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Cite This: Energy Fuels XXXX, XXX, XXX-XXX
pubs.acs.org/EF
Aromatic Hydrocarbon Production and Catalyst Regeneration in
Pyrolysis of Oily Sludge Using ZSM‑5 Zeolites as Catalysts
Jun Wang, Bing-Cheng Lin, Qun-Xing Huang,* Zeng-Yi Ma, Yong Chi, and Jian-Hua Yan
Institute for Thermal Power Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, Zhejiang 310027, People’s Republic of
China
ABSTRACT: ZSM-5 zeolites were selected as catalysts to promote the aromatization during pyrolysis of oily sludge. The total
aromatic yield and product distribution were investigated to evaluate the efficiency of the catalysts and the influence of operating
condition. The fresh and used catalysts were characterized by means of scanning electron microscopy, inductively coupled plasma
optical emission spectrometry, X-ray diffraction, and ammonia temperature-programmed desorption. Results show that the
highest catalytic activity (93.37%) was achieved with ZSM-5-O [the silicon/aluminum ratio (SAR) is 19] at a retention time of
40 s. The total aromatic yield increases with a longer retention time and higher catalyst dosage. An increase in the SAR value of
ZSM-5 zeolites will reduce its acid density and aromatization activity. The coke deposition leading to deactivation for zeolites was
observed, and calcination was used to regenerate the original catalytic performance. After regeneration, crystallinity was not
affected but the acidity was reduced because of dealumination. The regenerated zeolites showed comparable catalytic activity for
aromatization, and the tricyclic aromatic hydrocarbon content increased with reaction−regeneration cycles.
1. INTRODUCTION
Oily sludge is the solid hazardous waste generated from
petroleum exploitation, transportation, storage, and refinery. It
is in the form of stable emulsion and contains a high proportion
of petroleum hydrocarbons (PHCs). Consequently, the
recovery of the PHCs has attracted wide interest, and many
recover techniques, including solvent extraction, centrifugation
treatment, pyrolysis, microwave irradiation, and ultrasonic
treatment, have been developed.1 Among these technologies,
pyrolysis is the most promising method to recover valuable
liquid oils2 using catalysts or to obtain special hydrocarbon
components by designed pyrolysis conditions.3,4
Aromatic compounds are important and widely used
industrial raw materials for the synthesis of polymers.5
Especially, C8−C17 aromatic hydrocarbons play an important
role in fuel oil used for aviation turbines.6−8 Currently,
aromatics are mainly produced from petroleum and coal. For
example, lignin has been widely used for aromatic production
through pyrolysis for its rich source5 and high yields.9,10 As a
result of the depletion of fossil fuels, many researchers have
investigated the possibility of producing aromatic hydrocarbons
from waste materials, such as wood sawdust,11 bio-oils,12 waste
cardboard,13 and forest products.14
As a result of the high content of the oil fraction, oily sludge
has high potential for aromatic hydrocarbon production.
Previous studies15−18 have found many valuable aromatic
species in the pyrolysis products of oily sludge. Nazem et al.17
obtained mono- and polyaromatic compounds through direct
hydrothermal liquefaction of oily sludge from an Iranian oil
refinery. Evans et al.16 recovered C5−C11 hydrocarbons from
oily sludge, and the analysis results showed the predominance
of polar aromatic compounds, some of which belonged to the
polycyclic aromatic hydrocarbon (PAH) family. Qin et al.18
studied the pyrolysis treatment of oily sludge from the steel
industry in a fluidized bed reactor. Although the aromatic
hydrocarbon content in pyrolysis oil products was higher than
© XXXX American Chemical Society
that in feed oil, it was still rather low (6.68−23.54%). To
improve the yield of aromatic hydrocarbons through pyrolysis,
a catalyst is essential.
Zeolites, especially ZSM-5 and HZSM-5, have been wellknown as excellent catalysts in oil refinery, petrochemistry, and
pollution control.19−22 In comparison to other amorphous
silica−alumina catalysts, ZSM-5 zeolites possess higher acidity,
resulting in enhanced selectivity.23 More importantly, ZSM-5
has high resistance to deactivation as a result of its threedimensional and well-connected micropore structure.24 Many
studies have investigated aromatic hydrocarbon production
from various raw materials over ZSM-5 zeolites, which
exhibited remarkable capability.25 Mihalcik et al.26 and Li et
al.25 found significant improvement in aromatic hydrocarbon
production over ZSM-5 zeolites. The research of Liu et al.27
revealed that the aromatics could be generated directly from
lignite by catalytic fast pyrolysis over metal-loaded HZSM-5
and the aromatic yield was remarkably increased.
Although ZSM-5 zeolite has shown excellent performance in
aromatization, it will be deactivated by coke deposition.
Previous studies found that even the coke could be removed
by calcination at high temperatures (>450 °C) under an
oxidizing environment without any obvious framework
damage,28,29 some active catalytic aluminate would be burned
away,30−32 and it is very difficult to recover its original catalytic
performance.
This work is aimed to produce liquid products with a high
aromatic content during pyrolysis treatment of oily sludge over
ZSM-5 with different silicon/aluminum ratios (SARs). The
effects of the retention time, SAR, and catalyst dosage on the
product yield and quality were experimentally investigated.
Received: June 28, 2017
Revised: October 9, 2017
Published: October 10, 2017
A
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
Energy & Fuels
10 min, then ramped to 270 °C in 10 min, and then kept at 270 °C for
10 min.
The ammonia temperature-programmed desorption (NH3-TPD)
was carried out on a Finesorb-3010 (Finetech, Zhejiang, China) to
characterize the acid distribution on the ZSM-5 zeolite. The specimen
was first heated to 500 °C in a stream of helium (He, 60 mL/min) and
preheated at that atmosphere for 1 h. Then, the sample was cooled to
120 °C and subjected to ammonia (50% NH3/He, 60 mL/min) for 1
h to saturation. Then, the sample was heated to 700 °C at 10 °C/min
after blowing a sweep of argon (Ar, 60 mL/min) for 1 h. The peaks
were recorded by a mass spectrometer (MS), and the area
demonstrates the acid amount.
The total amount of Si and Al in the zeolites was quantified by
inductively coupled plasma optical emission spectrometry (ICP−OES,
iCAP6300, Thermo Fisher Scientific, Waltham, MA, U.S.A.). Prior to
the analysis, the samples were digested in a mixed solution of
hydrochloric acid (HCl), nitric acid (HNO3), and hydrofluoric acid
(HF). A mixture of 0.1 g of sample and 10 mL of solution was heated
in a polytetrafluoroethylene (PTFE) beaker on a heating plate until
clear and transparent. After cooling, the solution was diluted for
measurement.
Thermogravimetric (TG) analysis was performed using a TA
Instruments−Waters (New Castle, DE, U.S.A.) TGA Q50 device to
characterize carbon deposition on the zeolite catalysts. Samples were
heated from 50 to 900 °C at a heating rate of 10 °C/min with an air
flow rate of 60 mL/min.
Moreover, the deactivated zeolites were regenerated and reused
in the pyrolysis process. The finding of this paper can provide
essential and useful insight into the improvement of the
aromatic yield from oily sludge.
2. MATERIALS AND METHODS
2.1. Materials. The raw oily sludge was collected from the bottom
of a 50 000 m3 crude oil storage tank at Sinochem Xingzhong Oil
Staging Co., Ltd. The crude oil was imported from Middle East
countries. The water content was determined by the ASTM D95-05
procedure, and the total hydrocarbons were derived according to
Soxhlet extraction. The saturate, aromatic, resin, and asphaltene
(SARA) contents of the oil components were analyzed according to
the ASTM D2007-02 procedure.
Commercial spherical ZSM-5 zeolites with a 3−5 mm diameter
were purchased from Tianjin Yuanli Chemical Co., Ltd. The ZSM-5
zeolite with a lower SAR (19) was named as ZSM-5-O, and zeolites
with a higher SAR (267) were referred to as ZSM-5-H.
2.2. Experimental Setups. The research was carried out on a twostage fixed bed reactor.33 The oily sludge (1.0 g) sample was placed in
the first stage with the heating rate of 5 °C/min from room
temperature to 500 °C. The catalyst was loaded at the second stage,
which was kept at a constant temperature of 500 °C. The rapid cooling
of pyrolytic vapors was achieved in a gas washing bottle filled with
dichloromethane. The gas washing bottle was cooled by circulating
water to guarantee the collection of all of the condensable organics.
During the experiments, the inert atmosphere for the pyrolysis
procedure was kept by nitrogen flow. Prior to the pyrolysis, the ZSM-5
zeolite should be pretreated at 550 °C for 4 h in the flow of air.
The used ZSM-5-O zeolite was regenerated by calcination in the
flow of oxygen (200 mL/min) at 500 °C for 60 min. Then, the
calcined catalyst was reused in the catalytic pyrolysis of oily sludge
under the same conditions of fresh zeolite. The used and regenerated
ZSM-5-O zeolites were denoted as used ZSM-5-O and ZSM-5-Rx (x
refers to the reaction−regeneration cycle), respectively. The
regenerated ZSM-5-H catalysts were named as ZSM-H-Rx accordingly. The operating conditions of the pyrolysis experiments are listed
in Table 1.
3. RESULTS AND DISCUSSION
The water, oil, and solid fractions of the oily sludge, the
ultimate analysis, and the SARA results are listed in Table 2.
Table 2. Ultimate Analysis and SARA Results of the Oily
Sludge
oily
sludge
ultimate analysis (%)
Table 1. Operating Conditions for Oil Products
catalyst
residence time (s)
mass ratio (zeolite/sludge)
oil product
none
ZSM-5-O
ZSM-5-O
ZSM-5-O
ZSM-5-O
ZSM-5-H
ZSM-5-H
ZSM-5-H
ZSM-5-H
ZSM-O-R1
ZSM-O-R2
ZSM-H-R1
ZSM-H-R2
none
10
20
40
40
10
20
40
40
40
40
40
40
none
20
20
20
10
20
20
20
10
20
20
20
20
oil-N
oil-10s
oil-20s
oil-40s
oil-d10
oil-H-10s
oil-H-20s
oil-H-40s
oil-H-d10
oil-R1
oil-R2
oil-H-R1
oil-H-R2
water, solid, and oil fractions (wt %)
SARA fraction of oil (wt %)
a
Cada
Had
Oad
Nad
Sad
water by distillation
solid particles
oil by solvent extraction
saturates
aromatics
resins
asphaltenes
64.44
8.39
10.47
0.36
1.7
32.22
1.55
66.23
33.05
35.58
18.53
12.84
ad = air-dried basis.
The raw sludge sample possessed a low solid fraction (1.55%)
and a relative high C/H ratio (7.68). Over 66% of the oil is
saturates and aromatics, which is very suitable for aromatic
product recovery. Figure 1 shows the original sludge, recovered
pyrolysis oil, and catalyst before and after usage. The original
oily sludge sample is black and viscous, while the pyrolysis oil
products are yellow to brown. Furthermore, the pyrolysis oils
have better fluidity. Obvious coke deposition can be observed
on used ZSM-5 according to Figure 1, demonstrating the
deactivation. No significant difference can be seen between
fresh zeolites and regenerated zeolites in color.
The SARs of the fresh zeolites and regenerated zeolites,
determined by ICP−OES, were 267.3 (ZSM-5-H), 19.00
(ZSM-5-O), 21.20 (ZSM-5-R1), 22.48 (ZSM-5-R2), and
25.56 (ZSM-5-R3).
2.3. Analysis Methods. The microstructure of ZSM-5 zeolites was
studied by scanning electron microscopy (SEM, SIRON, FEI Co.,
Netherlands). X-ray diffraction (XRD, DMAX-RA, Rigaku, Tokyo,
Japan) was used to characterize the crystallographic structures of the
samples. The data were collected in the 2θ range of 5−50° with Cu Kα
radiation (λ = 0.154 06 nm).
The quantitative analyses of oil products from the catalytic pyrolysis
were conducted on a 7890B gas chromatograph with a 5977A mass
selective detector (GC−MSD, Agilent Technologies, Santa Clara, CA,
U.S.A.). The instrument was equipped with an extractor electron
impact (EI) ion source. The oven temperature was held at 50 °C for
B
DOI: 10.1021/acs.energyfuels.7b01855
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Figure 1. (a) Raw oily sludge, (b) pyrolysis oil products, (c) fresh
ZSM-5 zeolites, (d) used zeolites with coke, and (e) regenerated
zeolites.
Figure 3. Components of the liquid products derived from catalytic
pyrolysis with ZSM-5-O and ZSM-5-H at different residence times.
found that oils were mainly composed of aromatic hydrocarbons, while there was no aromatics in the raw materials. This
indicated the phenomenal aromatic selectivity of ZSM zeolites.
Twaiq et al.35 found that the yield of total aromatics decreased
with a higher SAR. The total aromatic yield decreased by 18%
with the SAR rising from 50 to 400. They proposed that the
lower acidity resulting from a high SAR decreased the
secondary cracking reactions and led to aromatic reduction.
The aromatic hydrocarbons contained in the catalytic
pyrolysis oils were mainly monocyclic aromatic hydrocarbons
(MAHs) and bicyclic aromatic hydrocarbons (BAHs), with a
small amount of tricyclic aromatic hydrocarbons (TAHs). The
MAHs accounted for 29.72% in oil-10s, 15.64% in oil-20s,
and11.17% in oil-40s. Meanwhile, the MAH contents of oil-H10s, oil-H-20s, and oil-H-40s were 36.93, 22.54, and 11.42%,
respectively. It is reported that the olefin cracking and
aromatization reaction mainly happened on the Brønsted acid
sites.36 Thus, the aromatization occurred more completely over
ZSM-5-O, which possessed more acid sites. The branches on
the MAHs were converted into benzene rings with deeper
aromatization, resulting in BAHs. Ultimately, MAHs generated
with ZSM-5-O decreased as a consequence of higher acidity. In
this paper, the reduction in the total aromatic yield over ZSM5-H was mainly caused by reduced alkenylbenzene. This
indicated that the aromatization reaction was not sufficient on
ZSM-5-H as a result of the lower acidity of zeolites, resulting
from a higher SAR.
3.2. Influence of the Residence Time and Dosage of
ZSM-5 Zeolites. It is suggested that a longer retention time
Figure 2. GC−MS data of pyrolysis oil without a catalyst.
3.1. Influence of the SARs on the Aromatic Yield and
Distribution. Figure 2 shows the gas chromatography−mass
spectrometry (GC−MS) data of the oil product (named oil-N)
from non-catalytic pyrolysis of oily sludge. As observed, the
main products of oil-N were saturates with a fraction over 60%
and aromatics accounting for 27.65% by weight. The rest are
organic compounds containing O, N, and S. The effects of SAR
on the component distribution and total aromatic yield under
different retention times (10, 20, and 40 s) were given in Figure
3. The catalyst/sludge mass ratio was 20. The oil products
derived with ZSM-5-O and ZSM-5-H were designated as oil-t
and oil-H-t (t refers to the residence time), respectively. The
associated GC−MS data of these oil products were plotted in
Figure 4.
As seen, the total aromatic yield over zeolites increased
significantly compared to that of oil-N. The maximum yields
over ZSM-5-O and ZSM-5-H were 93.37 and 87.33% at 40 s,
respectively. This indicated the extraordinary catalytic performance of ZSM-5 zeolites with various SARs. A similar
phenomenon was reported by other researchers using the
same catalysts. Cai et al.20 and Wang et al.34 carried out
experiments with ZSM-5 zeolites for bio-oil generation and
C
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
Energy & Fuels
Figure 4. GC−MS data of liquid products for ZSM-5 zeolites with SARs of 19 and 267 at 10, 20, and 40 s.
continuously aromatized. Thus, BAHs account for the largest
portion (over 60% for ZSM-5-O and 50% for ZSM-5-H) of the
total aromatic yield.
The total aromatic yield and product distribution changed
significantly with a lower zeolite dosage of 10:1. The residence
time for this set of experiments is 40 s to obtain a higher
aromatic yield. Oil-d10 and Oil-H-d10 were used to represent
can benefit the total aromatic yield and BAH selectivity. For
example, the MAH yields of ZSM-5-O and ZSM-5-H decreased
by 62.4 and 69.1%, while the BAH yield increased to 207 and
214%, with the residence time rising from 10 to 40 s. Significant
increases in naphthalene and methylnaphthalene are noticed. It
can be deduced that the gaseous products from the first stage
formed MAHs in zeolites, and then the branched olefins were
D
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
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Figure 5. Components of the liquid products derived from catalytic pyrolysis with a catalyst dosage of 10:1.
Figure 7. XRD patterns of the ZSM-5 zeolites (ZSM-5-O, used ZSM5-O, ZSM-5-R1, ZSM-5-R2, ZSM-5-R3, and ZSM-5-H).
Figure 6. GC−MS data of liquid products for zeolites with SARs of 19
and 267 with a zeolite dosage of 10:1.
E
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
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Figure 8. NH3-TPD profiles of fresh and regenerated zeolites.
Figure 11. Main components of pyrolysis oil produced with
regenerated zeolites as catalysts (retention time, 40 s; dosage, 20).
the oil products. The main compound distribution is illustrated
in Figure 5, and the gas chromatograms are shown in Figure 6.
The BAH yield was reduced in comparison to the liquid
products under a catalyst/feedstock ratio of 20:1. The BAHs
decreased over 9 and 5% for ZSM-5-O and ZSM-5-H,
respectively. Moreover, the total aromatic yield reduced as
well. The results reveal the incompletion of the aromatization
procedure, which resulted in intermediates.
3.3. Zeolite Characterization. Figure 7 shows the XRD
patterns of fresh ZSM-5 zeolites (ZSM-5-O and ZSM-5-H),
used ZSM-5-O, and regenerated zeolites (ZSM-5-R1, ZSM-5R2, and ZSM-5-R3). All of the XRD patterns exhibited the
same diffraction peaks in the ranges of 2θ = 7−10°, 22−25°,
and 30°, matching well with the standard pattern of the ZSM-5
zeolite.37 Hence, the regenerated zeolites still reserved the
initial structure of ZSM-5. The relative crystallinity values of
regenerated zeolites (ZSM-5-R1, 98.2%; ZSM-5-R2, 94.9%; and
ZSM-5-R3, 93.0%) are relative to the standard ZSM-5 zeolite
reference. Therefore, there is no obvious framework change or
damage caused by the regeneration process. Other researches
focusing on regeneration confirmed this conclusion.28
Figure 8 displays the NH3-TPD profiles of fresh ZSM-5
zeolites (ZSM-5-O and ZSM-5-H) and regenerated zeolites
(ZSM-5-R1, ZSM-5-R2, and ZSM-5-R3). Obviously, there is
only one prominent peak, which is ascribed to the Brønsted
acid site, in every profile. They are classified as Na-ZSM-5
zeolites, which contained a large quantity of Na+, and show
Figure 9. SEM micrographs of fresh, used, and regenerated ZSM-5
zeolites with a SAR of 19.
Figure 10. TG and DTG curves for used ZSM-5-O and used ZSM-5H.
F
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
Energy & Fuels
Figure 12. GC−MS data of liquid products over regenerated zeolites.
only one peak belonging to medium acid. The peak position of
ZSM-5-R1 (341 °C) changed slightly compared to that of
ZSM-5-O (342 °C). Meanwhile, the area of ZSM-5-O
decreased after being calcined, demonstrating lower acidity.
Moreover, the peak area and peak center (325 °C) of ZSM-5R2 decreased significantly compared to that of ZSM-5-R1.
However, the curve of ZSM-5-R3 changed slightly in the peak
center (322 °C) and area. Thus, the regeneration treatment
would cause a decrease in acid intensity and density. As shown
in Figure 8, the peak of ZSM-5-H centered at 289 °C and the
peak area was far lower than that of ZSM-5-O. This confirms
that zeolites with a higher SAR possess a lower acid intensity.36
The SAR of our catalyst samples rose from 19.00 to 25.56 after
the regeneration treatment and increased with more reaction−
regeneration cycles. This suggested that the regeneration
resulted in dealumination. Luo et al.29 and Campbell et al.30
also discovered the lower densities of acid sites in regenerated
ZSM-5 zeolites, especially the reduction in the concentration of
a strong acid site. They assumed that this was caused by
dealumination.
3.4. Regeneration of Used Catalysts. The surface
morphology of original ZSM-5-O zeolite, used zeolite, and
regenerated zeolites were investigated using SEM. The results
are shown in Figure 9. A significant carbon deposition can be
observed on the used ZSM-5 zeolite. The network structure of
original zeolite was destroyed, and the surface became more
compact. Obviously, the coke deposited on the surface was
removed, and the surface structure was recovered after
regeneration. No significant change is discovered on the
surface of recycled zeolites according to the micrographs.
Researchers have found that the main reason leading to
deactivation for zeolites was surface coke.29,31,32 The coke can
be oxidized at a high temperature with oxygen, air, or water
stream environment. The used zeolites were calcined in oxygen
stream to remove the coke. Figure 10 displays the TG−
differential thermogravimetric (DTG) curves of used ZSM-5-O
and used ZSM-5-H under air flow. Two evident peaks can be
observed in the DTG curve. The first peak (88 °C for used
ZSM-5-O and 96 °C for used ZSM-5-H) was ascribed to the
water evaporation. The other (542 °C for used ZSM-5-O and
583 °C for used ZSM-5-H) could be attributed to the
combustion of coke. It is reported that peaks at a high
temperature (500−600 °C) usually correspond with polyaromatic coke.38
The performance of regenerated zeolites was evaluated under
the same experimental conditions as fresh zeolites. The total
aromatic yield and component distribution are taken into
consideration. The main components of pyrolysis oils over
regenerated zeolites are listed in Figure 11, and the gas
chromatograms were shown in Figure 12. There is no
significant loss in the total aromatic yield, while the losses for
MAHs and BAHs are noticeable. Meanwhile, the TAH yield
G
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
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■
increases by about 30% (8.84, 9.2, and 9.07% for oil-R1, oil-R2,
oil-H-R1, and oil-H-R2, respectively) compared to oil products
over fresh zeolites. This indicates that the aromatic hydrocarbons in oils generated with regenerated zeolites owned more
benzene rings. It can be supposed that the hydrocarbons tended
to accumulate and polymerize in the zeolites, forming highmolecular-weight compounds. The decrease of the total
aromatic yield is reasonable, revealing the stable activity of
regenerated zeolites in aromatization.
The previous characterization displayed the decrease of acid
density in the regenerated zeolites, which was triggered by
dealumination during the calcination. Studies found that the
regeneration could increase the catalyst lifetime.30 Some
researchers proposed that the main factors were either the
dealumination or the residual coke.31,32 Zhang et al.32
discovered a modified texture of regenerated ZSM-5 zeolites
caused by the reaction−regeneration cycle. The total
concentration of acid sites and the ratio of strong acid sites/
weak acid sites decreased simultaneously. Thus, the reaction
became gentle and led to an obvious reduction in coke and
coking rate. This consequently affected the catalytic performance.
A slightly decreased total aromatic yield demonstrated the
stable activity, and the increased TAH yield revealed higher
selectivity. It is supposed that the performance of recycled
zeolites was attributed to the dealumination caused by
regeneration. The dealumination resulted in a modified texture
and lower acidity, leading to higher selectivity and a lower total
aromatic yield of zeolites, whereas too much reaction−
regeneration cycles would lead to a low total aromatic yield
and high macromolecular aromatics.
Article
AUTHOR INFORMATION
Corresponding Author
*Telephone: +86-0571-87952834. Fax: +86-571-87952438. Email: hqx@zju.edu.cn.
ORCID
Qun-Xing Huang: 0000-0003-1557-3955
Yong Chi: 0000-0001-6360-6198
Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS
This work was supported by the National Natural Science
Foundation of China (Grant 51576172) and the Innovative
Research Groups of the National Natural Science Foundation
of China (Grant 51621005).
■
REFERENCES
(1) Hu, G.; Li, J.; Zeng, G. Recent development in the treatment of
oily sludge from petroleum industry: A review. J. Hazard. Mater. 2013,
261, 470−490.
(2) Chiaramonti, D.; Oasmaa, A.; Solantausta, Y. Power generation
using fast pyrolysis liquids from biomass. Renewable Sustainable Energy
Rev. 2007, 11 (6), 1056−1086.
(3) Shie, J.-L.; Lin, J.-P.; Chang, C.-Y.; Shih, S.-M.; Lee, D.-J.; Wu, C.H. Pyrolysis of oil sludge with additives of catalytic solid wastes. J.
Anal. Appl. Pyrolysis 2004, 71 (2), 695−707.
(4) Shie, J.-L.; Chang, C.-Y.; Lin, J.-P.; Lee, D.-J.; Wu, C.-H. Use of
Inexpensive Additives in Pyrolysis of Oil Sludge. Energy Fuels 2002, 16
(1), 102−108.
(5) Clark, J. H. Green chemistry for the second generation
biorefinerySustainable chemical manufacturing based on biomass.
J. Chem. Technol. Biotechnol. 2007, 82 (7), 603−609.
(6) Huber, G. W.; Iborra, S.; Corma, A. Synthesis of transportation
fuels from biomass: Chemistry, catalysts, and engineering. Chem. Rev.
2006, 106 (9), 4044−4098.
(7) Bi, P.; Wang, J.; Zhang, Y.; Jiang, P.; Wu, X.; Liu, J.; Xue, H.;
Wang, T.; Li, Q. From lignin to cycloparaffins and aromatics:
Directional synthesis of jet and diesel fuel range biofuels using
biomass. Bioresour. Technol. 2015, 183, 10−17.
(8) Yan, Q.; Yu, F.; Liu, J.; Street, J.; Gao, J.; Cai, Z.; Zhang, J.
Catalytic conversion wood syngas to synthetic aviation turbine fuels
over a multifunctional catalyst. Bioresour. Technol. 2013, 127, 281−290.
(9) Lou, R.; Wu, S.-b.; Lv, G.-j. Effect of conditions on fast pyrolysis
of bamboo lignin. J. Anal. Appl. Pyrolysis 2010, 89 (2), 191−196.
(10) Pandey, M. P.; Kim, C. S. Lignin Depolymerization and
Conversion: A Review of Thermochemical Methods. Chem. Eng.
Technol. 2011, 34 (1), 29−41.
(11) Sun, L.; Zhang, X.; Chen, L.; Zhao, B.; Yang, S.; Xie, X.
Comparision of catalytic fast pyrolysis of biomass to aromatic
hydrocarbons over ZSM-5 and Fe/ZSM-5 catalysts. J. Anal. Appl.
Pyrolysis 2016, 121, 342−346.
(12) Rezaei, P. S.; Shafaghat, H.; Daud, W. M. A. W. Production of
green aromatics and olefins by catalytic cracking of oxygenate
compounds derived from biomass pyrolysis: A review. Appl. Catal.,
A 2014, 469, 490−511.
(13) Ding, K.; Zhong, Z.; Wang, J.; Zhang, B.; Addy, M.; Ruan, R.
Effects of alkali-treated hierarchical HZSM-5 zeolites on the
production of aromatic hydrocarbons from catalytic fast pyrolysis of
waste cardboard. J. Anal. Appl. Pyrolysis 2017, 125, 153−161.
(14) Wang, L.; Lei, H.; Bu, Q.; Ren, S.; Wei, Y.; Zhu, L.; Zhang, X.;
Liu, Y.; Yadavalli, G.; Lee, J.; Chen, S.; Tang, J. Aromatic hydrocarbons
production from ex situ catalysis of pyrolysis vapor over Zinc modified
ZSM-5 in a packed-bed catalysis coupled with microwave pyrolysis
reactor. Fuel 2014, 129, 78−85.
4. CONCLUSION
This work is aimed at aromatic production from pyrolysis of
oily sludge in a fixed bed reactor over ZSM-5 zeolites. Relative
compositions of pyrolysis oils (MAHs, BAHs, and TAHs) were
presented to show the effects of catalyst choice and operating
conditions. Zeolites exhibited strong aromatization, and the
highest activity of 93.37% was achieved over ZSM-5-O
(retention time = 40 s). The NH3-TPD profiles showed
lower acid intensity and weaker acid sites of ZSM-5-H zeolites,
resulting in a reduced aromatic hydrocarbon yield and more
alkenylbenzenes. A shorter retention time led to the formation
of MAHs, while the total aromatic yield decreased. It suggested
that the aromatization was enhanced with a longer residence
time, and the branched olefins were converted into benzene
rings, i.e., converting MAHs into BAHs. The total aromatic
yield decreased with a lower zeolite dosage, resulting from the
uncompleted reaction. To regenerate the used zeolites with
coke deposition, calcination was conducted under an oxygen
atmosphere. No framework damage or change has been
observed after calcination according to XRD patterns, which
is coincident with former studies. Nonetheless, dealumination
happened during regeneration and resulted in lower acidity,
which has been found on the regeneration procedure of ZSM-5
zeolites in previous works. The oil products with regenerated
zeolites possessed more TAHs and a slightly decreased total
aromatic yield, demonstrating the promotion of macromolecular aromatic compounds by the reaction−regeneration
cycle.
H
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
Article
Energy & Fuels
(15) Lin, B.; Wang, J.; Huang, Q.; Chi, Y. Effects of potassium
hydroxide on the catalytic pyrolysis of oily sludge for high-quality oil
product. Fuel 2017, 200, 124−133.
(16) Nkhalambayausi Chirwa, E. M.; Mampholo, C. T.; Fayemiwo,
O. M.; Bezza, F. A. Biosurfactant assisted recovery of the C5−C11
hydrocarbon fraction from oily sludge using biosurfactant producing
consortium culture of bacteria. J. Environ. Manage. 2017, 196, 261−
269.
(17) Nazem, M. A.; Tavakoli, O. Bio-oil production from refinery oily
sludge using hydrothermal liquefaction technology. J. Supercrit. Fluids
2017, 127, 33−40.
(18) Qin, L.; Han, J.; He, X.; Zhan, Y.; Yu, F. Recovery of energy and
iron from oily sludge pyrolysis in a fluidized bed reactor. J. Environ.
Manage. 2015, 154, 177−182.
(19) Degnan, T. F.; Chitnis, G. K.; Schipper, P. H. History of ZSM-5
fluid catalytic cracking additive development at Mobil. Microporous
Mesoporous Mater. 2000, 35−36, 245−252.
(20) Cai, Y.; Fan, Y.; Li, X.; Chen, L.; Wang, J. Preparation of refined
bio-oil by catalytic transformation of vapors derived from vacuum
pyrolysis of rape straw over modified HZSM-5. Energy 2016, 102, 95−
105.
(21) Emori, E. Y.; Hirashima, F. H.; Zandonai, C. H.; Ortiz-Bravo, C.
A.; Fernandes-Machado, N. R. C.; Olsen-Scaliante, M. H. N. Catalytic
cracking of soybean oil using ZSM5 zeolite. Catal. Today 2017, 279
(Part 2), 168−176.
(22) Zhang, H.; Cheng, Y.-T.; Vispute, T. P.; Xiao, R.; Huber, G. W.
Catalytic conversion of biomass-derived feedstocks into olefins and
aromatics with ZSM-5: The hydrogen to carbon effective ratio. Energy
Environ. Sci. 2011, 4 (6), 2297−2307.
(23) Sadrameli, S. M.; Green, A. E. S. Systematics of renewable
olefins from thermal cracking of canola oil. J. Anal. Appl. Pyrolysis
2007, 78 (2), 445−451.
(24) Van Donk, S.; Bitter, J. H.; De Jong, K. P. Deactivation of solid
acid catalysts for butene skeletal isomerisation: On the beneficial and
harmful effects of carbonaceous deposits. Appl. Catal., A 2001, 212
(1−2), 97−116.
(25) Li, G.; Yan, L.; Zhao, R.; Li, F. Improving aromatic
hydrocarbons yield from coal pyrolysis volatile products over
HZSM-5 and Mo-modified HZSM-5. Fuel 2014, 130, 154−159.
(26) Wang, Y.; Wang, J. Multifaceted effects of HZSM-5 (Protonexchanged Zeolite Socony Mobil-5) on catalytic cracking of pinewood
pyrolysis vapor in a two-stage fixed bed reactor. Bioresour. Technol.
2016, 214, 700−710.
(27) Mihalcik, D. J.; Mullen, C. A.; Boateng, A. A. Screening acidic
zeolites for catalytic fast pyrolysis of biomass and its components. J.
Anal. Appl. Pyrolysis 2011, 92 (1), 224−232.
(28) Liu, T.-L.; Cao, J.-P.; Zhao, X.-Y.; Wang, J.-X.; Ren, X.-Y.; Fan,
X.; Zhao, Y.-P.; Wei, X.-Y. In situ upgrading of Shengli lignite pyrolysis
vapors over metal-loaded HZSM-5 catalyst. Fuel Process. Technol. 2017,
160, 19−26.
(29) Zhang, J.; Zhang, H.; Yang, X.; Huang, Z.; Cao, W. Study on the
deactivation and regeneration of the ZSM-5 catalyst used in methanol
to olefins. J. Nat. Gas Chem. 2011, 20 (3), 266−270.
(30) Luo, C.-W.; Feng, X.-Y.; Liu, W.; Lia, X.-Y.; Chao, Z.-S.
Deactivation and regeneration on the ZSM-5-based catalyst for the
synthesis of pyridine and 3-picoline. Microporous Mesoporous Mater.
2016, 235, 261−269.
(31) Campbell, S. M.; Bibby, D. M.; Coddington, J. M.; Howe, R. F.
Dealumination of HZSM-5 Zeolites: II. Methanol to Gasoline
Conversion. J. Catal. 1996, 161 (1), 350−358.
(32) Kim, Y. H.; Lee, K. H.; Lee, J. S. The effect of pre-coking and
regeneration on the activity and stability of Zn/ZSM-5 in
aromatization of 2-methyl-2-butene. Catal. Today 2011, 178 (1),
72−78.
(33) Zhang, G.; Zhang, X.; Bai, T.; Chen, T.; Fan, W. Coking kinetics
and influence of reaction−regeneration on acidity, activity and
deactivation of Zn/HZSM-5 catalyst during methanol aromatization.
J. Energy Chem. 2015, 24 (1), 108−118.
(34) Huang, Q.; Wang, J.; Qiu, K.; Pan, Z.; Wang, S.; Chi, Y.; Yan, J.
Catalytic pyrolysis of petroleum sludge for production of hydrogenenriched syngas. Int. J. Hydrogen Energy 2015, 40 (46), 16077−16085.
(35) Twaiq, F. A. A.; Mohamad, A. R.; Bhatia, S. Performance of
composite catalysts in palm oil cracking for the production of liquid
fuels and chemicals. Fuel Process. Technol. 2004, 85 (11), 1283−1300.
(36) Liu, P.; Zhang, Z.; Jia, M.; Gao, X.; Yu, J. ZSM-5 zeolites with
different SiO2/Al2O3 ratios as fluid catalytic cracking catalyst additives
for residue cracking. Chin. J. Catal. 2015, 36 (6), 806−812.
(37) Nada, M. H.; Larsen, S. C. Insight into seed-assisted template
free synthesis of ZSM-5 zeolites. Microporous Mesoporous Mater. 2017,
239, 444−452.
(38) Guisnet, M.; Costa, L.; Ribeiro, F. R. Prevention of zeolite
deactivation by coking. J. Mol. Catal. A: Chem. 2009, 305 (1−2), 69−
83.
I
DOI: 10.1021/acs.energyfuels.7b01855
Energy Fuels XXXX, XXX, XXX−XXX
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