US 2018/0169567 A1Published application

Process for producing sodium carbonate/bicarbonate

AssigneeSolvay SA

InventorsEric VANDERVORST, David Jean Lucien SAVARY, Gérard DUPONT, Hugo WALRAVENS, Eric Pierre DUBOIS, Jean-Paul COQUEREL, Perrine DAVOINE, Karine CAVALIER, Ines HURTADO DOMINGEZ, Salvador ASENSIO

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

Process wherein a low CO2 content process gas generated by an ammonia-soda process unit or a refined sodium bicarbonate unit is enriched by using a Temperature Swing Adsorption CO2 concentration module into a CO2 enriched gas whose CO2 content is increased by at least +10% by volume on dry gas basis relative to the process gas, and which 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. The TSA CO2 concentration module comprises a stator and a rotor connected to the stator and rotatable relatively to the stator about a rotational axis, the rotor comprising a plurality of sectors, each sector containing a separation device to separate at least part of the CO2 from the process gas which is led into the separation device, and each sector being fluidically connected with at least one rotary active valve.

A process for producing sodium carbonate by an ammonia-soda process and/or for producing refined sodium bicarbonate, wherein:

enriching a low CO2 content process gas generated by an ammonia-soda process unit and/or generated by a refined sodium bicarbonate unit,
into a CO2 enriched gas by using a Temperature Swing Adsorption (TSA) CO2 concentration module,
and wherein said CO2-enriched gas has a CO2 content increased by:
at least +10% by volume on dry gas basis relative to the CO2 concentration of the low CO2 content process gas, and
subsequently recycling the CO2-enriched gas to the ammonia-soda process unit and/or to the refined sodium bicarbonate unit, in order:
to produce at least one product selected from the following:
group consisting of sodium carbonate, ammoniacal sodium bicarbonate, and refined sodium bicarbonate,
or to carbonate at least part of effluent from the ammonia-soda process unit and/or generated by the refined sodium bicarbonate unit,
and wherein the TSA CO2 concentration module is a gas separation unit for separation of CO2 from the process gas, wherein:
the gas separation unit comprises a stator and
a rotor which is connected to the stator and is rotatable relatively to the stator about a rotational axis,
the rotor comprising a plurality of sectors,
each sector containing a separation device to separate at least part of the CO2 from the process gas which is led into the separation device,
wherein each sector is fluidically connected with at least one valve,
the valve is a rotary active valve, the rotary active valve comprising a stator open area which is located in a stator valve region of the stator,
the rotor comprises a rotor valve region having a
rotor solid area which is overlappable with the stator open area in order to close the valve, and a rotor open area which is overlappable with the stator open area in order to open the valve,
wherein an extent of overlapping of the stator open area, the rotor solid area and the rotor open area is changeable by a rotation of the rotor relative to the stator, and
at least part of the CO2 separated in the separation device is led out the separation device by heating to produce the CO2 enriched gas.

16 more elements

Abstract

Claims20