PAPERmaking! Vol6 Nr2 2020

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SUN ET AL .

TABLE 2 Carbonation kinetic parameters of the LM and limestone during the chemical reaction controlled stage

a

t crcs (s)

R 2

Sample

N

t o (s)

k

X u

LM

1

0.0127

0.090

39

60

.998

5

0.0040

0.032

33

72

.993

10

0.0033

0.031

27

66

.993

15

0.0027

0.026

30

75

.980

PLM

1

0.0165

0.238

48

132

.988

5

0.0084

0.100

33

96

.962

10

0.0079

0.097

33

91

.950

15

0.0066

0.095

33

96

.962

PLM after 9 h prolonged carbonation

1

0.0250

0.361

51

102

.996

15

0.0169

0.140

36

67

.996

Limestone

1

0.0203

0.634

102

192

.996

5

0.0146

0.421

90

177

.996

10

0.0080

0.216

78

153

.995

a t crcs denotes the time duration of the chemical reaction controlled stage.

FIGURE 6

Effect of Cl content on CO 2 capture capacity of

calcium-based sorbent in the 1st cycle

FIGURE 7 Fitting results of the carbonation conversions of Cl-doped CaCO 3 with different Cl/Ca molar ratio during the chemical reaction controlled stage in the first cycle

TABLE 3

Carbonation kinetic parameters of Cl-doped CaCO 3 during chemical reaction controlled stage during the 1st cycle

Cl/Ca molar ratio

Surface area (m 2 /g)

Pore volume (cm 3 /g)

2

Sample

t 0 (s)

t crcs (s)

k

X u

R

0

0.0234

72

0.480

141

.993

0.08

12.01

CaCO 3

CaCO 3 + CaCl 2

0.25:100

0.0231

57

0.448

111

.993

0.06

12.2

CaCO 3 + CaCl 2

0.50:100

0.0229

48

0.358

90

.993

-

-

CaCO 3 + CaCl 2

1:100

0.0220

42

0.314

84

.992

0.042

10.62

CaCO 3 + CaCl 2

2:100

0.0174

24

0.110

42

.997

0.023

6.67

CaCO 3 + CaCl 2

4:100

0.0174

21

0.108

39

.998

-

-

ratio of 2:100 at the first cycle. The calcined LM and Cl- doped CaCO 3 with a Cl/Ca molar ratio of 2:100 show similar pore volume distribution characteristics, with less pores dis- tributed in the range of 10-100 nm compared with calcined

the poor CO 2 capture performance of the LM in chemical reaction controlled stage. Figure 8 shows the pore volume distribution of the cal- cined LM, CaCO 3, and Cl-doped CaCO 3 with a Cl/Ca molar

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