| abstract |
Process for producing sodium carbonate by an ammonia-soda process or for producing refined sodium bicarbonate, wherein: a low CO 2 content process gas generated by an ammonia-soda process unit or generated by a refined sodium bicarbonate unit is enriched into a CO 2 enriched gas by using a Temperature Swing Adsorption CO 2 concentration module, said CO 2 -enriched gas has a CO 2 content increased by: at least +10% by volume on dry gas basis relative to the CO 2 concentration of the low content process gas, and the CO 2 -enriched gas is subsequently recycled to the ammonia-soda process unit or optionally to the refined sodium bicarbonate unit, in order: to produce sodium carbonate, or sodium bicarbonate, or to carbonate at least part of effluent from the unit for producing sodium carbonate or bicarbonate, and wherein the TSA CO 2 concentration module comprises a stator and a rotor connected to the stator and is rotatable relatively to the stator about a rotational axis (A), the rotor comprising a plurality of sectors, each sector containing a separation device (SD) arranged to separate at least part of the CO 2 from the process gas (PG) which is led into the separation device (SD), and wherein each sector is fluidically connected with at least one rotary active valve. |