Hydrocarbon Processing - June 2021 - 54

Catalysts
TABLE 1. Pilot plant testing of the next-generation transalkylation catalyst vs. its predecessor
Target DEB conversion
Catalyst
Bz/PEB wt ratio
PEB WHSV, h-1
Temperature, °C
DEB conversion
TEB conversion
Heavies/EB, wt/wt
50
55
60
65
70
75
13
13.5
14
14.5
PEB recycle rate, kg/hr
5
FIG. 6. EB production rate vs. PEB recycle rate: Next-generation transalklyation catalystd
and the previously used catalystc
.
ation catalyst enabled TDCC to meet this
objective. As shown in FIG. 6, higher PEB
conversion with the new catalyst cycle enabled
TDCC to overcome the bottleneck
in the transalkylation section, resulting in
up to a 9% increase in EB production vs.
the previous cycle. At the time of the publication
of this article, the next-generation
transalkylation catalyst load has been on
stream for nearly 4 yr. The new catalyst
has shown exceptional stability, with a
very low aging rate, and it continues to
meet TDCC's expectations.
Takeaway. Rapid deployment of a nextgeneration,
high-activity transalkylation
catalystd
has provided TDCC a fit-forpurpose
technology solution for debottlenecking
its EB transalkylation plant.
The site was able to achieve 109% of design
capacity to allow market value capture
of $5.5 MM/yr. The novel transalkylation
catalyst presents higher activity
than its prior version. With the same load
size, higher single-pass PEB conversion
was achieved at a lower reactor temperature.
The next-generation transalkylation
54 JUNE 2021 | HydrocarbonProcessing.com
catalyst has been in stable operation-
with negligible aging-at TDCC's facility
since May 2017.
Overall, the high-activity transalkylation
catalyst provides operating flexibility
to achieve the following benefits:
* Debottleneck a transalkylation/
PEB loop to achieve higher
overall unit capacity
* Lower PEB recycle to save
PEB loop energy consumption
* Lower start-of-run temperature
slows catalyst aging rate,
providing a larger operating
temperature window and
increasing the cycle length
* Low-temperature operation reduces
heavies production to minimize fuel
value downgrading
* Lower initial catalyst fill cost,
with reduced load size for
constant unit capacity.
NOTES
a Badger Licensing's EBMaxSM
b ExxonMobil's EM-3300 catalyst
technology
c ExxonMobil's EM-3700 transalkylation catalyst
d ExxonMobil's EM-3750 transalkylation catalyst
15
Transalkylation
catalystc
2
1.1
194
65%
56%
0.59%
Next-generation
transalkylation catalystd
2
1.1
177
65%
60%
0.62%
2
1.1
190
60%
42%
0.63%
1
Target temperature
Transalkylation
catalystc
Next-generation
transalkylation catalystd
2
1.1
190
72%
83%
0.85%
LITERATURE CITED
Maerz, B. R., C. R. Venkat, S. S. Chen and D. N.
Mazzone, " EBMaxSM
: Leading-edge ethylbenzene
technology from Mobil/Badger, " DeWitt & Co. Inc.'s
1996 Petrochemical Review, Houston, Texas, March
1996.
2
Mazzone, D. N., P. J. Lewis, C. R. Venkat and B. R.
Maerz, " Mobil/Badger into the future, " Hydrocarbon
Asia, April 1997.
3
Next-generation catalystd
Previous catalystc
15.5
16
Cheng, J. C., T. F. Degnan, J. S. Beck, Y. Y. Huang, M.
Kalyanaraman, J. A. Kowalski, C. A. Loehr and D. N.
Mazzone, " A comparison of zeolites MCM-22, beta,
and usy for liquid phase alkylation of benzene with
ethylene, " Studies in Surface Science and Catalysis,
Volume 121, 1999.
4 Degnan Jr., T. F., C. M. Smith and C. R. Venkat,
" Alkylation of aromatics with ethylene and propylene:
Recent developments in commercial processes, "
Applied Catalysis A: General, November 2001.
ExxonMobil Catalysts and Licensing LLC, Fact
Sheet: " Cutting-edge catalysts for ethylbenzene production
ExxonMobil zeolite catalysts: Producing the
majority of the world's ethylbenzene. "
GEHONG LIU is the General
Manager of Tianjin Dagu Chemical
Co. Ltd. He has been working in
chemicals manufacturing for 18 yr
and has extensive management
experience in chloralkali chemicals
and the petrochemical industry.
Mr. Liu holds six patents and has published 12 peerreviewed
technical papers. He graduated from the
Wuhan Institute of Technology with a degree in
chemical engineering. He obtained a post-graduate
degree from Tianjin University.
RAM SUNDARARAMAN is a Staff
Engineer with ExxonMobil Chemical
Co. Dr. Sundararaman has 15 yr of
experience in catalyst and refining
technology development and holds
several U.S. patents. He earned a
PhD in fuel science from Penn State.
JAMES CAO is the Senior Technical
Sales Manager for aromatics
licensing with ExxonMobil
Catalysts and Licensing LLC.
He has more than 25 yr of
experience in heterogeneous
catalysis and its commercial
applications and holds 25 U.S. patents and various
international filings. Dr. Cao has been responsible
for technology licensing and catalyst sales of
xylenes, EB and cumene processes. He earned his
MS and BS degrees in chemical engineering from
Tsinghua University, and his PhD in chemical
engineering from the City University of New York.
EB product rate, x/hr

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