GT-TolAlk
SM
Typical Operating Conditions
Temperature (°C)
=
400 - 450
Pressure (kg/cm
2
)
=
1 - 5
WHSV (hr
-1
)
=
1 - 2
Paraxylene selectivity,wt.%
=
80-90+ min.
As with the STDP process, standalone installation of the GT-TolAlk can be combined with
crystallization to recover high-purity paraxylene. Based on a standalone application of GT-
TolAlk, the production and investment economics are presented below:
GT-TolAlk
SM
- Production & Investment Costs - 200,000 MTA paraxylene
Production costs ($/ton paraxylene):
Toluene requirement
204,000 MTA
Methanol requirement
120,000 MTA
Raw material costs
$ 370
By-product credits
$ (80)
Utility costs
$ 60
Fixed costs
$ 10
Cash Costs
$ 360
Total Investment cost
1
:
U.S.$ 70 MM
1
2000 USGC ISBL; includes reaction, distillation, and crystallization
There are several advantages to this toluene-based route.
·
Firstly, the toluene requirement per ton of paraxylene can be reduced from around 2.5
to 1.0 (when compared to STDP).
·
A much cheaper, and most likely to be abundant in the extended future, methanol
feedstock is used to maximize the conversion of the aromatic molecule into the
desired paraxylene.
·
As importantly, for producers that do not desire benzene co-product due to
processing objectives or local market conditions, the GT-TolAlk process produces
negligible benzene.
Sensitivity of production costs to toluene pricing for standalone installations of the
methylation process are presented below (Figure 2).
