Investigation of Carbon Black Production from Coal Tar via Chemical

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Investigation of Carbon Black Production from Coal Tar via Chemical Looping Pyrolysis Xu Jiang, Longlong Zhang, Fengyin Wang, Yongzhuo Liu, Qingjie Guo, and Cuiping Wang Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.5b02915 • Publication Date (Web): 16 Feb 2016 Downloaded from http://pubs.acs.org on February 22, 2016

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Energy & Fuels

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Investigation of Carbon Black Production from Coal Tar via Chemical Looping Pyrolysis

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Xu Jiang1, Longlong Zhang1, Fengyin Wang1, Yongzhuo Liu2, Qingjie Guo2,

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Cuiping Wang1,*

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1. Energy Engineering Research Institute, Qingdao University, Qingdao 266071, China

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2. College of Chemistry and Chemical Engineering, Qingdao University of Science and

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Technology, Qingdao, 266042, China

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Abstract: Chemical looping pyrolysis (CLP) process was used to produce reinforced

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carbon black (CB) in this paper, and the effects on energy conservation and emission

11

reduction of the method were investigated. The characteristics of the oxygen carrier (OC)

12

type, particle size, and reaction temperature on the CB yield and the morphological

13

structure were examined. In addition, the CB morphological structure and flue gas

14

emission were analyzed using the TEM, XRD, GC (Gas Chromatography), and flue gas

15

analyzer. The results indicated that when the same particle size and reaction temperature

16

were used, compared with CaSO4 OC, Fe2O3 OC was more effective at catalyzing coal tar.

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This catalysis occurred via the breaking of C-H bonds to generate CB and H2, and the

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probability of a gasification reaction between the lattice oxygen and the CB was lower.

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Therefore, the CB by Fe2O3 OC is of a higher yield and has a smaller and more uniform

1 2

*Corresponding author. Tel: 860532-85953720. E-mail: [email protected] (Cuiping Wang)

ACS Paragon Plus Environment

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particle size, as well as a more developed structure. With temperature increasing, the

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morphological structures of two types of CBs were improved. Two types of OCs have an

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inhibitory effect on NOx production, and the Fe2O3 OC is more effective for emission

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reduction.

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Keywords: chemical looping pyrolysis; oxygen carrier; carbon black; yield; gaseous

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pollutants reduction.

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1. Introduction

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Carbon black (CB) has a variety of applications (e.g., coloring agent,

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conductivity agent, and an ultraviolet screening agent) and is widely used in the

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fields of coatings, printing inks, plastics and others1,2. In addition, CB is also a

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type of widely used carbon material that is primarily used as a rubber reinforcing

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agent3, and its consumption in the rubber industry accounts for approximately

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89.5% of the total production. Experiments have shown that a smaller particle size,

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a larger specific surface area and a more developed dendritic structure could

34

effectively improve the reinforcing performance of CB4. Generally, when the CB

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particle size is less than 50 nm, the reinforcing performance is improved5.

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The CB production methods primarily include the contact method (e.g.,

37

channel, roller and disk methods), the thermal cracking method, the furnace

38

method (gas or oil furnace method), and others. Due to their large energy


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consumption, notable amount of pollution, lower yields and other factors, the first

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two methods are gradually being eliminated. The CB produced via the oil furnace

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method, which is the current primary production method, accounts for more than

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90% of the total output6. The principle of the oil furnace method is as follows:

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coal tar is sprayed into a reactor via compressed air and then comes into contact

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with high temperature flue gas (usually higher than 1800 ℃, which is produced

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from fuel oil combustion); as a result, the coal tar is rapidly gasified and

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pyrolyzed to generate CB. The carbon particle size is always finer with higher

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temperatures. Cold water must be sprayed to decrease the flue gas temperature

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and to terminate the deeper reaction of CB. In this method, the reaction

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temperature is notably high, meaning that the energy consumption is quite large.

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The injected cold water causes rapid increases of the flow rate and the moisture

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content in the exhaust gas; as a result, the heat value of the exhaust gas is reduced.

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In addition, the exhaust gas contains a large number of pollutant gases, such as

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NOx and SO27.

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Thus, a new method to produce reinforcing CB using chemical looping

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pyrolysis (CLP) is proposed in this paper. The principle was that the oxygen

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carriers (OCs) circulated between the air reactor (AR) and the pyrolysis reactor

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(PR) to achieve oxygen transfer. In the ideal PR, the OC lattice oxygen primarily

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reacted with the active H in coal tar, thereby promoting the generation of CB and


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reducing the OC. Next, the reduced OC returned to the AR, which was oxidized

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with air, realizing the OC regeneration and abundant heat release to maintain the

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whole cycle process8. The chemical looping reaction temperature (approximately

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1000 °C) is lower in a fluidized bed reactor9. From the theoretical deduction, the

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coal tar is evenly dispersed and pyrolyzed by fluidized OCs. The OC particles not

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only enhanced the heat transfer but also catalyzed the breaking of the hydrocarbon

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bonds and promoted the aggregation of carbon atoms into microcrystals. The

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residence time of the flow reaction passing through the high temperature region

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was controlled to adjust the process in which the microcrystals CB particles

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form10. Due to the lower reaction temperature, the energy consumption and

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irreversible loss were both reduced, and the thermal NOx also decreased.

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Generally, the OCs has an inhibitory effect on gaseous pollutants11. Therefore, this

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research is aimed to discover the new CB structure characteristics, energy

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conservation and emissions reduction using the CLP method for CB production.

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2. Experimental

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2.1 Materials

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The coal tar used in the experiments was obtained from the coking plant of

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Jinan Iron and Steel Company in Shandong Province, it is the byproduct of the

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coke furnace gas. At room temperature, the coal tar was dark brown with a


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pungent smell, and its liquidity was good after heating to 50 ℃. The proximate

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and ultimate analysis of the coal tar is shown in Table 1.

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Table 1 Proximate and ultimate analysis of the coal tar Proximate analysisa (wt%)

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Ultimate analysisa (wt%)

LHVb

M

V

FC*

A

C

H

O*

N

S

（MJ/kg）

3.22

66.47

30.22

0.09

91.34

5.43

1.25

1.06

0.92

38.191

Note：M-Moisture，V-Volatile，A-Ash，FC-Fixed Carbon，LHV-Low heat value；

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* The value was obtained via subtraction；

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a

As received basis；

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b

Dry basis.

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Due to their excellent performance of carrying oxygen and low price, two

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types of OCs were used in the experiments and they are also commonly used in

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many chemical-looping study works8-9,11. One was natural hematite and crushed in

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a crusher. The particles were screened into three groups, with particle sizes of

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approximately 0.1 mm, 0.5 mm and 1 mm. Each group was calcined for 2 h in a

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950 ℃ muffle furnace. The composition analysis of the calcined hematite is listed

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in Table 2. The second OC was analytic pure dihydrate calcium sulfate. The

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particles were also crushed and screened into three groups of the same sizes. The

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crystal water was removed after calcination for 2 h at 163 ℃. Its composition

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analysis is provided in Table 3.


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95

96

97

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Table 2 Chemical composition analysis of hematite Component

Fe2O3

Al2O3

SiO2

CaO

TiO2

K2O

Na2O

P2O5

Other

Content (%)

87.85

3.25

7.92

0.15

0.1

0.15

0.15

0.28

0.15

Table 3 Chemical composition analysis of gypsum Component

CaSO4

MgO

Al2O3

Fe2O3

SiO2

TiO2

Na2O

K2O

Other

Content (%)

93.26

2.39

0.31

0.13

0.58

0.01

0.06

0.05

3.21

2.2 Facility and method

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The testing apparatus is shown in Fig. 1. The apparatus primarily includes an

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intake pipe, a feeding device (for OC, coal tar), a discharge pipe, a two-stage

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heating furnace, a nitrogen cooling coil, a cyclone separator, and a double filter

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screen. The furnace is the PR in a CLP process, mainly used in our work for CB

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production; the OC regeneration process in AR is not involved in this apparatus,

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but in the Muffle furnace. The diameter of heating furnace is 32 mm, and the

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height is 700 mm. The electric heating element twines around the outer surface of

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the furnace, and the furnace and the heating element were coated using refractory

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material. The two-stage heating furnace is conducive to maintaining the operating

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temperature, and it even helps to realize different temperatures at two stages; the

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furnace temperatures at the two sections are the same in the current experiments.

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Two thermocouples are respectively arranged at the surface centers of two stages


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to measure the operating temperatures. jacket cooler feeding device N 2

coil

filter screen water

cyclone separator

second-stage heating

first-stage heating

intake pipe

discharge pipe

N2

111 112

Fig. 1. Schematic diagram of the experimental apparatus

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First, some of the OCs were added to the furnace through the feeding device.

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During the heating process, an appropriate amount of high purity nitrogen was

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preheated in the top coil; next, the N2 as fluidization gas was blown into the

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furnace through the bottom intake pipe, and then the air in the furnace was

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drained. When the temperature reached the set value, the coal tar and another

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portion of the OC particles were added to the furnace. According to the critical

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fluidization velocity of the OC (0.36 m/s for 0.5-mm-Fe2O3 OC, and 0.21 m/s for

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0.5-mm-CaSO4 OC), the fluidization gas flow was properly adjusted. The coal tar

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was pyrolyzed, resulting in formation of a carbon crystallite. The crystallites

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agglomerated to form CB particles. The CBs carried by the flue gas flow were


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cooled when passed through a N2 cooling coil and a water jacket cooler, and then

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a small amount of CB and most of the suspension of OCs were captured by a

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cyclone separator. Most CBs were collected with the double filter screen.

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Afterward, the flue gas was collected with a gas collecting bag periodically. When

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each experiment finished, the reduced OC was discharged through the bottom

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pipe and regenerated in the muffle furnace.

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Prior to the experimental studies, according to the principle of Gibbs free

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energy minimization, the reaction process was simulated using HSC chemistry

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software. When the mass ratios of hematite/tar and gypsum/tar are 1.3 and 1.6,

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respectively, the CB yield is higher. In this case, the oxygen supply from two

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types of OCs are approximately equivalent, which prevents the error caused by

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different oxygen supplies. Therefore, the actual experiments were conducted

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according to the two types of mass ratios. To guarantee coal tar pyrolysis, the

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design consumption of coal tar is approximately 0.3 kg/h. The mass flow rate of

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coal tar used in each experiment was 5 g/min. To prevent CaSO4 pyrolysis, the

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temperature in furnace was set to 700-900 °C as three experimental temperatures

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with a 100 °C interval.

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3. Results and discussion

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3.1 The influence of the OC particle size


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The OC particle size has an obvious effect on the yield and impurity content

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of the CB. The yield is equal to the collected CB mass divided by the carbon

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content of the coal tar. And the content of impurity in CB, including the mingled

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reduced OC powder and trace ash, is determined by calcining the CB sample at

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high temperature. When the CB burns out and the remaining mass is mainly the

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oxidized OC and ash, and the mass of reduced OC could be calculated, whose

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content is its mass divided by the sample mass.

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According to the HSC theoretical calculation and previous experimental

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verification, the OC activity increased with the reaction temperature increasing,

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and the CB yield also improved. So the compared effect of particle size is chosen

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the results when maximum reaction temperature of 900°C, the effect of the OC

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particle size is demonstrated as shown in Fig. 2. Fe2O3 impurity

100

Fe2O3 yield CaSO4 impurity

80

Mass fraction /%

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Energy & Fuels

CaSO4 yield 60 40 20 0

0.1

0.5

1

Particle size of oxygen carrier / mm

Fig. 2. Effect of the OC particle size on the CB yield and purity


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154 155

"Fe2O3 impurity" denotes the impurity content in CB when Fe2O3 is used as the OC. Similarly, "Fe2O3 yield" denotes the CB yield when the OC is Fe2O3.

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Fig. 2 shows that with an increasing particle size, the yields of the two types

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of CB decreased. The CB yields below the particle sizes of 0.1 mm and 0.5 mm

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are approximately the same; however, the yield for particle sizes of 1 mm

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decreases more than the former two. This result indicates that when the particle

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size is smaller, the OC reactivity is higher, which is beneficial to increase the

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effective contact area between the coal tar and the OC and to promote CB

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generation. For the similar particle size range used in this paper, the reaction rate

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is similar and the fluctuation in the CB yield is small. However, when the particle

164

size is too large, e.g., 1 mm, the reaction rate decreases and the CB yield is lower.

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The CB yield of Fe2O3 is slightly higher than that of CaSO4 in the current particle

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size range, which suggests that the reactivity between the Fe2O3 and coal tar is

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higher. Therefore, the Fe2O3 can more effectively catalyze the rupturing of the

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hydrocarbon bonds and promote the reaction between a lattice oxygen and

169

hydrogen, resulting in the remaining carbon. As a result, the CB yield is higher, as

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will be confirmed in the following chromatographic analysis.

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Although the yields for the CBs with a particle size of less than 0.1 mm are

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the highest, both types of CBs contain fewer OC impurities, and the impurity

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content of the CaSO4 CB is the highest. The other two groups have almost no


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impurities, indicating that the OC that has a smaller particle size is easier to mix

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into the CB gas flow. This mixing increases the impurity contents of the CB.

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Because the mechanical strength of CaSO4 is lower at a high temperature, it is

177

easy to be broken into fine particles, thereby introducing more impurities in this

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CB. Therefore, to ensure a high yield and to avoid the introduction of impurities,

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the 0.5-mm OC is more appropriate for the following experiments.

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3.2 Analysis of the CB quality as a function of the OC type and reaction

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temperature

(a) 800℃

(b) 900℃

Fig. 3. TEM images of the CB produced using Fe2O3 OC: (a) 800℃ and (b) 900℃ 182

Two types of CBs that were produced using different OCs were characterized

183

using TEM (Transmission Electron Microscopy). The images are shown in Fig. 3

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and Fig. 4. The CBs were both produced at 800℃ and 900℃. The effects of the

185

OC types and the reaction temperature on the CB quality are analyzed via the

186

differences in such factors as CB morphology and particle size.


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As shown in Fig. 3(a), the particle size of the CB produced using the Fe2O3

188

OC at 800℃ is approximately 40 nm. The particle sizes are relatively uniform,

189

their shapes are nearly spherical, and there are few complete single particles. Most

190

of the CB particles aggregate to form a dendritic aggregate, and a small amount of

191

the CB particles are aggregated more closely to form a larger CB block. The

192

particle sizes of the CB produced at 900℃ are smaller at approximately 20 nm.

193

The particle shape is similar to that of the CB produced at 800℃. However, these

194

CB particles are almost linearly connected, and they almost form a ring-shaped

195

aggregate. The overall size of the aggregate is slightly reduced, its spatial

196

structure is more developed, and the specific surface area is also larger. Hence, an

197

increase in the reaction temperature is beneficial to the decrease of CB particle

198

size and to the improvement of the spatial structure, which can enhance the

199

reinforcing performance, according to the reference2. The reason for the decrease

200

of the CB particle size may be due to the increase in the Fe2O3 reactivity at high

201

temperatures, which can more effectively catalyze the breaking of the

202

hydrocarbon bonds. While the lattice oxygen primarily reacts with hydrogen,

203

there is also a small number of CBs involved in the carbon gasification reaction.

204

This process decreases the aggregation of the remaining carbon chains, and

205

smaller crystallites appear. Thus, eventually, smaller CB particles form.


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(a) 800℃

(b) 900℃

Fig. 4. TEM images of the CB produced using the CaSO4 OC: (a) 800℃ and (b) 900℃

206

Fig. 4 shows the comparison of the CBs particle sizes of approximately 60

207

nm and 50 nm produced with CaSO4 under 800℃ and 900℃, respectively. These

208

CB particles are obviously larger than those produced with Fe2O3 OC at the

209

corresponding temperatures, and their size distributions are not uniform. For

210

example, for CBs produced at 800℃, the minimum particle size is less than 10 nm,

211

but the maximum is greater than 100 nm. As shown in Fig. 4(b), with an

212

increasing temperature, the uniformity of the CB particle sizes is slightly

213

improved, and the average particle size is slightly decreased. At the two

214

temperatures, the CBs produced using CaSO4 are spherical, and more complete

215

single particles are found. This phenomenon is more obvious at 900°C, in which

216

the particles are less connected with one another at the edges and the dendritic

217

aggregate formed. However, the aggregate’s spatial structure is undeveloped, the


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overall size is smaller, and there are fewer particles in it. At 800°C, the CB

219

particle gathers together, and the dendritic aggregate is almost not formed.

220

Comparing with CaSO4 OC, the Fe2O3 OC can more effectively catalyze the

221

breaking of the hydrocarbon bonds, then shorter carbon chains aggregate into

222

smaller crystallites. Therefore, eventually, the crystal order and crystallinity of

223

Fe2O3 CB is lower, and the CB particles are also smaller. Under the same

224

fluidization, the smaller CB particles are not easy to deposite and aggregate

225

together, thus the spatial structure of Fe2O3 CB aggregate is more developed.

226

Therefore, from the morphological structure comparison of two types of CBs,

227

under the same conditions, the Fe2O3 OC is better than the CaSO4 OC, and the

228

former is more suitable for the production of CBs.

229

Table 4 Some technical indices of the CBs Average particle size(nm)

Iodine absorption (g/kg)

DBP (10-5 m3/kg)

Standard / Experiment



Fe2O3 CB

26-30 / 30

82±7 / 78.5

102±7 / 99

CaSO4 CB

49-60 / 50

36±6 / 30.5

90±7 / 86

Sample

230

The DBP absorption, iodine absorption and average particle size of the CBs

231

produced from the two types of OCs at 900°C are listed in Table 4. The iodine

232

absorption of the CB produced with Fe2O3 is found to be higher, which indicates


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233

that its specific surface area is larger. In addition, the DBP absorption of this CB is

234

also higher, suggesting that the number of aggregates of these CB particles is

235

higher and that a large number of void volumes are formed; thus, the spatial

236

structure of this aggregate is more developed. This result is consistent with the

237

TEM analysis, which indicates that the test results are reliable. According to the

238

results of various technical indexes listed in national standard of the People's

239

Republic of China (GB 3778-2011), the Fe2O3 CB coincides with the hard CB

240

N330 and the CaSO4 CB coincides with the general purpose CB N660.

241

3.3 X-ray diffraction analysis 26°

2400

0.5mm Fe2O3 OC

2000

Intensity /(a.u.)

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Energy & Fuels

0.5mm CaSO4 OC

1600 1200

43.7°

800 400 0 10

20

30

40

50

60

70

80

90

2Theta / (degrees)

Fig. 5. X-ray diffraction of CBs respectively obtained by Fe2O3 OC and CaSO4 OC 242

The XRD patterns of the CB samples produced at 900°C are shown in Fig. 5.

243

The figure shows that both diffractograms display two broad peaks, implying that

244

the two samples are amorphous carbon materials with small regions of


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245

crystallinity. The peaks at 2θ ≈ 26° for the two samples correspond to the (002)

246

planes of graphitic structures, and the second peak at approximately 43.7° in both

247

samples corresponds to the (100) planes of the graphitic structure. Both of these

248

peaks serve as validation of the successful transformation of the CBs to graphitic

249

nanostructures at the high temperature.

250

The diffraction peak intensity (peak height) of the CaSO4 CB is generally

251

higher than that of the Fe2O3 CB. In addition, the peak intensity can

252

approximately reflect the degree of crystallinity and crystal order. The narrower

253

and more intense diffraction peak indicates that the crystallinity and crystal order

254

of the mini-crystals improved, but that the size is larger. Therefore, the XRD

255

results show that the crystal order and crystallinity of the Fe2O3 CB are lower and

256

that the minicrystal particle size became smaller. Thus, the CB particles composed

257

of these minicrystals are also smaller and irregular in shape. However, the

258

crystallinity of the CaSO4 CB is higher. Specifically, there are more of the larger

259

graphitic minicrystals, and its crystal order is also higher. Thus, the CB particles

260

are larger and nearly spherical. This result is consistent with the above TEM

261

analysis. In addition, we did not observe a sharp peak resulting from impurities in

262

the XRD patterns, indicating that the purity of the produced CBs in this

263

experiment is higher, which is in agreement with the results shown in Fig. 2.

264

3.4. Flue gas analysis


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Four gas components, specifically, H2, CO, CH4 and CO2, from the flue gas

266

were tested using gas chromatography and a flue gas analyzer. The volume

267

fraction of each component was calculated using the normalization method, and

268

the results are shown in Fig. 6. When Fe2O3 is used as the OC, the volume fraction

269

of CO2 in flue gas is significantly lower than that when CaSO4 is used as the OC.

270

However, the H2 volume fraction displays the opposite trend. This behavior may

271

be due to more effective catalysis of the Fe2O3 via the rupturing of the tar

272

hydrocarbon bond than CaSO4 to promote the generation of H2. The gasification

273

reactions between the remaining carbon and the lattice oxygen of Fe2O3 also

274

became difficult; this is beneficial to improve the yield of the Fe2O3 CBs. When

275

CaSO4 is used as the OC, the CO2 content is higher. However, the CO content is

276

lower, which indicates that the lattice oxygen of CaSO4 is more likely to react

277

with the remaining carbon for complete oxidation to the gas phase component,

278

namely, CO2. This lower CO content is also the reason for the low yield of CaSO4

279

CB. From the standpoint of carbon conversion, in the Fe2O3 CB production

280

process, the carbon converted to the gas phase is less than that when CaSO4 was

281

used. Therefore, Fe2O3 OCs are more suitable for the production of CBs.


Energy & Fuels

300

25

CaSO4

CaSO4 Fe2O3

250 Gas concentration /ppm

Fe2O3

20 Volume fraction /%

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 22

15 10 5

Emission limit 200 150 100 50 0

0 H2

CO CH4 Gas component

CO2

NOx SO2 Gas pollutant component

Fig. 6. Gas chromatographic analysis of the

Fig. 7. Analysis of the gas pollutant

gas component

concentration

282

The SO2 and NOx in the flue gas were tested using the flue gas analyzer, and

283

the results are compared with the emission limits (SO2 ≤ 105 ppm and NOx ≤ 195

284

ppm) in the 2015 CB industry access standards of China, which is displayed in

285

Fig. 7. The NOx concentrations in the flue gas are both lower than the emission

286

limit without any denitrification process because the temperature of chemical

287

looping pyrolysis is low, generating almost no thermal NOx. The probability of

288

nitrogen in the coal tar reacting with lattice oxygen of Fe2O3 is lower. Thus, the

289

NOx concentration in flue gas is also lower. However, the SO2 content in the flue

290

gas is both higher than the emission limits, hence the OCs both have less

291

inhibitory effect on the SO2 generation. Comparing with oil furnace method, the

292

reaction temperature in CLP process is much lower due to the catalytic effect of

293

OCs, which makes thermal NOx concentrations declined, thus the CLP method

294

has a certain synergistic effect to reduce the NOx emission. The SO2 concentration


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Energy & Fuels

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in the flue gas is higher when CaSO4 is used as the OC, which may be due to the

296

high temperature decomposition of CaSO4. This decomposition is also one of the

297

reasons for the limited use of CaSO4.

298

4. Conclusions

299

In view of the high energy consumption and pollution problems that result

300

from the production process of the oil furnace method, the method of chemical

301

looping pyrolysis to produce reinforcing CB was studied. The effects of the OC

302

type, particle size, and reaction temperature on the CB yield, quality and gas

303

emission were studied. The primary conclusions of the study are as follows:

304

(1) The CB yield increases as the OC particle size decreases, but there are

305

fewer OC impurities in the CBs when the particle size is too small. Therefore, the

306

size of the OC particles chosen in this experiment was 0.5 mm. With an increasing

307

temperature, the qualities of the two types of CBs both improved.

308

(2) Under the same conditions (the reaction temperature and particle size),

309

the activity of Fe2O3 OC was found to be higher than that of CaSO4 OC. Fe2O3

310

can more effectively catalyze the breaking of the hydrocarbon bonds in tar,

311

thereby promoting the generation of CB and H2. In addition, the gasification

312

reactions between the remaining carbon and lattice oxygens of Fe2O3 proceeded

313

with difficulty. Hence, the yield of Fe2O3 CB is higher. The particle size of the


Energy & Fuels

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

314

Fe2O3 CB is smaller and uniform, and the spatial structure of the aggregate is

315

more developed; thus, the reinforcing performance improved. However, the

316

particle size of the CaSO4 CB is larger and non-uniform, and the dendritic

317

structure is undeveloped, whereas the particle shape is more regular and nearly

318

spherical, making it a general purpose CB.

319

(3) The two types of OCs both have an inhibitory effect on NOx, and the

320

Fe2O3 OC is more effective to reduce emissions. In conclusion, the Fe2O3 OC is

321

more suitable for CB production via chemical looping pyrolysis.

322

Acknowledgments

323

The financial support was received from the Natural Science Foundation of

324

Shandong Province (Project No.ZR2015EM004).

325 326

References

327

(1) Leong, C.-K.; Aoyagi, Y.; Chung, D. D. L. Carbon black pastes as coatings for

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improving thermal gap-filling materials. Carbon 2006, 44 (3), 435-440.

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(2) Pawlyta, M.; Rouzaud, J.-N.; Duber, S. Raman microspectroscopy characterization of

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carbon blacks: spectral analysis and structural information. Carbon 2015, 84, 479-490.

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(3) Kreyenschulte, H.; Richter, S.; Götze, T.; Fischer, D.; Steinhauser, D.; Klüppel, M.;

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Heinrich, G. Interaction of 1-allyl-3-methyl-imidazolium chloride and carbon black and


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its influence on carbon black filled rubbers. Carbon 2012, 50 (10), 3649-3658.

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(4) Ono, K.; Yanaka, M.; Saito, Y.; Aoki, H.; Fukuda, O.; Aoki, T.; Yamaguchi, T. Effect

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(5) Le, H. H.; Ilisch, S.; Radusch, H.-J. Characterization of the effect of the filler

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dispersion on the stress relaxation behavior of carbon black filled rubber composites.

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(6) Zhu, W. Z.; Miser, D. E.; Chan, W. G.; Hajaligol, M. R. HRTEM investigation of some

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commercially available furnace carbon blacks. Carbon 2004, 42 (8-9), 1841-1845.

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the multi-cycle performance of coal/straw chemical loop combustion with α-Fe2O3 as the

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oxygen carrier. Energy Fuels 2014, 28 (6), 4162-4166.

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Yamaguchi, T. Influence of furnace temperature and residence time on configurations of


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Investigation of Carbon Black Production from Coal Tar via Chemical

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