DE1265328B - Process for the production of aromatic hydrocarbons from light hydrocarbon feeds - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

Clog

German Κί .: 23 b -1/04

Number: 1265 328

File number: E 29258IV d / 23 b

Filing date: May 7, 1965

Open date: April 4, 1968

When reforming hydrocarbons, especially using straight-run fractions for example a metal-of-the-platinum-group-on-alumina-catalyst, different reactions result, such as isomerization, dehydrocyclization, Dehydrogenation and hydrocracking, all of which lead to hydrocarbon products that increase Have octane ratings, usually greater than about 80 to 85 (Research, clear). However, the catalyst will when it has been used in such a system for a while, gradually through the deposition deactivated by coke particles on its surface, whereby the octane numbers of the product reformate drop. If the octane number requirements placed on a given system are to be constantly met, the catalyst activity must therefore be restored, usually by various regeneration techniques takes place in which the carbon is removed from the catalyst by contacting it with an oxygen containing gas is burned off.

From the French patent 1 313 074 a reforming process is known in which a platinum catalyst, containing about 0.05 to 2% halogen is used. The sulfur content in the known Process should be 10 to 20 ppm and must, if the feedstock is largely desulphurized, in In the course of the process, sulfur can be added again.

In addition, the service life is that of the known Processes used catalysts are not yet satisfactory, especially when using feeds with a high paraffin content can be used.

It has now been found that aromatic hydrocarbons can be obtained from light hydrocarbon feeds can advantageously produce substantial amounts of both paraffinic and contain naphthenic hydrocarbons, in which the dry hydrocarbon feed in the presence of a hydrogen-containing cycle gas with a previously reduced reforming catalyst, which consists of metals of the platinum group deposited on aluminum oxide, the total metal content is about 0.1 to 1.5 weight percent in a reforming reaction system Reforming conditions such as a temperature in the range of about 468 to 532 ° C, a throughput from 0.1 to 20 parts by weight of hydrogen feed per part by weight of catalyst per hour, a pressure of about 14 to 42 atmospheres and a ratio of about 3 to 55 moles of hydrogen per mole Hydrocarbon feed contacted and at least about 40 percent by volume off Method of manufacture

aromatic hydrocarbons from light

Hydrocarbon feeds

Applicant:

Engelhard Industries, Inc.,
Newark, NJ (V. St. A.)

Representative:

Dr.-Ing. W. Abitz and Dr. D. Morf,

Patent attorneys,

8000 Munich 27, Pienzenauer Str. 28

Named as inventor:

William C. Pfefferte, Middletown, N. J. (V. St. A.)

Claimed priority:

V. St. v. America May 8, 1964 (366174) -

Paraffins and 15 to 50 percent by volume of naphthenes feed a reforming process Aromatics is subjected to a research octane number of at least 90, preferably 95, if a mixture of platinum and palladium is used as the catalyst, the platinum content up to 60% by weight of the two metals, the water and sulfur content of the reforming reaction system total feed entering at any time during the introduction of the hydrocarbon feed into the system approximately 100 parts of water per million parts by volume of total feed in the vapor phase and 25 parts sulfur per million parts by weight total feed and the water content of the effluent withdrawn from the reforming reaction system at all times during the introduction of the hydrocarbon feed to below approximately Parts of water per million parts by volume of total effluent in the gas phase is regulated.

The reforming process is conventionally carried out under conditions in which the

809 537/519

3 4

Loading, ζ. B. a straight-run fraction, with reaction unit each faster than in the previous

a reforming catalyst at a temperature from which is deactivated. This deactivation occurs

about 468 to 524 ° C, a pressure of about 14 to 42 atmospheres, from maintaining a higher average

a throughput (space velocity) in the temperature range in the following reaction unit catalyst

from about 0.5 to 5 parts by weight of the charge per 5 sator layer.

Part by weight of catalyst per hour and one water- As a result, the catalyst is subject to the partial material to cycle ratio of about 4 to 12 mol of water deactivation in each subsequent reaction unit hydrogen per mole of raw gasoline charge together faster than in the previous one, and for safety reasons is brought. The catalyst becomes more conventional - a high-quality reformate becomes the catalyst wise used a supported platinum catalyst, the z. B. io periodically regenerated in the reaction units. Man about 0.1 to 1.5 percent by weight, preferably about this with a regenerative multilayer 0.3 contains up to 1.0% platinum, and the wearer can operate a system, e.g. B. the one reaction unit that Be aluminum oxide, e.g. B. can be one with a large upper- a so-called "swing" reaction unit, area and large pore size. Switch off such catalysts while the remaining reaction units can conveniently continue to operate in their normal duty cycle according to U.S. Patents 15. the 2,838,444 and 2,838,445. switched off reaction unit can be used for regeneration the implementation of these reforming work tion of the catalyst contained in it depressurized One usually draws a number of adiabatic and inert gas purges. After Catalyst layers, e.g. B. three, four, five or more purging leads to free oxygen-containing ReSchichten, and the hydrocarbon charge 20 generating gas through and begins the regeneration, The regeneration can take place at a temperature in the coating to the desired inlet temperature from approx. 371 to 510 ° C, in the final stage at approx be heated. Depending on the sharpness of the 454 to 510 ° C can be carried out. When the Kataly reforming conditions the mode of operation is restored as a sensor activity, d. H. the vast majority continuous, semi-regenerative or regenerative 25 part of the carbon deposits is burned off, draws. When a feed is available, the flow of oxygen is interrupted and the process begins to re-introduce a product from inert gas under conditions of low severity. To make sure a satisfactory octane rating is available, the complete removal of the oxygen can decrease Catalyst activity only decreases slowly and the pressure in the system can be relieved several times by Kaman Maintain catalyst usage times of 1 year or more and evacuate. Before switching the Rewerden back on. With such a system, it is economically a unit of action in the working stream that is not out of the circuit justified, regeneration options flow system injected hydrogen-rich gas, and after watch; the used catalyst is opened after the working pressure has been reached Usage time replaced by fresh catalyst. valves, putting the unit in the reforming cycle When the octane requirements are higher and 35 is turned on. Then you can do another More severe working conditions apply to the reaction unit in essentially the same way must, the catalyst activity drops faster, and treat.

the operating times are shorter, ie about 6 to 12 months when operating reforming units. During this period, about 4.24 to today, the degree of severity for the production of Re-35.31 m ³ charge per kilogram of catalyst is 40 formats with research octane numbers (lead-free) of about and to increase the working method as a semi-regenerative 100 or more. The reforming is to be designated by pativ. In the case of semi-regenerative work, refined feedstocks, such as those with, the entire system is switched off during the regeneration of the catalyst carried out on site and a paraffin content of at least about 40 volume points, with the achievement of research octane numbers. If the octane number requirements 45 (lead-free) from 100 still require higher degrees of severity and even stricter conditions have to be applied than when reforming low-paraffin use, the operating times are still material. Shorter reforming conditions that are too severe; the method of operation can be described as regenerative, including temperatures of about 482 to 524 ° C and temperatures of less than a pressure of about 7 to 28 atmospheres. Lower pressures a week than short-cycle regenerative and from 2 to 4 months are mainly used as long-cycle regenerative during high-temperature reforming. In the regenerative, because the dehydrocyclization of ven, essentially adiabatic multi-layer paraffins to aromatics with decreasing pressure zueaktionssystemen the fixed layers, and the yield advantages the necessity which contain the reforming catalyst, so a more frequent regeneration is arranged that they are weighed out of the charge after- 55 carbon formation on the catalyst of t, are flowed through each other and that one gets used to them- With certain types of input materials, the borrowed in the form of a layer from which the work- maintenance of yield-octane number- Removing the relationship cycle and regenerating the catalyst can, however, not be satisfied when reforming with extremely hot berries without the continuity of the treatment conditions. Having to interrupt such materials. The regenerated layer can hold at least about 40 percent by volume paraffins then turned back on while holding one and about 15 to 50 percent by volume naphthenes. The other layer for regeneration in the same octane rating depends in large part on the volume-way it takes out. This method of working is particularly suitable for the percentage of aromatics and isoparaffins in the catalyst layers or reaction format and accordingly with paraffin-rich units of measure, which in the working sequence of the initial materials are followed by an even higher degree than the reaction unit therein, preferably the volume percentage contained therein Paraffins, which are converted into the final reaction unit to the duration of the working cycle aromatics and isoparaffins. To extend that, since the catalyst in a following problem of maintaining a satisfactory

The yield-octane number relationship is thus with increasing paraffin content in relation to these concentrations and decreasing naphthene content exacerbated. Typical loads with high paraffin and mean naphthene content are described below based on their characteristic values.

Middle East

Kuwait

Arkansas

Specific weight (at 15.6 ° C)
ASTM distillation, ⁰ C

Start of boiling

10%

50%

90%

End of boiling

Paraffins, volume percent

Naphthenes, percent by volume

Aromatics, percent by volume

0.7608

133

139

149

172

192

66

20th

14th

0.7459

102
111
129
159
176

64

23

13th

116

148

181

The problems associated with maintaining satisfactory octane-yield relationships when reforming feedstocks with high paraffin and medium naphthene content are reinforced when they are highly pure with respect to sulfur, d. H. less than about 25 parts sulfur per million parts feed due to the rapid inactivation of the platinum metal catalyst.

It has already been proposed to add sulfur or sulfur compounds to the hydrocarbon crude in order to maintain the catalyst activity. For example, U.S. Patent 3,006,841 describes the addition of a sufficient amount of sulfur ^{to bring the} total sulfur content of the stock entering the reforming zone to about 0.01-0.06% of the total weight of the charge. Similarly, U.S. Patent 3,067,130 provides for the addition of a sufficient amount of sulfur to the feed in semi-regenerative reforming to provide a total sulfur content of the stock entering the reforming zone of around 300 parts per million parts of the feed. In practice, however, reforming feedstocks are subjected to pretreatment with hydrogen to remove both nitrogen and sulfur compounds, and after such pretreatment many refiners are reluctant to reintroduce the sulfur to reforming systems because of its known corrosive nature.

It has now been found that the use of platinum-palladium-on-aluminum oxide mixed catalysts particular advantages in terms of maintaining catalyst activity, maintenance the yield / octane number relationships and improved aging properties of the catalyst when reforming high-purity hydrocarbon mixtures with a high paraffin and medium naphthene content results in extremely severe reaction conditions. The initial activity of the platinum-palladium mixed catalysts is not as high as a metal content corresponding to a platinum catalyst, but the aging or deactivation rate of the platinum-palladium catalyst during processing of low sulfur feeds is much less, so one can see the yield-octane relationships can keep relatively constant over longer periods of use.

The extremely severe reaction conditions correspond to the conditions under which one reformates having a research octane number (unleaded) of at least about 90, preferably at least about 95 or greater

as obtained, and are generally in the following ranges: temperature about 468 to 532 ° C., preferably at least about 493 ° C., pressure about 14 to 42 atmospheres, preferably 25 to 35 atmospheres, cycle gas ratio about 3 to 55, preferably 5 to 20 Moles of hydrogen per mole of hydrocarbon feed and throughput about 0.1 to 10, preferably 0.5 to 3 parts by weight of feed per part by weight of catalyst per hour. The catalysts are platinum-palladium-on-aluminum reforming mixed catalysts with a total metal content of about 0.1 to 1.5 percent by weight, about 25 to 60 percent by weight of the total metal being formed by platinum. Such catalysts can also contain promoters. The material to be treated are the petroleum reforming materials that boil in the raw gasoline range and contain about 40 to 80 percent by volume, preferably about 60 to 75 percent by volume, paraffins and 15 to 50 percent by volume, preferably 20 to 30 percent by volume, naphthenes, since the advantages achieved according to the invention are all the greater , the higher the proportion of paraffins and the lower the proportion of naphthenes in the material to be treated. The hydrocarbon feed must also be substantially free of water and materials which would form water in the reaction zone and have a low sulfur content such that the water and sulfur content of the total feed, including recycle gas and hydrocarbon feed, are introduced into the reaction system during introduction of the hydrocarbon treatment stock occur, below about 100 parts of water per million parts by volume of total charge in the vapor phase and 25 parts of sulfur per million parts by weight of total charge and the water content of the stock withdrawn from the reforming system at all times during the hydrocarbon feed to the system below about 100 parts of water per million parts by volume of the entire flowing material is kept in the vapor phase.
The advantages of reforming according to the invention are most pronounced when there is no damage to the catalyst due to simultaneous contact of water and hydrocarbon-containing gas with a new or freshly regenerated catalyst at high temperatures.

7 8

temperatures in the order of magnitude of 454 to 593 ° C. Dwell and flow disturbances in the kleinxmd more before or during a work cycle the single-volume system was treaded to a minimum, as described in Auslegeschrif ti 236 70Ö. entire pure product continuously by means of a luftr Thus, as described there, the new or freshly actuated flow control valve is removed, the one from generated catalyst has preferably been operated using a back pressure registration regulator, and reduced by hydrocarbon-free hydrogen. continuously a product stabilization

In the production of the gate used according to the invention supplied in order to obtain a C ₅₊ liquid product and a platinum-palladium mixed catalyst, for the in the Rah Q gas. As no protection is claimed from the stabilizer of the invention, retained gas has been measured and various techniques can be used for sampling. Using a time-controlled solenoid valve For example, a mixture of aluminum can be diverted into an evacuated butyl rubber gas sample hydrosol, a platinum solution and a palladium bag. The circulating gas was subjected to the gel binding by dissolving together, drying a washer (NaOH on asbestos) and dryer and calcining. In a similar way, a lead can be used to remove water and acidic substances, such as a sulfur mixture of aluminum hydrosol and a platinum hydrogen. A conventional drop pressure system with one drop was used as the feed system or palladium solution together with the gel formation, and the resulting gel with the other was used. The feed metal solution before or after drying and / or was measured volumetrically. Impregnate with the charge before or after calcining. In ahn and circulating gas dryers, the water content can also be measured using an aluminum oxide gel 20 of the total charge of the unit in less than 100 space with a mixture of platinum and palladium parts of water per million parts of total charge in the solution before or after drying and / or Reduced vapor phase and with the scrubber any before or after calcining or on the other hand also sulfur from the circulating gas essentially first with one and then with the other solution in constant. The unit used here had proven to be reliable at any stage before or after drying 25 for the precise determination of the yield-ec- and / or before or after calcining the tan number relationships. On the other hand, it is also possible to separately impregnate the feed supplied to the unit was a part of the alumina gel separately with platinum and rich ma-palladium, desulphurised to 0.4 ppm sulfur, and the gels obtained to the material one at the time of the experiment in a technical formation of the Mix the finished catalyst. 30 plant treated type (American petroleum)

The following example serves as a further explanation with the following characteristic values: of the invention, with three trials for comparison

the first with an ASTM distillation, ° C

Platinum-on-aluminum oxide catalyst, the 0.6 Ge Boiling Start 105

contains weight percent platinum, the second with a 35 -.Q ₀ ι -I2O

Platinum-palladium-on-aluminum oxide mixed catalyst- '°

gate according to the invention, the 0.3 percent by weight 30% 132

Contains platinum and 0.3 percent by weight palladium, 500 / I44

and the third with a platinum-on-alumina catalyst, which contains 0.2 weight percent platinum. 40 '°

90% 172

Example end of boiling 188

Sulfur, ppm 0.4

A. A fluoride-free platinum-aluminum oxide catalyst 45 density at 15 6 ⁰ C 0 757

Sator made in accordance with U.S. Patent 2,838,444, '

with a platinum content of about 0.6 weight paraffins, volume percent 45

percent in the form of 1.6 mm pellets was in naphthenes, percent by volume 45

a reaction tube with an internal diameter of 2.54 cm. _ _o . v "i,", ",." ,. "" ♦ m

Made of stainless steel with enough tablet-shaped 50 ^aromas > volume percent 10

Aluminum oxide from 8 to 14 mesh size di-

Spergiert, around a catalyst zone of about 250 cm ^3. Hydrogen was injected into the system, which at

To maintain volume. After each feed, a ratio of about 7 moles of gas per mole of the reaction device was circulated into a thermostatically controlled feed. The worked bronze block furnace used; The layer temperature conditions, the yield and the product characteristics were compiled in Table I using platinum and platinum-rhodium. If not measured thermocouples. Each batch of catalyst, indicated differently, the recovery rates exceeded with nitrogen gas and then 97% (mostly 99%) overnight, while the yield expressed as a percentage of the charge in a slow hydrogen stream at about 482 ⁰ C and reduced atmospheric pressure. The mixture of 60 and based on a degree of recovery of 100% feed and cycle gas was calculated using the catalyst.

The analysis of the gas and liquid samples

Well a high pressure _{separator of small volume on C 1} - bis (^ -hydrocarbons was carried out gas chromatography, from the top of which a gas phase for the tographic. All components of a gas sample circulation and whose bottom a total product 65 were determined independently and then from condensable liquid plus the The results for error control added. All total gas generation subtracted and in a product analysis value was introduced from use for yield stabilizer. Converted to air-free calculation to reduce calculations.

Table I (experiment 1698)

10

working conditions

6 to

Duration of hydrogen supply

Hours 12 to 19 22 to 29 I 29 to 36! 36 to

43 to

Temperature, ⁰ C

Pressure, atü

Throughput, parts by weight per part by weight of catalyst per hour

Cycle ratio

Yield based on 100%
Recovery rate
C ₁ to C ₄ , weight percent ....

C ₆ , weight percent

C ₅₊ , percent by volume

Product characteristics.

Density at -15 ° C / g / cm ³

Aniline point, ° C

Aromatics, percent by volume

Research octane number, clear

+3 ml TEL **

479.11 35.2

1.995 6.99

18.2 80.3 75.7

0.8080 36.0 64 95.0 100.5 479.28
35.2

1,988
7.02

0.8050
37.6
63
94.1
99.7

495.77

35.2

1.995 7.00

21.9 76.1 70.6

0.8205 29.8 * 73 99.5 102.7

440.56

35.2

2.003 6.95

20.7 77.3 72.0

0.8188 30.4 * 72 99.1 102.6

495.79 35.2

2.003 6.96

19.4 87.6 73.4

0.8178 31.6 * 72 98.5 102.5

496.00

35.2

2.01 6.97

19.5 78.6 73.2

0.8180 32.0 71 97.8 101.9

Table I (continued)

Working conditions Hydrocarbon feed time hours

54 to 60 60 to 66 67 to 74 81 to 87 87 to 93 93 to 99 487.39 487.72 488.22 479.61 480.00 480.00 35.2 35.2 35.2 35.2 35.2 35.2 1.994 1.96 2.01 1,978 2.00 1.99 7.002 7.122 6,945 7.05 7.00 7.03 15.3
82.7
78.0 no
gas
in the bag 14.3
83.8
79.4 11.7
86.5
82.8 11.7
86.5
82.5 11.8
86.5
82.5 0.8070
37.2
63
93.1
99.5 0.8030
38.2
60
92.6
99.4 0.8035
38.2
61
93.0
99.5 0.7954
42.4
56
87.7
96.5 0.7988
41.8
56
87.0
96.1 0.7988
41.8
56
87.3
96.2

Temperature, ⁰ C

Pressure, atü

Throughput, parts by weight per part by weight of catalyst per hour

Cycle ratio

Yield based on 100%
Recovery rate
C ₁ to C ₄ , weight percent ....

C ₅ , weight percent

C ₅ +, percent by volume

Product characteristics,.

Density at -15 ° C / g / cm »

Aniline point, ⁰ C

Aromatics, percent by volume

Research octane number, clear

+3 ml TEL **

* Average of three readings.

Note A: Yield equilibrium H ₂ . ** TEL = tetraethyl lead.

B. This experiment was carried out in the same device and with the same loading as experiment (A) carried out. A platinum-palladium-on-aluminum oxide mixed catalyst was used as the catalyst with a platinum content of 0.3 percent by weight and a palladium content of 0.3 Weight percent made by mixing components (a) and (b) as follows became:

The component (a) was prepared from an alumina precursor parent mass with a content of about 75% of alumina trihydrate which had been activated by heating at 34O ⁰ C. This alumina was slurried in powder form in an amount of 2.21 kg (Al ₂ O ₃ content equal to 2 kg or 90.5%) in 8 liters of distilled water to form a slurry with a pH of 6.2.

809 537/519

11

Then a solution of palladium chloride in an amount of 600 ml with a content of 12 g (2 ⁰ I ₀ ) of palladium and 1.5% of hydrogen chloride was stirred into the slurry dropwise over the course of 15 minutes, at the end of this period the The pH of the slurry was 4.6. The slurry was then filtered without washing and dried.

To prepare component (b), 120 ml of chloroplatinic acid containing 12 g (10%) of platinum was added dropwise over 15 minutes to an alumina slurry [the equivalent used in the preparation of component (a)]. The pH of the slurry of IO

initially 6.2 was thereby reduced to 5.6. The slurry was then filtered without washing and dried.

The dried components (a) and (b), which contained 0.6 percent by weight of palladium and 0.6 percent by weight of platinum, were mixed in amounts corresponding to 1 kg of aluminum oxide on a dough mixer with about 600 ml of additional water and fed through openings of 1, 6 mm pressed. The compacts were dried, sifted to a length of approximately 6.4 mm, dried and then calcined ^{at 480 ° C. for approximately 6 hours in a stream of dry air.}

The work and product parameters are summarized in Table II:

Table II
(Attempt 1642)

working conditions

6 to duration of hydrocarbon feed

hours
12 to 18 I 18 to 24 I 27 to 34

34 to 41

Temperature, ⁰ C

Pressure, atü

Throughput, parts by weight per part by weight of catalyst per hour

Cycle ratio

Yield based on

C ₁ to C ₄ , weight percent

C ₅ , weight percent

C ₅₊ , percent by volume

Product characteristics

Density at -15 ° C, g / cm ³

Aniline point, ° C

Aromatics, percent by volume

Research octane number, clear

+3 ml TEL

478.00 479.67 480.00 , 496.00 496.00 35.2 35.2 35.2 35.2 35.2 1,988 1.956 1.958 1.995 1.995 7.02 7.18 7.16 7.04 6.99 - 13.2
84.9
80.9 13.3
84.8
80.8 21.5
76.6
71.7 - 0.8000
39.8
59
91.4
98.8 0.7999
40.0
59
92.0
98.8 0.8000
40.0
59
91.8
99.1 0.8150
32.4
70
98.8
103.5 0.8166
32.4
70
98.8
103.6

Tables (continued)

working conditions

41 to duration of the hydrocarbon feed

hours
to 57 1 57 to 63, 71 to 77 I 77 to 83

83 to 89

Temperature, ⁰ C

Pressure, atü

Throughput, parts by weight per part by weight of catalyst per hour

Cycle ratio

Yield based on

C ₁ to C ₄ , weight percent

C ₅ , weight percent

C _{5 + 3} percent by volume

Product characteristics

Density at -15 ° C, g / cm ³

Aniline point, ⁰ C

Aromatics, percent by volume

Research octane number, clear

+3 ml TEL

496.00 478.01 - 478.39 479.50 479.21 35.2 35.2 35.2 35.2 35.2 35.2 2.00 1.995 1.96 1.991 2.00 1,970 6.94 7.03 7.16 7.05 7.03 7.15 22.0
76.2
71.0 18.2
80.0
75.6 - 14.8
83.5
79.9 15.7
82.7
79.9 15.3
83.1
79.5 0.8140
32.6
70
98.6
104.1 0.8070
36.8
63
95.3
101.6 0.8080
36.4
65
96.4
102.6 0.7970
41.4
57
90.0
98.5 0.7970
41.4
57
90.3
98.5 0.7968
41.8
57
90.0
98.4

Note A: Yield equilibrium H _a .

13th

C. This experiment was carried out in the same apparatus and with the same loading as experiments (A) and (B) performed. A similar catalyst was

Sator as used in experiment (A), but only 0.2 percent by weight Contained platinum. The work and product parameters are summarized in Table III:

Table III
(Attempt 1708)

working conditions

8 to duration of hydrocarbon feed hours (grams)
to 20 I 23 to 30 I 30 to 37 I 37 to

44 to

Temperature, ⁰ C

Pressure, atü

Throughput, parts by weight per part by weight of catalyst per hour

Cycle ratio

Yield based on 100% degree of recovery

C ₁ to C ₄ , weight percent ...

C ₅ , weight percent

C ₅₊ , percent by volume

Product characteristics

Density at -15 ° C / g / cm ³

Aniline point, ⁰ C

Aromatics, percent by volume

Research octane number, clear

+3 ml TEL

479.27 35.2

2.007 7.00

14.2 84.1 80.0

0.8022 38.9 60 91.7 99.2

479.50 35.2

1.98
7.04

13.9
84.5
80.5

0.8010
39.0
60
91.5
99.0

495.72
35.2

1.995
7.02

20.3
77.8
72.5

0.8170
32.2
71
99.1
103.4

496.11

35.2

2.005 6.942

20.1
78.0
72.7

0.8166 32.2
70
98.9
103.2

496.00 35.2

2.00 7.02

19.6 78.6 73.5

0.8145 32.4 70 98.6 103.0

496.28 35.2

1.995 7.00

19.9 78.2 72.8

0.8153 32.4 * 70 98.6 103.5

Table HI (continued)

working conditions

54 to duration of hydrocarbon feed * hours (grams)
to 66 66 to 72 I 76 to 82 I 82 to

88 to

Temperature, ° C 487.11

Pressure, atü 35.2

Throughput, parts by weight per part by weight of catalyst per hour 2.004

Circulation ratio 7.00

Yield based on 100% degree of recovery

C ₁ to C ₄ , weight percent ... 15.2

C ₆ , weight percent 82.9

C ₆ +, volume percent 78.4

Product characteristics

Density at -15 ° C / g / cm ^{3 0.8045}

Aniline point, ⁰ C 37.4

Aromatics, percent by volume

Research octane number, clear 93.5

+3 ml TEL 100.1

*) Average of five readings.

Note A: Yield equilibrium Ha.

487.61 35.2 2.011
6,996

14.6
83.5
79.1

0.8040
37.6
63
94.0
100.0

487.61
35.2

1.998
6,963

15.4
82.7
78.1

0.8040
37.8
62
93.3
99.9

479.61
35.2

2.021 6.91

11.3
86.8
83.0

0.7970 41.4
56
88.0
97.0

479.61 35.2

1.996 6.97

H ₉ I 87.0 83.1

0.7974 42.4 55 87.1 96.8

479.72 35.2

1.992 7.015

11.2 87.0 83.0

0.7986 41.6

55

88.2

97.3

The experiments described in Tables I to III were 90 to 100 hours at temperatures of carried out to 496 ° C, the pressure being essentially constant at 35 atü, the cycle ratio im essentially constant at 7: 1 and the throughput essentially constant at 2 parts by weight per part by weight Catalyst was held per hour. The yield octane number relationships along with the Volume percent aromatics in these experiments are compared in Table IV. The table shows that although the clear octane number is 0.6 percent by weight Platinum containing catalyst in the beginning

is slightly higher than in the case of the platinum-palladium mixed catalyst, in the case of the first-mentioned catalyst but drops significantly, which shows the relatively rapid drop in catalyst activity. The table further shows that in addition to maintaining the clear octane number, the platinum-palladium mixed catalyst

Prey holds a relatively high value and a more constant volume percentage of aromatics in the reformate delivers.

These values show that the platinum-palladium mixed catalysts are particularly suitable for semi-regenerative and long-cycle regenerative reforming systems are suitable.

Table IV
Comparison of the yield octane number results according to Tables I to III

With
catalyst 10 Approximate duration of the hydrogen supply, hours 97.8 70 57 ⁰ C I 81 88 I 27 I 45 98.6 70 487.78 Result 479.44 18th Temperature, 98.6 93.1 479.44 479.44 0.6% pt 95.0 496.11 j 496.11 101.9 93.5 87.7 87.0 0.2% pt 91.7 479.44 99.5 103.5
104.1 95.8 88.0 87.6 0.3% pt
0.3% Pd } 91.4 94.1 99.1 73.2 99.5 90.3 90.0 Research octane number, 0.6% pt 100.5 91.5 98.8 72.8 100.1
102.1 96.5 96.1 lead-free 0.2% pt
0.37 "pt
0.3% Pd 99.2
} 98.8 91.9 102.7 71.0 78.0 97.0
98.5 97.0
98.4 0.6% pt 75.7 99.7 103.4
103.5 73 i 71 78.4 82.8 82.5 Research octane number
+3 ml (TEL) \
Tetraethyl lead [ 0.2% pt 80.0 99.0
99.0 70.6 71 75.6 83.0 83.0 f 0.3% pt
0.3% Pd } ^A 77.0 72.5 70 63 79.0 79.5 Yield, I. 0.6% pt 64, 80.5 71.7 63 56 56 C ₅ +, volume percentage 1 0.2% pt
Λ 1 0 / tit- 60 80.9 64 56 55 Aromatics I 0.3 7o pt
0.3% Pd ► 59 63 57 57 Volume percentage in the Refor- J 60 mat, Q _{+ β} Ι 59

Note A: Unsatisfactory material balance.

The values in Tables I through IV are in view of the values obtained in accelerated aging tests that are normally used for rejection or Evaluation of catalysts find application, surprising. Such a conventional, accelerated The aging test is more specific under the following test conditions with the catalyst in one layer Dilution has been carried out:

Throughput, parts by weight per part by weight of catalyst per hour 15

Pressure, atü 14

Circulation ratio 10: 1

Test period, hours 48

Expressed as the research octane number (lead-free), the values for the relative initial activity (R.A.) and relative lifetime (R.L.) or relative amount of product determined in 3501 per kilogram of catalyst. The sharpness of the reforming reaction under these conditions is likely to be influenced by small temperature differences difficult to control, so that the product of R.A. and R.L. divided by 1000, should enable the best comparison with the standard.

The accelerated aging tests compiled below (Table V) were used as "Standard" uses the same catalyst and the same charge as in Example 1 with the modification that the charge had not been desulfurized. The other tests had catalytic converters the specified specifications and the feed had the following characteristics:

ASTM distillation, ⁰ C

Initial boiling 73

10% 100

30% 114

50% 126

70% 138

90% 156

End of boiling 171

Sulfur, ppm 34

Density at 15 ° C, g / cm ³ 0.7328

Paraffins, percent by volume 61

Naphthenes,% by volume 30

Aromatics, percent by volume 9

Research Octane Number (unleaded) 33

The accelerated aging tests, however, are mainly a measure of activity of the platinum metal or the dehydrogenation activity are no indication of any advantage of the platinum-palladium mixed catalysts reforming high paraffin, medium naphthene, and low sulfur feeds.

Table V

catalyst

default

O, 6 ° / _o Pt

0.9% pt

0.2% pt

0.4% Pt - 0.2% Pd
0.3% Pt-0.3% Pd
0.2% Pt -0.4% Pd

R. A. R. L. 90 105 55 75 60 50 50 40 50 55 40 20th 40 25th

R. A. · R. L. 100

94.5 41.3 30 20 27.5 8 10

IO

Claims (2)

Claims: 1S 1. A process for the preparation of aromatic hydrocarbons from light hydrocarbon feeds containing substantial amounts of both paraffinic and naphthenic hydrocarbons, in which the dry hydrocarbon feed is in the presence of a hydrogen-containing cycle gas with a previously reduced reforming catalyst made from metals deposited on alumina Platinum group, the total content being about 0.1 to 1.5 weight percent, in a reforming reaction system under reforming conditions such as a temperature in the range of about 468 to 532 ^° C., a throughput of 0.1 to 20 parts by weight of hydrocarbon feed per part by weight of catalyst per hour, a pressure of about 14 to 42 atmospheres and a ratio of about 3 to 55 mol of hydrogen per mole of hydrocarbon feed, and at least approximately 40 volume percent paraffins and 15 to 50 volume percent naphthenes subjected to reforming to aromatics to achieve a research octane number of at least 90 is, characterized in that a mixture of platinum and as a catalyst Palladium is used, the platinum content being 25 to 60% of the weight of the two metals, the water and sulfur content of the total feed entering the reforming reaction system at any time during the introduction of the hydrocarbon feed to the system to less than about 100 parts of water each Million parts by volume of total charge in the vapor phase and 25 parts of sulfur per million parts by weight Total feed is maintained and the water content from the reforming reaction system effluent withdrawn at all times during the introduction of the hydrocarbon feed is regulated to below approximately 100 parts of water per million parts by volume of total effluent in the gas phase. 2. The method according to claim 1, characterized in that the catalyst previously with hydrocarbon-free Hydrogen has been reduced. Considered publications:
French Patent No. 1,313,074. 809 537/519 3.63 © Bundesdruckerei Berlin