Design and study of a novel ammonia‐based CO₂ capture process with bipolar membrane electrodialysis

Abstract

Aqueous ammonia is a promising absorbent in the field of post combustion CO₂ capture. However, the high volatilization of NH₃ results in a high energy requirement, as well as solid precipitation during the CO₂ regeneration process. A novel process was designed to reduce energy consumption and solve the problem. The bipolar membrane electrodialysis (EDBM) unit and CO₂ regeneration reactor were taken as the regeneration part. In the novel process, the bubble in the EDBM unit would be eliminated, and the regeneration of CO₂ and aqueous ammonia would be operated separately, which significantly reduced energy consumption and avoided the risk of precipitation during regeneration. According to the simulation and calculation results, the CO₂ regeneration energy consumption of the novel process using H₂SO₄ for CO₂ regeneration is 39.0% lower than that of the conventional ammonia‐based process, which shows good energy saving potential. Moreover, the novel process will be more competitive as membrane technology develops.