Underlying Roles of Polyol Additives in Promoting CO Capture in PEI/Silica Adsorbents.

Solid-supported amines having low molecular weight branched poly(ethylenimine) (PEI) physically impregnated into porous solid supports are promising adsorbents for CO capture. Co-impregnating short-chain poly(ethylene glycol) (PEG) together with PEI alters the performance of the adsorbent, delivering improved amine efficiency (AE, mol CO sorbed/mol N) and faster CO uptake rates. To uncover the physical basis for this improved gas capture performance, we probe the distribution and mobility of the polymers in the pores via small angle neutron scattering (SANS), solid-state NMR, and molecular dynamic (MD) simulation studies.

Carbon capture in polymer-based electrolytes.

Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO capture behavior and transport properties of these electrolytes after CO capture have not yet been studied. Here, we use a variety of nuclear magnetic resonance (NMR) techniques to explore the carbon speciation and transport properties of branched polyethylenimine (PEI) and PEI-grafted silica nanoparticles (denoted as NOHM-I-PEI) after CO capture.

Cold Temperature Direct Air CO Capture with Amine-Loaded Metal-Organic Framework Monoliths.

Zeolites, silica-supported amines, and metal-organic frameworks (MOFs) have been demonstrated as promising adsorbents for direct air CO capture (DAC), but the shaping and structuring of these materials into sorbent modules for practical processes have been inadequately investigated compared to the extensive research on powder materials. Furthermore, there have been relatively few studies reporting the DAC performance of sorbent contactors under cold, subambient conditions (temperatures below 20 °C). In this work, we demonstrate the successful fabrication of adsorbent monoliths composed of cellulose acetate (CA) and adsorbent particles such as zeolite 13X and MOF MIL-101(Cr) by a 3D printing technique: solution-based additive manufacturing (SBAM).

Direct Air Capture of CO Using Amine/Alumina Sorbents at Cold Temperature.

Rising CO emissions are responsible for increasing global temperatures causing climate change. Significant efforts are underway to develop amine-based sorbents to directly capture CO from air (called direct air capture (DAC)) to combat the effects of climate change. However, the sorbents' performances have usually been evaluated at ambient temperatures (25 °C) or higher, most often under dry conditions.

Support Pore Structure and Composition Strongly Influence the Direct Air Capture of CO on Supported Amines.

A variety of amine-impregnated porous solid sorbents for direct air capture (DAC) of CO have been developed, yet the effect of amine-solid support interactions on the CO adsorption behavior is still poorly understood. When tetraethylenepentamine (TEPA) is impregnated on two different supports, commercial γ-AlO and MIL-101(Cr), they show different trends in CO sorption when the temperature (-20 to 25 °C) and humidity (0-70% RH) of the simulated air stream are varied. IR spectroscopy is used to probe the mechanism of CO sorption on the two supported amine materials, with weak chemisorption (formation of carbamic acid) being the dominant pathway over MIL-101(Cr)-supported TEPA and strong chemisorption (formation of carbamate) occurring over γ-AlO-supported TEPA.

Single-Walled Zeolitic Nanotubes: Advantaged Supports for Poly(ethylenimine) in CO Separation from Simulated Air and Flue Gas.

Previous research has demonstrated that amine polymers rich in primary and secondary amines supported on mesoporous substrates are effective, selective sorbent materials for removal of CO from simulated flue gas and air. Common substrates used include mesoporous alumina and silica (such as SBA-15 and MCM-41). Conventional microporous materials are generally less effective, since the pores are too small to support low volatility amines.

Sub-Ambient Temperature Direct Air Capture of CO using Amine-Impregnated MIL-101(Cr) Enables Ambient Temperature CO Recovery.

Due to the dramatically increased atmospheric CO concentration and consequential climate change, significant effort has been made to develop sorbents to directly capture CO from ambient air (direct air capture, DAC) to achieve negative CO emissions in the immediate future. However, most developed sorbents have been studied under a limited array of temperature (>20 °C) and humidity conditions. In particular, the dearth of experimental data on DAC at sub-ambient conditions (e.

CO utilization in built environment the swing carbonation of alkaline solid wastes with different mineralogy.

Carbon mineralization to solid carbonates is one of the reaction pathways that can not only utilize captured CO2 but also potentially store it in the long term. In this study, the dissolution and carbonation behaviors of alkaline solid wastes (i.e.

Electrochemical approaches for selective recovery of critical elements in hydrometallurgical processes of complex feedstocks.

Critical minerals are essential for the ever-increasing urban and industrial activities in modern society. The shift to cost-efficient and ecofriendly urban mining can be an avenue to replace the traditional linear flow of virgin-mined materials. Electrochemical separation technologies provide a sustainable approach to metal recovery, through possible integration with renewable energy, the minimization of external chemical input, as well as reducing secondary pollution.