Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Process for production of diesel fuel
This invention relates to the production of
5 distillate (diesel fuel).
In accordance with the invention it has been
unexpectedly found that gasoline feedstocks prepared in a
particular manner can be readily processed into a
hydrocarbon product with a significant fraction boiling
10 in the distillate range.
The said gasoline feedstocks are prepared by
conversion of light olefins, using a zeolite catalyst
that is modified as hereinafter described.
~ . '~
-- 3
T The subsequent processing of the said gasoline
feedstocks in accordance with the invention may be
carried out using a conventional Friedel-Crafts catalyst.
The oligomerisatlon of light olefins over acid
5 catalysts is well known - see e.g. Kirk-Othmer
"Encyclopaedia of Chemical Technology" 3rd Edition 1978
John Wiley - Vol.4. p.362 - this gives a material useful
for gasoline blending stock. Higher severity
oligomerisation to materials in the distillate range is
10 possible, but the product, because of much skeletal
isomerisation and branching, suffers from low cetane
number e.g. tetra-iso-butylene-olefin oligomer of
isobutylene, cetane No. 15, compared with n-hexadecane
(cetane), cetane No. 100.
U.S. Patent Nos. 3,894,106, 4,062,~05 and
4,052,479 disclose the conversion of alcohols and ethers
to higher hydrocarbons by contact with a zeolite catalyst
having a silica to alumina ratio of at least 12 at about
260 to 450C. The preferred zeolite catalysts have
20 crystal densities which are not substantially below 1.6
grams per cubic centimeter. These special catalysts are
exemplified by ZSM-12* as in West German
Offenlegungsschrift No. 2,213,109, ZSM--21*and certain
modified naturally occurring zeolites. The synthetic
25 zeolites made using an organic cation are preferred.
Aromatization of hydrocarbon feedstocks over
zeolites is well known. U.S. Patent No. 3,760,024
discloses an aromatization process for a feedstock
comprising C2 to C4 paraffins and olefins comprising
30 contacting such a feedstock with crystalline
aluminosilicates of the ZSM-5*family. U.S. patent No.
3,756,942 discloses contacting a feeds-tock having a
boiling range of C5 to about 250F wi-th a crystalline
aluminosilicate zeolite of the ZSM-5 type, and US patent
35 4,150,062 d~scribes an invention which relates to
* Trade Mark
improved processing of light olefins of from 2 to 4
carbon atoms to product comprising high oc-tane gasoline
components. The process comprises contacting the olefin
feedstock in the presence of co-fed water with a catalyst
5 comprising a zeolite characterized by a silica/alumina
molar ratio of at least 12.
The crystalline aluminosilicate zeolites used
in the catalyst composition of the process of this latter
invention are referred to generally as -the ZSM 5 family,
10 or as behaving like ZSM-5, and include ZSM-5, ZSM-ll*
ZSM-12, ZSM-35*and ZSM 3~.
Olefin oligomerisation over zeolite of the
ZSM-5 family such as ZSM-12 has also been described in US
Patent 4,254,295. This disclosed a process for the
15 selective oligomerization of linear and branched chain C2
to C12 olefins and comprised contacting the olefins, in
the liquid phase, with a ZSM-12 zeolite at temperatures
from about 80F to about 400F. It was found that the
process provided selective conversion of the olefin feed
20 to oligomer products with high selectivity, the product
containing little or no light cracked products,
paraffins, etc.
Light olefins can be synthesised from alcohols
such as methanol using zeolite catalysts similar to those
25 described above, as in for example US Patent 4,025,576.
This shows that a feed comprising one or more compounds
selected from the lower monohydric alcohols with up to
four carbon atoms, and their simple or mixed e-ther
derivatives, at subatmospheric partial pressure, is
30 completely converted to a mixture comprising mainly light
olefins, by contact with a particular type of crystalline
aluminosilicate catalyst.
Although it is a generally accepted fact that
zeolites in the alkali metal form are of substantially
35 less catalytic activity, in some cases completely
* Trade Mark
~lZ3L%7~
-- 5
inactive, the conversion of methanol over alkali metal
modified zeolites has been described in US Patent
3899544. For conversion of alcohols and ethers to higher
hydrocarbons by zeolite catalysts, if the zeolite is
5 fully exchanged so tha-t its ca-tion content is
substantially alkali metal, it loses most of its activity
to catalyse this reaction. Such high alkali metal
content zeolites do however retain activity for sorne
catalytic roles, no-tably the dehydration of alcohols to
10 ethers.
When most of the alkali metal is exchanged out
of the zeolite and replaced by acid sites, (for example
by ammonium exchange followed by calcination to liberate
ammonia and leave a proton within the zeolite, or as in
15 the case of acid stable zeolites such as ZSM-5, by direct
exchange in acidic media) the catalyst is extremely
active for converting alcohols and/or ethers to higher
hydrocarbons. ~or example, in the conversion of methanol
to hydrocarbons in contact with an H-ZSM-5 zeolite
20 catalyst from which most of the alkali metal (usually
sodium) has been removed, the hydrocarbon yield at 100%
feed conversion is consisten-tly about 44 weight percent,
based upon methanol fed (i.e. little conversion to
dimethyl ether and other oxygenates). Where none of the
25 alkali metal has been removed the hydrocarbon yield is
zero.
It is an object of the present invention to
provide an improved process for the conversion of light
olefins into a hydrocarbon stock a substantial portion of
30 which boils in the distillate range with only a minor
portion boiling in the gasoline range.
In accordance with and fulfilling this object,
one aspect of this invention resides in the discovery
-that when the conversion of lower olefins, by which we
35 mea~ C3-C6 olefins and mixtures thereof, to higher
~ 6
hydrocarbons, particularly hydrocarbons boiling in the
gasoline boiling range, e.g. C5 to 196C, is carried out
over a zeolite modified in a particular manner, the
resulting gasoline can be readily processed, using for
5 example a Friedel-Crafts catalyst, into a hydrocarbon
stock with a significant fraction boiling in the
distillate range. The conversion is carried out at about
100C to 450C, preferably 300 to 450C, up to about 50
atmospheres, and about 0.5 to 50 liquid hourly space
lO velocity.
The catalyst modification which makes possible
the improved operation described herein is to ensure that
a significant portion of the cation sites of the
aforementioned zeolite is occupied by basic cations,
15 notably Lewis or Bronsted bases such as elements of Group
Ia, IIa or Va of the Periodic table. Specific ca-tions
which have been found to be particularly useful are those
which contain sodium, potassium, calclum, nitrogen and
phosphorus, either alone or in appropriate cationic
20 complex form.
The zeolites used as catalysts are usually
obtained from a composition containing an organic cation.
After initially producing the zeolite crystal structure
desired with its original organic and alkali metal
25 cations, it is dried, and then may be directly calcined,
in which case the organic cations are removed by
oxidation to produce a zeolite containing alkali metal
cations. The alkali metal can be exchanged ei-ther with
other metal ions or with ammonium ions or both. Where
30 acid sites are desired ammonium cations are used. The
ammonium form oE the zeolite, upon calcination to remove
ammonia, leaves the hydrogen form of the zeolite. The
order of exchange and calcination is variable with
~ 2~ f~7~
-- 7
several different sequences of operation reported to give
special results for particular purposes well known in the
art.
The catalyst of this invention can be prepared
5 by converting all of the cationic sites to the alkali
metal form and then exchanying a proportion of the alkali
metal cations for acid or other "active" cations.
Alternatively an acid form zeolite can be subjected to
exchange with appropriate alkali metal moieties.
Another method o~ obtaining the catalyst of.
this invention is to mix the hydrogen (acid) form of the
zeolite with a solid matrix or binder which has available
alkali-cations. Although we do not wish to be limited by
any theoretical or postulated mechanism for the observed
15 beneficial results, we observe that, after the influence
of calcination, the composite ca-talyst performs as if a
portion of the zeolite component had been exchanged by
alkali metal.
Another method of obtaining the catalyst of
20 this invention is to use the as-made zeolite; that is, a
~eolite containing both organic and alkali metal cations,
and calcining the zeolite (with or without binder, as
powder or pellet) so as t.o remove a portion of the
organic cations. I-t will be appreciated that the
25 relative amount of organic and alkali-metal cation will
be dependent on such things as the nature of the organic
moie-ty, the relative concentrations of organic and
alkali-metal in the synthesis-gel and to some extent the
silica-alumina ratio of the zeolite, the rela-tive
30 proportion of which can be adjusted by methods well known
to -those skilled in the art. It will also be appreciated
that in this embodiment, the catalyst is not subjected to
ion exchange after synthesis (see examples 13, 20, 27 and
32 below).
7~
-- 8
Accordingly, the invention provides a process
for conversion of lower olefins to hydrocarbons boiling
in the gasoline boiling range, characterised in that the
lower olefins are converted by contact with a zeolite
5 catalyst which has been modified by substituting a
significant portion of the cation sites thereof by basic
cations, whereby the gasoline produced is capable of
further processing into a hydrocarbon produc-t with a
significant fraction boiling in the dis-tillate range.
In a preferred embodiment of the invention ~he
catalyst comprises a zeoli-te and a binder, said catalyst
containing at least 0.2%, preferably at least 0.3%, of
exchangeable basic cations, determined as oxide, on the
total weight of the catalyst.
The catalyst may comprise up to 90% by weight
binder, such as bentonite or alumina, but is preferably
within the range of 25% to 75~.
The zeolite is preferably of the ZSM family,
having an A12O3 content of at least 1~ by weight. Whilst
20 the lower limits of alumina, and hence alkali metal, in
the zeolite are determined by the need for sufficient
ca-talytic activity, the upper l.mits are determined by
the maximum level of zeolitic alumina that can be
tolerated by a given zeolite. For example, it is well
25 known that ZSM-5 will typically have maximum alumina
contents at about 4.5% by weight; in -this case the
maximum alkali-metal con-ten-t would correspond -to about
80% of this value, calculated on a mola.r basis. Other
zeoli-tes can have much higher alurnina contents, so that
30 the corresponding maximum alkali content would be
proportionally higher.
Those skilled in the art will realize that, on
the basis of the above, the ca-talys-t (zeoli-te plus
binder) of the present inven-tion preferably has 20% of
~2~7~
g
the exchangeable basic cations on a molar basis relative
to the alumina content of the zeolite. More preferably
the figure is 30%.
In a further preferred embodiment of the
5 invention a process for production of diesel fuel
comprises the following steps:-
(a) converting lower olefins at temperatures
between about 100 to 450C. preferably be-tween
260 to 450C and more preferably between 300
and 450C, pressures up to about 50
atmospheres, and LHSV of about 0.5 to 50hr 1,
in contact with a zeolite catalyst which has
been modified by substituting a significant
portion of the cation sites thereof by basic
cations, preferably a catalyst comprising a
zeolite and a binder, said catalyst containing
at least 0.2%, and preferably at least 0.3~, of
exchangeable basic cations, determined as
oxide, on the total weight of the catalyst, to
produce a first hydrocarbon product containing
hydrocarbons boiling in the gasoline boiling
range'
(b) converting the said first hydrocarbon product
by contact with a Friedel-Crafts ca-talyst into
a second hydrocarbon product a substantial
portion of which boils ln -the distillate range
with only a minor portion boiling in the
gasoline range.
7;~
- 10 -
Preferably the second hydrocarbon produc-t
comprises at least 40gO~ and more preferably at least 50
by weight distillate boiling at ~235C, and preferably
less than 50%, and more preferably less than 40%, by
5 weight gasoline.
It has been noted that a zeolite catalyst of
this invention has alkali metal and acid cationic sites.
It may also have other cationic sites, such as
hydrogenation/dehydrogenation components, incorporated
10 for given purposes. These other sites are to be
considered as part of the acid site group and are not to
be considered as replacing alkali metal cation moieties.
These additional components can be incorporated with the
zeolite catalyst by impregnation, vapor deposition or
15 exchange, as may seem desirable.
It has been ascertainecl that the catalysts of
this invention are capable of converting alcohols such as
methanol into an olefinic gasoline, but the catalyst
deactivates quickly, e g. over a period of about five
20 hours on line, making practical use of these ca-talysts
for alcohol conversion difficult. Surprisingly, it has
been found that 012fin conversion over the ca-talysts
continues to give useful yields of liquid product for
much longer periods, e.g greater than thir-ty hours on
25 line before reactivation, by for example air-calcination,
is required.
The present invention has further ascertained
that the product hydrocarbon stock produced from olefins
over alkali-metal containing zeolites such as described
30 above can be easily converted by trea-tment with a Lewis
acid catalyst such as aluminium chloride into a product
rich in distillate fraction. The catalyst particularly
useful for the conversion of the hydrocarbon s-tock can be
termed a Friedel-Crafts catalyst, a detailed description
7~
of which can be found in "Friedel-Crafts and Related
Reactions" G.A. Olah (ed) Vols 1-4, Interscience, 1953-
65.
The invention will be further illus-trated by
5 the following non-limiting examples.
Example 1
This example describes the synthesis of ZSM 5
with a high sodium content.
Aluminium wire (2.51g) was dissolved in sodium
10 hydroxide solution (15.2g in lOOg water). The solution
was then added to colloidal silica (667g of Ludox HS40
(trade mark), 40% SiO2) and stirred. Tetra-
propylammonium bromide (147.8g) in water (lOOOg) was then
added and the whole vigorously stirred to a homogeneous
15 gel. The gel was stiffened by the addition of sodium
chloride (250g). The zeolite was crystallized from the
mixture by heating the gel in an autoclave to 175C, with
stirring, for 16 hours. The zeolite was obtained from
the mother liquor by filtration and washing with
20 distilled water. The as-made zeolite was then washed
with 2M hydrochloric acid and then calcined (500~ in
moist air for 16 hrs.). The product analysed at ].~6%
A1203 and 1.7~ Na20 (i.e. all Al expressed as ~-t ~ A1203
and all Na expressed as Wt ~ Na20).
25 Example 2
This examp].e describes a further synthesis of
high sodium con-tent ZSM-5.
The zeolite was prepared in an analogous manner
-to that described in Example 1 e~cep-t tha-t -the weigh-ts of
30 active componen-ts were: aluminium wire (1.28~) sodium
hydroxide (7.5g); colloidal silica (336.6g), tetra-n-
propylammonium bromide (73.9g). The same quantities of
7~
- 12 -
water and sodium chloride were used as for Example 1.
After acid washing, calcination and drying, the product
was analysed at 1.18% A1203 and 0.3~ Na20.
Example _
This describes the conversion of propylene over
high sodium ZSM-5.
Samples of zeolite from examples 1 and 2 were
mixed with bentonite (33~ by weight bentonite) and water,
then extruded. The extrusions (3mm) were dried and
10 calcined at 500C. They were then charged (72g plus 40g
of inert alumina spheres) into a downflow tubular
reactor. Propylene was passed at 36 litres/hr over the
catalyst at about 300C and the liquid products condensed
(123g of liquid). The liquid was analysed by gas-
15 chromatography (12.5m, SP2100, fused silica column) and asimulated distillation profile obtained. The results are
shown in Table 1 and indicate the product consists
predominantly of material boiling in the gasoline-range.
Table 1
Simulated Distillation Profile of Liquid
Produc-t from Example 3.
Fraction _imulated Boiling Range Wt %
~gasoline <196C 93.4
jet-fuel 196 - 235C 4.3
25 middle distillate 1 235 - 317C 1.7
middle distillate 2 >317C 0.7
Example 4
This describes the conversion of the liquid
product obtained in Example 3 into material boiling in
30 the distillate range.
7~
- 13 -
The liquid (30g) and anhydrous aluminium
chloride (lOg) were refluxed (for 3 hours). The mixture
was then hydrolysed by shakiny with water (approx. 200
cc) and the hydrocarbon fraction obtained by separation
5 and filtration. The liquid product was subjected to the
same chromatographic analysis as in Example 3; the
results of the simulated dis-tillation profile are shown
in Table 2 and clearly demonstrate the increase in
boiling points obtained by AlC13 treatmen-t.
10 Table 2
Simulated Distillation Profile of Liquid
Product from Example 4.
.
Fraction Simulated Boiling Range Wt ~
gasoline <196C 28.6
1~ jet-fuel 196 - 235C 12.9
middle distillate 1 234 - 317C 27.8
middle distillate 2 >317C 30.6
__
_xample 5
This describes the conversion of propylene over
20 acid ZSM-5 (H-Z5M-5).
H-ZSM-5 was obtained by a preparation similar
to that described in Example 1. The final product was
converted into a low sodium form by further washing the
product with 2M hydrochloric acid, then giving the
25 product a further calcination. The product was
fabricated into extrudates (as described in Example 3)
and used -to convert propylene (25L/hr over 47g of
catalyst at approx. 350C). The resulting liquid product
(62g) was subjected to the same gas-chromatographic
30 analysis as described in Example 3. The results are
~2~7~
- 14 -
shown in Table 3 and illustrate the product had a very
similar boiling-point profile as the product of Example
3.
Table 3
Simulated Distillation Profile of I.iquid
Product from Example 5.
Fraction Simulated Boiling Range Wt %
gasoline ~196~C 91.6
jet~fuel 196 - 235C 5.7
1 ¦ middle distillate 1 235 - 317C 2.2
middle distillate 2 317C 0.5
. _ I
Example_6
The liquid product of Example 5 was then
treated with aluminium chloride as hydrolysed as
15 described in Example 4. The resultant liquid was again
analysed by gas-chromatography and the simulated
distillation profile obtained (Table 4). Comparison of
Tables 4 and 2 demonstrates the ineffectiveness of the
Friedel-Crafts treatment in Example 6 in tha-t the major
~0 portion of the product remains in the gasoline boiling-
range.
Tab]e 4
Simulated Distilla-tion Profile of the Product
obtained from Aluminium Chloride Treatment of Liquid
25 Product obtained from Example 5.
Fraction Simulated Boilinq Range Wt %
_ _, ..
gasoline 196 C 76.9
jet-fuel 196 - 235C 5.7
middle distillate 1 235 - 317C 4.6
30 middle distillate 2 317C 12.8
~z~
- 15 -
Examples 7-13
These examples describe the characteristics of
catalysts used in following examples.
Table 5
5 ~ ~ Zeolite _
Analysis Catalyst Analysis (a)
~ample ~Codo 5102/A1203 ~ si~2 /~]23 /3~2 %~e23
7 A1 95 86.0 7.4 0.56(b)
8 A2 40 80.8 8.0 0.88(b)
9 A3 95 85.9 7.6 0.681.33
A4 40 78.5 8.0 1.311.19
1511 A5 95 77.5 6.4 1.181.08
12 A6 9S 8'~.07.0 1.281.21
13 A7 = .2 1.501~26
(a) analyses, on a weight basis, of a 2/1, zeoli-te/bentonite
extrusion, expressing all metal as its oxide.
(b) not determined.
(c) molar.
(d) impurity in bentonite.
The zeolites were synthesised by
25 crystallisation of silica/alumina gels usiny tetra-n-
propylammonium cation as organic templating cation. They
2~
- 16 -
were modified to differing sodium content as illustrated
in Table 5. In examples 7 and 3 the catalysts were made
from the "as-made" zeolites by ion-exchanging with
hydrochloric acid (2M) and calcining the catalyst twice.
5 The sodium content of the zeolite before fabrication was
very lol,l. The zeolites were then mixed with bentonite
(2/1, w/w) and formed in-to extrusions. For catalysts in
Examples 9, 10, 11, the zeolites (from separate
syntheses) were ion-exchanged and calcined only once.
10 The catalyst of Example 12 was the same as Example 11,.
but was further washed with ammonium/sodium ion solution
The catalyst of Example 13 was the "as-made" zeolite i.e
received no ion-exchanges or calcinations before mixing
with bentonite and forming into a catalyst. This
15 illustrates the effect of leaving the tetra-n-
propylammonium cations in the zeolite.
Examples 14-20
These examples illustrate the use of catalysts
of Examples 7-13 to prepare gasolines of varying olefinic
20 con-tent. Propylene, at 1 atm. pressure, was passed over
a packed bed of the catalyst held at 300C. After
cooling to ambient the product gasolines were collected
and the quantity of aliphatics present determined by NMR
and GLC, and the gasolines characterised by RON (clear).
25 The results are given in Table 6.
- 17 -
Table 6
Example Catalyst WHSV Max Temp Liquid I(A/O) ~/Oaliphatics RON
(hr_l) (C), (a) Yield (clear)
__ (b) (c)
14 Ex7 2.4 483 0.509.0 41.3 100.0
Ex8 1.5 455 0.474.7 53.5 98.6
16 Ex9 2.2 445 0.490.5 79.5 95.5
10 17 Ex10 1.6 449 0.591.7 80.9 96.8
18 Exll 2.6 410 0.470.19 81.5 95.5
19 Ex12 2.8 433 0.340.20 83.3 92.3
Ex13 0.9 383 0.580.34 75.2
_
15 (a) hot spot temperature.
(b) gg 1 of propylene converted.
(c) Ratio of aromatic proton intensity/olefin proton
intensity by lH N.M.R.
(d) from G.L.C.
Examples 14 and 15 illustrate that extensive
exchange of the zeolite to remove alkali-cation results
in higher a.romatic content gasoline than if the zeolite
is ion-exchanged and calcined just once (Examples 16-18).
Example 19 illustrates tha-t excessive back exchange with
25 sodium ions may reduce unduly the activity of the
catalyst (liquid yield ~0.34 gg propylene fed).
Example 20 illustrates that "as-made" catalysts which may
retain significant portions of alkyl qua-ternary cations
~2~,~7~
- 18 -
and/or their decomposition products are effective
catalysts. It should be noted -that all products were
acceptable as gasolines of high (>90) RON (clear).
Examples 21-27
These illustrate the conversion of the
gasolines described in Examples 14 20 into products
boiling greater than 196C.
Samples of yasolines described in Examples 14-
20 were treated with anhydrous aluminium chloride under
10 reflux conditions. After three hours the reaction was
stopped by adding water. The organic phase was separated
and analysed by a G.L.C. simulated distillation technique
and by N.M.R. The results are given in Table 7.
Table 7
Product s.P.
(simulated distillation)
20 ~xample Produc I(A/O) ~196 196-235 235-317 C
21Ex 14 6.8 69.4 10.0 9.3 11.3
22Ex 15 2.7 51.2 10.0 16.3 22.5
23Ex 16 0.4 49.1 8.4 20.2 22.4
24Ex 17 0.4 4501 17.0 22.4 15.6
25 25 Ex 18 0.3 25.6 12.2 29.6 32.6
26 Ex 19 0.4 33.6 8.7 25.1 32.6
27 Ex 20 0.3 3~.3 11.1 27.0 31.6
7~
-- 19 --
Although all the gasoline feedstocks gave some
products higher in boiling point than gasoline (<196C),
the produc-ts of Examples 21 and 22 in which the zeolite
had received multiple ion exchange and calcination were
5 inferior to the other products. Although Example 23 is
similar to 22 t the performance in the former case is
preferred because more product in the middle distillate
range (235-317C) is obtained. These examples serve to
illustrate that good yields of middle dis-tillate and
10 higher products can be obtained from propylene by using
catalysts of high exchanyeable alkali-content, and tha-t
excessive removal oE the alkali by ion-exchange hinders
the production of distillate boiling products (Examples
21 and 22).
From the above it will be evident -that
preferred catalysts are represented by Examples 1, 2, 9,
10, 11 and 13.
Examples 28, 29
These examples serve to illustrate the effect
20 of on-stream time on the conversion of propylene to
gasoline over the alkali-metal containiny zeolites.
The results are given in Table 8. As can be
seen the performance of both catalysts changes with
time-on-stream, but the preferred catalyst (Example 29)
25 is that one containing a zeolite with only one ion-
exchange treatment and where the change in performance is
less severe. Bo-th catalysts produce high yields of
aromatics at early -time on line but for the preferred
catalyst, this aroma-tic yield rapidly falls to a very low
30 value within 340 min. on-stream-time.
~;27~
- 20 -
Table 8
Example 28 Catalyst Ex-8, WHSV = l.lhr
._
Time Max TempLiquid I(A/O~ %Aliphatics
on- (C) Yield
5 stream (gg 1 propene
(min) converted)
_ ~
190 455 0.41 17.6 33
309 4~9 0.51 6.1 46
509 (424) 0.57 1.8 49
10751 433 0.53 1.2 60
996 452 0.39 0.8 67
1212 447 0.41 0.6 66
_
Example 29 Catalyst Ex-10, WHSV - 1.6hr
. _ .
Time Max Temp Liquid(a)I(A/O) %Aliphatics
15 on- (C) Yield
stream (gg 1 propene
(min) conv~rted)
. _ _ _ _
180 449 0.54 ~ 8.6 45.0
340 437 0.65 0.4 71.0
20475 423 0.65 0.1 90.0
610 424 0.64 0.2 83.5
820 416 0.61 0.3 87.~
920 413 0.59 0.3 90.6
1105 398 0.49 0.01 89.4
25 1260 3~2 0.47 0.01 90.8
.~ . . ..
7~
- 21 -
Examples_30, 31
These illustrate the conversion of butylenes
over the preferred catalyst as described in ~xample 9.
5 The results are given in Table 9. These results show
that light olefins such as l-butene and isobutene can be
converted to olefinic gasolines over the alkali-me-tal
containing catalysts.
Experiments using ethylene failed to give
10 significan-t yields of gasolines under similar conditions.
Table 9
Example 30 l-Butene Feed WHSV = lhr 1
15 Time On Line Ternp ~ Liquid Yield I(A/O) %Aliphatics
(min) (C) (gg-l l-butene
I converted)
180 366 .64 0.5 76.4
20 335 361 .76 0.2 74.6
470 359 .77 0.2 76.4
528 358 .73 0.1 79.1
718 354 .78 0.1 77.7
7~
- 22 -
_
Example 31 Isobutene Feed WHSV = lhr 1
Time On Line ¦ T C ¦ Liquid Yleld I(A/O) %Aliphatics
(min) (max) (gg isobutene
converted)
_
150 348 .64 0.4 70.9
290 344 .73 0.2 75.8
445 342 .73 0.1 78.6
10595 340 .72 0.1 78.4
760 340 .80 0.1 77.7
970 340 .71 0.08 78.2
1270 340 .78 0.07 80.4
1425 325 .64 0.07 80.1
, ~ :
15 Example 32
This illustrates the beneficial use of
potassium as alkali-metal to influence the performance of
the zeolite.
A catalyst was formed in a si~ilar manner to
20 that described in Example 13 except in that the starting
gel contained only potassium as the alkali-metal.
Reaction with propylene, in a similar manner to
that described in Example 20, gave a gasoline of very low
aromatic content (I(A/O) <0.1) wi-th a RON (clear) of
25 ~6.1.
Examples 33 and 34
These illustrate -that alkaline earth ca-tions of
Group IIa beneficially produce an olefinic gasoline but
those of Group IIb give an aromatic gasoline.
~2~;~7~
- 23 -
Zeolites similar to those described in Examples
7 and 1 were treated with calcium and zinc exchange
solutions respec-tively. Af-ter exchange and forming into
extrusions (2/1, zeolite/bentonite) the catalysts
5 contained 3.50% CaO and 0.77% ZnO respectively.
Propylene was passed over the catalysts in a
similar manner to that described for Example 14-20. The
results are given in Table 10.
Table 10
lC Exchange WHSV TC ~ =
ExampleCatlon (hr~l) (max) Yield( ) I(A/O)
33Ca 0.9 412 0.50 0.36
34Zn 1.84 267 0.42 0.63
466 0.22 16.7
15 (a) g g 1 of propylene fed, average value.
The calcium treated zeoli-te (Example 33) gives
an olefinic gasoline with acceptable yield. The zinc
treated catalyst (Example 34) appears only useful at low
temperatures, higher temperatures giving higher yields of
20 aromatics.
Examples 35-42
These examples serve to illustrate that
olefinic gasolines produced by the preferred catalysts
can be converted, by a variety of catalys-ts, into a
25 product containing significant quantities of ]cerosene,
distillate and fuel-oil. The results are shown in Table
11, where an olefinic gasoline feed was obtained from
propylene using the catalyst described in Example 9.
7~
- 24 -
Erom the results, aluminium chloride, boron
trifluoride on silica-alumina, aluminium chloride on
silica-alumina, and phosphoric acid on kieselguhr gave
reasonable yields of products higher in boiling point
S than gasoline. Hydrogen fluoride treated silica-alumina
gave somewhat lower yields, as did the zeolite of Example
42.
These results illustrate that dis-ti].la-te range
products can be produced from the olefinic gasolines
10 described above by a wide variety of solid-acid
catalysts, as well as homogeneous catalysts such as
aluminium chloride.
7~
-- 25 --
T ab l e_
Treatment _ ~ it lated Di stillation _
Gasoline Kerosene Distillate Oil
_ _ _
_ Starting Nil 91.6 3.4 3.6 1.4
Gasoline
Ex 35 ~lC13 Reflux 45.5 13.8 32.5 8.2
180 mins.
25 wt.%
AlC13
Ex 36 BF on 130 C 55-.3 11.5 21.4 11.8
Si13ica- overnight
alumina 25 wt.%
catalyst
Ex 37 BF3 on 130 C 62.6 11.5 17.1 8.9
Silica- overnight
alumina 12.5 wt.%
catalyst
Ex 38 AlC13 on 130 C 68.6 10.4 13.9 7.2
silica~ overnight
alumina 25 wt.%
catalyst
25 Ex 39 H3P04 on 130C 80.0 10.6 7.6 1.8
kieselguhr overnight
25 wt.%
catalyst
Ex 40 HF on 130C 84.87.4 5.6 2.3
silica- overnight
alumina 25 wt.%
catalyst
_
7~)~
- 26 -
Table 11 (continued)
Catalyst Treatment Simulated Distillation
Gasoline Kerosene ~ t~ Fue
_
Ex 41 BF3, HF 130 C 87.1 6.1 4.6 2.3
on silica- overnight
alumina 25 wt.%
catalyst
Ex 42 Exa~ple 7 130 C for 87.3 5.0 4.8 2.
5 hours
catalyst _ _
7t:~
- 27 -
Example 43
-
This example illustrates tha-t methanol
conversion over the preferred catalyst is unstable, and
conversion can only be main-tained for a ].lmited on-
S stream-time.
A down flow reactor was charged with 70g of a
catalyst formed as in Example 9. Methanol (at W~ISV
~2.1hr 1) was passed over the catalyst at 360C. A hot-
spot developed near the top of the bed, reaching 564C.
10 After five hours on stream the hot spot had travelled to
the bottom of the bed indicating deactivation of the
catalyst. It is well known that conversion falls to very
low levels when -the hot spot is lost from the catalyst
bed, hence the effective useful on-stream-time for
15 methanol conversion was only 5 hours.
Example 44
This example illustrates the conversion of
dimethylether (DME) over a high sodium catalyst.
Dimethylether (1000 ml min 1) was passed over a
20 catalyst (70g) as described in Example 43. The details
of the conversion are given in Table 12.
~L2~L~7~
- 28 -
Table 12
-
~ _ ._____ . ,
Time onSet Temp. Max %DME in
line (C) Temp gas phase Hot spot position
(min (C) products
5 cumulative) (a)
_
350 547 nil top of bed
300 350 572 1.8 bottom of bed
420 400 566 6.9 middle of bed
660 475 579 1.1 bottom of bed
750 475 557 54.4 bottom of bed
(a) Liquid products condensed out at ambient
temperature.
These results illustrate tha-t -the preferred
catalysts, although capable of converting dimethylether,
can only do so for a llmi-ted -time on-line and that
increasing -the bed temperature fails to overcome the
activity decay. This is in con-trast to conversion of
20 ligh-t olefins, propylene, butylene etc., which are able
to undergo conversion for much longer periods before
regeneration is required~
- 29 -
It will be clearly understood that the
invention in its general aspects is not limited to the
specific details referred to hereinabove.
