Enhancement of CO₂ Absorption in Water through pH Control and Carbonic Anhydrase–A Technical Assessment

Abstract

This paper provides an industrial-scale technical assessment of absorption of CO 2 in water to react into bicarbonate (HCO 3 − ), with the goal of storing HCO 3 − in the oceans as a carbon sequestration technology. A potential advantage of the process is that it will not require a CO 2 transport and storage infrastructure that will be expensive for small-scale and remote emission sources. Process simulations are utilized to estimate absorber column length and for mass flow estimations of water and base required for a target capture rate of 90%. The results indicate that the process is technically feasible under specific conditions, with pH regulation being highly important, although the demand for base represents a limiting factor. Yet, a potential niche for the process is CO 2 capture at smaller plants emitting small amounts of CO 2 .

Palladium-Catalyzed Regioselective Arylation of Unprotected Allylamines

“…Meanwhile, the amine product can also be partially stabilized by reaction with CO 2 . Notably, although the exact role of the added water is not known, it has been postulated to change both the kinetics and enthalpic favorability of carbamate formation and is clearly necessary for reproducibly higher yields (see Supporting Information for more details). − …”

Defect Engineering of Graphene to Modulate pH Response of Graphene Devices

“…It should be noted that all experiments were done in DI water with 200 ppm of NaCl (3.4 mM) in order to eliminate the impact of ionic strength changes on the sensing responses. When DI water is left to equilibrate with the atmosphere (∼400 ppm of CO 2 ), the dissolved CO 2 (g) forms carbonic acid (a weak acid) and lowers the pH down to ∼5.5 . Therefore, moving down from pH 5.5 to 3, the current increases gradually due to the protonation of −COO – to COOH (Figure S3a–c).…”

“…When DI water is left to equilibrate with the atmosphere (∼400 ppm of CO 2 ), the dissolved CO 2 (g) forms carbonic acid (a weak acid) and lowers the pH down to ∼5.5. 64 Therefore, moving down from pH 5.5 to 3, the current increases gradually due to the protonation of −COO − to COOH (Figure S3a−c). Since the protonation of −COO − p-dopes the FLG, the concentration of majority carriers in the chemiresistive film increases and therefore with it the current.…”

Biogas impurities: environmental and health implications, removal technologies and future perspectives

“…For example, alkali carbonates and amines are the potential solvents, but suffer from unhurried absorption kinetics ( Kunze et al., 2015 ), while enzymes are activators or catalysts used in enhancing the absorption kinetics of carbon dioxide. In such a case, the formation of bicarbonates during the conversion is a rate limiting step of carbon dioxide absorption ( Beiron et al., 2019 ). The absorption capacity (absorbed volume) has been improved by a factor of >4 by the addition of carbonic anhydrase at 0.2–30 wt.…”