Calcium-based Sorbents Development

Speaker: Wenqiang LIU State Key Laboratory of Coal Combustion, HUST, China

Email: wenqiang.liu@hust.edu.cn

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