Experimental comparison of regeneration methods for CO<sub>2</sub> concentration from air using amine-based adsorbent
Year of publication
2021
Authors
Elfving, Jere; Kauppinen, Juho; Jegoroff, Mikko; Ruuskanen, Vesa; Järvinen, Lauri; Sainio, Tuomo
Abstract
Comparison of different regeneration options for direct air capture (DAC) has usually been limited to only consider pure CO<sub>2</sub> production, limiting the process options to e.g. temperature-vacuum swing adsorption (TVSA) or steam-stripping. In this work, detailed experimental comparison is conducted of temperature swing adsorption (TSA/TCSA) and TVSA for DAC. Particularly, TVSA is assessed with air or inert gas purge flow (TVCSA) and without purge flow. The working capacity, regeneration specific energy requirement (SER) and adsorbent regenerability of these processes was compared. For all other studied regeneration options except TVSA without purge flow, over 85% regeneration was obtained already at 60 °C. Isobaric TSA at 60 °C had the lowest regeneration SER of 4.2 MJ/kg<sub>CO2</sub>. Coupling TSA with mild vacuum improved desorption rate and increased working capacity from 0.47 to 0.51 mmol<sub>CO2</sub>/g<sub>sorbent</sub>, requiring 7.5 MJ/kg<sub>CO2</sub> for regeneration. Without purge flow, TVSA resulted in only 0.39 mmolCO2/gsorbent with the SER of 8.6 MJ/kg<sub>CO2</sub> at 100 °C. Due to lower allowable regeneration temperature of 60 °C, mild vacuum TVSA with air flow also had a lower cyclic capacity decrease rate of 0.26 %/cycle compared to 0.38 %/cycle with TVSA without purge flow at 100 °C. However, using 100 °C with air flow in the TVSA process lead to a significant capacity decrease of 0.6 %/cycle. Therefore, using either air or inert purge flow below 100 °C coupled with mild vacuum has benefits over the TVSA process with no inflow in terms of CO<sub>2</sub> productivity, specific energy requirement and adsorbent regenerability. For utilization purposes that require low-concentration CO<sub>2</sub>, TVSA with purge flow should thus be considered as a viable regeneration option for direct air capture along with isobaric TSA.
Show moreOrganizations and authors
Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Journal
Volume
404
Article number
126337
ISSN
Publication forum
Publication forum level
3
Open access
Open access in the publisher’s service
Yes
Open access of publication channel
Partially open publication channel
License of the publisher’s version
CC BY
Self-archived
No
Article processing fee (EUR)
1650
Year of payment for the open publication fee
2021
Other information
Fields of science
Chemical sciences; Chemical engineering
Keywords
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Language
English
International co-publication
No
Co-publication with a company
No
DOI
10.1016/j.cej.2020.126337
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes