DE1208024B - Process for making a high octane gasoline - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

Clog

German KL: 23 b -1/04

Number: 1 208 024

File number: C 20007IV d / 23 b

Filing date: October 21, 1959

Opening day: December 30, 1965

The development leading to the manufacture of engines with ever greater compression ratios Following, the petroleum refineries have supplied gasoline products with ever increasing octane ratings. These Octane values or numbers are determined according to standard methods, namely by comparing with Standard fuels in a single cylinder engine under special speed conditions, Ignition timing, air-fuel ratio, inlet temperature of the mixture, etc. The two usual ones Methods for determining the octane number are called "Research" (CFR-R) or F-1 octane determination and referred to as the "older Motor Method" (CFR-M) or F-2 octane determination. The octane number represents an essential characteristic for the quality xs a gasoline, d. H. its performance in the average motor vehicle engine.

For the production of fuels with a high octane number, such as those used today for engines with a high compression ratio If necessary, refining processes are used which result in the formation of aromatic To a large extent reinforce hydrocarbons. Typical for this are the catalytic reforming processes, in which naphthenes are dehydrated. Although a gasoline with a high aromatic content Hydrocarbons have a high octane value (F-1 octane number) and in relation to the octane number certain engines with high compression ratio can satisfy, it turned out that these usual Octane values relating to the quality of the gasoline and its performance under actual operating conditions can be misleading. Because although aromatic hydrocarbons with 10 or more Carbon atoms (boiling point above 165 ° Q give the fuel an appropriate octane number, the fuels containing such aromatics tend to form deposits in the engine, whereby the octane number required for the engine is increased and undesirable during the combustion process Appearances are triggered.

In particular in the case of some of the conventional gasoline fuels with a high content of aromatic compounds, it was found that the determined F-1 octane value is incorrect as a criterion for the performance in motor vehicle traffic. A more precise description of the performance of a gasoline fuel, especially when it is used in today's engines with a high compression ratio, is the "road value" or the "road octane number", which according to the "Modified Uniontown Test" (Coordinating Research Council designation F-28), a test method for producing a gasoline currently in common use in the automotive and petroleum industries
high octane value

Applicant:

California Research Corporation,

San Francisco, Calif. (V. St. A.)

Representative:

Dr. W. Beil and A. Hoeppener, lawyers,

Frankfurt / M.-Höchst, Adelonstr. 58

Named as inventor:

John Walter Scott Jr., Ross, Calif. (V. St. A.)

is averaged. After this test, the knock resistance of fuels in motor vehicles is assessed on the road or on a chassis dynamometer (corresponds to operation on the road), namely at the Speed at which the greatest tendency to knock occurs. The one determined for the test fuel Street octane number corresponds to that of a comparison mixture of fuels with the same Ignition timing shows the same light knock as the test fuel. She is generally on various of the popular car models are determined and an average value is calculated. While the values obtained in this way actually correspond to reality insofar as the fuels are actually road tested, such tests are costly and time consuming. Besides, they are as a result of the test vehicles selected differently by the various laboratories subject. For this reason it has become the custom in the automotive and petroleum industries that Street octane values on the one hand from a relationship between F-I and F-2 values and calculate them on the other hand to determine from extensive practical road tests. The one in such a series of experiments Results obtained were from the Petroleum Laboratory, E. I. du Pont de Nemours & Company, Inc., preprint No. 2, Section C-3 (Midyear Meeting of the American Petroleum Institute's Division of Refining, May 14, 1957) and are in the Proceedings of the Institutes «included. Within this program

509 760/315

3 4

A total of seventy-four typical fuels components are coordinated so that

according to the Modified Uniontown test procedure stra- a catalyst strength (the term is used after-

tested. In current automobiles (explained standing) from about 0.1 to 2.0 is obtained. the

the resulting Straten octane isocracking equipment was found to operate at a pressure of at least

values essentially correspond to the values that 5 approx. 28 kg / cm ² and an average catalyst

known from FI and F-2 values using sator temperature of about 150 to 37o C. ⁰

using the following equation: Through the critical coordination of the procedural

Street octane value variables in connection with the tuning of the

". , “ _Λ . -_ - _,. ..,. . Catalyst components made it possible at the same time

= 0.5 (FI + F-2 octane value) + 4.0. _{10 to} achieve several conversions, such as the isomeric

While the F-I- ization, disproportionation and preferably hy- and F-2 octane numbers actually determined laboratory cracking, so that lower-boiling, cyclic To represent torium data, the street octane values are compounds in high molar yields as well generally arise using the above lower-boiling paraffins in which the Equation has been determined. 15 Ratio of isoparaffins to normal paraffins

The invention relates to a method for conversion is higher than in thermodynamic equilibrium, Development of an essentially nitrogen-free The production of low-boiling paraffins in which Hydrocarbon fraction with selected boiling point - the ratio of iso compounds to normal range and certain content of aromatics and bonds is considerably higher than in the thermodynamic Non-aromatics in high octane gasoline; it 20 balance, is essential for achieving the is hereinafter referred to as the isocracking process. special road octane properties of the synthe-Das The method according to the invention is characterized by the characteristic gasoline and is illustrated by the fact that that a petroleum fraction with an isocracking process according to the invention is substantially different from the holds in aromatic hydrocarbons from common hydrocracking or reforming processes at least 30 percent by volume, a content of basic 25 deviates.

Nitrogen less than 0.0025% and a boiling point - Under these conditions it becomes a gasoline fraction

Range between 165 and 345 ° C together with min- obtained with 5 and more carbon atoms and at least 355 m ^{3 of} hydrogen per cubic meter of petroleum fraction - lower aromatics content than the starting point in an isocracking plant with a material that is below about 165 ° C boils and has a road hydrating component on an active 30 octane number (leaded) of at least 95. It is acidic cracking catalyst support and one particularly advantageous to conduct the process so that catalyst having hardness of about 0.1 to 2.0 in per cubic meter of converted feed brings more than contact, with the isocracking plant consuming about 177 m ^{3 of} hydrogen will.
Pressure of at least about 28 kg / cm ^a and mean boiling points or ranges indicated were

Catalyst temperatures of 150 to 370 ° C. are operated, depending on the boiling range in question, and that a circulating gas stream with high water content is preferably obtained from the ASTM distillation process D-86 or D-158 obtained. With regard to the determination of the boiling substance content in areas under high pressure and the distillation points of the feed gas-liquid separation system and these and product fractions, a tolerance of 10 percent by volume, together with added hydrogen in the iso 40, was granted in order to return to the practical cracking system, then, if necessary, limits that are set for the refinery distillation plant and C ₁ - C ₃ - or Q - C ₄ products in a lower process take better account of gas-liquid separation applications operated at lower pressures. The boiling point given as 165 to 345 ° C separates and from the remaining, normal range relates to such charges, liquid material, a gasoline fraction with a 45 in which at least the 10% and 90 ° / ₀ distillation boiling point of below about 165 ° C and a higher point within the stated range, a boiling fraction which, if necessary, reformed and / while a product specified with a boiling range below 165 ° C or can be returned to the isocracking plant includes a product fraction, wins. at least the 90% point at 165 ° C or

The method according to the invention leads to the result being below this.

Creation of a high quality gasoline fraction that burns cleanly when performing the above conversion and a street (leaded) octane value of ventilation process can be obtained from the isocracking plant at least 95 has. Such leaking material is "leaded" onto fuels in any way denotes, the 0.79 ecm tetraethyl lead are worked. Usually a circular (TAB) included per liter. 55 gas stream with high hydrogen content in a sub

For the process according to the invention, a high pressure gas-liquid separation plant between about 165 and 345 ⁰ C boiling coal is separated, which is selected together with added hydrogen hydrogen fraction, which is returned to the isocracking plant at least 30 vol. Then containing lum percent aromatic hydrocarbons, C ₁ - C ₃ - or C ₁ - C ₄ products are separated in one and their nitrogen content to a content of 60 gas-liquid basic nitrogen compounds operated under lower pressures by less than a keits separation plant, whereby a normal- 0.0025% was reduced. This selected evidence remains liquid material from which the feed is introduced in a mixture with at least 355 m ³ , synthetic product according to the invention (preferred hydrogen per cubic meter feed in an iso, a gasoline fraction with 5 or more coal cracking plant, in which it is introduced with a poly- 65 material atoms and a boiling point of below about functional catalyst comes into contact. This 165 ° C) either by itself or together with higher catalyst consists of a hydrogenation component boiling gasoline fractions can be obtained on an active, acidic cracking carrier. The two These two optionally applicable extraction

methods are described in Example 1 and 2, respectively. Can be in. If it leads to as hydrocarbons any case, the methods are referred to a significant, so they can still other atoms yield of gasoline fraction with 5 and more, such as nitrogen, oxygen, SChv / efel, as well as various carbon atoms, which is below about 165 ⁰ C boils and contain metals commonly found in petroleum and a street octane (leaded) value of at least 95 other distillates of natural origin. Too owns. the non-aromatic hydrocarbon components

From the products of the isocracking plant, all acyclic coals can be included in the feed not only a gasoline fraction with a boiling hydrogen, especially paraffins, also naphthenic point of below about 165 ° C, but also hydrocarbons that, if they are added a fraction that should be above said petrol ι ο, from natural or synthetic paraffin fraction boils and a high content of higher niche crude oils or, as raffinates, by solution boilers aromatic hydrocarbons (aid extraction or other known processes, for example with 10 and 11 carbon atoms) with which aromatics of non-aromatic carbons has. These higher boiling fractions can be separated from hydrogen Petrol can be added and sources can also be 15. The content of the charge at bafür Aromatic hydrocarbons. Any nitrogen can thereby in the usual way if so, they can be catalytically reformed to determine that the feed is contained in ice Naphthenes to dehydrate, causing the vinegar to dissolve and the solution with perchloric acid in ice-aromatics and the octane value is further improved, titrated with vinegar, usually becoming crystals as an indicator. The higher-boiling fractions (whether cataly- 20 violet is used.

table reformed or not) but can also be used in the production of these selected charges

Isocracking plant can be recycled to it in raw gasoline, certain kerosene distillates and low-boiling (z. B. below 165 ⁰ C) products, gas oils, circulating oils, etc. can be used. These with high knock resistance and improved ver can be distilled off directly, z. B. from petroleum, or to convert combustion properties. 25 They can come from various procedures, in particular

The products from the isocracking plant that result from the thermal or catalytic cracking of the end point of the gasoline fraction or fractions from petroleum, gilsonite, shale, coal tar or boiling, materials obtained from other sources can be obtained up to substantial conversion be returned to the isocracking plant or withdrawn.

and for suitable refining purposes, namely 30 obtained from the latter processes and for the production of jet fuels, suitable feeds for the invention are the ten gasoline, co-solvents or the like. Uses so-called "circulating oils", which are generally a will. have a relatively high aromatic content

To get the street octane (weighted) one by one and are heat resistant enough to go no further Isocracking process according to the invention produced 35 to be cracked. The considered um-gasoline product always above the F-1 octane value (running oils are drained from the cracking system) of the product, it turned out to be necessary materials distilled off and do not belong agile, the content of aromatic as well as to the soil products, which after distilling off non-aromatic compounds have a critical effect on the more volatile (i.e. boiling below 345 ° C) parts to coordinate driving variables. So after 40 of these materials will be left behind. So you are not preferred embodiment of the invention is a residue product.

selected petroleum fraction, which is between 165 and Suitable feeds can also be thereby

345 ⁰ C boils, at least 30 percent by volume aro- can be obtained by keeping various charges of matic hydrocarbons and at least 20 percent by volume of aromatic to non-aromatic hydrocarbons while achieving a certain selected percent by volume of aromatic to non-aromatic hydrocarbons and mixing a content of basic nitrogen of hydrocarbons . Thus, aromatic extracts below 0.0025%, among the following extracts, which in some cases may be desirable as such as feed, precisely controlled conditions of iso, can be subjected to highly paraffinic or cracking, whereupon a product arises, naphthenic Fractions are mixed. One whose butan-free, boiling below about 165 ⁰ C share 50 important process variable that a road octane value (gebleit) has a substantially at least 95 impact on the process and the preparation of the features that consistently gebleit over the F-1 octane number ( ) desired gasoline product is that of the gasoline product will lie. Control of the nitrogen content of the feed.

As already mentioned, any conventional hydrocarbon distillate concentration can be used as feed for the inventive process 345 ^° C., the nitrogen content of which, if necessary, reduces this nitrogen content to less than by hydrofining or other processes to 0.001% and a noticeable further improvement in a basic nitrogen content of less than 0.0025% can be achieved. These nitrogen concentrations can be reduced and the gasoline product required to meet the requirements 60 by treating the charge with hydrogen with regard to the aromatic and non-aromatic at elevated temperatures and pressures in the counter-content that can be achieved for the production of the specific hydrogenation catalyst is enough. The term "aromatics" is used in the usual cracking effectiveness and low tendency to saturation, ie it excludes all hydrocarbons of the aromatics. Catalysts of this type are substances which have at least one aromatic nucleus are known in the art. Particularly good results are obtained and with different aliphatic or nits are achieved with such catalysts that other groups substituted or unsubstituted smaller amounts of oxides of metals, such as molyb-

Danish, zircon and cobalt, and a large amount of aluminum oxide contain. Do the materials treated in this way comply with the regulations relating to the boiling range and aromatic content, they can be passed directly into the isocracking stage according to the invention. Otherwise they must be fractionated beforehand in order to obtain the required feed.

In general, a basic nitrogen content of more than 0.0025% causes a reduction in the Catalyst performance, which is reflected in both the effectiveness of the process and the product distribution reflects.

Have said feeds having a maximum basic nitrogen content of 0.0025% usually a total nitrogen content of less than about 0.01% as common refining streams normally have a total nitrogen content that is about three to four times as high as the content of basic nitrogen. With regard to this known distribution of nitrogen compounds, it is today It is common practice to determine only the basic nitrogen, as this investigation is simpler and less expensive is than the total nitrogen determination. It is also known that the non-basic nitrogen compounds are quickly converted into basic nitrogen compounds in the feed as soon as they are mixed with the Come into contact with the isocracking catalyst. So if of feed streams for the isocracking plant the We are talking about containing only basic nitrogen compounds, or their content of basic and non-basic Nitrogen compounds does not correspond to what is usually encountered, it is advisable to use the Feeding for the isocracking plant as such define that contains less than about 0.01% total nitrogen.

A particular advantage of the isocracking process is that it can be used for processing aromatic feeds from the so-called "middle distillates", especially those boiling between 165 and 345 ° C., provided that critical process conditions are observed. Such charges include, as already mentioned, the heavy raw gasoline, gas oils, kerosene distillates and circulating oils, etc. The importance of the distillation point 165 ° C has already been made in relation to the desired conversion of aromatic hydrocarbons, which have 10 or more carbon atoms and have disadvantageous combustion properties , set out in better-burning, lower molecular weight cyclic compounds. With regard to the distillation end point, it was found that aromatic distillate feeds with a boiling point above about 345 ^° C. greatly reduce the effectiveness of the process by rapidly fouling the catalyst. This catalyst fouling is caused by excessive deposition of carbonaceous substances and not only results in the catalyst having to be regenerated frequently, but also leads to low yields of the desired gasoline product, since higher temperatures must be used in order to carry out the conversion with the now to effect less powerful catalyst.

In addition to the prescribed boiling range and nitrogen content, which affect the effectiveness of the isocracking process, the composition of the feed, ie the ratio of aromatics to non-aromatics, is a critical variable that affects the quality and performance of the synthetic gasoline product produced. In order to produce a synthetic, 5 or more carbon atoms containing gasoline product having a boiling point below 165 ⁰ C, burns clean and a road octane number (gebleit) has at least 95, the feed must contain at least 30 volume percent aromatic hydrocarbons. As this minimum aromatic content is exceeded, the road octane number also increases, as can be seen from the table below.

In order to show the effect of the aromatic content on the quality of the product, a series of tests carried out under typical isocracking conditions, the catalyst composition, the temperature, pressure, space velocity and hydrogen content were kept constant and only the feeds and their aromatic content were changed. In these experiments, their results are summarized in the table below, the following feeds were used:

(1) A light, unprocessed gas oil that is 15% aromatics contained and came from a Venezuelan crude oil;

(2) a heating oil, i.e. a straight-distilled raw California gasoline containing 24% aromatics;

(3) a hydrofined feed containing 42% aromatics and catalytic from a mixture cracked and direct distilled petrol consisted of Californian crude oils;

(4) a catalytic circulating oil containing 49% aromatics and made from a catalytic, with California crude oils fed to the cracking plant;

(5) an SO ₂ extract with an aromatics content of 60% obtained by treating a directly distilled raw gasoline from California;

(6) another SO ₂ extract which contained 69% aromatics and was obtained by extraction of a light catalytic circulating oil from a catalytic fluidized bed plant;

(7) a heavy distillate from a platinum catalyst and a Californian one Crude oils fed into the reforming plant with an aromatic content of 93% and

(8) a selected aromatic fraction with an aromatic content of 98% from those in a catalytic Materials obtained from reforming processes.

Further characteristics of these charges are given in the table, e.g. B. the different octane numbers and other characteristics of the products obtained by conversion in an isocracking reactor. In any case, the "product" represents the debutanized portion of the materials withdrawn from the isocracking plant with a boiling point below about 165 ° C.

Temperature = 345 ° C; Pressure = 84 kg / cm ² ; Hourly space velocity of liquid feed = 2; H ₂ = about 1150 m ³ / m ³ ;

Operation = one pass, no return; Catalyst = NiS on silica-alumina;

Product = that part of the withdrawn materials with a boiling point up to about 175 ° C (C ₅ ⁺ - hydrocarbons).

(D product (2) product (3 ) product (4) product (5) product (6) product (7) product (8th) product Light gas oil 0 Hydrofinished
Heating oil 0 Hydrofinished
heavy raw gasoline 0 Hydrofinished
catalytic
Circulating oil 0 Hydrofinished
SO ₂ extract
(directly distilled
Petrol) 0 Hydrofinished
SO ₂ extract
(Circulating oil) 0 Reformate Additional aromatics Be
dispatch 9 Be
dispatch 15th Be
dispatch 32 Be
dispatch 27 Be
dispatch 36 Be
dispatch 37 Be
dispatch 67 Be
dispatch 68 Basic stick
material, % 0.0004 D 86 0.0003 D 86 0 D 86 0.0001 D 86 track D 86 0.0001 D 56 0 D 86 0 D 86 Aromatics, volume
percent 15th 46 24 54 42 58 49 32 60 51 69 51 93 62 98 72 ASTM Destilla
tion D 158 67 D 158 73 D 86 79 D 158 58 D 158 81 D 158 77 D 86 108 D 86 118 Beginning 83 164 92 188 100 166 90 140 102 194 102 172 132 180 138 10 ° / o 236 104 198 111 191 118 221 113 196 120 220 121 177 143 183 147 30% 127 214 128 193 136 238 132 203 136 234 137 181 151 184 154 50% 270 160 227 148 198 156 248 153 214 153 244 154 184 160 186 162 70% 183 244 179 198 174 257 164 225 164 254 164 190 171 188 176 90% 304 89.4 268 92.4 207 98.0 272 97.6 240 99.0 270 98.3 208 102.5 193 103.1 End point 323 92.5 311 94.3 235 98.4 299 98.8 260 99.3 300 98.8 252 101.6 212 102.0 Octane numbers
(+ 3 ecm
Tetraethyl lead)
FI 80.7 Ul
g road
1 octane value ....

11 12

The catalyst consisted of NiS (2.5% Ni) to contain up to 95% silica. In the described one silica-alumina carrier (87% SiO ₂ ) with tests, a high cracking performance was found in crushed form. The strength (as used below of material of this type, which is about 90%

explained) this catalyst was 0.42. Contained silica and when first used one

In these comparative experiments, the 5 activity of 46 and a surface area of about passage achieved were 5 and 430 m ^a / g.

products containing more carbon atoms that are below The hydrogenation-dehydrogenation component of the

the initial boiling point of the feed, in the case of catalyst can be one or more metals

all beers VI containing more than 30% aromatics. and VIII. Group of the Periodic Table

Shipments consistently over 60%. In the experiments io or their oxides or sulfides exist. Typical

(4) and (5) the degrees of conversion were 79 and examples are the oxides and sulfides of

77.5%. Molybdenum, tungsten or chromium along with

As can be seen from the table above, metals such as nickel or cobalt and their oxides only have street octane values (leaded) above 95, and so do sulphides. Various metals are also suitable if the aromatic content of the charge is around 30% of subgroups I or II, such as copper or cad. It can also be seen that, albeit the mium and their oxides and sulfides. Possibly road octane value with an aromatic content that can more than one hydrogenation-dehydrogenation loading of over about 80% tends to be present under component, so z. B. compositions to lower the Fl value, the street octane value of these two or more oxides and / or sulfides of products is still so high that this difference 20 molybdenum, cobalt, nickel, copper, chromium and between the octane values is only small Meaning zinc,
Has. Depending on its effectiveness, the amount of

In the isocracking process which has the above hydrogenation-dehydrogenation component within

Shipments must also be subject to the relatively wide limits between about 0.1

Process variables critically matched 35 and 30%, based on the weight of the whole

will vary depending on the particular combination of Um- catalyst. Within these limits

To achieve conversions that are reflected in the physical, the named constituent should be

and chemical properties of the synthetic are used, so that an adequate catalyst

Reflect product. The main versator uptime at an acceptable conversion

driving variables that the desired combination is achieved. However, it should be

of reactions and therefore with the iso are those that are below the applied reaction

crack processes are to be identified, the conditions represent a substantial saturation of the aromatics,

composition of the catalyst and the reaction except for any strongly substituted,

temperature or temperature control. This is to aromatic compounds and polynuclear, aromatic

do not mean that the other process variables cause 35 matic connections. In general

are insignificant for the isocracking process, but have been found to be components that are metals of the group

It is to be said that the said VIII contain, more effectively than those which the others,

Process variables are particularly critical. contain the above metal groups. you will be

As already mentioned, a poly- therefore preferably used as a catalyst in the above,

Functional catalyst applied, which comes from a 40 lower reaction temperatures, especially at

Hydrogenation component on an active, acidic mean catalyst temperatures below about

Crack carrier consists in which the catalytic grains used from 315 to 345 ° C. It was also found

components are coordinated so that the strength of that among the compounds with metals of the group

Catalyst is about 0.1 to 2.0. The crack VIII converts the sulphides of nickel and cobalt into the green

constituent or carrier can produce one or more acidic results, especially with regard to

Substances such as silica-alumina, silica-magnesia are more desirable to achieve a greater proportion

a composition of silica, alumina and isoparaffin products.

Zirconia, as well as certain, with an acid. The coordination of the catalytic components. traded clays and similar materials which are necessary to achieve the desired selectivity in the process according to the invention, provided that these acidic substances are required, will have a substantial cracking effect, in some cases based on the "catalyst hardness" (S _a ) of the catalyst the acidic character of the crack composition is determined. This property of the component, e.g. B. by adding halides. Catalyst can be determined by subjecting the catalyst to a standard test, of Lewis or Bjronsted acidity, by subjecting the catalyst to a standard test to achieve this, in which a trimethylbenzene, e.g. B. can. More precisely, the cracking component of the pseudocumene, or an equilibrium mixture of catalyst, as it is used in gasoline production from trimethylbenzenes, which is pressed from a catalyst, should have an effectiveness of at least approximately table reformed raw gasoline [determined according to the » Cat. Α «procedure. When using the latter, a close- (J. Alexander and HG Shimp, National 60 boiling fraction with a D-So-Distillations-Petroleum News, 1944, Vol. 36, p. R-537; J. A1 e χ a η - Range from about 159 to 168 ° C and a C ₉ -ArO-der, Proc. Am. Petroleum Inst., 1947, Vol. 27, mat content of at least 95 percent by volume ver-p. 51)]. Preferably the cracking component has to be turned. At. In this experiment, the Be isocracking catalyst will have an activity of min feed with a space velocity of at least 30. 65 gene feeds of 2 per hour along with a preferred cracking support for the catalyst ^{composition consists of about 1600 m 3 of} hydrogen per cubic meter of feed made from synthetically produced by passed the test catalyst, whereby the silica-alumina compositions, the about 75 catalyst ^{temperature to about 345 0} C and the pressure

13 14

holds at 84 kg / cm ^2. While this trial condition is sudden relaxation to atmospheric pressure

in general for the evaluation of the liquid product fractionated to, based on

considerable number of catalyst mixtures - the volume of the feed, the percentage

are suitable, a change in the experimental proportion of the ^{product boiling below about 150 °} C. turned out to be

conditions attached where the conversion 5 determine. This is the synthetic product. Of the

degree per pass exceeds 60%, which then increases the aromatic content of the feed and the synthetic

The case is when the catalyst is very effective. In table product z. B. by chromatographic

in such cases the test temperature, e.g. B. on about analysis (FIAM method) and the catalysis

300 ⁰ C, and the space velocity per Sator hardness S _{a is} calculated using the following formula:

Hour of liquid charging adjusted so that io .

a conversion of 40 to 60% per pass S _a = —J- - 1,

is achieved. This procedure continues for so long (usually ^Ap

about 2 to 5 hours), until the where Af = volume percent aromatics in the BeSystem has stabilized, and then until sending and A _v = volume percent aromatics in which a corresponding product sample is present. After 15 mentioned product.

As shown below, the above formula is derived from the following general relationships:

Aromatic hydrogenation index (An) ^a Aromatic cracking index (A _c ) '
whereby

% Aromatics in the feed (Af) -% aromatics in the product fraction, j _ boiling below the initial boiling point of the feed (A _v)

% Aromatics in the feed (Af) '

% Aromatics in the proportion of product that boils below the initial boiling point of the feed (Ap) ^c % aromatics in the feed (Af)

It follows from the above equations that they are obtained by impregnating comminuting

30 th, optionally dried silicon-aluminum

^ r _ Af oxide complexes with the solution of a compound

Ap ' of the metal or metals concerned and

Firing the impregnated mass, which is then with

In the isocracking process according to the invention, the hydrogen treated and then sulfided catalyst hardness should be about 0.1 to 2.0. A 35 will, preferably with dimethyl disulfide. The 5Ό value of over 2.0 shows an undesirably high level of hydrogen consumption, depending on the temperature, the pressure, the in-loss of aromatics in the product as well as a large amount of hydrogen and the boiling range. On the other hand, an S _a value of feeds in the isocracking process in the range below 0.1 can normally indicate the formation of mixed with hydrogen the feed either in aromatics, which is not desirable for the liquid, vapor or liquid-vapor purposes according to the invention, because then as a result of the off phase are introduced into the reaction plant. The storage of carbon, etc., a rapid de-activating charge will occur in admixture with at least about four of the catalyst. Catalysts whose 355 m ^{3 of} hydrogen per cubic meter of total feed ■ So value is above the desired range can be introduced (ie fresh feed plus recirculated feed, usually by setting the 45 kung accordingly), with the stated amount of hydrogen of the hydrogenation-dehydrogenation constituent being about 2655 to 3550 m ³ per cubic meter can be corrected. Can be sent. In most cases, even with relatively low operating temperatures in the isocracking plant, temperatures of around 178 to 355 m ³ are particularly good results with regard to hydrogen per cubic meter of total converted to a high conversion per pass, with a good 50 charge that is below the initial boiling point of selectivity and a relatively small Lei fresh charge is boiling, is used. The hydrogen added to the feed, which is not regenerated repeatedly, is obtained with catalysts which consist of 1 to 1 to usually consist of circulating gas that is produced from the silica produced from 10% nickel sulfide on the aforementioned, synthetically produced from the hydrofining and / or isocracking plant Alumina mixtures are obtained from 55 material and fresh hydrogen. In practice, the hydrogen content of the circulation gas is generally over 75 percent by volume. Advantageously, following catalysis ^B principle, for example, amounts of the catalysts used in the Isocrackanlage: applied pressure greater than about 28 kg / cm ^2. It can be nickel sulfide (2.5% Ni) on silica-alumina 60 up to 210 or even 350 kg / cm ² . The ^{preferred pressure range:} cobalt sulfide (4% Co) on silica-alumina is between about 42 and cobalt sulfide (2% Co) 105 kg / cm ² . A pressure of less than about 28 kg / cm ⁸ and leads to reduced degrees of conversion per through-chromium sulfide (3.5% Cr) on silica-alumina rate and to shorter operating times, since an increased molybdenum sulfide (2% Mo) on silica-alumina 6g There is a tendency for the naphthenes to dehydrate to give aroma nickel sulfide (1% Ni), which is accompanied by contamination of the catalyst and sator mixture by carbon-containing compounds, molybdenum sulfide (1% Mo) on silica-alumina. On the other hand, has a pressure of over

about 140 kg / cm ² normally result in inadmissible saturation of the aromatics. However, if a pressure of more than 140 kg / cm ² , e.g. B. desired in operation without regeneration, the tendency caused by the high hydrogen pressure to saturate the aromatics by using a catalyst composition of low hardness or, in other words, such a catalyst can be canceled or compensated in which the hydrogenating component of catalytic metals and whose compounds exist which are relatively less active, e.g. B. cobalt, chromium and / or molybdenum compounds and nickel in sulfide form.

In general, the isocracked feed can flow at a space velocity of the liquid feed per hour from about 0.2 to 5 volumes (calculated as liquid) per surface volume of the catalyst in the reaction plant is introduced; the preferred space velocity of the liquid feed per hour is about 0.5 to 3.

According to the preferred embodiment of the invention, the temperature at which the reaction should be as low as possible (provided that the degree of conversion per pass is corresponding), since the operating time below 370 ° C is longer, the lower the initial temperature. For each conversion, the allowable initial temperature depends on the efficiency of the catalyst, since with the more effective catalysts (i.e. those that under the given working conditions cause a relatively high degree of conversion per pass) the system can be put into operation at lower initial temperatures.

According to the preferred embodiment of the process according to the invention, the isocracking process is carried out at a given space velocity under such conditions that a relatively constant degree of conversion of at least 20%, preferably from about 20 to 70% per pass is achieved. In this type of implementation, the temperature of the catalyst is increased periodically in order to keep the degree of conversion relatively constant for each pass. However, the process can also be carried out at a constant temperature of about 370 ^° C. or below. Under these conditions, the degree of conversion gradually decreases per pass, and the process is terminated at an arbitrarily chosen degree of conversion.

The process can also be carried out in stages at constant temperatures, with the temperature of the catalyst is kept constant within a certain period of time until the degree of conversion has dropped to a certain value, whereupon the temperature is increased until the initial one Degree of conversion is approximately reached. This step-by-step increase in temperature is then repeated.

The low temperature maintained in the isocracking process is an important feature for the Quality and yield of the product and also results in advantages for the process itself. One of the essential factors for achieving the special road octane values of the synthetic ones according to the invention produced gasoline fraction is the predominant production of isoparaffins, which is higher, than is required by thermodynamic equilibrium. This is particularly important in the field of paraffinic hydrocarbons, have 5 or more carbon atoms, since the normal paraffins in this range are only small Have octane values and reduce the combustion properties of the fuel. This extraordinary strong formation of isoparaffins is in contrast to the usual hydrogenation process, e.g. B. the usual hydrocracking, which provide synthetic paraffins in which the ratio of iso to Normal paraffins is essentially at or below the thermodynamic equilibrium.

The following values show how the use of low temperatures affects the ratio of iso- to normal paraffins in the synthetic paraffin products. In the embodiment, a hydrofined circulation feed with a boiling point of 188-235 ⁰ C and a content of basic nitrogen was treated under 0.0001% (the hydrofined feed of Example I) under the following conditions:

Pressure, kg / cm ^a 84

Ha consumption, m ³ / m ³ 213

Space velocity of the
liquid feed
1.67 per hour

Gas circulation, m ³ / m ³ 1060

Conversion,% 60

Working method circulation

Catalyst .-. · 2.5% Ni

Silica--
Clay

The following results were achieved:
Temperature, ⁰ C 343

C ₆ paraffins,
Iso to
Normal paraffins

Observed 28

Balance 4.0

The maintenance of a low temperature is also reflected in the high yields of synthetic liquid product, ie of product boiling below the initial boiling point of the feed. At operating temperatures below about 370 ^° C., the yields of synthetic liquid product are consistently high, while at higher temperatures the yields of liquid product are lower and too much gas is produced. So could z. B. are maintained, the yield of synthetic, 5 or more C-atoms comprising hydrocarbons within a temperature range of 315-370 ⁰ C to approximately 94 percent by volume in the process described in Example I, in which a hydrofined naphtha fraction a Isocrackung was subjected. At a temperature of about 425 ^° C., the yield of liquid product fell rapidly and was approximately 86.5%.

Simultaneously with the Low If the yield of synthetic product liquid at temperatures above about 370 ⁰ C a correspondingly increased gas formation occurs (C ₁ -C ₃ gases). To illustrate this weight loss caused by the formation of relatively worthless gases, is

17 18

on F i g. 1 referenced, in which the methane production corresponds to the in F i g. 3 reproduced

is graphed in the procedure of Example I. relationships.

As can be seen from the fact that methane production is The process of the invention is negligible practically feasible at operating temperatures below about 370 ⁰ C with both resting bed catalysts as well. However, if the temperature rises above 370 ^° C. using a moving catalyst or, then the methane production quickly becomes a fluidized bed catalyst. In the former, the process-limiting factor. It rises, as can be seen from the case, the catalyst is ^{regenerated in situ at certain time intervals on the curve, between 370 and 427 °} C., but it is possible, when used, to increase approximately fifteen times. Such methane formation from catalysts to be used according to the invention not only represents a loss of io with a relatively high efficiency in many charges, but also requires (if the operating time is to be extended so long that hydrogen is recirculated, as is uneconomical in technical applications, facilities for the Regene process must be the case) to provide for cleaning of the catalyst. In the case of the sufficiently contaminated hydrogen working with hydrogen or the removal of a part of the moved catalyst, or the processes known to use, special containers of higher pressure are used around the hydrogen partial, in which parts of the catalyst have more or pressure of the recycled Gas can be regenerated less continuously within permissible limits in order to then hold. As a result, not only are the costs returned to the actual isocracking plant increased, but due to the increased proportion,
of undesired gases, the yield is also 20 q _ _; "_ _; "1 _T

. , DCl S DlCl 1

reduced.

Other advantages in terms of yield and the feed used in this experiment

the quality of the product can be achieved if it comes from a heavy petroleum fraction, the

Process at low temperature carried out a mixture of by thermal and catalytic is, are by the F i g. 2 reproduced. This represented cracking of obtained materials, where

Figure shows in graphical representation the roads for both the thermal and the catalytic

Octane liter numbers which are used in various operational cracking operations for crude gas oils of Californian origin

temperatures obtained and from those in Example I were applied. This raw gasoline fraction, which between

obtained data were calculated. This characteristic- boiled around 104 and 227 ° C and 0.014 to 0.015% tion is usually used as a measure of performance. 30 basic nitrogen was thereby

a refining plant used and calculated lines that you can use them at a pressure of 56 kg / cm ² ,

is derived from the product: liters of gasoline per liter converted to a space velocity of the liquid charge

Delter charge times the octane number of the product per hour of 2 and a temperature between 370

recovered gasoline. The street octane liter and 400 ⁰ C along with about 620 m ^{3 of} hydrogen each

rises between 315 and 370 ⁰ C to its maximum value of 35 cubic meters of raw gasoline through a hydrofinishing

and then falls with increasing catalyst sent, the cobalt oxide (2 ⁰ I ₀ cobalt)

temperatures drop quickly. If other charges, on a support made of simultaneously precipitated molybdenum

z. B. catalytic circulating oils, etc., used and oxide-aluminum oxide (9% molybdenum) contained. In

processed according to the invention, 53 to 71 m ^{3 are obtained similar to this hydrofining process}

Curves as in Fig. 2 (which practically only consumes 40 hydrogen per cubic meter of feed

move vertically). and the basic nitrogen of the withdrawn material

From an economic point of view almost as below 0.0001 ° / ₀ decreased. After distilling

as important as the favorable product yields of the material obtained from the hydrofining plant

after that at low temperature (below 370 ^° C.), a liquid fraction, the following one, was obtained

working method is the fact 45 dates revealed:
that the conversion of the feed via a

A longer period of time can be carried out if the conversion- Specific gravity 0.8398

ment initiated at temperatures of below 370 ⁰ C aniline point, ⁰ C 31.4

will. This is graphically in the curves of FIG. 3 aromatics content, 42 volume percent

shown. These data relate to experiments, 50 basic nitrogen, ° / ₀ <0.0001

which were introduced at various temperatures, F-1 octane (leaded) 80.7

however, the remaining conditions are essentially

remained unchanged. Each of these curves shows how ASTM-D-86 Distillation, ⁰ C

high the temperature during the entire experiment, initial boiling point 188

had to be increased to a conversion of 55 10 ° / ₀ 191

Maintain 60% per pass. In the case of 30% 193

Experiments initiated at higher temperatures had to be 50% 195

slightly increased space velocities applied 70% 198

to the stated degree of conversion to 90% 207

right. 60 end point 235

The in F i g. The absolute reaction times shown in 3 depend largely on the isocracking catalyst used in each case. This hydrofined fraction or isocrack charge can be ^{preheated to 304 ° C together with 1780 m 3} H ₂ per cubic depending on the relative catalyst performance and the meter charge and with a kinetic factor such as degree of conversion and 65 space velocity of 1.67 at a pressure of space velocity, can be increased or decreased. 84 kg / cm ² on the above-described manner by a In all cases, however, the general relationship of the nickel sulfide catalyst is passed (2.5 weight between top temperature and duration of the test in percent Ni) on silica-alumina contained. the

The temperature of the feed-hydrogen stream introduced into the plant was then gradually increased until the degree of conversion per pass was 60%. At this point, ie when the average catalyst ^{temperature in the plant was 343 °} C. and the plant was in operation for a total of 8 hours, the ^{amount of hydrogen was reduced to about 1150 m 3} per cubic meter and kept at this level until the end of the experiment. The process was carried out in such a way that all unconverted parts of the output were returned to the isocracking plant, that is, the recycling was carried out until complete conversion was achieved.

The degree of conversion was maintained at 60% per pass characterized in that as long as average increased the temperature to about 0.15 per hour ⁰ C until the system an average temperature of 399 ° C was reached. At this point the plant was in continuous operation for 590 hours. Above 399 ° C, the temperature had to be increased much more quickly to maintain a 60% conversion rate. Thus, the temperature after 690 hours 412 ° C after 720 hours 427 ° C and after 740 hours, was stopped as the process 44O ⁰ C. The calculation gave a hydrogen consumption of about 230 m ³ per cubic meter in synthetic product converted Gesamtbeschikkung.

, Was an analysis of the product, which was carried out when the temperature of the system approximately 376 ⁰ C, gave a yield of gasoline (boiling point between that of the C ₅ compounds and 182 ° C; 90% point = 164 ° C) of 92.7 percent by volume , based on the volume of the raw gasoline feed introduced into the system. This gasoline product contained a total of 26 percent by volume aromatics, between 1 and 2 percent by volume C ₁₀ aromatics and had an F1 value of 98.5, an F-2 value of 92.5 and a street octane value of 99.5.

At the end of the experiment, it was found that the isocracking plant's catalyst was slightly on the can be regenerated in a conventional manner by burning in a nitrogen stream with controlled oxygen content could, whereupon after reduction and conversion of the catalyst in the sulfided form the plant under Achieving essentially the same results could be put back into operation.

This circulating oil was first hydrofined by passing it ² at a pressure of 56 kg / cm at a temperature of 410 ⁰ C and a space velocity of liquid feed per hour of 2 together with 530 m ³ of hydrogen per cubic meter Beschikkung by a catalyst of cobalt oxide (3 , 7% Co) on a carrier made of precipitated aluminum oxide-molybdenum oxide (7% Mo). After removing the hydrogen, ammonia and other, normally gaseous components, the material from the hydrofining plant had the following properties:

Specific gravity 0.8772

Aniline point, ⁰ C 34

Aromatic content, percentage by volume 49 to 50

Basic nitrogen,% <0.0005

Boiling range, ASTM-D-158 distillation in ° C

Initial boiling point 166

10% 221

30% 238

50% 248

70% 257

90% 272

Endpoint 299

Example II

A light Californian catalytic circulating oil was used as the feed for this process Origin used, which showed the following data:

Specific gravity 0.8944

Aniline point, ⁰ C 32

Aromatic content, volume percentage 50

Basic nitrogen,% 0.0153

Boiling range ASTM-D-158 distillation, ⁰ C

Initial boiling point 204

10%
30%
50%
70%
90%

233
243
251
258
274

Endpoint 297

This hydrofined feed was then isocracked in the manner described above subjected, using a catalyst containing nickel sulfide (2.5% Ni) on a silica-alumina support contained. The catalyst had previously been used in three isocracking experiments; after At the end of each experiment, he was regenerated in a hydrogen atmosphere and then reduced been sulfided.

The Isocrackverfahren was carried out so that the preheated feed mixed with 0.1 volume percent dimethyl disulfide, and 2130 m ³ H ₂ per cubic meter of feed to 332 ⁰ C and the heated mixture at a space velocity of liquid feed per hour of 1.53 at a Pressure of 84 kg / cm ^{2 passed} through the catalyst. The temperature of this stream was gradually increased until the conversion per pass was 50%. After the plant had been in operation for 8 hours, the mean catalyst temperature was 338 ^° C. At this point the hydrogen content of the charge was reduced to 1725 m ³ per cubic meter and held at this level until the end of the experiment. The procedure was carried out so that all traced non-converted parts of the discharge, in particular about 204 ⁰ C in the boiling part Isocrackanlage.

The degree of conversion could be kept at about 50% per pass by gradually increasing the temperature at a relatively constant rate, the catalyst temperatures being 343, 358, 371, 385 after the end of continuous operation for 60, 125, 160, 400 and 430 hours and 388 ^° C., respectively. However, the temperature then had to be increased much more rapidly to maintain a conversion rate of 50%. So when the operating time was extended to 475, 510, 525, 535 and 540 hours

Temperatures of 399, 413, 427, 441 and 454 ° C are reached.

An analysis of the product was removed from the system, while working at a temperature of about 377 ⁰ C, gave a yield of gasoline (boiling point between that of the C ₅ compounds and 204 ⁰ C) of 104.5 per cent by volume. This gasoline, which contained 29 volume percent aromatics, had an F1 value of 95, an F-2 value of 89.5 and a road octane value of 96.3. Of this C ₆ -204 ° C gasoline fraction, approximately 75% consisted of hydrocarbons with a boiling point of up to 166 ° C. This fraction contained 25 percent by volume aromatics and had an F1 value of 96, an F-2 value of 90.5 and a street octane value of 97.3. The gasoline fraction with a boiling point between 166 and 204 ° C contained a relatively large percentage of aromatics with 10 or more carbon atoms and was therefore less suitable for high-quality fuels.

Claims (2)

Patent claims: 1. A process for producing a gasoline with a high octane value, characterized in that along a petroleum fraction having a content of aromatic hydrocarbons of at least 30 volume percent, a basic nitrogen content of less than 0.0025%, and a boiling range of 165-345 ⁰ C. with at least 355 m ^{3 of} hydrogen per cubic meter of petroleum fraction in an isocracking system with a catalyst consisting of a hydrogenating component on an active acidic cracking catalyst carrier and having a hardness of about 0.1 to 2.0, the isocracking system at a pressure of at least about 28 kg / cm ² and average catalyst temperatures of 150 to 370 ° C, and that a circulating gas stream with a high hydrogen content is preferably separated from the product obtained in a gas-liquid separation system under high pressure and this is separated off together with added hydrogen returns to the isocracking plant, then optionally C ₁ -C ₃ or C ₁ -C ₄ products are separated in a gas-liquid separation plant operated at lower pressures and a gasoline fraction with a boiling point of below about 165 ° C. and a higher-boiling one from the remaining, normally liquid material Fraction that can optionally be reformed and / or returned to the isocracking plant wins. 2. The method according to claim 1, characterized in that the hydrogen consumption per cubic meter of charge which is converted into a product boiling below the initial boiling point of the charge is at least 178 m ³ . For this purpose, 1 sheet of drawings 509 760/315 12.65 © Bundesdruckerei Berlin