Synthesis of CaO-Based Sorbents for CO2 Capture by a Spray-Drying Technique
Wenqiang Liu,*,† Junjun Yin,‡ Changlei Qin,‡ Bo Feng,*, ‡ and Minghou Xu†
†
State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan
430074, China
‡
School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, Queensland
4072, Australia
Sorbent Characterization, 1 table and 5 figures included
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Sample Characterization
1) Sorbents Preparation
Two more sample (CG-MG75-1 and CG-MG75-2 ) were produced to investigate the effect of spray drying
operating conditions (pump settings). The preparation was the same as that for CG-MG-75 and the operating
conditions are shown in Table S1.
2) Porosimetric Analysis
Porosimetric analysis was performed on three uncalcined sorbents (u-CG-MG75, u-CG-MG75-1 and u-CGMG75-2). The nitrogen adsorption isotherms of samples were measured at 77 K within the relative pressure of
10–6~1 by a TriStar 3000 specific surface area and pore size analyser (Micromeritics Co., USA). Before
measuring the isotherms, the sorbents were dried at 140 °C for 48 h and then degassed to 40 mbar at 250 °C for
48 h.
3) Particle Size Distribution
The particle size distributions of three calcined sorbents (CG-MG-75, CG-MG75-1 and CG-MG75-2) were
measured using a Master Mini particle size analyzer (Malvern Instruments Ltd).
4) Morphologies Changes with Cycles
The morphology changes of the sorbent CG-MG-75 before cycles and after 44 cycles were observed with a JEOL
JSM-6610 scanning electron microscope (SEM). The powders were dispersed on the surface of conductive
adhesive carbon tab and platinum-coated using an EIKO IB-5 Sputter Coater for 5 min (approximately 15 nm
thick) to obtain a better electronic signal. All SEM images were obtained from secondary electrons with 20 kV of
accelerating voltage.
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Table S1. Specific BET surface areas of uncalcined sorbents collected from cyclone after spraying drying
under the conditions in Table 1S1.
Sample Name
BET Surface Area before
Calcination(m2/g)
u-CG-MG-75
7.7227
u-CG-MG-75-1
8.1828
u-CG-MG-75-2
6.8367
3
0.05
30
u-CG-MG-75
u-CG-MG-75
0.04
dV/dlogD (cm3/g.nm)
Relative Pressure (P/Po)
25
20
15
10
5
0.02
0.01
0
0
0
0.2
30
0.4
0.6
0.8
1
1
100
1000
Pore Diameter (nm)
BJH Desorption
0.05
u-CG-MG-75-1
25
u-CG-MG-75-1
dV/dlogD (cm3/g.nm)
0.04
20
15
10
5
0.03
0.02
0.01
0
0
0
0.4
0.2
Adsorption
Desorption
0.6
0.8
1
1
10
Relative Pressure (P/Po)
100
1000
Pore Diameter (nm)
BJH Desorption
0.05
30
u-CG-MG-75-2
u-CG-MG-75-2
25
0.04
dV/dlogD (cm3/g.nm)
Relative Pressure (P/Po)
10
Relative Pressure (P/Po)
Adsorption
Desorption
Relative Pressure (P/Po)
0.03
20
15
10
5
0.03
0.02
0.01
0
0
0
0.2
Adsorption
Desorption
0.4
0.6
0.8
1
1
Relative Pressure (P/Po)
10
100
1000
Pore Diameter (nm)
BJH Desorption
Figure S1. Isotherm Linear Plot and BJH Pore Size Distributions for the Sorbent u-CG-MG-75, u-CGMG-75-1 and u-CG-MG-75-2.
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Figure S2: Particle Size Distributions of Three Calcined Sorbents (CG-MG-75, CG-MG75-1 and CGMG75-2) Prepared Under Different Spray Drying Conditions.
5
CaO Conversion (3 minutes carbonation) VS Cycle No.
1
0.8
CaO Conversion
0.6
0.4
0.2
0
0
2
4
CA-MA-75
CH-CE-75
6
8
10 12 14
Number of Cycle
CL-MA-75
CG-MG-75
16
18
20
22
CaO160nm-CE-75
Figure S3: 3-Minute Conversion of Multi Cycles of Carbonation and Calcination of Sorbents Produced
Using the Spray Drying Technique .
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A
B
Figure S4: SEM Images of Sorbent CG-MG-75 (A) Before Cycles, and (B) After 44 Cycles
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