Adsorbents for the Motor Fuel HF Alkylation Process
The motor fuel HF alkylation process catalytically combines C3-C5
olefins with isobutane to produce motor fuel alkylate, which is ideal
for producing reformulated gasoline. There are two major licensors
of this technology. Both licensors require careful control of the moisture
content of both the feed olefin and saturate streams in order to minimize
acid consumption. UOP adsorbents, both molecular sieves and aluminas,
are highly-efficient dehydration adsorbents in this application.
When the feeds are contaminated by high levels of other contaminants, such
as oxygenates (MTBE raffinate) or nitriles (FCC product contaminants), it’s
desirable to remove such contaminants so as to minimize acid consumption and
by-product formation. The UOP Oxygenate Removal unit (ORU) and the UOP Nitrile
Removal unit (NRU) employ molecular sieve adsorbents that are highly effective
in the purification of olefin-containing streams.
Each of the products from the HF alkylation process – propane, butanes
and alkylate – contain traces of HF, as well as combined fluorides. In
order to meet LPG specifications (C3 and C4 fractions), refiners employ activated
alumina adsorbents to catalyze decomposition of the combined fluorides at elevated
temperatures followed by removal of the HF formed by this reaction. Some refiners
also employ these adsorbents to reduce the fluoride content of the alkylate
product. Temperatures of 350°F– 450°F are necessary to catalytically
decompose the organic fluorides to HF and an olefin. The HF produced rapidly
reacts with the high surface area, high porosity alumina to form aluminum fluoride,
thereby removing fluorides from the hydrocarbon streams. You can look to UOP
A-202HF and P-188 adsorbents as commercially proven, cost-effective solutions
for this application.
UOP also offers a unique Recoverable Aluminum Fluoride (RALF) program for the
recovery of the alumina product from spent material. All spent alumina needs
to meet certain specifications (> 95% of the time) before the alumina can
be reprocessed in this program. Once approved, for a nominal shipping charge,
you will have a cost-effective source for reprocessing and reusing your spent
alumina.
For more information on our HF alkylation adsorbent solutions, contact us using our information request form or
contact your local sales office.
For more on related UOP technologies, click on the following links:
Light Olefin Conversion to Gasoline
Linear Alkylbenzene Production
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