Production of crystalline sodium bicarbonate using CO2 recovered from another alkali production process

Abstract

A process for the joint production of crystalline sodium bicarbonate and another alkali compound, in which the step for producing such alkali compound generates CO2 as a byproduct, at least a portion of which is used as a feed to the sodium bicarbonate production step. The produced alkali compound is preferably crystalline sodium sulfite. The joint production process preferably employs as feedstock one or more sodium carbonate liquors derived from trona ore. A gas feed which contains CO2 byproduct is subjected to a gas treatment which may include water removal and/or compression before it is used to produce sodium bicarbonate crystals from a sodium carbonate liquor. Such gas feed may comprise a reactor offgas exiting a sulfite reactor; a vent gas exiting a feed or surge tank; a decarbonation gas exiting a decarbonation unit; a vent gas vented from a crystallizer heater; or combinations of two or more thereof.

Dependencies are inferred from the claim text.