ISSN 0965ꢀ5441, Petroleum Chemistry, 2016, Vol. 56, No. 1, pp. 33–37. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © O.S. Travkina, R.Z. Kuvatova, I.N. Pavlova, Ahmed Kanaan Ramadan, A.F. Akhmetov, B.I. Kutepov, 2016, published in Neftekhimiya, 2016, Vol. 56, No. 1,
pp. 41–45.
Isomerization of
n
ꢀHexane on BinderꢀFree Shaped Platinumꢀ
Containing Mordenite
O. S. Travkinaa, R. Z. Kuvatovaa, I. N. Pavlovaa, Ahmed Kanaan Ramadanb,
A. F. Akhmetovb, and B. I. Kutepova
aInstitute of Petroleum Chemistry and Catalysis, Russian Academy of Sciences, Kazan, Tatarstan, Russia
bUfa State Technical University of Petroleum, Ufa, Bashkortostan, Russia
eꢀmail: ink@anrb.ru
Received January 19, 2015
Abstract—A catalyst has been prepared as binderꢀfree shaped MORꢀtype zeolite in the H form promoted
with 0.5 wt % platinum, and nꢀhexane conversion over this catalyst has been studied. It has been found
that the selectivity for C4–C6 isoparaffins on the new catalyst is about 90% at 300°C, a feed space velocity of
1.5 h–1, and a hydrogen pressure of 3 MPa, with the hexane conversion being 80.0–83.0 wt % and the selecꢀ
tivity for isohexane making 83.0–86.0%. It has been shown that the new catalyst is stable for 50 h onꢀstream
under these conditions.
Keywords: MOR type zeolite, pellets, catalyst, isomerization,
DOI: 10.1134/S0965544115080186
nꢀhexane
Heterogeneous catalytic isomerization of normal length) in the Na form was synthesized according to
С5–С6 paraffins is becoming increasingly important in the procedure described in [4, 5] in a 5ꢀL crystallizer
the production of motor fuels. In addition, isomerizaꢀ autoclave equipped with a gate stirrer (60 rpm), elecꢀ
tion of pentane is used in the production of isoprene by tric heating, and a sampler. The silica ratio
twoꢀstep dehydrogenation of isopentane [1, 2]. One of
the catalysts used in industrial hydroisomerization
processes of light paraffins is the bifunctional catalyst
consisting of a MORꢀtype zeolite in the H form and
0.4–0.6 wt % platinum [3]. The catalyst also contains
30 wt % ꢀAl2O3 as a binder, the presence of which
lowers the concentration of strong acid sites to almost
the same extent.
Gorshunova et al. [4] described a process for preꢀ
paring granulated MOR type zeolite without a binder
(MORꢀBF) in the Na form to have the porous strucꢀ
ture made by not only microꢀ, but also mesoꢀ and
macropores. It may be assumed that the catalyst based
on this zeolite will have a higher concentration of catꢀ
alytically active sites as compared with catalysts in
which the zeolite was shaped with a binder. In addiꢀ
tion, the MORꢀBF zeolite pellets are much stronger,
since they are ensembles of intergrown crystals. This
(
SiO2/Al2O3) of both zeolites was 10.
Samples of these zeolites with different degrees of
decationation were prepared by ion exchange in an
aqueous solution of ammonium nitrate at = 80–
90
, a ratio of NH+4 cations in the solution to Na+
cations in the zeolite of = 1.5 gꢀequiv/gꢀequiv, pH =
5.5–7.0, and a duration of
Т
°C
γ
G
τ
= 1 h followed by heat
treatment in air at 540–650
°C for 4–6 h. The degree of
exchange of Na+ for Н+(αNa
)
above 0.7 was achieved as
a result of several exchange treatments without interꢀ
mediate calcination.
Procedures for determining the chemical and
phase compositions, equilibrium adsorption capacity
(mg/g) of zeolite for water vapor ((AH O
)
) and benꢀ
pore, cm3/g), and specific
S
sp, m2/g) are described elsewhere [4].
2
zene (AC H ), pore volume (
V
6
6
surface area (
study is devoted to the synthesis of a novel
isomerization catalyst on the basis of this crystalline
aluminosilicate and testing it in the conversion of
hexane under hydrogen pressure at different temperaꢀ
tures and feed space velocities.
nꢀparaffin
The acid properties of the aluminosilicates were
studied using the technique of ammonia temperatureꢀ
programmed desorption (TPD) [6].
nꢀ
Transformations of
tems obtained in this way were studied in a flow
reactor with a catalyst charge of 5 cm3 at 250–400
an
ꢀC6H14 feed space velocity of 1–3 h–1, and a
hydrogen pressure (PH ) of 3.0 MPa and flow rate of
nꢀhexane on the catalytic sysꢀ
°С,
n
EXPERIMENTAL
2
Powdered MORꢀtype zeolite and MORꢀBF zeolite
(pellets of a 1.6–2 mm diameter and a 3–6 mm
1300–1700 L/(Lcat h). The choice of nꢀhexane as a
33