DD161193A3 - PROCESS FOR PREPARING CATALYSTS FOR HYDROCARBON CONVERSION - Google Patents

Abstract

The invention relates to a process for the preparation of catalysts for hydrocarbon conversion under reforming conditions. The catalysts consist essentially of alumina and also contain a hydrogenation-dehydrogenating metal component combination consisting of elements of I. to II. Subgroup, the IV. Main group and / or the VI. to VIII. Subgroup, as well as halogen. Preferred components of VII. And VIII. Subgroup are rhenium and platinum. The preparation of the catalysts is carried out by a sol-gel conversion of two-stage peptized alumina hydrogels, whereby the resulting hydrosols are reduced in combination with a part of the activating components in order to ensure an even distribution. Another part of the active components is uniformly impregnated on the moldings.

Description

Field of application of the invention

The invention relates to a process for the preparation of catalysts for hydrocarbon conversion with alumina as the main component, a uniformly distributed over the catalyst molding hydrogenation-dehydner-active Metallkomponentenkombmation and halogen.

Characteristic of the known technical solutions

For the conversion of hydrocarbons of the gasoline boiling range in the presence of hydrogen, catalysts are used which contain a hydrogenation-dehydrogenation-active metal component, preferably platinum at low concentrations, on a porous aluminum oxide. The properties of such catalysts can be determined by a number of additives, for example rhenium, indium, germanium, Tin, lead, titanium, cadmium, etc. are influenced in a favorable manner The catalysts mentioned are in the form of strands (WP C 10g / 199537), hollow strands (DD-WP 121 255) or spheres (DE-OS 2222550, US-PS 3950243) used.

In the preparation of spherical catalysts, the utility properties of the catalysts are often adversely affected by a number of factors of influence, due to the nature and conditions of the preparation of the starting materials. For example, dry alumina hydrogels from precipitation and hydrolysis reactions can only be processed unsatisfactorily to form spherical particles of good quality. In order to achieve a uniform distribution of the active components or of a portion of the active components, a number of processes are known. DE-OS 2013511 recommends to dry a common slurry of hydrated alumina with the addition of platinum and rhenium compounds and process it into a molding. In US Pat. No. 3,827,973 a common precipitation of the active components platinum and lead to an alumina component is proposed. In both cases, the platinum is partially incorporated into the alumina and thus not fully effective. According to US Pat. No. 3,645,660, US Pat. No. 3,745,112 and US Pat. No. 3,790,503, the active components germanium and tin are incorporated into the catalyst by incorporating appropriate compounds in an aluminum hydroxide cholundol as the starting material and then shaping into spherical particles. These processes are characterized by specific requirements for the starting materials which lead to the fact that alumimumoxiahydrogele present in dried form can be processed only insufficiently and these known procedures are therefore only limitedly applicable to the catalyst preparation

Object of the invention

The aim of the invention is a Verranren, in which by technologically simple process steps Reformierka'alysatorsn can be prepared from relatively well crystallized starting products which have a uniform distribution of the dissecting components on the molding cross section

Explanation of the essence of the invention

The object of the crfindurg oestano dar n, which required for the preparation of the catalysts Peotisaticn the Aluminiurroxidhydrogeie so zl, allow that oei the Weiterverarbe'th mechanically strong and hocnporose.ror-rxorcer arise and Glübzitig uniform distribution of the required Aktivkompcnenten without additional Ooerationen, if possible This task was invented by a writer for the preparation of catalysts for water-jet reformulation, ce alumina as the main component, and a non-ferrous metal coreactant como onate oestenend from elements and / or their Veromdungen the V! oisVHI Neoergr ^ pce of the IV main group and / осэ ^г i ois il subgroupoe as well as halogen sources where the requirements for cereals, <atalvsatorencne ~ your <oagulation before mixtures, ie consist essentially of АІитмпіитохісп / arosoien erra cn; wire / orwiece-c: Aiur-in the urrox dnydroceie containing oohmt in this case with зте ^г Sas see 5гі; е cilde ⁿ the acid> n Ѵіоіѵегпзиг s Scu'9 / -vdroge 'from 0 C5 Dis 0 25 ce · 43UrTIe ^{1 -} Oe ^1- S ¹ Jr г em hvdrosol 1 slight discrepancy '_ and V skos did a wash ^ e ^ s'; from SO or SCo'_mgew3-ce't this. · rc сысп Зепапокгс be 323 ois -123. <vcr;"gs<veise at 353 оіь-03 <шге-э о ve-: b> s24n in sin Hvdroscl H" ¹ It wished that Disoersiorsg'ad overrun The ^ vdrosci Il 'one cries into <ог-отзі cn ~ t ^ r ТэіІ = he 2 \: / e'2 ~ da ~ <c ~ core ^ ts'- oes: erend = us Ve'iri-donger, at least one E'emertes sls csr 'os

-2- 215 540

II subgroup of the VI subgroup of the IV main group and / or the VII subgroup in amounts of 0 01 to 10 Ma% with respect to the respective element in the finished catalyst, at Feststorfkonzentrationen of 150 to 700g / l, optionally 150 to 400g / l by means of a coagulation medium mechanically solid particles These are thermally post-treated in a conventional manner at temperatures up to 923 K. Thereafter, the further activating components, in particular from the VII and / or VIII transition group, uniformly applied in a simultaneous or consecutive Impräqnierungsschritt on the moldings and the catalysts thus prepared dried at temperatures up to 473K and optionally calcined at temperatures up to 850K

The proposed method makes no special demands on the used Aluminiumoxidhydrogele, which are preferably Bohmitic nature The proposed two-stage peptization leads to hydrosols of high dispersity due to a strong cross-linking on the one hand mechanically extraordinarily stable catalyst moldings and on the other hand, an intensive interaction between the alumina and the active components uniform distribution of the latter ensured

The combination of the active components with the hydrosols can be carried out both with the hydrosol I and with the hydrosol ¹ or else at another point in the preparation or treatment of the hydrosols. Preferred for this purpose is the use of the hydrosol II to be adjusted solids concentrations of 150 to 700 g / l , optionally 150 to 400 g / l, are particularly advantageous

As a result of the high degree of crosslinking with other substances, for example alumina hydrogels and / or aluminum oxides, the hydrosol may be mixed without adversely affecting the catalyst preparation. Thus, the bulk density and porosity of the catalyst to be prepared can be modified within wide limits. For the peptization of the hydrogels, nitric acid Hydrohalic acids or carboxylic acids are preferably used. As coagulants, ammonia water is generally used

The active components used for the combination with the hydrosols are preferably used in the form of water-soluble or acid-soluble compounds. The use of finely ground oxidic materials which are less soluble is likewise possible

For applying the active components to the shaped material, in particular from VII and / or VIII subgroup advantageously water-soluble compounds of the elements are used, which are preferably impregnated from a common solution The solution quantity may correspond to the capacity of the catalyst moldings, but preferably at least two times greater Solution amount applied

The erfmdungsgemaß prepared catalysts have advantageous properties for the conversion of hydrocarbons under reforming conditions

The invention will be explained in more detail using an exemplary embodiment

exemplary

A solution of aluminum nitrate (about 100 g Al ₂ O ₃ ZI, about 25 g HNO ₃ / I) was precipitated using ammonia water at a pH of 3 3 and a temperature of 343 K to form an alumina hydrogel. The suspension was filtered on a filter press and the filter cake was washed with distilled water The resulting filter cake contained 23.5% by weight Al ₂ O ₃ 10 kg of the moist filter cake were transferred to the hydrosol I in a mixing vessel with the addition of 0.1851 50% nitric acid at room temperature The molar ratio HNO ₃ to Al ₂ O ₃ amounts to 0.1 Em part of the hydrosol I prepared was converted by five hours of stirring at 375 K in the hydrosol Il, which was then cooled to room temperature

3 kg of hydrosol I and 2 kg of hydrosol II were intimately mixed with each other. 115 ml of an ethanolic solution of germanium tetrachloride having a concentration corresponding to 50 g of Ge / I were incorporated in this mixture. The molding compound thus prepared was passed through nozzle-like outlets at the bottom of a cylindrical container in ammonia water After separation from the aqueous phase, the spherical particles dried at about 380K and subsequently calcined at about 800K. The calcined shaped articles were soaked with an aqueous solution containing hexachloroplatric acid, perrhenic acid and hydrochloric acid for 5 hours, the Moldings were constantly covered by the solution The excess solution was removed after this time, the impregnated moldings dried at about 380K and 3 hours calcined at 770K They had the following composition

0 35 ³ OP ^ Hn 0 35% rhenium 0 5 ° o germanium, 1.3% chlorine

In a catalytic hydrocarbon reforming test, the catalyst prepared had advantageous properties

Claims (2)

215 540 claims for invention A process for the preparation of catalysts for hydrocarbon conversion, the alumina as the main component, a hydrogenation-dehydrogenating metal component combination consisting of elements and / or their compounds of Vl to VIII transition group, IV main group and / or derl to II subgroup, and halogen, wherein the formation of the catalyst particles is achieved by coagulation of mixtures consisting essentially of alumina hydrosols, characterized in that predominantly boehmite-containing alumina hydrogels having a basic salt-forming acid in acid / hydrogel molar ratio of 0.05 to 0.25 at room temperature converts a hydrosol I low dispersity and viscosity with a water content of 60 to 90%, the hydrosol I by treatment at 323 to 423 K, preferably at 353 to 403 K, within 0.1 to 24 hours in a hydrosol II with the desired degree of dispersion , the hydrosol II in combination with zumin at least a portion of the activating components, consisting of compounds of at least one element from the I to II subgroup, the Vl subgroup, the IV main group and / or the VII subgroup, in amounts of 0.61 to 10% by mass with respect to the respective element in the finished Catalyst forms at solid concentrations of 150 to 700g / l by means of a coagulation medium to mechanically solid particles, this thermally post-treated in a conventional manner at temperatures up to 923 K, further activating components, in particular from the VII and / or VIII transition group in a simultaneous or Konsekutiven impregnation on the molds evenly applied and the catalysts thus prepared at temperatures up to 473K and optionally calcined at temperatures up to 850K 2 A method according to item 1, characterized in that the catalysts metals of the VIII subgroup of the Periodic Table, preferably platinum, or the VIII, and VII subgroup, preferably platinum and rhenium, in amounts of 0.01 to 1.5Ma -% and halogen , preferably chlorine, in amounts of from 0.2 to 3% by mass and also metals and / or compounds thereof from the IV main group, the Vl subgroup and / or the I to II subgroups in amounts of from 0.01 to 5% by mass, based on the respective element included.