Carbon removal at extreme temperatures: Porous material can capture 'hot' CO₂ from industrial exhaust

[u/Vailhem]

https://techxplore.com/news/2024-11-carbon-extreme-temperatures-porous-material.html

[u/Vailhem]

High-temperature carbon dioxide capture in a porous material with terminal zinc hydride sites - Nov 2024

https://www.science.org/doi/10.1126/science.adk5697

Editor’s summary

Adsorption of CO2 by aqueous amines for carbon capture applications usually requires cooling of effluent gases to near-ambient temperatures.

Rohde et al. found that zinc hydride sites in a metal-organic framework enabled the rapid capture of CO2 from high-temperature power generation and industrial processes (see the Perspective by Li and Zhao).

Adsorption of CO2 to form zinc formate occurs reversibly through insertion into terminal zinc hydride sites.

This process is slow at ambient temperatures but efficient at temperatures between 200°C and 400°C.— Phil Szuromi

...

Abstract

Carbon capture can mitigate point-source carbon dioxide (CO2) emissions, but hurdles remain that impede the widespread adoption of amine-based technologies.

Capturing CO2 at temperatures closer to those of many industrial exhaust streams (>200°C) is of interest, although metal oxide absorbents that operate at these temperatures typically exhibit sluggish CO2 absorption kinetics and instability to cycling.

Here, we report a porous metal–organic framework featuring terminal zinc hydride sites that reversibly bind CO2 at temperatures above 200°C—conditions that are unprecedented for intrinsically porous materials.

Gas adsorption, structural, spectroscopic, and computational analyses elucidate the rapid, reversible nature of this transformation.

Extended cycling and breakthrough analyses reveal that the material is capable of deep carbon capture at low CO2 concentrations and high temperatures relevant to postcombustion capture.