Method for producing a catalyst,particularly for standard parafines isomerization

The present invention relates to a process for the preparation of a catalyst suitable for use in the isomerization of normal paraffins.

Catalysts which have been produced by deposition of at least one noble metal of Group VII of the Periodic Table of the Elements are characterized by high efficiency and selectivity for the isomerization of normal paraffins. In order to produce suitable catalysts for this purpose, it is necessary to replace the mouldable metal cations, initially present in the moodstone, almost entirely with hydrogen ions. This substitution can be accomplished by treating the moodstone with an aqueous acid solution or by treating the moodeeite with an aqueous solution of an ammonium compound followed by calcination.

It has been found that catalysts prepared by deposition of at least one precious metal of Group VIII of the Periodic Table of the Elements, which was first treated with an aqueous acid solution and then with an aqueous solution of an ammonium compound, exhibited greater efficacy for isomerization of normal paraffins. catalysts prepared by depositing at least one noble metal of Group VIII of the Periodic Table of Elements on moodinite, which moudinite was previously treated with either an aqueous solution of the acid or an aqueous solution of the ammonium compound. Furthermore, it has been found that for the isomerization of non-refractory paraffins the efficiency of catalysts produced by depositing at least one noble metal of Group VII of the Periodic Table of Elements could be effected on a wax which had previously been subjected to the above two-stage treatment. further increased by treating the mouddnit with an aqueous acid solution, by the preparative addition of potassium and / or sodium ions to an aqueous acid solution having a normality in the range of 0.5 to 3.0 in g / l corresponding to at least ten times the nominal value of said acid solution.

From the base catalyst material obtained as described above, catalyst particles can be prepared by high pressure molding. To give sufficient compressive strength to these catalyst particles to be used on a technical scale, catalyst catalysts are usually used. the basic material is thoroughly mixed first. With an anaophobic binder consisting essentially of at least one metal oxide of Groups II, III and IV of the Periodic Table of Elements, the mixture thus obtained is formed under high pressure.

It has also been found that improved catalyst performance for normomeric paraffin isomerization has been achieved.<img file="CS224625B2_D0001.tif" />A conventional one-step moodenite treatment by a two-step treatment using an aqueous acid solution to which no alkali metal ions have been added will be fully maintained if the base catalyst material is intimately mixed with the amoophene binder and formed under high pressure. It was believed that this would also be the case with the further improvement achieved by adding metal ions to the aqueous acid solution. However, this finding is incorrect. It has been found experimentally that when the catalyst contained in the catalyst catalyst was subjected to the above two-step treatment, an aqueous acid solution was added to which alkali metal ions were added to further improve the alkali metal addition to the catalyst. % of the aqueous acid solution does not occur at all when the base catalyst material is mixed with an ammonia binder and formed under high pressure.

It would be advantageous to produce catalyst particles of sufficient compressive strength to be used on a technical scale, while maintaining the previously formed optimum suitability for leonite. normalizing paraffins, which suitability is achieved by subjecting the morddens to said two-stage treatment, in the presence of an aqueous acid solution to which the metal ions have been added.

It has now been found that such catalyst particles can be produced by applying noble metals of Group VII of the Periodic Table of Elements not as usual to the processed moorerite, but to the amoophene binder matrix.^:They are at least one metal oxide of Groups II, III and IV of the Periodic Table of the Elements. By thoroughly mixing the processed mordonite with an aaoophobic binder material that encapsulates a noble metal of Group VIII of the Periodic Table of Elements and shaping thus obtained. high pressure mixtures can be used to prepare catalysts that actually meet both of the above requirements.

It is therefore an object of the present invention to provide a process for the preparation of a catalyst suitable for normal paraffins, comprising treating the solution with the first addition of potassium ions and / or sodium ions to an aqueous acid solution having a pH of 50. La &amp; ^^ í cointartš tl^rtpOⁿ 2.0. x 1 (° Л of blending normant in the range^0,5 and^of In addition, in g / liter, it is at least ten times the normal value of an aqueous acid solution, and then treated with an aqueous solution. The solution of the ammonium compound thus treated is then mixed with a material consisting of at least one metal oxide from the traces II, III and IV of the Periodic Table, on which at least one noble metal from the trace VIII of the Periodic Table has been deposited. and formed - the mixture is then shaped.

Both the organic and inorganic acids can be used as the acids in the acid solution used according to the invention. Preferably, hydrochloric acid is used. Preferably, the aqueous acid solution is in the range of 1.0 to 2.0. The addition of potassium and / or sodium ions to an aqueous acidic solution may be used. organic and inorganic salts. Very good results can be obtained when treated with the aqueous acidic solution to which the potassium and / or sodium ions (also referred to as the acidic treatment) have been treated using an aqueous solution of at least one acid, which solution is saturated at least one potassium and / or sodium salt. An acidic aqueous solution containing sodium ions is preferably used for the acid treatment. It is also advantageous to use a potassium and / or sodium salt derived from the same acid used for the salt. acid treatment The acid treatment is preferably carried out at an elevated temperature, in particular at a temperature close to the boiling point of the acidic aqueous solution.

<img file="CS224625B2_D0002.tif" />

Both organic and inorganic ammonium compounds can be used to treat mordenite with an aqueous ammonium compound solution. By ammonium compound is meant any compound capable of forming an armonium ion. It is preferred to use simple ammonium compounds, especially ammonium nitrate. The preferred aqueous solution of the ammonium compound is in the range of 0.1-10. The aqueous solution of the ammonium compound can be treated at room temperature or at elevated temperature.

The time required for each of these treatments depends on the end-fermentation of the roots used, their temperature and the number of contacts. As a rule, each treatment should take at least 30 minutes, preferably at least one hour. It may be advantageous to repeat the acid treatment or the treatment with an amorphous compound, or both, somewhat. It is preferred to repeat or continue treatment with the aqueous solution of the ammonium compound until the alkali metal can be liberated in an amount determined by analysis.

After treatment with the ammonium compound, the mooddent is in the ammonium cycle. Kilcination of the ammonium oordenite removes the nitrogen atoms introduced by the treatment to give a moodcent in the hydrogen cycle. Conversion of ammonium oordenite to mooddent in hydrogen. The cycle can be carried out before or after mixing with an amoophic material containing a noble metal of Group VIII of the Periodic Table of the Elements.

In the preparation of the catalyst according to the process of the invention. is processed every day! admixed with an amoophic material consisting essentially of at least one metal oxide of Groups II, III and YV of the Periodic Table to which at least one noble metal of Group VII of the Periodic Table has been deposited. Examples of oxides suitable as carriers for noble metals of Group VIII of the Periodic Table of the Elements are alumina, quartz oxide, magnesium oxide, zirconium oxide and boiling oxide. Preferably, alumina is used. Precious metals of Group VII of the Periodic System of Elements that may be present on the oxide (s) of metals of Groups II, III and IV of the Periodic System of Elements are platinum, palladium, rhodium, ruthenium, iridim, and osmium, of which the preferred metal is platinum. The catalyst may contain two or more noble Group VIII noble metals.

The amount of Group VIII noble metal present in the finished catalyst is preferably in the range of 0.01 to 5%, in particular 0.1 to 1.5%, based on the weight of the finished catalyst. The finished catalyst comprises a yesophobic material in a weight range of preferably 5 to 50% to which a noble Group VII metal is deposited. The precious metals of Group VII are preferably deposited on said oxides by impregnation. The high pressure shaping can be carried out, for example, by table casting or by pulling.

The catalysts produced by the process according to the invention are very suitable for use in the isomeric or paraffin isomeric form of hydrogen. Typically, paraffins which are subjected to a dragon treatment, preferably have 4 to 10, and in particular 4 to 7, carbon atoms in the molecule. Isomerization of the above-mentioned low molecular weight Umornirsi standard paraffins in the presence of hydrogen^bvykle ^peq^ádand ^pat temperatures ranging from 150 to 3⁰⁰ ° C at a pressure in the range of 0.3 to 5 MPa at a rate relative to mooddeH in n -cylol in the range of ^0,5 to 1 ° ^togk^G-,.h · ·^pat a molar ratio of hydrogen to feed of 0.5: 1 to 10: 1. The isomerization is preferably carried out under the following conditions:^tep ^ o ^ a ²3⁰ and²⁸⁰ ° ^ tla^to 1 a^of 4 ^Mpand a гу ^ Нв ^ relationship^ofen^and to wod ^^ íit v · H⁺-cycle 1.0 ^andž · 5.0 k^G.to^G_,.h^_'.

Isomerization of low molar spheroids is a preferred method for upgrading light petroleum fractions, such as overhead fractions, obtained by direct de-distillation. Compared to isopar affine with a wall number of carbon atoms, normal paraffins have a low octane number; their presence in light gasoline fractions. is therefore undesirable. Conversion of the paraffins contained in these fractions into isanes increases the octane number. The isoparaffins also contained in these gasoline fractions can be freeze-dried from them prior to isolation, for example by de-distillation or by means of screening networks. Since these paraffins are equilibrium, the product leaving the isomerization reactor still contains some moos of unconverted paraffins.

These paraffins can be isolated from the isomerization product, for example by Cessillation or by means of molelnival sieves, and recycled to the isomerization process. It is also possible to add the isomerization product to the original mixture of normal paraffins with isoparaffins, to isolate the mixture of isophalanins, for example, SiO2. or by means of a molar eye screen, and isomerizing the blend of normal paraffins according to the method of the invention.

The invention is illustrated by the following example.

Example

For the isomerization experiments described below, five catalysts were prepared as described below.

Caaslysizer 1 g of 20 g of sodium moodant and 200 ml of 1.5 N hydrochloric acid are heated under reflux for one hour. The solid material was then separated, washed with water and refluxed for 1 hour with 200 ml of 1.0 M ammonium nitrate solution. This ammonium nitrate treatment was repeated twice, each time with a fresh ammonium nitrate solution. After each treatment, the solid material was filtered and washed with water. Platinum is then deposited on the ammonium molding thus obtained by treating the ammonium mooroent with an aqueous solution of the platinum compound. The solid was then filtered and dried at 120 ° C. The platinum deposited ammonium monohydrate thus obtained is tabletted at a pressure of 4900 MPa and milled. In this way, fractions with particles having a diameter in the range of 0.2 to 0.6 mm are screened from the ground mill. The fraction obtained by separation is converted into a catalyst¹ 'by ^ofe is tolonized at 5⁰⁰ Deň: 32 ° C.

Catalyst 2

The catalyst is prepared in a substantially steep manner, such as Catalyst 1, except that in this case, the platinum deposited ammonium moodoent is thoroughly mixed with 4: 1 alumina powder, after which it is only subsequently identified.

Catalyst 3

This catalyst is prepared in a substantially similar manner to Catalyst 1, except that 1.5 N k selins are used. hydrochloric acid, to which is added sodium chloride in an amount of 400 g liter.

Catalyst 4

The catalyst is prepared essentially in the same manner as catalyst 3, except that in this case the flame-treated ammonium mooddent is thoroughly mixed in a 4: 1 weight ratio with the same aluminum oxide powder used in the catalyst preparation prior to tabletting. 2.

Catalyst 5

A mixture of alumina and platinum, containing a lithium content of 1.2% per 100 pots of alumina, is prepared by treating the powdered alumina with an aqueous solution of a platinum compound, also used in the preparation of catalysts 2 and 4, respectively. followed by a ^andtlclnovaním ^pmp 500 ° C. Mordedt amoiný, z ^^^ ain jato mmeiprodikt^při vý^Bě Catalyst 3 a ⁴, is dried at this ¹²⁰ ° C and mixed with the mixture^withe uve^dwith a mixture of platinum and aluminum oxide in the ratio 4: 1. The resulting mixture is tabletted at a pressure of 4900 MPa and then ground. A fraction having a particle diameter in the range of 0.2 to 0.6 mm is collected by sieving from the milled material. This sieve-isolated fraction is converted by calcination at 500 ° C into a 5 &amp; quot; catalyst.

Catalyst 6

A mixture of alumina and platinum, containing 0.4% by weight of platinum per 100% by weight of alumina, is prepared by treating an alumina powder, which was also used in the preparation of catalysts 2 to 4, followed by drying and kaleinizing at 500 ° C. The ammonium mordenite obtained as an intermediate in the preparation of catalysts 3 and 4 is dried at 120 ° C and thoroughly mixed with the above-mentioned 1: 1 platinum-aluminum oxide mixture. The resulting mixture is tabletted at a pressure of 4900 MPa and then ground. A fraction having a particle diameter in the range of 0.2 to 0.6 mm is collected by sieving from the milled material. This fraction collected by sieving is converted to a catalyst 6 by calcination at 500 ° C.

Isomerisation Tests • The above five catalysts, all containing platinum by weight

0.3, based on 100% by weight of mordenite in the H * -cycle, is used for the isomerization of n-pentane. Isomerization is performed under the following conditions:

<td>Temperature: Pressure:</td><td>250 ° C 3 MPa</td>

<td>Speed, based on mordenite in H⁺-cycle Molar ratio Hg / at-</td><td>2 kg.kg ^ .h *¹</td>

<td>feedstock Test duration:</td><td>25 hours</td>

<td>The results of these experiments here are the mean between 10 and</td><td>are given in the table. The weight percent of isopentane in the product? 25 »operating hours.</td>

Table

<td>Experiment no.</td><td>Catalyst no.</td><td>Mass amount of isopentane (%) in the product</td>

<td> 1</td><td> 1</td><td> 64,1</td>

<td> 2</td><td> 2</td><td> 64,0</td>

<td> 3</td><td> 3</td><td> 67,3</td>

<td> 4 ,</td><td> 4</td><td> 63,5</td>

<td> 5</td><td> 5</td><td> 66,9</td>

Of Experiments 1-5, only Experiment No. 5 is an isomerization experiment according to the invention. In this experiment, a catalyst prepared according to the process of the invention is used. Other experiments are outside the scope of the invention and are presented here for comparison.

A comparison of the results obtained in Speech 1 to 2 shows that mixing the platinum and mordenite mixture in the H-cycle with alumina as a binder prior to high pressure molding does not affect the behavior of the finished catalyst particles.

A comparison of the results obtained in Experiments 3 and 4 shows that the mordenite behavior in H is improved⁺If the mixture of platinum and mordenite in the H-cycle is mixed with alumina as a binder prior to forming under high pressure, the cycles formed by the addition of sodium ions to the acidic solution are completely lost.

The result of experiment 5 shows that it is poor in the production of the catalyst particles by the process according to the invention^pReading in mordee ^ uv H -cycle ^ ^Eosažen^E jato vtsle^EE^kpři^eá% of sodium ions into the acidic solution is fully preserved in the finished catalyst bases.