Hydrocarbon Engineering - March 2017

64 / 160

Techno-economic analysis
As described earlier, the overall process consists of three
steps, which can be carried out in simple fixed bed reactors.
The first step is the commercially available process of
methanol dehydration to DME over a mild solid-acid
catalyst. After removing the water content from the product
effluent from the first reactor, DME along with isobutane is
fed into a second reactor where they are reacted over a
specifically designed catalyst to yield olefins in a
thermoneutral way. Water resulting from the dehydration of
DME is phase separated out and the hydrocarbon mixture
consisting of light olefins and butanes is fed to the alkylation
reactor. The final product is primarily a mixture of
isoparaffins, which can serve as high quality gasoline
blendstock.
A preliminary economic assessment was made using
current catalyst performance data. Since raw material costs
account for over 80% of the cost of production, the
analysis does not include utilities or catalyst costs.
Equipment costs were developed using in-house
correlations and algorithms. The offsite costs (OSBL) were
estimated to be 25% of the inside battery limits (ISBL) costs,
in keeping with the installation of the plant in a
semi-industrial location with some access to existing
infrastructure. Results of the techno-economic analysis
(TEA) are shown in Table 2.
At the current US methanol and butane prices, M2Alk
produces high octane alkylate well below current gasoline
prices. Additionally, the use of simple adiabatic fixed bed
reactors in M2Alk results in significantly lower capital
investment compared to MTG processes.
Conclusion
US motorists are using more ‘premium’ high octane
gasoline as low oil prices led to cheaper fill ups at the
pump. Octane demand will keep growing in the long-term
as fuel economy standards strengthen. As auto
manufacturers build more high compression engines in
anticipation of more stringent US Corporate Average Fuel
Economy (CAFE) standards through 2025, more octane will
be needed in the domestic gasoline pool to fuel those
higher performance vehicles.
The Exelus process, unlike gas to liquids (GTL) and MTG,
which only monetise natural gas, also provides a monetisation
route for NGLs. It combines cheap, readily available butanes
and methanol to generate olefins that can then be alkylated
to produce premium quality high octane blendstock to meet
the growing needs of the US gasoline market. M2Alk produces
a high octane isoparaffinic product. The insignificant
production of aromatics, absence of olefins and the ultra low
sulfur content of alkylate from M2Alk make it a unique
process for monetising not only natural gas, but NGLs as well,
worldwide. Using M2Alk, Exelus has now developed
technologies to produce high octane alkylate from feedstocks
ranging from natural gas and petroleum to bio-ethanol.
References
1. 'Methanol To Gasoline Technology: An Alternative to Liquid Fuel
Production', GTL Technology Forum, (2014).
PROVEN QUAL ITY
Made inGermany
Global Presence
Qualified Support
Quality Service
QUALITY MEANS TO US:
FULFILLING THE MOST STRINGENT REQUIREMENTS.
Our maintenance solutions for the petrochemical industry:
• Laser shaft and geometric alignment
• Portable vibration analysis and field balancing
• Online Condition Monitoring
• ATEX / IECEx compliant equipment.
INNOVATION MADE IN GERMANY.
Find out how we boost uptime.
PRÜFTECHNIK Dieter Busch AG
Oskar-Messter-Str. 19-21
85737 Ismaning
Tel.: +49 89 99616-0