Efficient Ag₂O–Ag₂CO₃ Catalytic Cycle and Its Role in Minimizing the Energy Requirement of Amine Solvent Regeneration for CO₂ Capture

Abstract

The worldwide large-scale deployment of the state-of-the-art CO2 capture technique is being delayed due to the overwhelmingly high energy consumption in the stripper. Here, we reveal an efficient Ag2O–Ag2CO3 catalytic cycle and analyze its activity in the amine solvent regeneration step which is capable of greatly minimizing the energy requirement by desorbing greater amounts of CO2 at up to 1000% higher desorption rate, at low temperature, e.g. 80 °C. After substantially improving the CO2 desorption, the Ag2O converts into Ag2CO3 which is even more efficient. The Ag2CO3 ultimately decomposes into Ag2O in the amine regeneration step, and this cycle continues. The validity of the cyclic catalytic behavior was tested for ten cycles. Furthermore, the mechanism of Ag2O/Ag2CO3 facilitated CO2 desorption was elucidated using 1H and 13C nuclear magnetic resonance spectroscopy.

Evaluation of the electrochemical performance of Ag containing AAO layers after extended exposure to a model corrosive medium

“…[14] The beneficial properties of silver and its ions are not limited only to their confirmed bactericide properties, recently widely investigated [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Materials, containing this element possess also definitively catalytic [41][42][43] and photocatalytic [44][45][46][47][48][49][50][51][52][53][54][55][56][57] properties. Furthermore, Bu et al [58] have proposed even hydrogen production by Ag2O based photocatalyst.…”

A Review on Enhancing Solvent Regeneration in CO2 Absorption Process Using Nanoparticles

“…This is also an important property when evaluating the cyclic ability of the nanoparticle, as a larger pore size can avoid the pores being blocked with the large carbamate molecules and maintain the catalytic efficiency after several absorption-desorption cycles. The role of acidic sites (Lewis acid and Bronsted acid) of a nanoparticle is substantial and it has, in fact, been proven to be more influential than the MSA [27,75,89]. A study has shown that an increase in the Bronsted acid sites (BAS) would also have a larger positive impact to the CO 2 desorption rate in comparison with the physical properties of the catalyst, which have less impact [87].…”

“…Lately, in 2019, Bhatti et al [89] continued to study the effect of Ag 2 O and Ag 2 CO 3 for amine solvent regeneration at a temperature of around 80 • C. The solvent used 30 wt% MEA with 5 wt% of each metal oxide nanoparticle. They reported an astounding increase in desorption rate of CO 2 up to approximately 1000%, which greatly reduced the energy consumption.…”

Materials and system design for direct electrochemical CO2 conversion in capture media

“…As the C-N bond in carbamate is weakened, it could be broken with less energy and CO2 can be released more easily. 30,31 Presently, direct capture media electrolysis products are limited to C1 products (i.e., CO and formate; Table 1). Progress into the transformation of CO2 into multicarbon (C2+) products has been sought after.…”