Capítulo 3. Plan de negocio
3.4. FODA
Investment, US$ million 363
Products, metric tpy
Raffinate 252,000
LPG 68,000
Benzene 264,000
Paraxylene 700,000
Pure hydrogen 49,000
Utilities, per metric ton of feed
Electricity, kWh 64.3
Steam, metric ton (–0.37)
Water, cooling, m3 5.7
Fuel, Gcal 1.6
Commercial plants: UOP is the world’s leading licensor of process tech-nology for aromatics production. UOP has licensed more than 600 sepa-rate process units for aromatics production, including over 260 CCR Platforming units, 139 Sulfolane units, 93 Parex units, 75 Isomar units, 54 Tatoray units and 38 THDA units.
UOP has designed 93 integrated aromatics complexes, which produce both benzene and paraxylene. These complexes range in paraxylene production capacity from 21,000 to 1.7 million metric tpy.
Licensor: UOP LLC, A Honeywell Company - CONTACT
Petrochemical Processes 2010 2010
Petrochemical Processes Home Process Categories Company Index
Paraxylene
Application: To produce a desired xylene isomer (or isomers) from a mix-ture of C8 aromatics using the UOP Isomar and Parex processes.
Description: Fresh feed containing an equilibrium mixture of C8 aro-matic isomers is fed to a xylene splitter (1). Bottoms from the splitter are then separated (2) into an overhead product of o-xylene and a by-product of C9+ aromatics. Overhead from the splitter is sent to a UOP Parex process unit (3) to recover ultra-high-purity p-xylene. If desired, high-purity m-xylene may also be recovered using the MX Sorbex pro-cess. Remaining components are recycled to the UOP Isomar process unit reactor (4) where they are catalytically converted back toward an equilibrium mixture of C8 aromatic isomers. Hydrogen-rich recycle gas is separated (5) from the reactor effluent before fractionation (6) to re-move light-cracked byproducts overhead. The remaining C8 aromatics are then combined with the fresh feed and sent to the xylene splitter (1).
The feedstock consists of a mixture of C8 aromatics typically derived from catalytically reformed naphtha, hydrotreated pyrolysis gasoline or an LPG aromatization unit. The feed may contain up to 40% ethylbenzene, which is converted either to xylenes or benzene by the Isomar reactor at a high-conversion rate per pass. Feedstocks may be pure solvent extracts or fractional heartcuts containing up to 25% nonaromatics. Hydrogen may be supplied from a catalytic reforming unit or any suitable source.
Chemical hydrogen consumption is minimal.
o-Xylene product purity of up to 99% is possible, depending on the composition of the feed and fractionation efficiency. The Parex unit is capable of producing 99.9% pure p-xylene with per pass recovery greater than 97%.
Operating conditions: Moderate temperature and pressure require-ments permit using carbon and low-alloy steel and conventional process equipment.
Yields: Typical yields of key products from a Parex-Isomar complex:
Composition Fresh feed, wt. units Product, wt. units
Benzene – –
Ethylbenzene 17.2 –
p-Xylene 18.3 78.8
m-Xylene 41.8 –
o-Xylene 22.7 10
Economics: Estimated inside battery limits (ISBL) erected and utility costs are given for a Parex-Isomar complex which includes the xylene column, US Gulf Coast site in 2009.
Investment, US$ per metric ton of feed 150–200 Utilities, US$ per metric ton of p-xylene product 30
Commercial plants: Since 1971, UOP has licensed 93 Parex units and 75 Isomar units.
Licensor: UOP LLC, A Honeywell Company - CONTACT
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Petrochemical Processes 2010 2010
Petrochemical Processes Home Process Categories Company Index
Copyright © 2010 Gulf Publishing Company. All rights reserved.
Paraxylene
Application: The UOP PX-Plus XP Process converts toluene to par-axylene and benzene. The parpar-axylene is purified to 99.9+ wt% via single-stage crystallization and a wash column. The benzene purity is 545-grade by fractionation.
Description: The PX-Plus XP Process is composed of three processing steps:
(1) Selective toluene disproportionation, via the PX-Plus Process (2) Fractionation for recovery of recycle toluene and benzene product
(3) The Badger/Niro paraxylene crystallization process, where single-stage crystallization and crystal wash columns are used.
In the PX-Plus technology, fresh toluene is combined with recycle gas, heated and fed to a fixed-bed reactor. The para-selective catalyst produces xylene product with 90% paraxylene in the xylenes. Reactor effluent flows to a separator, where the recycle gas is recovered, and the liquid product is sent to a stripper.
In the fractionation section, stripper bottoms are fed to a benzene column, where the benzene product is recovered and the unconverted toluene is fractionated for recycle. The toluene column bottoms are sent to a rerun column where the paraxylene concentrated fraction is taken overhead.
In the Badger/Niro crystallization unit, the xylenes are fed to a single-stage crystallization section that uses continuous suspension crystallization. In this section, the paraxylene is purified with a single refrigerant compressor system, and the mother liquor rejected. The purified paraxylene is fed to a Niro wash column section where ultra-high-purity paraxylene is produced by countercurrent crystal washing.
Components of this flexible technology are especially suited for capacity expansion of existing paraxylene production facilities.
Yields:
Toluene conversion per pass 30%
Paraxylene yield, wt% 36
Benzene yield, wt% 43
Light ends, wt% < 8
Paraxylene recovery 93.5%
Paraxylene purity, wt% 99.9
Economics: Capital investment per metic tpy of paraxylene product
EEC, US$ 285
Utilities per mt of paraxylene product
Electricity, kWh 172
Steam, HP, metric ton 2.48
Steam, LP, metric ton 3.76
Water, cooling, m3 27
Fuel, MMkcal 0.5
Commercial plants: Three PX-Plus units have been brought online. Two Badger/Niro licensed and process packages were produced for three Badger/Niro crystallization projects.
Licensor: UOP LLC, A Honeywell Company, The Shaw Group, Inc., and Niro Process Technology B.V. - CONTACT
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