Carbon Dioxide Fixation by Precipitating NaHCO₃ via Carbonation of NaOH-Dissolved Ethanol Aqueous Solution

Abstract

The present study investigates the mineral carbonation process that produces sodium bicarbonate (NaHCO3) precipitates, which could be one carbon capture and utilization/storage option. The NaHCO3 precipitates are generated via the mineral carbonation of 3 g of NaOH-dissolved ethanol aqueous solution, of which the ethanol concentration ranges from 50.5 to 97% (for convenience, named 50.5S–97S). In this region, the amount of generated NaHCO3 precipitates is parabolically increased as the ethanol composition increased and is a maximum 5.82 g at 85S. However, the yield of NaHCO3 precipitates is at a maximum 5.7 mg/(g of NaOH·g of ethanol) [the mass of ethanol in the denominator is not the consumed value but the value used to calculate the yield of NaHCO3 precipitates] at 80S, which equates to the amount of CO2 that could be fixed by 3.0 mg of CO2/(g of NaOH·g of ethanol). At this condition, Na+ compositions in the precipitates and in the filtrate are 86.87 and 13.13%, respectively. In addition, ethanol concentrations of 50.5S–97S after carbonation are almost not changed as 50–97%, because ethanol is not a reactant of the carbonation in this region. Therefore, NaHCO3 precipitate, which is a CO2 fixation material that is widely used for various purposes, could be simply obtained via the carbonation of NaOH-dissolved ethanol aqueous solution with high yield, without ethanol loss. However, in the carbonation with solution less than 50.5%, NaHCO3 is not precipitated due to its relatively high water composition, and in a 97.5% or higher ethanol concentrated solution, sodium ethyl carbonate (SEC; C2H5COONa) begins to be precipitated. In addition, the amount of precipitated NaHCO3 increased linearly according to the amount of NaOH feed with a rate of 1.88 g of NaHCO3/g of NaOH at 80S, which corresponds to the amount of fixed CO2 being 0.99 g of CO2/g of NaOH.

The Capture and Transformation of Carbon Dioxide in Concrete: A Review

“…CO 2 is captured and stored chemically through chemical reactions with chemical capture reagents (alkaline compounds or catalysts) to form alcohols, carboxylates, carbonates, etc. [63][64][65]. Compounds containing alkalis are usually used to capture CO 2 using hydroxides, alkanolamines, and carbonates.…”

Effluents and residues from industrial sites for carbon dioxide capture: a review

“…Extensive studies have been conducted on the use of methanol and ethanol, which are among the most used industrial solvents to capture carbon dioxide by coupling them with potassium or sodium hydroxides to induce chemical absorption Wee 2016, 2017;Mun et al 2018;Pak et al 2022). In one of their studies, they proposed the use of aqueous solutions of ethanol (60-100 w/w%) with 3 g of potassium hydroxide to produce potassium carbonate, bicarbonate and ethyl carbonate, in a series of bubble columns at ambient conditions (Pak et al 2022).…”

“…The highest absorption of carbon dioxide and production of potassium ethyl bicarbonate was observed for the solution of 90 w/w% ethanol. Similarly, solutions of aqueous ethanol (50.5-97 w/w%) were tested with sodium hydroxide, this time in a single column, for the production and precipitation of sodium bicarbonate (Mun et al 2018). It was found that the maximum formation of sodium bicarbonate was for 80 w/w% ethanol, while for higher concentrations of ethanol, sodium ethyl carbonate was favored and precipitated.…”

Mineral Carbonation for Carbon Utilization in Microalgae Culture

“…38−41 Mineral carbonation process has been used to produce a large variety of carbonate minerals such as, e.g., calcite (CaCO 3 ), 42,43 nesquehonite (MgCO 3 •3H 2 O), 44−46 hydromagnesite Mg 5 (CO 3 ) 4 (OH) 2 •4H 2 O), 47 magnesite, 39,41 and sodium bicarbonate (or nahcolite, NaHCO 3 ). 48,49 If carbonates are designed to be reused, e.g., to supply carbon to microalgae, the formation of metastable phases is preferred as they can precipitate quickly and dissolve promptly. This article presents experimental and modeling efforts to determine the kinetics of microalgae growth in the presence of dissolving carbonate minerals such as, e.g., sodium and magnesium carbonates, and select the best operating conditions to achieve optimal algae growth.…”

“…CO 2 is dissolved into alkaline wastewater or brine to precipitate carbonates, which are then dissolved for microalgae growth. Conventional mineral carbonation aims at permanently fixing CO 2 into stable carbonate that can be disposed of or reused. , During the precipitation of the carbonates, hydrated phases may form which eventually transform into stable solid phases. − Mineral carbonation process has been used to produce a large variety of carbonate minerals such as, e.g., calcite (CaCO 3 ), , nesquehonite (MgCO 3 ·3H 2 O), − hydromagnesite Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O), magnesite, , and sodium bicarbonate (or nahcolite, NaHCO 3 ). , If carbonates are designed to be reused, e.g., to supply carbon to microalgae, the formation of metastable phases is preferred as they can precipitate quickly and dissolve promptly.…”