Investigation of the capacity decay of a CdO-NaI mixed sorbent for pre-combustion CO2 capture

Christian Vogt, Thomas Gegenbach, Lan-Yun Shery Chang, Gregory Paul Knowles, Alan Loyd Chaffee

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The mechanisms for the loss of both CO2 working capacity and mass from a CdO–NaI composite were investigated to better assess the potential use of the material to facilitate the pre-combustion capture of CO2 from syngas. Fresh activated material was used to analyse sorption and desorption using a CO2–N2 mixture. Mass spectrometric analysis of the exit gas revealed the loss of elemental iodine from the system over the period, attributed to the oxidation of iodide. Thermogravimetric analysis using iodine vapour suggested the iodide loss reaction to be a partially reversible equilibrium. X-ray photoelectron spectroscopy revealed the formation of a highly oxidised iodine species on the surface of the sorbent during initial calcination in both air and N2, but this compound vanished after the use of the sorbent in 25 CO2 sorption cycles. Elemental mapping showed that iodine was dislocated from the sodium, which it was considered to be originally associated to, supporting the theory of oxidation and evaporation (and possible re-deposition). Transmission electron microscopy revealed that the sorbent consisted of regular, spherical nanoparticles of approx. 250 nm diameter, which became more irregularly-shaped after CO2 sorption cycles, considered to be due to void/crack formation caused by density changes upon calcination and carbonation. In situ powder X-ray diffraction revealed an increase in crystallinity of both CdO and NaI upon heating to CO2 sorption temperature of 325 °C in N2 atmosphere, compared to room temperature. If the oxidation of the iodide promoter can be inhibited, this is likely to improve the multicyclic CO2 sorption stability of this material for future use.
Original languageEnglish
Pages (from-to)5162-5175
Number of pages14
JournalJournal of Materials Chemistry A
Volume3
Issue number9
DOIs
Publication statusPublished - 2015

Cite this

@article{7efc8d9950a94013bfad1a8f030b25ed,
title = "Investigation of the capacity decay of a CdO-NaI mixed sorbent for pre-combustion CO2 capture",
abstract = "The mechanisms for the loss of both CO2 working capacity and mass from a CdO–NaI composite were investigated to better assess the potential use of the material to facilitate the pre-combustion capture of CO2 from syngas. Fresh activated material was used to analyse sorption and desorption using a CO2–N2 mixture. Mass spectrometric analysis of the exit gas revealed the loss of elemental iodine from the system over the period, attributed to the oxidation of iodide. Thermogravimetric analysis using iodine vapour suggested the iodide loss reaction to be a partially reversible equilibrium. X-ray photoelectron spectroscopy revealed the formation of a highly oxidised iodine species on the surface of the sorbent during initial calcination in both air and N2, but this compound vanished after the use of the sorbent in 25 CO2 sorption cycles. Elemental mapping showed that iodine was dislocated from the sodium, which it was considered to be originally associated to, supporting the theory of oxidation and evaporation (and possible re-deposition). Transmission electron microscopy revealed that the sorbent consisted of regular, spherical nanoparticles of approx. 250 nm diameter, which became more irregularly-shaped after CO2 sorption cycles, considered to be due to void/crack formation caused by density changes upon calcination and carbonation. In situ powder X-ray diffraction revealed an increase in crystallinity of both CdO and NaI upon heating to CO2 sorption temperature of 325 °C in N2 atmosphere, compared to room temperature. If the oxidation of the iodide promoter can be inhibited, this is likely to improve the multicyclic CO2 sorption stability of this material for future use.",
author = "Christian Vogt and Thomas Gegenbach and Chang, {Lan-Yun Shery} and Knowles, {Gregory Paul} and Chaffee, {Alan Loyd}",
year = "2015",
doi = "10.1039/c4ta07085b",
language = "English",
volume = "3",
pages = "5162--5175",
journal = "Journal of Materials Chemistry A",
issn = "2050-7488",
publisher = "The Royal Society of Chemistry",
number = "9",

}

Investigation of the capacity decay of a CdO-NaI mixed sorbent for pre-combustion CO2 capture. / Vogt, Christian; Gegenbach, Thomas; Chang, Lan-Yun Shery; Knowles, Gregory Paul; Chaffee, Alan Loyd.

In: Journal of Materials Chemistry A, Vol. 3, No. 9, 2015, p. 5162-5175.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Investigation of the capacity decay of a CdO-NaI mixed sorbent for pre-combustion CO2 capture

AU - Vogt, Christian

AU - Gegenbach, Thomas

AU - Chang, Lan-Yun Shery

AU - Knowles, Gregory Paul

AU - Chaffee, Alan Loyd

PY - 2015

Y1 - 2015

N2 - The mechanisms for the loss of both CO2 working capacity and mass from a CdO–NaI composite were investigated to better assess the potential use of the material to facilitate the pre-combustion capture of CO2 from syngas. Fresh activated material was used to analyse sorption and desorption using a CO2–N2 mixture. Mass spectrometric analysis of the exit gas revealed the loss of elemental iodine from the system over the period, attributed to the oxidation of iodide. Thermogravimetric analysis using iodine vapour suggested the iodide loss reaction to be a partially reversible equilibrium. X-ray photoelectron spectroscopy revealed the formation of a highly oxidised iodine species on the surface of the sorbent during initial calcination in both air and N2, but this compound vanished after the use of the sorbent in 25 CO2 sorption cycles. Elemental mapping showed that iodine was dislocated from the sodium, which it was considered to be originally associated to, supporting the theory of oxidation and evaporation (and possible re-deposition). Transmission electron microscopy revealed that the sorbent consisted of regular, spherical nanoparticles of approx. 250 nm diameter, which became more irregularly-shaped after CO2 sorption cycles, considered to be due to void/crack formation caused by density changes upon calcination and carbonation. In situ powder X-ray diffraction revealed an increase in crystallinity of both CdO and NaI upon heating to CO2 sorption temperature of 325 °C in N2 atmosphere, compared to room temperature. If the oxidation of the iodide promoter can be inhibited, this is likely to improve the multicyclic CO2 sorption stability of this material for future use.

AB - The mechanisms for the loss of both CO2 working capacity and mass from a CdO–NaI composite were investigated to better assess the potential use of the material to facilitate the pre-combustion capture of CO2 from syngas. Fresh activated material was used to analyse sorption and desorption using a CO2–N2 mixture. Mass spectrometric analysis of the exit gas revealed the loss of elemental iodine from the system over the period, attributed to the oxidation of iodide. Thermogravimetric analysis using iodine vapour suggested the iodide loss reaction to be a partially reversible equilibrium. X-ray photoelectron spectroscopy revealed the formation of a highly oxidised iodine species on the surface of the sorbent during initial calcination in both air and N2, but this compound vanished after the use of the sorbent in 25 CO2 sorption cycles. Elemental mapping showed that iodine was dislocated from the sodium, which it was considered to be originally associated to, supporting the theory of oxidation and evaporation (and possible re-deposition). Transmission electron microscopy revealed that the sorbent consisted of regular, spherical nanoparticles of approx. 250 nm diameter, which became more irregularly-shaped after CO2 sorption cycles, considered to be due to void/crack formation caused by density changes upon calcination and carbonation. In situ powder X-ray diffraction revealed an increase in crystallinity of both CdO and NaI upon heating to CO2 sorption temperature of 325 °C in N2 atmosphere, compared to room temperature. If the oxidation of the iodide promoter can be inhibited, this is likely to improve the multicyclic CO2 sorption stability of this material for future use.

UR - http://pubs.rsc.org.ezproxy.lib.monash.edu.au/en/content/articlepdf/2015/ta/c4ta07085b

U2 - 10.1039/c4ta07085b

DO - 10.1039/c4ta07085b

M3 - Article

VL - 3

SP - 5162

EP - 5175

JO - Journal of Materials Chemistry A

JF - Journal of Materials Chemistry A

SN - 2050-7488

IS - 9

ER -