Styrene monomers in high quality - Process analytics optimizes styrene monomer production - Digital Asset Management
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Analytical Products
and Solutions
Styrene monomers
in high quality
Process analytics optimizes
styrene monomer production
usa.siemens.com/process-analytics
Challenge Customer’s benefit from PGC
Styrene is one of the most important There are three types of processes • Multiple analytical tools for adapting
monomers for the polymer industry. generally used – suspension, solution the hardware perfectly to the ana-
Today the total annual production of and mass (bulk) polymerization. lytical needs
styrene is around 25 million tons and • Liquid injection modules optimize
is estimated to increase to 40 million Solution the vaporization of liquid samples
tons by 2020, so that the production Styrene plants are equipped with • Broad range of column types and
of styrene is one of the most impor- comprehensive measuring and control columns switching technologies
tant industrial processes. instrumentation in order to comply
• Sensitive detectors to determine
The colorless oily liquid is an aromatic with the requirements of quality,
trace components
olefin with the chemical formula safety and energy efficiency control.
Field instrumentation includes process • Airless oven minimizes utility costs
C6H5CH=CH2. It is easy to be polymer-
ized due to the presence of a carbon analyzers and analyzer systems to
double bond. It is a main monomer monitor in detail the production steps
block for the production of polysty- by analyzing the process flow streams
rene and other polymer derivatives. for their composition and communi-
cate the measured data to the central
Polystyrene is a hard, stiff, brilliantly control system. For that, Siemens
transparent synthetic resin. It is widely process analytics offers well proven
employed in the food-service industry analyzer and analyzer systems togeth-
as rigid trays and containers, dispos- er with specific application knowledge.
able eating utensils, and foamed cups, Process gas chromatographs (PGC)
plates, and bowls. Polystyrene is also and gas analyzers are part of field
copolymerized, or blended with other instrumentation in styrene monomer
polymers, lending hardness and rigid- production plants.
ity to a number of important plastic
and rubber products. Siemens PGC in a plant.
Styrene production 1 / 4
Let’s have a deeper look
into the details
The most common technology for in the EB process. The mixture is then by steam from a super heater. The
manufacturing styrene monomer is distilled to recover EB, and to recycle steam is the source of heat and it
the dehydrogenation of ethylbenzene. benzene and higher ethylated ben- removes coke that tends to form on
Most of the world’s actual styrene zenes. The latter are trans-alkylated the iron oxide catalyst. On the other
production is carried out using this with benzene to form additional EB. hand the reactor effluent is cooled
technology. Licenser like CB&I/Lum- The recycle benzene is sent back to by generating steam.
mus, Badger/Total or Versalis use the alkylator and transalkylation The dehydrogenated mixture is dis-
alkylation of benzene with ethylene reactor vessels and the EB product tilled to recover SM product, recycle
to produce ethylbenzene (EB) as to the dehydrogenation section of EB, as well as benzene and toluene
intermediate. In a second step super- the styrene unit. Sampling points for by-products. Inhibitors are added to
heated steam is used to produce measuring are the O2-concentration prevent styrene polymerization.
styrene monomer (SM) from ethyl- at the outlet of the alkylation reactor The measuring task in this production
benzene by dehydrogenation. and chemical byproducts at the step are: O2-, N2, CO- and CO2 con-
ethylbenzene reactor. centrations in fuel gas to compressor,
The ethylbenzene (EB) process as
various by-products during distillation
first production step uses a fixed- During the styrene monomer process
and fractionation processes.
bed zeolite catalyst, which provides as the second production step the
a run duration of several years. To dehydrogenation of EB to SM and by- For the third production step to poly-
get a mixture of alkylated benzenes products is the major reaction. This merize styrene to polystyrene there
and excess benzene the alkylation catalytic reaction is endothermic. are three types of processes generally
of benzene with ethylene is involved The reaction heat will be supplied used – suspension, solution and mass
(bulk) polymerization.
Styrene monomer production process
Naphtha , LPG, … PS: Polystyrene - (C8H8)n
EPS: Enpandable Polystyrene
ABS: Acrylonitrile-Butadiene-Styrene
Aromatics (C8H8·C4H6·C3H3N)n
Benzene Ethylene
Ethylbenzene Styrene Monomer
PS EPS ABS
Styrene production 2 / 4Siemens Product Description
In order to comply with the require-
Ethylbenzene production process
ments of quality, safety and energy
efficiency control styrene plants are
Benzene (Recycle) Ethylbenzene
equipped with comprehensive measur- 2
ing and control instrumentation. 1
Field instrumentation includes process
analyzers and analyzer systems to
monitor in detail the production steps
Distillation
Distillation
Distillation
Alkylation
Reactor
by analyzing the process flow streams
Transalkylation
for their composition and communi-
Reactor
cate the measured data to the central Benzene
control system.
Siemens process analytics supports
with its high performance PGC
MAXUM edition II, the Continuous Ethylene Polyethyl Benzene
Gas Analyzers (Series 6 and SIPROCESS
Sampling Location Measuring Measuring Siemens
GA700) and the in-situ gas analyzers point and application component range Analyzer
SITRANS SL and LDS 6 together with 1 Alcylation reactor outlet 02 0–5% OXYMAT 7
specific application knowledge. or SITRANS SL
2 Ethylbenzene purity o-Xylene, m-Xylene, High ppm Maxum edition II
Process gas chromatograph (PGC) p-Xylene, Benzene, to low % level
MAXUM edition II represents the top Toluene, Cumene, Styrene
technology in process gas chromatog-
raphy for analyzing liquids and vapor
process samples.
Styrene monomer production process
Siemens process analytics offers a
comprehensive portfolio of continuous
Benzene
extractive and in-situ measuring gas Recycle Ethylbenzene
analyzers. The analyzers can be easily 2
Distillation
Distillation
integrated into the Totally Integrated
Automation (TIA) concept and are Dehydrogenated mixture
programmed using SIMATIC PDM Off gas
software a PROFIBUS DP/PA interfaces. Ethylbenzene
Distillation column
Compressor Toluene
5
1
Styrene Monomer
Steam Dehydrogenation 4
reactor Separator
3
Distillation
Condensate
Tar
Sampling Location Measuring Measuring Siemens
point and application component range Analyzer
1 Fuel gas to compressor 02 0–2% OXYMAT 7
SITRANS SL
N2, O2, CO, C02 Low to medium Maxum edition II
% level
2 Recycle ethylbenzene Nonaromatics Low to medium Maxum edition II
Benzene, Toluene % level
Styrene
3 Styrene distillation – Styrene Nonaromatics Medium to high Maxum edition II
plateau Ethylbenzene % level
m-/p-Xylene
4 Fractionation overhead – Ethylbenzene Medium to low Maxum edition II
SM purity m-Xylene p-Xylene ppm level
Phenylacetylene
Alpha-Methylstyrene
Cumene
5 Toluene fractionation Benzene 0-2% Maxum edition II
bottom
Styrene production 3 / 4Process gas chromatograph (PGC) SITRANS SL SIPROCESS GA700 OXYMAT 7
MAXUM edition II The measuring principle of the diode With its long service life, the
MAXUM edition II represents the laser gas analyzer SITRANS SL is based SIPROCESS GA700 OXYMAT 7 is an
top technology in process gas chroma- on the specific light absorption of exceptionally reliable measuring
tography for analyzing liquids and different gas components. SITRANS SL device and can even handle small
vapor process samples. The multiple with its extremely rugged design and measuring ranges (0 to 0.5% O2).
analytical tools such as injectors, minimum maintenance requirements With its vibration compensation
ovens, sensitive detectors or columns is suitable for fast and non-contact and physically suppressed zero point
adapt the hardware perfectly to the measurement of gas concentrations (99.5 to 100% O2) it delivers highly
analytical needs. The airless oven in process or flue gases. The sensors precise measurements. The module
reduces utility costs as well as the (transmitter and receiver) are meant can be operated in either a rack or
use of corrosion-resistant materials to be mounted directly on the process wall-mounted housing. Furthermore,
when required for the application. with no need of sampling systems. the operating concept is based on a
The hardware for processing the clearly laid-out menu structure. The
When the chromatographs are in-
measurement signal into a concen- advantages offered by the OXYMAT 7
stalled on an Ethernet network, the
tration value as well as monitoring, make it indispensable for many appli-
“Gas Chromatograph Portal” software
control and serving of the communi- cations in incineration plants, in
provides real-time analysis and main-
cation means are also integrated into environmental protection, or in qual-
tenance information for reliable moni-
two main modules. ity assurance monitoring purity, and
toring and control.
many more areas.
Siemens Case Study
November 2019
Harald Mahler, Business Development Manager
Siemens Industry, Inc.
Process Industries and Drives
100 Technology Drive
Alpharetta, GA 30005
1-800-365-8766
Subject to change without prior notice
Order No.: PIACS-00025-0919
All rights reserved
Printed in USA
© 2019 Siemens Industry, Inc.
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