Systematic Approach to Degradation Studies in Catalyst Based Amine CO2 Capture Process

The effects of climate change have attracted concern globally which has led to an increase in research focused on diverse plans and technologies for mitigation. The use of solid catalyst in an amine based post-combustion CO2 capture (PCCC) has become a very attractive option as developments are actively ongoing to address some of the challenges that the conventional capture system faces. This research work evaluated the role that a new super acid, proprietary desorber catalyst (PDC) catalyst has on the amine degradation rate using a formulated optimum 4M DMAE/AMP equimolar blend in a full cycle bench scale CO2 capture pilot plant system. Three solvent blends, 4M DMAE/AMP, 2M PEI/AMP (0.3/1.7) and 2M PEI/HMDA (0.3/1.7) were screened in a preliminary study and compared with 4M BEA/AMP. 4M DMAE/AMP emerged as the optimum solvent amongst all the three formulated ones with high points of improvement in the desorption performance parameters. DMAE/AMP is a good replacement for BEA/AMP as it addresses the problem of potential nitrosamine and nitramine formation. Two basic catalysts, proprietary absorber catalyst (PAC), and activated carbon spheres (ACS) and one acid catalyst, PDC were also synthesized, characterized, screened, and compared with the existing basic catalyst, KMgO/CNT’s and acid catalyst, Ce(SO4)2/ZrO2 respectively to evaluate their performances and how suitable they are for use in the PCC process compared to the existing ones. The introduction of ACS in the absorption system increased the rate at which the amine solvent absorbed CO2 by approximately 33 %. In the case of PAC, an absorption rate enhancement of approximately 29 % was obtained. PDC enhanced the CO2 desorption rate by approximately 25 % higher than the non-catalytic desorption using 4M DMAE/AMP. Degradation studies were finally conducted to examine the role that the solid acid catalyst, PDC plays in the stability of the selected amine blend system in a bench-scale pilot plant set-up. PDC inhibited the oxidative degradation rate of both DMAE and AMP by 25 % and 59 % respectively. This means 2M of DMAE would be depleted in 62 days in the presence of PDC compared to 46 days without PDC in an oxidative environment. Similarly, it would take 139 days for 2M of AMP to be depleted compared to 57 days without the presence of PDC. This translates into huge savings in operational cost if PDC is used as a catalyst to both enhance the desorption and limit degradation. The findings of this work would open up new discussions on how solid basic or acid catalysts can be beneficial in addressing one of the major drawbacks to the PCC technology, i.e. degradation.

Name thesis:degree_name

Master of Applied Science (MASc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Engineering - Process Systems

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2021

Author dc:creator

• Nugloze, Dzifa

Advisor dc:contributor.advisor

• Idem, Raphael

Committee members dc:contributor.committeemember

• deMontigny, David
• Supap, Teeradet

Language dc:language.iso

en

DOI

https://doi.org/10.82465/4011

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/14978