Integrated Brine Salinity Reduction, CO2 Capture, and Valuable Product Recovery via Modified Solvay Process: An Overview

The experimental findings unequivocally demonstrate the superiority of the modified Solvay process concerning its CO
2
capture efficiency, sodium removal capabilities, and energy efficiency. Notably, while the modified Solvay process outperforms the conventional Solvay process in sodium removal, it is imperative to acknowledge that further enhancements are necessary through process optimization and the implementation of multistage treatment strategies. Despite the fact that both the Solvay and modified Solvay processes involve the substitution of some sodium chloride with calcium chloride, the one-stage modified Solvay process achieved an overall salinity reduction of 19%. Nevertheless, it is essential to recognize that the treated brine remains unsuitable for agricultural and industrial applications until additional treatment measures are employed. This highlights the pressing need for innovative technologies to address these limitations and make the treated brine more versatile. This work aims to give an assessing overview of a novel CO
2
capturing and brine desalination technology, founded on a modified Solvay process, with the primary goal of reducing brine salinity, capturing CO
2
, and recovering commercially valuable products such as magnesium hydroxide, sodium bicarbonate, calcium sulfate, and calcium chloride. The findings illustrate the efficacy of the novel desalination technology in achieving a recovery rate of approximately 51 % for
$\text{Na}^{+}$
, 93.59% for
$\text{Ca}^{2+}$
, 79% for
$\mathrm{K}^{+}$
, and 43.63% for
$\mathrm{C}1^{-}$
. Furthermore, the process successfully captured up to 60 grams of CO
2
per 1000 milliliters of treated brine. These results establish the newly introduced method as a promising technique. The Solvay process and its modified variants confront significant challenges in lowering brine salinity for potential applications in agriculture and industry due to competing reactions and CO
2
gas-brine mixing limitations. Additionally, the high solubility of sodium bicarbonate poses a challenge, leading to reduced overall desalination efficiency. This research endeavors to address these challenges and enhance the practical viability of brine desalination processes while generating valuable by-products via novel procedure.