Applied Chemical Engineering

Preparation and decarburization characteristics of SiO2-Al2O3 composite aerogel modified by potassium carbonate

Jingnan Guo

School of Electrical and Power Engineering, Taiyuan University of Technology

Yanlin Wang

School of Electrical and Power Engineering, Taiyuan University of Technology

Baihe Guo

School of Electrical and Power Engineering, Taiyuan University of Technology

Xiaolei Qiao

School of Electrical and Power Engineering, Taiyuan University of Technology

Xiaofei Wang

School of Electrical and Power Engineering, Taiyuan University of Technology

Jinrong Guo

School of Electrical and Power Engineering, Taiyuan University of Technology

Yan Jin

School of Electrical and Power Engineering, Taiyuan University of Technology

DOI: https://doi.org/10.24294/ace.v5i2.1643

Keywords: SiO2-Al2O3 Composite Aerogel, CO2 Adsorption, Carbonation Characteristics, Microscopic Characteristics

---

Abstract

In this paper, the preparation of potassium carbonate modified SiO₂-Al₂O₃ composite aerogel, the carbonation characteristics of K₂CO₃ and the decarburization characteristics of regeneration cycle were studied. The influence of loading rate on CO₂ adsorption was studied by using a fixed bed reactor, and the microstructure of the samples was analyzed by combining SEM and BET. The results show that during the alkali fusion sintering of Na₂CO₃, the Si-O-Si and Si-O-Al bonds break, the crystal structure is destroyed, and the covalent bond of mullite is transformed into the ionic bond of nepheline. Through orthogonal test, taking the specific surface area of aerogel as the measurement index, the optimal calcination conditions are determined as follows: 900 ℃, reaction for 60 min, Na₂CO₃ addition ratio of 0.5. The more K₂CO₃ is loaded, the less the corresponding active sites on the surface of the carrier. When the loading is 30%, the maximum CO₂ adsorption capacity is 2.86 mmol·g^–1. Excess K₂CO₃ will plug the pore structure, destroy the diffusion of CO₂, and reduce the diffusion and utilization efficiency. The percentage of mesoporous pore volume decreased from 94.21% to 89.32%, indicating that the active component K₂CO₃ was mainly filled in the mesoporous. After 10 cycle regeneration tests, the CO₂ adsorption capacity of the adsorbent decreased by 10.49%. The pore structure of the adsorbent was stable and the decarburization performance was excellent.

---

References

1.Sun Q. Analysis of the current situation of China’s carbon emission market construction. Value Engineering 2019; 38(26): 120–121.

2.Zhang T, Ma W, Qi X, et al. Characteristics and sources of organic carbon and element carbon in PM2.5 in the urban areas of Beijing. Environmental Chemistry 2018; 37(12): 2758–2766.

3.Zhao C, Chen X, Zhao C. Research progress of CO2 capture technology using dry alkali-based sorbents. Journal of Power Engineering 2008; 28(6): 827–833.

4.Cui S, Cheng W, Shen XD. Mesoporous amine-modified SiO2 aerogel: A potential CO sorbent. Energy & Environmental Science 2011; 4(6): 2070–2074.

5.Dong W, Chen X, Yu F, et al. Carbonation characteristics of sodium-based solid sorbents for CO2 capture. Journal of China Coal Society 2015; 40(9): 2200–2206.

6.Liang C. Study on CO2 capture performance of biomass-templated CaO-based sorbent pellets [MSc thesis]. Nanjing: Nanjing Normal University; 2019.

7.Yang F, Fu J, Zou C, et al. Synthesis of MgCl2 modified carbon materials for CO2 adsorption. Environmental Chemistry 2019; 38(11): 2555–2562.

8.Lee SC, Kim JC. Dry potassium-based sorbents for CO2 capture. Catalysis Surveys from Asia 2007; 11(4): 171–185.

9.Lee SC, Choi BY, Lee TJ, et al. CO2 absorption and regeneration of alkali metal-based solid sorbents. Catal Today 2006; 111(3): 385–390.

10.Zhao CW, Guo YF, Li CH, et al. Remove of low concentration CO2 at ambient temperature using several potassium-based sorbents. Applied Energy 2014; 124(7): 241–247.

11.Zhao C. Investigations on CO2 capture characteristics of dry potassium-based sorbent (in Chinese) [PhD thesis]. Nanjing: Southeast University; 2011.

12.Lee SC, Chae HJ, Lee SJ, et al. Novel regenerable potassium-based dry sorbents for CO2 capture at low temperatures. Journal of Molecular Catalysis B: Enzymatic 2009; 56(2): 179–184.

13.Liu Y, Xu L, Song K, et al. Carbonation characteristics of supported K2CO3/5A adsorbent. Chemical Engineering 2018; 46(7): 12–16.

14.Guo YF, Zhao CW, Sun J. Facile synthesis of silica aerogel supported K2CO3 sorbents with enhanced CO2 capture capacity for ultra-dilute flue gas treatment. Fuel 2018; 215(3): 735–743.

15.Chen S, Zhao C, Zhao C. Development of CO2 capture technology using solid potassium-based sorbents. Journal of Power Engineering 2010; 30(7): 542–549.

16.Feng J, Gao Q, Wu W, et al. Effect of silica content on structure and properties of Al2O3-SiO2 aerogels. Chinese Journal of Inorganic Chemistry 2009; 25(10): 1758–1763.

17.Yu Y, Ma R, Wang G, et al. Preparation and characterization of Al2O3 bulk aerogel with high specific surface area and low density. Journal of Materials Engineering 2019; 47(12): 136–142.

18.Liu B, Liu M, Chen X. Preparation of SiO2-Al2O3 composite aerogel with high specific surface area by sol-gel method from coal gangue. CIESC Journal 2017; 68(5): 2096–2104.

19.Chen N, Yan Y, Hu Z, et al. Research of SiO2-Al2O3 aerogel with fly ash. Journal of Wuhan University of Technology 2011; 33(2): 37–41.

20.Pu K, Chen N, Li B. Study on the preparation of silicon-aluminum aerogel from fly ash (in Chinese). Development Guide to Building Materials 2017; 15(18): 1672–1675.

21.Xu Z. Study on the preparation & modification and pelletization of sodium-based CO2 solid sorbents [MSc thesis]. Nanjing: Southeast University; 2019.

22.Guo BH, Wang YL, Guo JN, et al. Experiment and kinetic model study on modified potassium-based CO2 adsorbent. Chemical Engineering Journal 2020; 399: 125849.

23.Amiri M, Shahhosseini S. Optimization of CO2 capture from simulated flue gas using K2CO3/Al2O3 in a micro fluidized bed reactor. Energy and Fuels 2018; 32(7): 7978–7990.

24.Kong Y, Shen XD, Cui S, et al. Development of monolithic adsorbent via polymeric sol-gel process for low-concentration CO2 capture. Applied Energy 2015; 147: 308–317.

25.Linneen N, Pfeffer R, Lin YS. CO2 capture using particulate silica aerogel immobilized with tetraethylenepentamine. Microporous and Mesoporous Materials 2013; 176: 123–131.

26.He Y, Li Z, Xi H. Research progress of gas-solid adsorption isotherms. Ion Exchange and Adsorption 2014; 20(4): 276–289.

27.Kong Y, Jiang GD, Fan MH, et al. A new aerogel-based CO2 adsorbent developed using a simple sol-gel method along with supercritical drying. Chemical Communication 2014; 50(81): 12158–12161.

28.Huang YQ, Liu HC, Yuan HY, et al. Migration and speciation transformation of K and Cl caused by interaction of KCl with organics during devolatilization of KCl-loaded model biomass compounds. Fuel 2020; 277: 118205–118215.