Calcium-based Sorbents Development
Speaker: Wenqiang LIU State Key Laboratory of Coal Combustion, HUST, China
Email: [email protected]
Scope
• Background • Synthesis Method 1: Wet Mixing • Synthesis Method 2: Spray Drying • Summary
Why CO2 Capture? Source: BP BP Statistical Review 2011
Calcium Looping Process (CLP)
Carbonator
CaCO3
CaO
CO2 to be compressed and sequestered
CO2 containing gas mixture
Carbonator: CaO+CO2àCaCO3Regenerator: CaCO3à CaO+CO2
Regenerator
CO2-free gas
Power Plant With CLP
Oxy-fuel combustion to supply energy
recovery of heat: Q1, Q2, Q3, Q4
Flue-gas desulfurization
Q1
Q2 Q3
Q4
Reason for Loss-in-Capacity
Liu et al.2012(a)
Precursors Studies
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10
No. of cycle
Con
vers
ion,
X
calcium acetate hydrate-CaO
calcium lactate-CaO
calcium oxide (<160nm)-CaO
calcium carbonate(microscale)-CaOcalcium hydroxide-CaO
calcium carbonate (<70nm)-CaOcalcium propionate-CaO
calcium formate-CaO
calcium citrate tetrahydrate-CaOcalcium D-gluconatehydrate-CaO
0
0.2
0.4
0.6
0.8
1
0 50 100 150 200
Co
nve
rsio
n, x
Number of cycle
CC-CaOCG-CaOGrasa & Abanades's equationAbanades & Alvarez's equation
(Conditions for all tests: Carb 650°C, 30 mins, 15% CO2 partial pressure), Cal: 900°C, 10 mins, N2
Loss-in-Capacity Analysis ①
CaCO3 product layer, resist CO2
separated particles
CO2
Optimum: small & separated particles
Loss-in-Capacity Analysis ②
Inert Solid
Ultrafine CaO Particles
WM Sorbent Synthesis ① Procedure
Wet Mixing (WM) Method Procedure
Dry Mixing Suspension Mixing Sol Mixing Wet Mixing
Liu et al. Energy Fuels, 2012, 26 (5), pp 2751–2767
WM Sorbent Synthesis ②
3D percolation theory! ~82 wt% CaO
WM Sorbent Synthesis ③ STEM-EDS Pictures
Inert Solid
Ultrafine CaOParticles
Sorbent Synthesis-Spray Drying
Spray Drying Method
Liu et al.2012(b)
Sample Name Inlet Temp. (C)
Aspirator Setting (m3/h)
Pump Settings (ml/min)
Nozzle Air Flow (l/h)
CA-MA-75 200 38 7.5 421
CL-MA-75 200 38 7.5 421
CG-MG-75 200 38 7.5 421
CG-MG-75-1 200 38 4.5 421
CG-MG-75-2 200 38 1.5 421
CaO160nm-CE-75 200 38 7.5 541
CH-CE-75 200 38 7.5 541
0
0.2
0.4
0.6
0.8
1
0 5 10 15 20 25 30 35 40 45
CaO
Con
vers
ion
Time (min)
CG-MG-75
Calcium D-gluconate - CaO
B
0
0.2
0.4
0.6
0.8
1
0 5 10 15 20 25 30 35 40 45
Capt
ure
Capa
city
(g/g
)
Time (min)
C
Summary
• CaO Precursors are Very Important for Synthesis
• A Wet Mixing Method was Used for Sorbent Synthesis
• Spray Drying was Used for Quick Drying during Synthesis
Acknowledges
引用文献: • Liu, W., Low, N.W., Feng, B., Da Costa, J.C., and Wang, G.X. ‘Calcium Precursors for the Production of
CaO Sorbents for Multicycle CO2 Capture’, Environmental Science and Technology 2010 (a), 44 (2), pp 841–847.
• Wet Mixing • Liu, W., An, H., Qin, C., Yin, J., Wang, G.X., Feng, B., and Xu, M. ‘Performance Enhancement of
Calcium Oxide Sorbents for Cyclic CO2 Capture - A Review’, Energy Fuels, 2012, 26 (5), pp 2751–2767
• Liu, W., An, H., Qin, C., Yin, J., Wang, G.X., Feng, B., and Xu, M. ‘Synthesis of CaO-Based Sorbents for CO2 Capture by a Spray-Drying Technique’, Environmental Science and Technology, 1st Revision
• Qin, C., Yin, J., An, H., Liu, W., and Feng, B. ‘Performance of Extruded Particles from Calcium Hydroxide and Cement for CO2 Capture’, Energy and Fuels 2012, 26 (1), pp 154–161.
• Barker, R., 1974. The reactivity of calcium oxide towards carbon dioxide and its use for energy storage. Journal of Applied Chemistry and Biotechnology 24, 221-227