Mineral carbonation (MC) using recyclable ammonium salts pH swing processes is considered among the
most promising MC techniques to store CO2 permanently. However, the main key challenge to use this
process at large scale is related to the energy consumption associated to the regeneration of the
employed additives and in particular to the separation of the salt to be regenerated from the water
solution.
This work investigates the feasibility of a liquid-liquid extraction technique to replace the energy intensive
salts/water separation step. Also, the CO2-balance of a 500MW coal-fired based power plant with an
integrated pH swing MC facility was investigated. Different operating conditions were investigated,
including temperature, reaction time, pressure, solid to liquid ratio (S/L), reagents concentration and
stirring rate. An ammonium sulphate/water separation higher than 90% was achieved at 25 C, 10 min,
1 bar, 200 g/l S/L ratio, 70% methanol and, 350 rpm. The associated energy consumption was calculated,
resulting in an energy saving of 35% in comparison to water evaporation. The process resulted carbon
negative when water evaporation was replaced by extraction technique, with 33% of CO2 sequestered
by using a S/L ratios of 300 g/l.