Reduction of Calcination Temperature in the Calcium Looping

Subscriber access provided by TUFTS UNIV

Article

Reduction of calcination temperature in the Calcium Looping process for CO2 capture by using Helium: In-situ XRD analysis Jose Manuel Valverde, and Santiago Medina ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.6b01966 • Publication Date (Web): 12 Oct 2016 Downloaded from http://pubs.acs.org on October 14, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Sustainable Chemistry & Engineering is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Sustainable Chemistry & Engineering

1

Reduction of calcination temperature in the Calcium Looping

2

process for CO2 capture by using Helium:

3

In-situ XRD analysis

4

Jose Manuel Valverdea∗ , Santiago Medinab

5

6

a

Faculty of Physics. University of Seville. Avenida Reina Mercedes s/n, 41012 Sevilla, Spain b

X-Ray Laboratory (CITIUS), University of Seville,

7

Avenida Reina Mercedes, 4B. 41012 Sevilla, Spain

8

∗

Corresponding author: Email: [email protected]

9

Keywords: Global warming; Greenhouse gases; Carbon Capture;

10

Chemical Looping; Energy penalty; Sorbent regeneration

1

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

11

Abstract

12

Limestone (CaCO3 ) calcination to yield CaO plays a central role on a myriad of natural and

13

industrial processes among which the recently emerged Calcium Looping (CaL) process to

14

capture CO2 is gaining a great relevance in the last years. A main drawback of this process

15

however is that calcination to regenerate the CaO sorbent particles must be necessarily car-

16

ried out in short residence times and under high CO2 partial pressure in order to extract a

17

highly concentrated CO2 stream from the calciner reactor. This requires rising up the calciner

18

temperature typically over 930◦ C , which brings about an important energy penalty to the

19

technology. Calcination can be speeded up by superheated steam through a chemical action

20

involving H2 O adsorption but this catalytic effect leads also to excessively friable CaO solids.

21

This poses an inconvenient for their transport in practice using circulating fluidized bed re-

22

actors since very fine particles that result from fracturing cannot be recovered by commercial

23

cyclones. The in-situ XRD analysis reported in this work shows that by using Helium even at

24

relatively small concentration, the calcination rate of limestone is notably enhanced even at

25

high CO2 partial pressures, as corresponds to CaL conditions, whereas the structure and reac-

26

tivity of the generated CaO remains unchanged as compared to calcination using other balance

27

gases such as N2 or O2 . This would allow reducing significantly the calciner temperature at

28

CaL conditions, thus mitigating the energy penalty for CO2 capture.

2


Page 2 of 23

Page 3 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

29


I.

INTRODUCTION

Limestone (CaCO3 ) calcination:

30

CaCO3 CaO + CO2 (g)

∆r H 0 = +177.8kJ/mol

(1)

31

to obtain lime (CaO) is of great relevance for a large number of natural and industrial

32

processes. In the last years, it has gained a renewed interest as it plays a main role on the

33

Ca-looping (CaL) process for CO2 capture, which has been successfully demonstrated at

34

pilot-scale level [1–5]. In this process, CaO particles become carbonated at contact with the

35

flue gas in a gas-solid circulating fluidized bed (CFB) reactor (carbonator) operated under

36

atmospheric pressure and typically at temperatures around 650◦ C . The carbonated solids

37

are then driven into a second CFB reactor (calciner) wherein CaO particles are regenerated

38

by calcination for their use in a new cycle. The final goal of this process is to retrieve

39

a highly concentrated CO2 stream from the calciner to be compressed and stored, which

40

implies that calcination must be necessarily performed under high CO2 partial pressures

41

(typically under 70-90% CO2 vol. concentration at absolute atmospheric pressure [6, 7]).

42

This is currently achieved in 1-2 MWth pilot-scale plants by burning fossil fuel in the calciner

43

using O2 (oxy-combustion). However, oxy-combustion brings about a notable energy penalty

44

to the process, additional CO2 is released and the regenerated CaO particles rapidly loose

45

reactivity towards carbonation due to promoted sintering and deactivation by ashes and

46

irreversible sulphation [8–12].

47

Thermochemical data [13–15] shows that the CO2 partial pressure for the calcina-

48

tion/carbonation reaction to be at equilibrium (Peq ) at a given temperature T is given

49

by 3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Peq (atm) ≈ 4.083 × 107 exp(−20474/T )

Page 4 of 23

(2)

50

Thus, the minimum temperature for calcination under a CO2 partial pressure P = 0.8 atm

51

(as typical of the calcination environment) would be Tcal ≃ 880◦ C . Nevertheless, a further

52

constraint of the CaL process is that calcination must be attained in short residence times

53

(on the order of a few minutes). Lab-scale experimental observations and pilot tests show

54

that this is only feasible if the temperature in the calciner is increased up to ≈ 950◦ C [4, 5],

55

which raises significantly the specific energy consumption for CO2 avoided (SPECCA) [16].

56

Thus, understanding the underlying physicochemical mechanisms that govern the kinetics

57

of limestone calcination becomes specially important for the large-scale deployment of the

58

CaL technology.

59

If the CO2 partial pressure in the calcination environment P is much smaller than Peq it is

60

generally accepted that the rate of CaCO3 conversion is ruled by the calcination temperature

61

T and can be well fitted by an Arrhenius law

dα = r(T, P ) f (α) dt

( )γ P r(T, P ) = A exp(−E1 /RT ) 1 − Peq

(3) (4)

62

Here α is the conversion degree (ratio of mass of CaCO3 calcined to the initial mass), r is the

63

surface reaction rate, f (α) is a mechanistic-rate function [17], A is a pre-exponential term, γ

64

is an empirical exponent of order unity, R = 8.3145 J/mol-K is the ideal gas constant and E1

65

is a positive activation energy, which is around the calcination enthalpy change E1 ≈ ∆r H 0

66

[18]. However, a through understanding of the kinetics of limestone calcination is still

67

lacking [19–24]. Recent in-situ XRD and 2D-XRD analysis coupled to thermogravimetry 4


Page 5 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


68

and in-situ transmission electron microscopy indicate that calcination takes place through

69

a CaO crystallographic transformation [22, 24, 25]. Accordingly, calcite crystals would

70

decompose into a metastable CaO∗ form and CO2 , which remains adsorbed to the solid.

71

In a second step, CO2 desorption is accompanied by the structural transformation of CaO∗

72

into the stable CaO structure, which is an exothermic step despite the overall calcination

73

reaction is endothermic. In the limit of low CO2 partial pressures (P/Peq ≪ 1), the reaction

74

is just limited by chemical decomposition since CO2 desorption and the CaO structural

75

transformation occur extremely fast [22]. On the other hand, this step becomes severely

76

hindered as the CO2 partial pressure approaches the equilibrium pressure. Consequently,

77

calcination under partial CO2 pressures close to the equilibrium pressure is characterized by

78

very long nucleation periods [24, 25]. Experimental observations show that for a fixed value

79

of P/Peq close to unity the reaction rate reaches a maximum at a certain critical temperature

80

Tc above which the nucleation period is prolonged as the temperature is increased while the

81

apparent activation energy becomes negative due to the exothermicity of the structural

82

transformation. Thus, if calcination has to be carried out under high CO2 partial pressure

83

(as is the case of the CaL process) the calcination temperature has to be increased well

84

beyond the equilibrium temperature in order to decrease the value of P/Peq below typically

85

0.6 for the reaction to be completed in a few minutes [24, 25]. In practice, this means that

86

the temperature of the calciner reactor has to be kept around ≈ 950◦ C [4, 5, 26].

87

A subject of active discussion concerning limestone calcination is why the presence of

88

certain gases in the calcination environment such as superheated steam or Helium acceler-

89

ates calcination and by which mechanisms these gases might have an effect, if any, on the

90

mechanical strength and reactivity of the formed CaO [27, 28]. Early experimental observa-

91

tions dating back to the beginning of the 20th century [27] pointed out towards a relevant 5



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 23

92

role of the heat conductivity of the gases present in the calciner environment on limestone

93

decomposition. Thus, heat transfer would be promoted for calcination under superheated

94

steam or Helium with high thermal conductivities thereby causing an effective acceleration

95

of the reaction. On the other hand, more recent in-situ XRD studies have shown that the

96

enhancement effect of steam would be related to adsorption of H2 O molecules which is faster

97

and more significant than CO2 adsorption thus facilitating desorption of the latter as a nec-

98

essary step for decarbonation [28]. A side effect of this chemical action is the production of

99

small CaO nanocrystals highly reactive towards carbonation, which would be in principle

100

beneficial for CO2 capture. A further consequence is that CaO particles formed by calcina-

101

tion under superheated steam are quite friable [29, 30], which can be an added advantage

102

for cement and fertilizers production. Yet excessive fracturing of the solids poses a serious

103

inconvenient to the CaL process since very fine particles entrained by the gas in circulating

104

fluidized bed reactors cannot be recovered by commercial cyclones (typically with a cut off

105

particle diameter around 10 µm) [1].

106

The purpose of the present work is to investigate the structural transformation that takes

107

place during calcination of limestone under different gases such as N2 , O2 , and He by means

108

of in-situ XRD analysis. These gases are commonly employed indistinctively in thermo-

109

gravimetric tests to study the capture performance of CaO based sorbents during multicycle

110

carbonation/calcination cycles [4]. Yet, any effect of these gases on the calcination kinetics

111

and/or structural transformation so far dismissed could have also a significant influence on

112

the CO2 capture performance of the regenerated CaO as it is seen to occur for example

113

when superheated steam is injected in the calciner reactor [31, 32]. 6


Page 7 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

114


II.

MATERIAL AND METHODS

115

A powdered natural limestone of high purity (99.6% CaCO3 ) from Matagallar quarry

116

(Pedrera, Spain) has been used. Volume weighted mean particle size is 9.5 µm as measured

117

by laser diffractometry using a Malvern Mastersizer 2000 instrument. Figure 1 shows a

118

schematic layout of the experimental setup employed for studying calcination of this lime-

119

stone by means of in-situ XRD analysis. A controlled gas flow at atmospheric pressure

120

is passed downwards across a thin layer of the powder sample (150 mg), which is evenly

121

distributed over a porous ceramic plate (1 cm dia.). In this way, the gas is homogeneously

122

distributed across the powder, which promotes the gas-solid contacting efficiency thus facil-

123

itating mass and heat transfer.

MFC

MFC

N2,O2,He

CO2

FIG. 1: Schematics of the experimental setup used for the in-situ XRD calcination tests. The gas mixture is achieved by means of a pair of mass flow controllers (MFC) duly calibrated for the type of gas used (either CO2 , N2, O2 or He).

124

The gas flow rate is controlled by means of a pair of MKS thermal based mass flow con-

125

trollers (100 sccm full range), which allows us testing the calcination behavior of limestone

126

under environments of different gas mixtures at accurately controlled proportions. Calci7



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 23

127

nation tests have been carried out under pure CO2 , N2 , O2 and He as well as mixtures of

128

these gases in which the CO2 volume concentration was fixed to 80% as representative of

129

the calcination environment in the CaL process for CO2 capture. The total gas flow rate

130

was fixed to 100 sccm in all the tests. One of the MKS flow controllers was calibrated for

131

CO2 as received while calibration for the other one was originally made for N2 . Correction

132

factors for this controller were taken into account when other gases (He and O2 ) were used

133

according to their specific heat and density.

134

A Bruker D8 Advance powder diffractometer has been employed equipped with an Anton

135

Paar XRK 900 high temperature chamber and a fast response/high sensitivity detector

136

(Bruker Vantec 1) with radial Soller slits. This reactor chamber is specifically designed for

137

the kinetic analysis of gas-solid reactions at high temperatures avoiding any dead volumes

138

to ensure homogeneous filling with the reaction gas. The furnace heater has been carefully

139

designed for avoiding temperature gradients across the sample. Accurate measurement and

140

control of temperature is achieved by means of NiCr/NiAl thermocouples placed close to

141

the sample holder. 60 mm Gobel mirrors (Bruker, Germany) for Cu Kα radiation (0.15405

142

nm wavelength) with parallel Johansson geometry in the incident beam were employed.

143

Instrumental contribution for structural adjustments and resolution were checked in a wide

144

range of diffraction angles by using Corundum, LaB6 and silicon standards.

145

In a typical calcination test the temperature is increased at 10◦ C /min from ambient

146

temperature while XRD scans of duration ∆t = 295 s in the range 20◦ < 2θ 880◦ C . Yet, the kinetics of limestone

277

calcination under high CO2 partial pressure becomes extraordinarily slow nearby the equi-

278

librium as CO2 desorption and the CaO structural transformation are hindered. Thus,

279

the calcination temperature has to be increased up to ≈950◦ C for calcination to be fully

280

achieved in short residence times (typically below 10 minutes), as required in practice, by

281

means of oxy-combustion, which imposes an important energy penalty to the technology.

282

An effective method to catalyze the calcination reaction is to inject superheated steam in

283

the calciner, but the CaO particles regenerated in the presence of steam are characterized

284

by a rather small crystallite size and very high friability, which is a serious drawback for 17



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 23

285

the technology. This work reports an in-situ XRD analysis of limestone calcination under

286

diverse atmospheres. Calcination tests were carried out under pure gases (CO2 , N2 , O2 ,

287

He) and mixtures of these gases in which the CO2 concentration was fixed to 80% vol. as

288

representative of the calcination atmosphere in the CaL process for CO2 capture. The re-

289

sults obtained show that the presence of Helium in the calcination environment leads to a

290

significant acceleration of the reaction, which is arguably due to the enhancement of heat

291

transfer and CO2 diffusivity. Thus calcination under a 80% CO2 /20% He vol/vol mixture is

292

fully achieved in a few minutes (< 10 min) at temperatures just slightly above 900◦ C while

293

it takes more than 30 minutes when O2 or N2 are used as balance gases instead of He. At the

294

same time, the crystal structure and reactivity of the CaO formed remains unchanged when

295

using Helium as balance gas as compared to O2 or N2 , which indicates that CaO friability

296

is not promoted as is the case when using superheated steam to catalyze the reaction. The

297

results of the present study suggest that using He in the calcination environment of the

298

CaL process would lead to a significant decrease of the calcination temperature while the

299

mechanical strength of the particles is not affected.

300

V.

ACKNOWLEDGEMENTS

301

This work was supported by the Spanish Government Agency Ministerio de Economia y

302

Competitividad (contract CTQ2014-52763-C2-2-R). The X-ray the Functional Characteriza-

303

tion services of the Innovation, Technology and Research Center of the University of Seville

304

(CITIUS) are gratefully acknowledged. 18


Page 19 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

305

306

307


VI.

REFERENCES

[1] Blamey, J.; Anthony, E. J.; Wang, J.; Fennell, P. S. Prog. Energ. Combust. Sci. 2010, 36, 260–279.

308

[2] Romano, M. C. Chemical Engineering Science 2012, 69, 257 – 269.

309

[3] Arias, B.; Diego, M.; Abanades, J.; Lorenzo, M.; Diaz, L.; Martinez, D.; Alvarez, J.; Sanchez-

310

311

312

313

314

Biezma, A. International Journal of Greenhouse Gas Control 2013, 18, 237–245. [4] Perejon, A.; Romeo, L. M.; Lara, Y.; Lisbona, P.; Martinez, A.; Valverde, J. M. Applied Energy 2016, 162, 787 – 807. [5] Hanasoge, S.; Miesch, M.; Roth, M.; Schou, J.; Schssler, M.; Thompson, M. Space Science Reviews 2015, 1–21.

315

[6] Ylatalo, J.; Parkkinen, J.; Ritvanen, J.; Tynjala, T.; Hyppanen, T. Fuel 2013, 113, 770–779.

316

[7] Romano, M. C.; Martinez, I.; Murillo, R.; Arstad, B.; Blom, R.; Ozcan, D. C.; Ahn, H.;

317

318

319

320

321

322

323

324

325

Brandani, S. Energy Procedia 2013, 37, 142 – 150. [8] Rodriguez, N.; Alonso, M.; Grasa, G.; Abanades, J. C. Chemical Engineering Journal 2008, 138, 148–154. [9] Romeo, L. M.; Lara, Y.; Lisbona, P.; Escosa, J. M. Chemical Engineering Journal 2009, 147, 252 – 258. [10] Martinez, A.; Lara, Y.; Lisbona, P.; Romeo, L. M. International Journal of Greenhouse Gas Control 2012, 7, 74 – 81. [11] Martinez, A.; Lara, Y.; Lisbona, P.; Romeo, L. M. Environmental Science & Technology 2013, 47, 11335–11341.

19



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

326

327

Page 20 of 23

[12] Martinez, I.; Grasa, G.; Murillo, R.; Arias, B.; Abanades, J. Chemical Engineering Journal 2013, 215–216, 174–181.

328

[13] Barin, I. Thermochemicaldata of pure substances; Weinheim: VCH., 1989.

329

[14] Garcia-Labiano, F.; Abad, A.; de Diego, L.; Gayan, P.; Adanez, J. Chemical Engineering

330

Science 2002, 57, 2381 – 2393.

331

[15] Stanmore, B.; Gilot, P. Fuel Processing Technology 2005, 86, 1707 – 1743.

332

[16] Ortiz, C.; Valverde, J. M.; Chacartegui, R. Energy Technology 2016, n/a–n/a.

333

[17] Khawam, A.; Flanagan, D. R. The Journal of Physical Chemistry B 2006, 110, 17315 – 17328.

334

[18] Galwey, A. K.; Brown, M. E. Thermochimica Acta 2002, 386, 91 – 98.

335

[19] Boynton, R. S. Chemistry and Technology of Lime and Limestone; Wiley: New York, 1980;

336

For general practical information, the interested reader is recommended perusal of the first

337

edition (1966).

338

339

[20] Criado, J. M.; Gonzalez, M.; Malek, J.; Ortega, A. Thermochimica Acta 1995, 254, 121 – 127.

340

[21] L’vov, B. V.; Polzik, L. K.; Ugolkov, V. L. Thermochimica Acta 2002, 390, 5 – 19.

341

[22] Rrodriguez-Navarro, C.; Ruiz-Agudo, E.; Luque, A.; Navarro, A. B.; Ortega-Huertas, M.

342

American Mineralogist 2009, 94, 578 593.

343

[23] Michele, P.; Loic, F.; Michel, S. Thermochimica Acta 2011, 525, 93 – 102.

344

[24] Valverde, J. M.; Medina, S. Phys. Chem. Chem. Phys. 2015, 17, 21912–21926.

345

[25] Valverde, J. M. Chemical Engineering Science 2015, 132, 169–177.

346

[26] Ströhle, J.; Junk, M.; Kremer, J.; Galloy, A.; Epple, B. Fuel 2014, 127, 13 – 22, Fluidized

347

Bed Combustion and Gasification CO2 and SO2 capture: Special Issue in Honor of Professor

348

E.J. (Ben) Anthony.

20


Page 21 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


349

[27] Berger, E. E. Industrial & Engineering Chemistry 1927, 19, 594–596.

350

[28] Wang, Y.; Thomson, W. J. Chemical Engineering Science 1995, 50, 1373 – 1382.

351

[29] Maclntire, W. H.; Stansel, T. B. Industrial & Engineering Chemistry 1953, 45, 1548–1555.

352

[30] Blamey, J.; Manovic, V.; Anthony, E. J.; Dugwell, D. R.; Fennell, P. S. Fuel 2015, 150, 269

353

354

355

– 277. [31] Donat, F.; Florin, N. H.; Anthony, E. J.; Fennell, P. S. Environmental Science & Technology 2012, 46, 1262 – 1269.

356

[32] Asano, K.; Fujimoto, K.; Yamaguchi, Y.; Ito, S. Reactivity of Carbonates in Superheated

357

Steam under Atmospheric Pressure. Inorganic and Environmental Materials. 2014; pp 225–

358

228.

359

360

[33] (Ed.), R.-A. Y. The Rietveld Method ; IUCr Monographs on Crystallography 5; Oxford University Press: New York, 1993.

361

[34] Le Bail, A. Powder Diffraction 2005, 20, 316–326.

362

[35] Bruker, A. Bruker AXS GmbH, Karlsruhe, Germany Search PubMed 2009,

363

[36] Sarrion, B.; Valverde, J. M.; Perejon, A.; Perez-Maqueda, L.; Sanchez-Jimenez, P. E. Energy

364

365

366

Technology 2016, 4, 1013–1019. [37] Valverde, J. M.; Sanchez-Jimenez, P. E.; Perez-Maqueda, L. A. The Journal of Physical Chemistry C 2015, 119, 1623–1641.

367

[38] Vargaftik, N. B.; Yakush, L. V. Journal of engineering physics 1977, 32, 530–532.

368

[39] Gupta, G.; Saxena, S. Molecular Physics 1970, 19, 871–880.

369

[40] Saxena, S.; Chen, S. Molecular Physics 1975, 29, 1507–1519.

370

[41] Jain, P.; Saxena, S. Molecular Physics 1977, 33, 133–138.

21



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

371

372

373

374

375

376

Page 22 of 23

[42] Yokomizu, Y.; Hayashi, Y.; Matsumura, T.; Majima, A.; Uchii, T.; Suzuki, K. IEEJ Transactions on Power and Energy 2013, 133, 867–874. [43] Green, D.; Perry, R. Perry’s Chemical Engineers’ Handbook, Eighth Edition; McGraw Hill professional; McGraw-Hill Education, 2007. [44] Cussler, E. Diffusion: Mass Transfer in Fluid Systems; Cambridge Series in Chemical Engineering; Cambridge University Press, 1997; pp 119–125.

377

[45] Taketomo, E.; Fujiura, M. Porous materials for concentration and separation of hydrogen or

378

helium, and process therewith for the separation of the gas. 1984; US Patent 4,482,360.

379

[46] Diaz, B.; Cuadrado, P.; Marcos-Fernandez, A.; Pradanos, P.; Tena, A.; Palacio, L.;

380

Lozano, A. E.; Hernandez, A. Industrial & Engineering Chemistry Research 2014, 53, 12809–

381

12818.

22


Page 23 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


For Tables of Contents Use Only

High Temperature chamber

X-ray tube

Detector

O2 N2

He

Limestone sample

CO2 Gas output

Reducon of calcinaon temperature in the Calcium Looping process for CO2 capture by using Helium: In-situ XRD analysis Jose Manuel Valverde, San ago Medina

XRD analysis shows that the Calcium-Looping process for CO2 capture is enhanced by using Helium in the calcinaon environment without compromising sorbent resistance to a ri on

23


Reduction of Calcination Temperature in the Calcium Looping

Recommend Documents