Globally, the elevation of carbon dioxide (CO2) levels due to the anthropogenic effect poses a serious threat to the ecosystem. Hence, it is important to control and/or mitigate the level of CO2 in the atmosphere, which necessitates novel tools. Herein, it is proposed to improve CO2 sequestration by using model complexes based on the enzyme carbonic anhydrase (CA) in aqueous tertiary amine medium. The effect of substituents on the model CA model complexes on CO2 absorption and desorption was determined by using a stopped-flow spectrophotometer to follow pH changes through coupling to pH indicator and a continuous stirred-tank reactor (CSTR). The CO2 hydration rate constants were determined under basic conditions and compound 6, which contained a hydrophilic group, showed the highest absorption or hydration levels of CO2 (2.860×103 L mol-1 s-1). In addition, CSTR results for the absorption and desorption of CO2 suggest that simple model CA complexes could be used in post-combustion processing. © 2015 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

Nirmala Grace A

Centre for Nanotechnology Research

Vellore Campus

Sivanesan D

Choi Y

Lee J

Youn M.H

Park K.T

Kim H.-J

Jeong S.K.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

ChemSusChem

Amine-based postcombustion CO2 capture technology has a great potential to control CO2 emissions but is expensive because a huge amount of thermal energy is required for solvent regeneration due to poor CO2 desorption kinetics. Tertiary amines can be efficiently regenerated, but the poor CO2 absorption kinetics are a major limitation to its large-scale deployment. Here, we synthesized tripodal nitrate salt and its metal catalysts and investigated catalytic activity in a highly concentrated tertiary amine medium, N-methyldiethanolamine (MDEA), for the CO2 capture process. To analyze the catalytic performance, the rate constant for CO2 hydration, CO2 absorption rate, and CO2 desorption rate were experimentally studied. The gathered results suggest that catalyst 2 can improve the CO2 absorption and CO2 desorption efficiencies by 35% and 21%, respectively. On the basis of the obtained results, the possible reaction mechanism is also presented. These findings can provide a new route for energy-efficient CO2 capture using tertiary amines. © 2019 American Chemical Society.

ACS Sustainable Chemistry & Engineering

Catalytic Characteristics of Metal Catalysts and Nitrate Salt of a Tripodal Ligand in a Basic Medium for Postcombustion CO2 Capture Process

An improved CO2 sequestration method is proposed that uses new catalysts, specifically a series of tertiary amine nitrate salts, in an aqueous tertiary amine medium.

RSC Advances

The salt-based catalytic enhancement of CO2 absorption by a tertiary amine medium

One aspect of the attempt to restrain global warming is the reduction of the levels of atmospheric CO2 produced by fossil fuel power systems. This study attempted to develop a method that reduces CO2 emissions by investigating the absorption of CO2 into sterically hindered amine 2-amino-2-methyl-1-propanol (AMP), the acceleration of the absorption rate by using the enzyme carbonic anhydrase (CA), and the conversion of the absorption product to stable carbonates. CO2 absorbed by AMP is converted via a zwitterion mechanism to bicarbonate species; the presence of these anions was confirmed with 1H and 13C NMR spectral analysis. The catalytic efficiency (kcat/Km), CO2 absorption capacities, and enthalpy changes (ΔHabs) of aqueous AMP in the presence or absence of CA were found to be 2.61 × 106 or 1.35 × 102 M-1 s-1, 0.97 or 0.96 mol/mol, and -69 or -67 kJ/mol, respectively. The carbonation of AMP-absorbed CO2 was performed by using various Ca2+ sources, viz., CaCl2 (CAC), Ca(OOCCH3)2 (CAA), and Ca(OOCCH2CH 3)2 (CAP), to obtain various polymorphs of CaCO 3. The yields of CaCO3 from the Ca2+ sources were found in the order CAP &gt; CAA &gt; CAC as a result of the effects of the corresponding anions. CAC produces pure rhombohedral calcite, and CAA and CAP produce the unusual phase transformation of calcite to spherical vaterite crystals. Thus, AMP in combination with CAA and CAP can be used as a CO 2 absorbent and buffering agent for the sequestration of CO 2 in porous CaCO3. © 2013 American Chemical Society.

Langmuir

CO2Absorption and Sequestration as Various Polymorphs of CaCO3Using Sterically Hindered Amine

Journal of Chemical Technology & Biotechnology

The use of carbonic anhydrase to accelerate carbon dioxide capture processes

The Journal of Physical Chemistry C

Harvesting CaCO3 Polymorphs from In Situ CO2 Capture Process

Catal. Sci. Technol.

Improving carbon capture from power plant emissions with zinc- and cobalt-based catalysts

Energy Environ. Sci.

A review of techno-economic models for the retrofitting of conventional pulverised-coal power plants for post-combustion capture (PCC) of CO2

Carbon Dioxide Sequestration by Using a Model Carbonic Anhydrase Complex in Tertiary Amine Medium

Journal	Data powered by TypesetChemSusChem
Publisher	Data powered by TypesetWiley
ISSN	1864-5631
Open Access	0