Kolmetz.com CMAI 2000 Joe Page 3
Performance
Competitor
GT-STDP
SM
Toluene conversion, %
28-30
28-30
Paraxylene, wt%
11.4
11.5 12.0
C
8
aromatics, wt%
13.7
14.0 15.0
Benzene/Xylenes (mole)
1.34
1.18 1.21
Standalone installation of the GT-STDP can be combined with crystallization to recover
high-purity paraxylene. Crystallization is the most efficient way to recover paraxylene from
the high-concentration streams. In addition to the reaction and crystallization equipment, a
distillation train (to recover the benzene, toluene, and paraxylene-rich stream) is required.
A consistent way to measure and compare the various technologies is to use a cash cost
of production (CCOP) based on a set of assumed feedstock and product prices, along
with a capital investment for the construction. The cash cost of production incorporates
the basic production costs of feedstock, utilities, and by-product credits, without
considering depreciation or capital charges. Based on a standalone application of GT-
STDP, the production and investment economics are presented below:
GT-STDP
SM
- Production & Investment Costs - 200,000 MTA paraxylene
Production costs ($/ton paraxylene)
Toluene requirement
460,000 MTA
Raw material costs
$ 780
By-product credits
$ (515)
Utility costs
$ 85
Fixed costs
$ 15
Cash Costs
$ 365
Total Investment cost
1
:
U.S.$ 75 MM
1
2000 USGC ISBL; includes reaction, distillation, and crystallization
GT-TolAlk
SM
- Toluene Alkylation
In the GT-TolAlk process, toluene is alkylated with methanol to produce paraxylene at a
very high selectivity (>85 wt%) on a proprietary high-silica zeolite catalyst. The reaction is
conducted in the presence of hydrogen and water in a specific molar ratio in a fixed bed
catalytic reactor. The effluent from the reactor is cooled and directed to a product
separator and a stripper column. The stripper bottoms is fed to the product distillation
section for separation into the various aromatic fractions. Typical operating conditions for
the GT-TolAlk are shown below.
