Maximum synergistic effect in the coupling conversion of bio-derived furans and methanol over ZSM-5 for enhancing aromatic production

Article abstract of DOI:10.1039/c3gc42251h

We firstly propose the coupling conversion of bio-derived furans and methanol over ZSM-5 for enhancing aromatic production. The coupling conversion of bio-derived furans and methanol was conducted in a continuous fixed bed reactor. 2-Methylfuran (MF) was used as a probe molecule to identify the possible reaction pathways. The effects of the methanol to MF molar ratio, reaction temperature and weight hourly space velocity (WHSV) on the product distribution from the coupling conversion of MF and methanol were investigated. The experimental results showed that the aromatic yield from the coupling conversion of MF and methanol is about 5.2 times higher than that of the catalytic fast pyrolysis of only MF. In addition, it can also enhance the yield of olefins, the selectivity of xylenes and reduce coke formation. These results indicate that there is a significant synergistic effect between MF and methanol. The synergistic effect could be attributed to the methanol-to-olefins reactions, the Diels-Alder reactions of furans with olefins, and the alkylation reaction of benzene/toluene with methanol occurring during the coupling conversion of MF and methanol. The reaction conditions for maximizing the synergistic effect were a methanol to MF molar ratio of 2 at 550 °C. Moreover, the comparative study of the coupling conversion of different bio-derived furans (MF, 2,5-dimethylfuran (DMF), furfural (FF) and furfuryl alcohol (FA)) and methanol were also considered in this study. The coupling conversion of DMF and methanol exhibited maximum yields of aromatics, olefins and a minimum yield of coke, suggesting that DMF is the best candidate of bio-derived furans for aromatic production in the coupling conversion of bio-derived furans and methanol. the Partner Organisations 2014.

Full text of DOI:10.1039/c3gc42251h

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Maximum synergistic effect in the coupling
conversion of bio-derived furans and methanol
over ZSM-5 for enhancing aromatic production
Cite this: DOI: 10.1039/c3gc42251h
Anqing Zheng, Zengli Zhao,* Sheng Chang, Zhen Huang, Kun Zhao, Hongxiang Wu,
Xiaobo Wang, Fang He and Haibin Li
We firstly propose the coupling conversion of bio-derived furans and methanol over ZSM-5 for enhancing
aromatic production. The coupling conversion of bio-derived furans and methanol was conducted in a
continuous fixed bed reactor. 2-Methylfuran (MF) was used as a probe molecule to identify the possible
reaction pathways. The effects of the methanol to MF molar ratio, reaction temperature and weight hourly
space velocity (WHSV) on the product distribution from the coupling conversion of MF and methanol
were investigated. The experimental results showed that the aromatic yield from the coupling conversion
of MF and methanol is about 5.2 times higher than that of the catalytic fast pyrolysis of only MF. In
addition, it can also enhance the yield of olefins, the selectivity of xylenes and reduce coke formation.
These results indicate that there is a significant synergistic effect between MF and methanol. The synergis-
tic effect could be attributed to the methanol-to-olefins reactions, the Diels–Alder reactions of furans
with olefins, and the alkylation reaction of benzene/toluene with methanol occurring during the coupling
conversion of MF and methanol. The reaction conditions for maximizing the synergistic effect were a
methanol to MF molar ratio of 2 at 550 °C. Moreover, the comparative study of the coupling conversion
of different bio-derived furans (MF, 2,5-dimethylfuran (DMF), furfural (FF) and furfuryl alcohol (FA)) and
methanol were also considered in this study. The coupling conversion of DMF and methanol exhibited
maximum yields of aromatics, olefins and a minimum yield of coke, suggesting that DMF is the best can-
didate of bio-derived furans for aromatic production in the coupling conversion of bio-derived furans and
methanol.
Received 1st November 2013,
Accepted 20th January 2014
DOI: 10.1039/c3gc42251h
www.rsc.org/greenchem
addition, bio-derived furans are generally considered as pyrol-
ysis intermediates in the catalytic fast pyrolysis of biomass.9
Introduction
Diminishing fossil resources, combined with increasing con- The in-depth investigation into catalytic fast pyrolysis of bio-
cerns regarding energy security, rising fuel prices and environ- derived furans is beneficial for a better understanding of the
mental problems, are the main driving forces in the reaction chemistry of catalytic biomass pyrolysis.
development of alternative ways to satisfy the growing demand
The critical problems facing catalytic fast pyrolysis of bio-
for chemicals and fuels.1–5 Biomass is the only current renew- derived furans are low aromatic yield, low selectivity of specific
able source of organic carbon which can be used as an alterna- aromatic production (e.g., xylenes) and significant coking of
tive to fossil fuel for producing liquid fuels and chemicals. catalysts.7,8,10,11,13 In order to overcome these challenges, co-
Bio-derived furans, such as furfural (FF), furfuryl alcohol (FA), conversion of biomass-derived furans with ethylene or propy-
2-methylfuran (MF), and 2,5-dimethylfuran (DMF), are impor- lene is proposed.14,15 Currently, there are two different routes
tant platform molecules that can be produced by hydrolysis to form aromatics from co-conversion of furans and ethylene/
and subsequent dehydration of hemicellulose and cellulose propylene. One is the co-conversion of DMF and ethylene in
from biomass.4,6 Catalytic fast pyrolysis of bio-derived furans the liquid phase to form p-xylene, in a high selectivity (up to
over ZSM-5 is a promising technology for producing targeted 90%) over solid acid catalysts. But this reaction typically
aromatics, e.g., benzene, toluene and xylenes (BTX).7–13 In requires high pressure (10–1500 psig), a long residence time
(1–48 h) and an organic solvent as the reaction medium.15–18
The other is a co-catalytic fast pyrolysis of furans with ethy-
lene–propylene in the gas phase over ZSM-5, the advantages of
Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion,
this route are that it is carried out under ambient pressure and
Chinese Academy of Sciences, Guangzhou 510640, PR China.
that it has a very short residence time (4 s).14,19 However, the
E-mail: zhaozl@ms.giec.ac.cn
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yield and selectivity of specific aromatic production in the gas constant flow HPLC piston pump (P501, Surwit Technology
phase are relatively low compared to that of the liquid phase Inc.). For a typical run, the flow rate of the mixtures was set to
route. Both of the two routes have been identified as efficient 0.12 g min−1, and 1.20 g of the catalyst was used in the catalyst
methods to enhance aromatic production as the aromatics can bed. All of the runs were performed at atmospheric pressure. A
be produced directly by the Diels–Alder reaction of furans with two-stage condenser within a cooling ethanol jacket (held at
olefins followed by a dehydration reaction.14,16
−5 °C) and two-stage gas washing bottles using ethanol as a
Unfortunately, ethylene and propylene are flammable gases solvent (held at 0 °C) were used to trap the liquid products.
and thus hard to store and transport. Considering that ethy- After the reactions, the condensers were washed with ethanol.
lene and propylene can be generated by the catalytic conver- The liquid products in the ethanol were analyzed and quanti-
sion of methanol over ZSM-5,20–23 the coupling conversion of fied by GC/MS. The gas phase products were collected with air
bio-derived furans and methanol over ZSM-5 could be an bags and analyzed by GC/FID and GC/TCD. The coke yield was
efficient alternative method for enhancing aromatic pro- obtained by measuring the carbon content of spent catalyst.
duction. So far, the coupling conversion of bio-derived furans
and methanol has not yet been studied. Zhang and coworkers
reported that catalytic fast pyrolysis of wood and alcohol mix-
tures can enhance the yield of petrochemicals (aromatics and
Methods of data processing
olefins). It was found that the yield of the petrochemicals The aromatic, oxygenate, coke and non-condensable gas yields
increased with an increasing H/Ceff ratio (hydrogen to carbon (alkanes, olefins, CO and CO2) along with aromatic selectivity,
effective ratio) of feedstocks.24,25 However, the mechanism of were defined as follows:
this is not clearly understood. An insight into the coupling
conversion of bio-derived furans and methanol can provide a
better understanding of the reaction chemistry of co-catalytic
fast pyrolysis of wood and alcohol mixtures. In this study, MF
Moles of carbon in aromatic production
Aromatic yield ¼
Moles of carbon in feedstocks
ꢀ 100%;
is used as a probe molecule to identify the possible reaction
pathways for the coupling conversion of bio-derived furans
Moles of carbon in spent catalyst
Moles of carbon in feedstocks
Coke yield ¼
ꢀ 100%;
ꢀ 100%;
and methanol. The effects of the methanol to MF ratio, reac-
tion temperature and weight hourly space velocity (WHSV) on
the product distribution from the coupling conversion of MF
and methanol are investigated. Moreover, a comparative study
of the coupling conversion of different bio-derived furans (MF,
DMF, FF and FA) and methanol is also considered in this
study.
Non-condensable gas yield
Moles of carbon in non-condensable gas
¼
Moles of carbon in feedstocks
Aromatic selectivity
Moles of carbon in specific aromatic species
Total moles of carbon in all aromatic species
Experimental
Reagents and catalyst
¼
ꢀ 100%:
Methanol (99.5%) and ethanol (99.7%) were obtained from the
Guangzhou chemical reagent factory. The bio-derived furans,
including 2-methylfuran (98%), 2,5-dimethylfuran (99%), fur-
fural (99%), and furfuryl alcohol (98%), were purchased from
Aladdin reagent. The HZSM-5 catalysts (Si/Al = 25), with a BET
surface area of 416 m2 g−1, used in this study were purchased
from the Catalyst Plant of Nankai University.
Coupling conversion of bio-derived furans and methanol
The coupling conversion of bio-derived furans and methanol
was conducted in a continuous fixed bed reactor. The fixed
bed reactor was built from a 15 mm inner diameter quartz
tube. The sieved ZSM-5 particles with a size of 0.18–0.425 mm
were held in the reactor by quartz beads and quartz wool.
Prior to the reactions, bio-derived furans and methanol were
physically mixed with different molar ratios. Argon (99.999%)
was used as the carrier gas. The gas flow rate was set to
300 mL min−1 by a mass flow meter. The mixtures of furans
Fig. 1 Carbon yield of BTX, olefins and coke as a function of methanol
to MF molar ratio from the coupling conversion of MF and methanol.
Reaction conditions: ZSM-5 catalyst, reaction temperature: 550 °C,
and methanol were introduced into the argon stream by a WHSV: 6 h−1, carrier gas flow rate: 300 mL min−1, reaction time: 15 min.
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and changed the overall carbon selectivity. The conversion of
MF increased from 39.8% to 96.5% when the methanol to MF
molar ratio increased from 0 to 3. With regards to the overall
Results and discussion
Effect of methanol to MF molar ratio
Fig. 1 shows the carbon yield of BTX, olefins and coke from carbon selectivity, the selectivity of CO, alkanes and coke from
the coupling conversion of MF and methanol at different the coupling conversion of MF and methanol were obviously
methanol to MF molar ratios. As shown in Fig. 1, in contrast to lower than that of the catalytic fast pyrolysis of only MF or
the catalytic fast pyrolysis of only MF, the coupling conversion methanol, indicating that the Diels–Alder reactions are domi-
of MF and methanol remarkably enhanced the BTX, olefins nant and can suppress the reactions of decarbonylation, de-
and reduced coke yield, indicating that there is a significant alkylation and polycondensation in the coupling conversion of
synergistic effect between MF and methanol. It should be MF and methanol. The aromatic selectivity was also signifi-
noted that the maximum BTX yield of 47.7% was achieved cantly influenced by the MF to methanol molar ratio. Com-
with a methanol to MF molar ratio of 2. It is about 5.2 times pared to the catalytic fast pyrolysis of only MF or methanol,
higher than the yield of BTX from the catalytic fast pyrolysis of the coupling conversion of MF and methanol decreased the
only MF. This result implies that the optimal methanol to MF selectivity of benzene and increased the selectivity of xylenes,
molar ratio for a maximum synergistic effect is 2, and the while the selectivity of toluene changed slightly. In the inde-
dominant reaction in the coupling conversion of MF and pendent catalytic fast pyrolysis of MF, ethylene and propylene
methanol is the Diels–Alder reaction of MF with ethylene, in accounted for about 63% and 37% of the total olefins, respect-
which 1 mol MF can react with 1 mol ethylene, which obtained ively. The selectivity to ethylene increased slightly when metha-
by 2 mol methanol, for producing toluene. The yield of olefins nol was co-fed to MF.
from the coupling conversion of MF and methanol increased
According to the detailed production distributions, the
rapidly with an increase in the methanol to MF molar ratio. reaction pathways possible for the coupling conversion of MF
The maximum yield of olefins (42.1%) was obtained by the and methanol are illustrated in Fig. 2. Methanol first under-
independent catalytic fast pyrolysis of methanol. Table 1 sum- goes a methanol-to-olefin (MTO) reaction to form ethylene and
marizes the detailed product distributions from the coupling propylene, with aromatics and coke as byproducts. These
conversion of MF and methanol at different methanol to MF olefins and MF can undergo further Diels–Alder reactions to
molar ratios. As shown in Table 1, the coupling conversion of form toluene and xylenes. The aromatic selectivity can be
MF and methanol dramatically increased the conversion of MF tuned by the alkylation reaction of benzene/toluene with
methanol. In addition, MF can undergo an hydrogenolysis
reaction to form furan and methane in which hydrogen is pro-
duced by the cracking of methanol. MF and furan can be con-
Table 1 Detailed product distributions from the coupling conversion of
verted into butadiene and allene by decarbonylation. The
butadiene and allene can further undergo oligomerization and
cracking reactions to form olefins. Benzene can be produced
by a Diels–Alder reaction of furan with ethylene or dimeriza-
tion/dehydrogenation of allene. Thus we can conclude that the
MTO reaction, Diels–Alder reaction of furans with olefins, and
alkylation reaction of benzene/toluene with methanol could be
responsible for the synergistic effect in the coupling conver-
sion of MF and methanol. The increase in yield of olefins from
the coupling conversion of MF and methanol could be due to
the MTO reaction of methanol. The increase in aromatic yield
and decrease in coke yield could be attributed to the Diels–
Alder reaction of furans with the olefins produced by the MTO
reaction. The increase in selectivity of xylenes and the decrease
in selectivity of benzene could be due to the alkylation reaction
of benzene/toluene with methanol. These reaction pathways
can also give a good explanation for the changes in the
product distribution of the catalytic fast pyrolysis of biomass
when alcohol mixtures were added to the reactor feed.24
MF and methanol with different methanol to MF molar ratios
Methanol to MF
molar ratio
Product distribution
MF
1/1
2/1
3/1
Methanol
MF conversion (%)
Methanol conversion (%)
Total carbon conversion (%) 39.8
39.8
—
48.3
100
56.9
94.8
100
96.3
96.5
100
97.8 100
—
100
Overall carbon selectivity (%)
Aromatics
Olefins
Oxygenatesa
Alkanesb
CO
19.8
26.0
0
6.5
21.0
1.9
31.0
24.1
8.3
7.2
13.0
1.7
50.8
20.5
0.8
8.1
9.5
37.8 15.9
29.4 42.1
0
11.2 23.5
9.5 13.9
1.5 3.0
0
CO2
1.3
Coke
24.7
14.7
9.0
10.7 1.6
Aromatic selectivity (%)
Benzene
Toluene
35.4
46.9
15.9
1.8
20.9
49.1
25.6
4.5
22.5
47.5
27.5
2.5
22.9 28.3
47.1 53.2
25.9 16.1
4.1 2.4
Xylenes
Alkylbenzenesc, indenes,
naphthalenes
Effect of reaction temperature
Olefin selectivityd (%)
Ethylene
Propylene
Fig. 3 shows the carbon yields of BTX, olefins and coke from
the coupling conversion of MF and methanol at different reac-
tion temperatures. As shown in Fig. 3, the yields of BTX,
olefins and coke were a strong function of the reaction temp-
erature. The coupling conversion of MF and methanol at
62.9
37.1
67.3
32.7
69.2
30.8
69.1 65.6
30.9 34.4
a Furan and DMF. b CH4, C2H6 and C3H8. c Ethylbenzene, 1-ethyl-3-
methylbenzene, mesitylene and hexamethylbenzene. d C3+ olefins
(<1%) were neglected in this calculation.
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Fig. 2 Proposed reaction chemistry for the coupling conversion of MF and methanol.
increasing temperature. In contrast, the yield of coke
decreased with increasing temperature. The maximum yield of
olefins and minimum yield of coke were obtained at the reac-
tion temperature of 600 °C. This suggests that a higher temp-
erature
favors
cracking
reactions
and
suppresses
polycondensation reactions. Table 2 summarizes the detailed
product distributions from the coupling conversion of MF and
methanol at different reaction temperatures. As shown in
Table 2, the conversion of MF increased with increased temp-
erature and reached 100% at 600 °C. The aromatic selectivity
was also a function of temperature. The selectivity of benzene
and toluene increased with increasing temperature. Conver-
sely, the selectivity of xylenes decreased with increasing temp-
erature, suggesting that the dealkylation reaction begins to
dominate at a higher temperature. A similar result was also
seen by Yu-Ting Cheng for the reactions of the co-conversion
of furans with olefins.14
Fig. 3 Carbon yield of BTX, olefins and coke as a function of reaction
temperature from coupling conversion of MF and methanol. Reaction
conditions: ZSM-5 catalyst, methanol to MF molar ratio: 2, WHSV: 6 h−1
carrier gas flow rate: 300 mL min−1, reaction time: 15 min.
,
Effect of WHSV
550 °C produced the maximum yield of BTX, indicating that
the optimal reaction temperature for the maximum synergistic
effect is 550 °C. The yield of olefins increased gradually with
Fig. 4 shows the carbon yields of BTX, olefins and coke from
the coupling conversion of MF and methanol at different
WHSV. WHSV is defined as the mass flow rate of MF–
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Table 2 Detailed product distributions from the coupling conversion of
MF and methanol at different reaction temperatures
Table 3 Detailed product distributions from the coupling conversion of
MF and methanol at different WHSV
Reaction temperature (°C)
WHSV
Product distribution
450
500
550
600
Product distribution
1
3
6
10
MF conversion (%)
Methanol conversion (%)
Total carbon conversion (%)
50.2
100
64.4
71.6
100
79.7
94.8
100
96.3
100
100
100
MF conversion (%)
Methanol conversion (%)
Total carbon conversion (%)
100
100
100
95.8
100
97.0
94.8
100
96.3
72.7
100
80.5
Overall carbon selectivity (%)
Overall carbon selectivity (%)
Aromatics
Olefins
Oxygenatesa
Alkanesb
CO
CO2
Coke
39.5
21.2
7.4
7.4
6.8
1.3
16.4
44.4
22.6
3.1
8.5
10.3
1.8
50.8
20.5
0.8
8.1
9.5
1.3
9.0
44.3 Aromatics
27.0 Olefins
56.7
14.8
0
6.9
10.2
1.3
10.2
51.1
18.8
0
7.1
9.6
1.7
11.8
50.8
20.5
0.8
8.1
9.5
1.3
9.0
41.3
26.4
3.3
8.2
11.4
1.1
0
8.7
Oxygenatesa
Alkanesb
10.0 CO
2.5
7.5
CO2
Coke
9.3
8.2
Aromatic selectivity (%)
Benzene
Toluene
Aromatic selectivity (%)
14.2
41.5
37.7
6.6
18.9
45.2
31.8
4.1
22.5
47.5
27.5
2.5
29.1 Benzene
49.2 Toluene
20.2 Xylenes
24.2
49.9
23.0
2.9
21.6
48.0
27.5
2.9
22.5
47.5
27.5
2.5
21.4
43.4
31.1
4.1
Xylenes
Alkylbenzenesc, indenes,
naphthalenes
1.5
Alkylbenzenesc, indenes,
naphthalenes
Olefin selectivityd (%)
Ethylene
Propylene
Olefin selectivityd (%)
63.6 Ethylene
36.4 Propylene
59.2
40.8
65.8
34.2
69.2
30.8
69.5
30.5
73.1
26.9
69.2
30.8
69.2
30.8
a Furan and DMF. b CH4, C2H6 and C3H8. c Ethylbenzene, 1-ethyl-3- a Furan and DMF. b CH4, C2H6 and C3H8. c Ethylbenzene, 1-ethyl-3-
methylbenzene, mesitylene and hexamethylbenzene. d C3+ olefins methylbenzene, mesitylene and hexamethylbenzene. d C3+ olefins
(<1%) were neglected in this calculation.
(<1%) were neglected in this calculation.
the WHSV increased from 1 to 3, and then decreased gradually
as WHSV further increased. Table 3 shows the detailed
product distributions from the coupling conversion of MF and
methanol at different WHSV. As shown in Table 3, the conver-
sion of MF increased with decreasing WHSV and achieved
100% at WHSV of 1. Regarding the overall carbon selectivity,
the selectivity of aromatics decreased with increasing WHSV,
while the selectivity of alkanes exhibited an opposite trend.
The selectivity of CO reached a minimum value of 9.5% at
WHSV of 6 h−1. The increasing WHSV has a positive effect on
aromatic selectivity. As the WHSV increased from 1 to 10, the
selectivity of xylenes increased from 23.0% to 31.1%, whereas
the selectivity of toluene decreased from 49.9% to 43.4%.
These results show that the suitable WHSV for the coupling
conversion of MF and methanol was less than or equal to 6.
Fig. 4 Carbon yield of BTX, olefins and coke as a function of WHSV
from the coupling conversion of MF and methanol. Reaction conditions:
ZSM-5 catalyst, reaction temperature: 550 °C, methanol to MF molar
ratio: 2, carrier gas flow rate: 300 mL min−1, reaction time: 15 min.
Coupling conversion of different bio-derived furans with
methanol
Fig. 5 shows the carbon yields of BTX, olefins and coke from
the coupling conversion of different bio-derived furans and
methanol. As shown in Fig. 5, the coupling conversion of DMF
and methanol gave maximum yields of BTX and olefins. The
yield of BTX from the coupling conversion of MF and metha-
nol was close to that of the coupling conversion of DMF and
methanol. However, the yields of BTX from FF and FA were far
less than that of the coupling conversion of DMF and metha-
nol. The lowest yield of coke was also obtained by the coupling
conversion of MF and methanol, suggesting that DMF is the
methanol mixtures divided by the mass of catalyst used in the
reactor. In this experiment, the mass flow rate of mixtures was
altered from 0.02–0.2 g min−1 while the mass of catalyst was
kept constant. As can be seen from Fig. 4, the yields of BTX,
olefins and coke were also a function of WHSV. As the WHSV
increased from 1 to 10, the yield of BTX decreased from 55.1%
to 31.9%, while the yield of olefins increased from 14.8% to
21.3%. The coke yield increased first from 10.2% to 11.5% as
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and methanol was far more than that of the coupling conver-
sion of MF/DMF, indicating that FF and FA favor the decarbo-
nylation reaction. These bio-derived furans also displayed
different aromatic selectivity. The coupling conversion of FF
and methanol exhibited the maximum selectivity of benzene
and the minimum selectivity of xylenes. This result could be
explained by the reaction chemistry of the coupling conversion
of FF and methanol. In the coupling conversion of FF and
methanol, FF first underwent the decarbonylation reaction to
form furan and CO, while methanol underwent the MTO reac-
tion to form mainly ethylene. Ethylene and furan further
underwent the Diels–Alder reaction to form benzene. It is of
note that the selectivity of xylenes from the coupling conver-
sion of DMF and methanol at 450 °C was larger than that at
550 °C, implying that DMF favors the dealkylation reaction at a
higher temperature.
Fig. 5 Comparison of carbon yield of BTX, olefins and coke from the
coupling conversion of different bio-derived furans and methanol. Reac-
tion conditions: ZSM-5 catalyst, reaction temperature: 550 °C except
DMF-450, DMF-450: 450 °C, WHSV: 6 h−1, methanol to MF molar ratio:
2, carrier gas flow rate: 300 mL min−1, reaction time: 15 min.
Conclusion
The advance of the catalytic fast pyrolysis of bio-derived furans
is hindered by several critical issues: low aromatic yield, low
selectivity to high value-added aromatic products (e.g., xylenes)
and significant coking of catalysts. We have demonstrated that
the coupling conversion of bio-derived furans and methanol is
an effective method to simultaneously address these chal-
lenges because of the significant synergistic effect between
bio-derived furans and methanol. The best reaction conditions
for maximizing the synergistic effect were a MF to methanol
molar ratio of 2 at 550 °C. The synergistic effect in the coup-
ling conversion of MF and methanol could be attributed to the
MTO reaction, Diels–Alder reaction of furans with olefins, and
alkylation reaction of benzene/toluene with methanol. More-
over, compared to MF, FF and FA, DMF is the best of the bio-
derived furans for obtaining aromatic production in the coup-
ling conversion of bio-derived furans and methanol. These
findings provide a simple, green, efficient and cost effective
way for simultaneously overcoming the existing bottlenecks in
the catalytic fast pyrolysis of bio-derived furans and would
help the understanding of the reaction chemistry of co-conver-
sion of biomass and alcohol mixtures.
Table 4 Detailed product distributions from the coupling conversion
of different bio-derived furans and methanol
Feedstock species
Product distribution
MF
DMF DMFa FF
FA
MF conversion (%)
Methanol conversion (%)
Total carbon conversion (%)
94.8 100
76.2 100
100
100
100
100
100
100
100
96.3 100
82.1 100
Overall carbon selectivity (%)
Aromatics
Olefins
Oxygenatesb
Alkanesc
CO
CO2
Coke
50.8
20.5
0.8
8.1
9.5
1.3
9.0
55.0
23.5
0
8.2
5.7
1.1
6.6
48.6
23.8
0
9.0
3.9
0.7
14.1
29.4
23.0
1.0
6.0
27.6
2.9
24.2
27.8
5.0
7.1
16.7
3.0
10.1
16.1
Aromatic selectivity (%)
Benzene
Toluene
22.5
47.5
27.5
2.5
20.3
46.2
29.7
3.8
14.6
37.7
38.7
9.0
31.9
48.5
17.8
1.8
24.6
44.1
28.7
2.7
Xylenes
Alkylbenzenesd, indenes,
naphthalenes
Olefin selectivitye (%)
Ethylene
Propylene
69.2
30.8
69.8
30.2
61.3
38.7
66.8
33.3
69.1
30.9
Acknowledgements
The authors gratefully acknowledge the National Natural
Science Foundation of China (grant no. 51376186) for finan-
cial support of this work.
best of the bio-derived furans for aromatic production in the
coupling conversion of bio-derived furans and methanol.
Table 4 shows the detailed product distributions from the
coupling conversion of different bio-derived furans and metha-
nol. The coupling conversion of different bio-derived furans
with methanol exhibited very distinct overall carbon selectivity.
The selectivity of CO from the coupling conversion of FF/FA
References
1 G. W. Huber, J. N. Chheda, C. J. Barrett and J. A. Dumesic,
Science, 2005, 308, 1446–1450.
2 G. W. Huber, S. Iborra and A. Corma, Chem. Rev., 2006,
106, 4044–4098.
Green Chem.
This journal is © The Royal Society of Chemistry 2014

View Article Online
Green Chemistry
Paper
3 G. W. Huber and A. Corma, Angew. Chem., Int. Ed., 2007, 15 C. L. Williams, C. C. Chang, P. Do, N. Nikbin,
46, 7184–7201.
S. Caratzoulas, D. G. Vlachos, R. F. Lobo, W. Fan and
4 R. J. van Putten, J. N. M. Soetedjo, E. A. Pidko, J. C. van der
P. J. Dauenhauer, ACS Catal., 2012, 2, 935–939.
Waal, E. J. M. Hensen, E. De Jong and H. J. Heeres, Chem- 16 C. C. Chang, S. K. Green, C. L. Williams, P. J. Dauenhauer
SusChem, 2013, 6, 1681–1687. and W. Fan, Green Chem., 2014, 16, 585–588.
5 K. Pupovac and R. Palkovits, ChemSusChem, 2013, 6, 2103– 17 P. T. M. Do, J. R. McAtee, D. A. Watson and R. F. Lobo, ACS
2110. Catal., 2013, 3, 41–46.
6 B. Saha and M. M. Abu-Omar, Green Chem., 2014, 16, 24– 18 N. Nikbin, P. T. Do, S. Caratzoulas, R. F. Lobo,
38.
P. J. Dauenhauer and D. G. Vlachos, J. Catal., 2013, 297,
7 Y. Zhao, T. Pan, Y. Zuo, Q.-X. Guo and Y. Fu, Bioresour.
Technol., 2013, 147, 37–42.
8 W.-L. Fanchiang and Y.-C. Lin, Appl. Catal., A, 2012,
419–420, 102–110.
35–43.
19 Y. T. Cheng, Z. P. Wang, C. J. Gilbert, W. Fan and
G. W. Huber, Angew. Chem., Int. Ed., 2012, 51, 11097–
11100.
9 T. R. Carlson, Y. T. Cheng, J. Jae and G. W. Huber, Energy 20 W. Z. Wu, W. Y. Guo, W. D. Xiao and M. Luo, Fuel Process.
Environ. Sci., 2011, 4, 145–161. Technol., 2013, 108, 19–24.
10 T. R. Carlson, G. A. Tompsett, W. C. Conner and 21 F. L. Bleken, S. Chavan, U. Olsbye, M. Boltz, F. Ocampo and
G. W. Huber, Top. Catal., 2009, 52, 241–252. B. Louis, Appl. Catal., A, 2012, 447, 178–185.
11 T. R. Carlson, T. R. Vispute and G. W. Huber, Chem- 22 C. T. W. Chu and C. D. Chang, J. Catal., 1984, 86, 297–
SusChem, 2008, 1, 397–400. 300.
12 H. Y. Zhang, Y. T. Cheng, T. P. Vispute, R. Xiao and 23 C. D. Chang, C. T. W. Chu and R. F. Socha, J. Catal., 1984,
G. W. Huber, Energy Environ. Sci., 2011, 4, 2297–2307. 86, 289–296.
13 S. Shao, H. Zhang, R. Xiao, D. Shen and J. Zheng, Bioenergy 24 H. Y. Zhang, T. R. Carlson, R. Xiao and G. W. Huber, Green
Res., 2013, 1–10. Chem., 2012, 14, 98–110.
14 Y. T. Cheng and G. W. Huber, Green Chem., 2012, 14, 3114– 25 P. A. Horne, N. Nugranad and P. T. Williams, J. Anal. Appl.
3125.
Pyrolysis, 1995, 34, 87–108.
This journal is © The Royal Society of Chemistry 2014
Green Chem.