plant and a renewable source like hydropower. The three vapour compression configurations outperformed the standard CO₂ absorption configuration in energy requirement, actual CO₂ emissions reduction and in CO₂ avoided cost reduction. The best performance was achieved by the combined rich and lean vapour compression configuration. The reboiler heat, equivalent heat and CO₂ avoided cost reduction performance was 24 – 30 %, 16 -18 % and 13 – 16 % respectively. However, the performances in energy, CO₂ emissions reduction and CO₂ avoided cost are only marginally better than the lean vapour compression configuration. The use of renewable electricity, like hydropower electricity will help CO₂ capture processes to achieve higher CO₂ emission reduction and lower CO₂ avoided cost compared to fossil fuel based electricity.