Thermal effect and kinetic analysis on co-pyrolysis of furnace slag with cellulose from biomass

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Energy (2019) 000–000 440–445 EnergyProcedia Procedia158 00 (2017) www.elsevier.com/locate/procedia

10th th

International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, 10 International Conference on Applied Energy China(ICAE2018), 22-25 August 2018, Hong Kong, China

Thermal and kinetic analysis on co-pyrolysis of furnace Thermal effect effect and kinetic Symposium analysis on onDistrict co-pyrolysis furnace slag slag The 15th International Heating andof Cooling with cellulose from biomass with cellulose from biomass Assessing the feasibility of using the heat demand-outdoor a,b Zhiqiang Wua,b*,Yaowu Liaa, Jun Zhaobb, Liwei Mabb, Xi Zhangbb, Haiyu Mengcc, Donghai Zhiqiang Wu *,Yaowu Li , Jun , Liwei , Xi Zhang , Haiyu Meng forecast , Donghai temperature function for Zhao a long-term heat demand Xubb Madistrict Xu *, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre

a and Technology,a Xi’an Jiaotong University, b c c School ofa,b,c Chemical Engineering Xi’an, Shaanxi, 710049, P.R. China a b School of Chemical Engineering and Technology, Xi’an University, 710049, P.R. China Key Laboratory of Thermo-Fluid Science & Engineering, Ministry of Jiaotong Education, School of Xi’an, EnergyShaanxi, and Power Engineering, Xi’an Jiaotong b Key Laboratory of Thermo-Fluid Science &University, Engineering, Ministry of Education, School China of Energy and Power Engineering, Xi’an Jiaotong Xi’an, Shaanxi Province 710049, a IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal c University, Shaanxi Province China State Key Laboratory of Eco-hydraulics in Northwest AridXi’an, Region ofAvenue China, Xi’an 710049, University of Technology, Xi’an, Shaanxi, 710048, P.R.China b Veolia Recherche & Innovation, 291 Dreyfous Daniel, 78520 Limay, France c State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an, Shaanxi, 710048, P.R.China c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France

I. Andrić a

Abstract Abstract Metallurgical industry accounts for 20.40% of the total energy consumption in the industry of China. Energy saving from furnace Abstract Metallurgical industry accounts for 20.40% the total consumption of in China. the industry Energy from furnace slag of the steel industry is essential for theofclean and energy green development Thus,ofinChina. this paper, thesaving thermal effect and slag of the steel industry is essential for the clean and green development of China. Thus, in this paper, the thermal effect kinetic analysis of the biomass mixed with furnace slag at different mass ratios (10 wt%, 30 wt.% and 50 wt.%) was investigated District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasingand the oC. (10 kinetic analysis the biomass with furnace slag at different ratios wt%, 30was wt.% andare 50returned wt.%) investigated selected as the was primary organic via TGA under different heating from ambient temperature to 900 greenhouse gasofemissions frommixed therate building sector. These systemsmass require highCellulose investments which through the heat oC. Cellulose was selected as the primary organic via TGA under different rateconditions frommethod ambient temperature 900 policies, compound intobiomass, and heating iso-conversional appliedrenovation forto calculating activation energy. The maximum decomposition sales. Due the changed climate andwas building heat demand in the future could decrease, compound in biomass, and iso-conversional method was applied for calculating activation energy. The maximum decomposition rate and temperature of maximum decomposition rate get higher as the heating rate increases. Furnace slag shows positive prolonging the investment return period. rate ofpaper maximum decomposition rate of get higher as the heating ratetheory increases. Furnace shows positive synergistic effectsofunder 30% mass ratio with 6% higher volatile yield than that from calculation. Theslag average activation Theand maintemperature scope this is to assess the feasibility using the heat demand – outdoor temperature function for heat demand -1, 260.81 -1, 132.79 -1 and synergistic effects under massSlag-CE-30, ratio within6% higher(Portugal), volatile that theory calculation. The average activation kJ·mol kJ·mol 159.45 energy values ofdistrict CE, Slag-CE-10, Slag-CE-50 were yield 187.54 kJ·mol forecast. The of30% Alvalade, located Lisbon wasthan used as-1from a case study. The district is consisted of 665 -1 -1 -1values energy CE,inSlag-CE-10, Slag-CE-30, Slag-CE-50 wereThree 187.54 kJ·molscenarios , 260.81(low, kJ·mol , 132.79 kJ·mol and 159.45 . thatofvary kJ·mol buildings both construction period and typology. weather medium, high) and three district -1. kJ·mol renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Copyright © 2018 Elsevier All rights reserved. compared results fromLtd. a dynamic heat demand model, previously developed and validated by the authors. © 2019 The©with Authors. Published by Elsevier Ltd. th International Conference on Applied Copyright 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee Theisresults showed when onlythe weather change is license considered, the marginof of the error10could be acceptable for some applications This an open accessthat article under CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/) th International Conference on Applied Selection and peer-review under responsibility of the scientific committee of the 10 Energy (ICAE2018). (the error inunder annual demand was than 20% for all weather scenarios However, after introducing Peer-review responsibility of lower the scientific committee of ICAE2018 – Theconsidered). 10th International Conference on Appliedrenovation Energy. Energy (ICAE2018). scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). Keywords: slag;coefficient Cellulose; biomass; CharonStructure The valueFurnace of slope increased averageEvolution; within the range of 3.8% up to 8% per decade, that corresponds to the Keywords: Furnace slag; Cellulose; biomass; Char Structure Evolution; decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: +0-86-02982665836; fax: +0-86-02982665836. Cooling. * Corresponding author. Tel.: +0-86-02982665836; fax: +0-86-02982665836. E-mail address: [email protected] E-mail address: [email protected] Keywords: Heat demand; Forecast; Climate change

1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. 1876-6102 Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the 10 th International Conference on Selection and peer-review under responsibility the scientific Selection and peer-review under responsibility of the scientific committee of the 10 th International Conference on Applied Energy (ICAE2018). Applied Energy (ICAE2018). 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 – The 10th International Conference on Applied Energy. 10.1016/j.egypro.2019.01.129

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1. Introduction In 2014, the metallurgical industry in China consumed about 868 million tons of standard coal, accounting for 20.40% of the total energy consumption in the industry. Metallurgical industry shows great potential because of the waste heat resource in slag. Moreover, the amount of liquid slag whose sensible heat per ton of molten slag is equivalent to 60 kg of standard coal in China is about 343 million tons, equivalent to about 20.58 million tons of standard coal. The output of steel slag and blast furnace slag is relatively high, which are 105.04 million tons and 238.34 million tons, equivalent to 7.085 million tons of standard coal and 14.19 million tons of standard coal. However, there is no effective technology to recycle the blast furnace slag and steel slag with high-quality waste heat resource at present. Furthermore, a significant amount of sensible heat energy is dissipated in vain, which means the enormous potential of energy conservation and emission reduction. Water quenching is a conventional treatment method within the physical and chemical methods for blast furnace slag, which can be concretely divided into OCP, RASA, TYNA, INBA and MingTe method according to the technological process[1, 2]. The water quenching slag treatment technology is known as having problems such as the massive consumption of the fresh water, the low utilization of sensible heat, and the pollutant emission of sulfur dioxide, hydrogen sulfide, et al. It is unable to adapt to the urgent demand for energy saving and emission reduction in iron and steel industry in China. Thus, it is necessary to find a efficient and pollution-free technology to recycle liquid slag. The chemical method has been proved to be an effective way to employ the waste heart and convert some heat energy into chemical energy[35]. At present, some thermochemical conversion of all-component biomass and blast furnace slag has been reported[3-8]. The diversification of biomass types leads to the diversification of product distribution. In this paper, cellulose, the main component of biomass, was selected to mix with furnace slag for pyrolysis via TGA. 2. Materials and Methods 2.1. Materials The furnace slag composition data is shown in Table 1. The main components of the furnace slag are CaO, SiO 2, Al2O3, and MgO, which accounts for 38.02%, 36.33%, 10.46% and 8.4%, and also contains a small amount of FeO, about 0.48%. The alkalinity of the furnace slag is about 1.02. Cellulose (CE), which contributes about 30-50 wt% of the lignocellulosic biomass, was purchased from Sigma– Aldrich Co., Ltd. Table 2 shows the ultimate and proximate analyses of CE. It is mainly composed of carbon, oxygen and hydrogen elements and the proximate analysis indicates that the volatile products dominate with a small amount of fixed carbon. Table 1. Analysis of the furnace slag. FeO

SiO2

Al2O3

CaO

MgO

MnO

BaO

S

K2O

Na2O

V2O5

TiO2

ZnO

0.48

36.33

10.46

38.02

8.4

1.07

2.44

1.43

0.908

0.429

0.03

0.840

0.006

Table 2. Proximate and ultimate analyses of CE. Proximate analysis (wt. %, ad) Moisture, M

Ash, A

Volatile, V

Fixed carbon, FC

Ultimate analysis (wt. %, daf) Carbon, C

Hydrogen, H

4.67 0.07 93.37 1.89 51.47 ad: Air-dried; daf: Dry ash-free; t: Total content; c: Calculated by difference.

2.87

Nitrogen, N

Sulfur, St

Oxygen, Oc

1.69

0.03

43.93

2.2. Experimental method Thermogravimetric analysis was performed via an HCT-2 Thermogravimetric analyzer (Beijing Henven Instrument). Approximately 10mg of the sample was measured in each trial for mitigating the heat and mass transfer

Zhiqiang Wu et al. / Energy Procedia 158 (2019) 440–445 Author name / Energy Procedia 00 (2018) 000–000

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3

effects and was heated from 25 oC to 900 oC with three heating rates(10, 20, 40 oC·min-1) under a nitrogen flow of 60 ml·min-1. Detailed information about the method can be found in previous research[9-11]. 2.3. XRD characterization of furnace slag As can be seen from Figure 1, XRD analysis on the furnace slag with different particle size was in agreement the result from table 1.

(a) Furnace slag 0.1-0.15mm

(b)Furnace slag 0.075-0.1mm

(c)Furnace slag less than 0.075mm

Figure 1. XRD analysis on furnace slag under various diameter

3. Results and Discussion 3.1. Pyrolysis characteristics Figure 2.shows the pyrolysis characteristics of CE under different heating rates(10, 20, 40 oC·min-1). The CE curve displays an obvious mass conversion at 310 - 450 oC. CE showed the maximum peak value at 341 oC with 3.92 %·min-1, 353 oC with 4.87 %·min-1, 361 oC with 7.00 %·min-1 under the heating rates of 10, 20, 40 oC·min-1.

o

CE-10 C/min o CE-20 C/min o CE-40 C/min

α/%

60 40 20 0

200

400

600 o

Temperature/ C

800

o

CE-10 C/min o CE-20 C/min o CE-40 C/min

-1

80

(b) 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 -5.5 -6.0 -6.5 -7.0 -7.5

DTG/%·min

(a) 100

200

400

600

800

Temperature/oC

Figure 2. Conversion and DTG curves of CE under different heating rates

Figure 3 and Figure 4 illustrate the conversion and DTG curve of CE mixed with 10% and 30% furnace slag. The temperature of maximum decomposition rate moves toward the higher side as the heating rate increases. The devolatilization index (Di) was applied to estimate the pyrolysis performance and the definition of D i as follows: Di =Rmax/(TinTmaxΔT1/2). The meaning of parameters is shown in Table 3, and these parameters can be obtained from the TG and DTG profiles. Table 3 lists several characteristic parameters of thermal behavior of copyrolysis of CE and furnace slag under 20 oC·min-1. CE showed the maximum peak value at 353 oC with 4.36%·min-1. DTG profiles of 10% slag, 30% slag and 50% slag were observed with the values of 4.06%·min-1,

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3.22%·min-1 and 2.02%·min-1, at 356 oC, 358 oC and 360 oC, respectively. Also, the devolatilization index (Di) was calculated to estimate the performance of volatile matters releasing. A higher value of D i meant that the releasing of volatile was more easily. Di of CE, Slag-CE-10, Slag-CE-30, and Slag-CE-50 are 139.39, 129.36, 92.99, 52.22 108 %·min-1·oC -3, which means the addition of slag may inhibit the volatile product during the pyrolysis process.

o

Slag-CE-10-10 C/min o Slag-CE-10-20 C/min o Slag-CE-10-40 C/min

α/%

60 40 20 0

200

400

600

o

Slag-CE-10-10 C/min o Slag-CE-10-20 C/min o Slag-CE-10-40 C/min

-1

80

(b) 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 -5.5 -6.0 -6.5 -7.0 -7.5

DTG/%·min

(a) 100

200

800

400

600

800

Temperature/oC

o

Temperature/ C

Figure 3. Conversion and DTG curves of CE mixed with 10% furnace slag under different heating rates

o

Slag-CE-30-10 C/min o Slag-CE-30-20 C/min o Slag-CE-30-40 C/min

α/%

60 40 20 0

200

400

600

800

o

Slag-CE-30-10 C/min o Slag-CE-30-20 C/min o Slag-CE-30-40 C/min

-1

80

(b) 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 -5.5 -6.0 -6.5 -7.0

DTG/%·min

(a) 100

o

200

Temperature/ C

400

600

Temperature/oC

Figure 4. Conversion and DTG curves of CE mixed with 30% furnace slag under different heating rates Table 3. Thermal behavior of pyrolysis parameters from co-pyrolysis of CE and furnace slag under 20 oC·min-1

Parameters

CE

Slag-CE-10

Slag-CE-30

Slag-CE-50

Tin(oC)

313

316

313

321

Rmax(%·min-1)

-4.36

-4.06

-3.22

-2.02

Tmax(oC)

353

356

358

360

△T1/2(oC)

28.3

27.9

30.9

33.4

Di(10-8%·min-1·oC -3)

139.39

129.36

92.99

52.22

Solid yield(%)

11.85

19.32

32.63

59.13

WExp (%)

88.15

80.68

67.37

40.87

WCal(%)

-

79.34

61.71

44.08

800

Author name / Energy Procedia 00 (2018) 000–000

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Zhiqiang Wu et al. / Energy Procedia 158 (2019) 440–445

444 (a) 100

(b) 0 (b ) 0

80

-1 -1

40

DTG/%·min

TG/%

60

DTG/%·min

-1

-1

CE Slag-CE-10 Slag-CE-30 Slag-CE-50 Slag

20 0

200

-2

-2 -3 -4 -5

-3

300

350

400

600 o

800

450

CE Slag-CE-10 Slag-CE-30 Slag-CE-50 Slag

-4

Temperature/ C

400 o

Temperature/ C

200

400

600

800

o

Temperature/ C

Figure 5. Comparison of TG and DTG curves of CE mixed with different mass ratio of furnace slag

3.2. Synergistic effect The experimental values from the TG profiles were compared with the calculated values to evaluate the synergistic effects from co-pyrolysis of Slag and Cellulose.WExperimental is the testing value from TG profile of CE and the mixtures while WCalculated is obtained by the sum of individual sample TG profiles, which can be defined as follows: WCalculated = XCWC+XSWS. Where XC and XS are the mixing ratios of Cellulose and Slag in the mixture, and WC and WS are the mass losses from the TG profiles of individual samples with the same experimental condition as the mixture. Table 3 shows the final experimental, and calculated weight loss of CE mixed with 10%, 30% and 50% under 20oC·min-1. For the mixture of 10% slag, the experimental and calculated values are almost the same, which means there are no synergistic effects. However, as the slag ratio increase to 30%, the synergistic effects may present positive effect on transfer of volatile via the experimental weight loss of 67.37%, approximately 6% higher than the calculated value. Moreover, the mixture of slag leads to a higher yield of solid with the mass ratio of slag increasing to 50%. 3.3. Kinetic analysis 4. Table 4. Kinetic parameters from co-pyrolysis of CE and slag

α 0.2 0.3 0.4 0.5 0.6 0.7 0.8 average

CE E(kJ·mol-1) 213.93 200.73 189.13 188.54 177.10 175.35 167.98 187.54

Slag-CE-10 Slag-CE-30 Slag-CE-50 R2 E(kJ·mol-1) R2 E(kJ·mol-1) R2 E(kJ·mol-1) R2 0.9952 322.18 0.9973 148.58 0.9773 189.46 1.0000 0.9960 281.51 0.9915 139.94 0.9832 170.32 1.0000 0.9975 271.13 0.9953 134.33 0.9866 157.82 1.0000 0.9971 255.27 0.9893 132.87 0.9903 156.61 0.9999 0.9986 248.65 0.9900 128.63 0.9910 153.65 0.9999 0.9991 233.00 0.9816 123.13 0.9915 147.52 0.9999 0.9995 213.93 0.9769 122.07 0.9932 140.78 1.0000 260.81 132.79 159.45 -

Table 4 and Figure 6 shows the kinetic parameters of the samples calculated through the KAS method. The R2 of the average energy (E) estimated with a series of conversion rate (0.20-0.80) were close to 1, indicating the data met with satisfaction. The average activation energy (E) values of CE, Slag-CE-10, Slag-CE-30, Slag-CE-50 were

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187.54 kJ·mol-1, 260.81 kJ·mol-1, 132.79 kJ·mol-1, and 159.45 kJ·mol-1. For Slag-CE-30, the values of E under all α were smaller than those of other samples, which illustrate that the synergistic effects on transfer of volatile. (a)

KAS

CE Slag-CE-10 Slag-CE-30 Slag-CE-50 Slag

E/kJmol

-1

300

200

100

0.2

0.4

0.6

0.8



Figure 6. Distribution of activation energy from co-pyrolysis of CE and furnace slag.

5. Conclusion In this work, the thermal effect and kinetic analysis of the cellulose and the mixture with furnace slag at different ratios were investigated under different heating rate. The TG curve of CE displays an obvious mass conversion at 310 - 450 oC. The maximum decomposition rate and temperature of maximum decomposition rate get higher as the heating rate increases. Furnace slag shows positive synergistic effects under 30% mass ratio with 6% higher volatile yield than that from theory calculation, consistent with the result of the lowest average active energy of 132.79

kJ·mol-1 among these samples.

Acknowledgments This work was supported by the National Key R&D Program of China (Grant No: 2017YFB0603603) and National Natural Science Foundation of China (Grant Nos: 51606149, 21576219). References [1] A.M. Rashad, A Brief Review on Blast-Furnace Slag and Copper Slag as Fine Aggregate in Mortar and Concrete Based on Portland Cement, Rev Adv Mater Sci, 44 (2016) 221-237. [2] C. Kambole, P. Paige-Green, W.K. Kupolati, J.M. Ndambuki, A.O. Adeboje, Basic oxygen furnace slag for road pavements: A review of material characteristics and performance for effective utilisation in southern Africa, Constr Build Mater, 148 (2017) 618-631. [3] S.Y. Luo, C.J. Yi, Y.M. Zhou, Bio-oil production by pyrolysis of biomass using hot blast furnace slag, Renew Energ, 50 (2013) 373-377. [4] W.J. Duan, Q.B. Yu, J.X. Liu, T.W. Wu, F. Yang, Q. Qin, Experimental and kinetic study of steam gasification of low-rank coal in molten blast furnace slag, Energy, 111 (2016) 859-868. [5] S.Y. Luo, J. Fu, Y.M. Zhou, C.J. Yi, The production of hydrogen-rich gas by catalytic pyrolysis of biomass using waste heat from blastfurnace slag, Renew Energ, 101 (2017) 1030-1036. [6] W.J. Duan, Q.B. Yu, K. Wang, Q. Qin, L.M. Hou, X. Yao, T.W. Wu, ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system, Energ Convers Manage, 100 (2015) 30-36. [7] X. Yao, Q.B. Yu, H.Q. Xie, W.J. Duan, Z.R. Han, S.H. Liu, Q. Qin, The production of hydrogen through steam reforming of bio-oil model compounds recovering waste heat from blast furnace slag, J Therm Anal Calorim, 131 (2018) 2951-2962. [8] Y.Q. Sun, Z.T. Zhang, S. Seetharaman, L.L. Liu, X.D. Wang, Characteristics of low temperature biomass gasification and syngas release behavior using hot slag, Rsc Adv, 4 (2014) 62105-62114. [9] Z. Wu, W. Yang, X. Tian, B. Yang, Synergistic effects from co-pyrolysis of low-rank coal and model components of microalgae biomass, Energ Convers Manage, 135 (2017) 212-225. [10] Z. Wu, W. Yang, H. Meng, J. Zhao, L. Chen, Z. Luo, S. Wang, Physicochemical structure and gasification reactivity of co-pyrolysis char from two kinds of coal blended with lignocellulosic biomass: Effects of the carboxymethylcellulose sodium, Appl Energ, 207 (2017) 96-106. [11] Z. Wu, W. Yang, L. Chen, H. Meng, J. Zhao, S. Wang, Morphology and microstructure of co-pyrolysis char from bituminous coal blended with lignocellulosic biomass: Effects of cellulose, hemicellulose and lignin, Applied Thermal Engineering, 116 (2017) 24-32.