Water washing to minimise ammonia loss

“Scrubbing technologies are broadly used in the chemical industry to limit the emission of harmful compounds to the atmosphere [6]. Among them, water washing and further acid washing using aqueous sulphuric acid (H2SO4) solutions are implemented in the CAP for the post-treatment of the FG [3][14][15][16]. In order to minimize NH3 losses and fresh NH3 make-up, the washing water is regenerated and NH3 is recuperated by means of thermal energy using steam, which increases the energy consumption of the capture process. Water washing of the CO2-depleted FG and solvent recuperation by thermal regeneration are also implemented in mild-temperature NH3-based capture processes such as the Korea Institute of Energy Research (KIER) process and the Research Institute of Industrial Science and Technology (RIST) process [17]. However, the higher temperature of such processes leads to higher NH3 concentrations in the FG exiting the CO2 absorber, which requires thermal energy demands for NH3 recuperation comparable to the thermal energy needed for the regeneration of the solvent used for CO2 capture [18]. “

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