Multicycle Performance of CaTiO3 Decorated CaO-Based CO2 Adsorbent Prepared by a Versatile Aerosol Assisted Self-Assembly Method.

Ren-Wei Chang,Chin-Jung Lin,Ya-Hsuan Liou

doi:10.3390/nano11123188

Ren-Wei Chang, Chin-Jung Lin + Show 1 more

Open Access

https://doi.org/10.3390/nano11123188

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Abstract

Calcium oxide (CaO) is a promising adsorbent to separate CO2 from flue gas. However, with cycling of carbonation/decarbonation at high temperature, the serious sintering problem causes its capture capacity to decrease dramatically. A CaTiO3-decorated CaO-based CO2 adsorbent was prepared by a continuous and simple aerosol-assisted self-assembly process in this work. Results indicated that CaTiO3 and CaO formed in the adsorbent, whereas CaO gradually showed a good crystalline structure with increased calcium loading. Owing to the high thermal stability of CaTiO3, it played a role in suppressing the sintering effect and maintaining repeated high-temperature carbonation and decarbonation processes. When the calcium and titanium ratio was 3, the CO2 capture capacity was as large as 7 mmol/g with fast kinetics. After 20 cycles under mild regeneration conditions (700 °C, N2), the performance of CO2 capture of CaTiO3-decorated CaO-based adsorbent nearly unchanged. Even after 10 cycles under severe regeneration conditions (920 °C, CO2), the performance of CO2 capture still remained nearly 70% compared to the first cycle. The addition of CaTiO3 induced good and firm CaO dispersion on its surface. Excellent kinetics and stability were evident.

Highlights

The global climate-change phenomenon has become an important concern in recent years because of excessive CO2 emissions, and this situation will continue because our energy supply originates mostly from fossil-fuel combustion and in the few years
Calcium is an abundant element on earth, and its oxide form, Calcium oxide (CaO), can capture CO2 and change it to the carbonate form, CaCO3, via carbonation
Owing to fixed titanium precursor addition amounts, the larger ratio corresponded with more calcium-precursor loading

Summary

Introduction

The global climate-change phenomenon has become an important concern in recent years because of excessive CO2 emissions, and this situation will continue because our energy supply originates mostly from fossil-fuel combustion and in the few years. Capturing CO2 from flue gas and transporting it to a suitable site for storage is a solution for CO2 -emission reduction [1,2,3]. Calcium is an abundant element on earth, and its oxide form, CaO, can capture CO2 and change it to the carbonate form, CaCO3 , via carbonation. The oxide form can be regenerated back by CO2 removal through decarbonation. CaO-based adsorbents can be used repeatedly by combining carbonation and decarbonation processes [4,5,6,7,8]. The nontoxicity and low cost of CaO-based adsorbents enable them to become excellent potential candidate for CO2 -adsorption application

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Results

Conclusion