EP1509583B1 - Microcrystalline paraffin, method for producing microcrystalline paraffins - Google Patents

Description

The invention first relates to a microcrystalline paraffin. In addition, a method for producing a microcrystalline paraffin.

Conventional petroleum derived microcrystalline paraffin (also known as microwaxes) consists of a mixture of saturated room temperature solid hydrocarbons having a chain length distribution of C ₂₅ to C ₈₀ . In addition to n-alkanes, the microcrystalline paraffins contain branched isoalkanes and alkyl-substituted cycloalkanes (naphthenes) as well as - albeit usually small - proportions of aromatics. The content of iso-alkanes and naphthenes ranges between 40 and 70% as determined by the EWF Standard Test Method for Analysis of Hydrocarbon Wax by Gas Chromatography. The quantitative dominance of isoalkanes (and naphthenes) determines their microcrystalline structure.

The solidification range is between 50 and 100 ° C according to DIN ISO 2207. The needle penetration has values between 2 x 10 ^-1 and 160 x 10 ^-1 mm according to DIN 51579. The solidification point and the needle penetration are used to distinguish between the microcrystalline paraffins between plastic and hard microcrystalline paraffins. Soft plastic microcrystalline paraffins (so-called petrolatum) are fast with pronounced adhesiveness and have solidification points of 65 to 70 ° C and penetration values of 45 to 160 x 10 ^-1 mm. The oil contents are between 1 and 15%. Plastic microcrystalline paraffins are readily malleable and kneadable and have solidification points between 65 and 80 ° C and penetration values of 10 to 30 x 10 ^-1 mm. The oil contents can be up to 5%. The hard microcrystalline paraffins are tough and slightly adhesive with freezing points from 80 to 95 ° C and penetration values 2 to 15 x 10 ^-1 mm. The oil contents amount to a maximum of 2% (see Ullmann's Encyclopedia of Industrial Chemistry, VCH Verlagsgesellschaft 1996 ).

Microcrystalline paraffins have a high molecular weight and thus high boiling points. They are so far from the residues of vacuum distillation of petroleum and from precipitates of petroleum in its storage (bottom residue, residue wax) won, in technologically very complex and costly process with multiple stages, for example deasphalting, solvent extraction, dewaxing, de-oiling and refining. The de-oiled microcrystalline paraffins contain sulfur, nitrogen and oxygen compounds as impurities. They are therefore not completely odorless and have a dark yellow to dark brown color. The refining required therefore takes place depending on the later use by bleaching (technical applications) or by hydrorefining (applications in the food and pharmaceutical industries).

Microcrystalline paraffins are mainly used as a mixture component in paraffin or wax mixtures. The use is usually in areas up to 5%. In particular, the hardness and melting point of these mixtures should be increased and flexibility and oil-binding improved. Typical applications include, for example, the manufacture of waxes for impregnation, coating and laminating for the packaging and textile industries, heat seal and hot melt adhesives, and pharmaceutical and cosmetic products, including chewing gum. Furthermore, they are used in potting and cable compounds as well as plastics in general but also in the candle, rubber and tire industries as well as in care, anti-slip and anti-corrosion agents.

From the WO01 / 74971 It is known to gently isomerize a Fischer-Tropsch product with a wide boiling range, which also contains liquid product components, and to recover a wax from the liquid hydroisomerate by distilling off the lighter fractions. The hydrogenation temperature is given in a range of 204 to 343 (but example: 348) ° C, the lower, not even exemplified temperature range, in terms of feasibility appears questionable. With the wax thus obtained, the high-boiling components of the starting product are blinded. The catalyst typically mentioned is a cobalt-molybdenum catalyst on alumino-silicate. Suitable zeolites are zeolite Y or ultrastable zeolite Y. Unfavorable in this proposal appears that one must use an additional process step, distillation, which makes the production of the soft microcrystalline wax more expensive.

From the DE 69 418 388 T2 is a hydroisomerization of n-type paraffins solid at room temperature with more than 15 carbon atoms using a catalyst based on a Group VIII metal, in particular platinum, and a beta zeolite structurally similar boron silicate to liquid products described in the Production of lubricating oils are suitable.

In the DE 695 15 959 T2 describes the hydroisomerization of waxy feedstocks into liquid products suitable for the production of lubricating oils. In this case, a temperature of 270 ° to 360 ° C and a pressure of 500 to 1500 psi or 3.44 MPa to 10.36 MPa applied. The hydrogen is fed to the reactor at a rate of 1,000 to 10,000 SCF / bbl and the wax at 0.1 to 10 LHSV. The catalyst is based on a metal component on a porous, heat-resistant metal oxide support, in particular on 0.1 to 5 wt .-% of platinum on alumina or zeolites, such as Offretit, zeolite X, zeolite Y, ZSM -5, ZSM- 2 etc.

The feed to be isomerized may be any wax or waxy material, such as slack waxes or Fischer-Tropsch wax. The isomerization product is liquid and the starting material for the production of lubricating oil components.

Starting from the cited prior art, the object of the invention is to provide a novel microcrystalline paraffin and a process for the production of microcrystalline paraffin.

This object is solved by the subject matter of claim 1 or claim 5. It should be noted that the microcrystalline paraffin, preparable by catalytic hydroisomerization at temperatures above 200 ° C, from FT paraffins with a C chain length distribution in the range of 20 to 105, using a catalyst based on a beta zeolite, with a pore size between 0.5 and 0.8 nm, wherein the catalyst further comprises a hydrogenation metal of VIII. Subgroup of the Periodic Table and the content of the hydrogenation metal is 0.1 to 2 MA .-%. The microcrystalline paraffin produced is not liquid at 25 ° C, but at least pasty to solid with a needle penetration of less than 100 x 10 ^-1 , measured according to DIN 51579. Compared to the natural micro waxes such a microcrystalline paraffin is free of naphthenes and aromatics. Despite isomerization, crystallinity has been preserved. Continuous production with defined properties is possible. The production is possible even in one process step. There is provided a microwax product in the low and high solidification point range. Continuous or discontinuous catalytic hydroisomerization of FT paraffins can be carried out. With regard to FT paraffins as such, particular reference is made to the statements made by A. Kühnle in Fette. Soap. Paint, Volume 84, pages 156 ff. "Fischer-Tropsch waxes Synthesis, Structure, Properties and Applications "Briefly, the FT paraffins are paraffins prepared by the Fischer-Tropsch process in a known way from synthesis gas (CO and H2) in the presence of a catalyst at elevated temperature ,

A process for softening Fischer-Tropsch wax is disclosed in U.S. Pat WO-A-0 174 969 described.

They represent the highest-boiling fraction of the hydrocarbon mixture. The result is essentially long-chain, less branched alkanes, which are free of naphthenes and aromatics and of oxygen and sulfur compounds.

Such FT paraffins with a high proportion of n-paraffins and a C chain length in the range of C ₂₀ to C ₁₀₅ are converted by the method described here to high-melting, microcrystalline paraffins with a high proportion of iso-paraffins.

1. A. Einsatz von FT-Paraffin als Ausgangsmaterial
   1. a) mit einer C-Kettenlänge im Bereich von C₂₀ bis C₁₀₅,
   2. b) vorzugsweise mit einem Erstarrungspunkt im Bereich von 70 bis 105°C, insbesondere ca. 70, 80, 95 oder 105 ° C nach DIN ISO 2207,
   3. c) einer Penetration bei 25° C von 1 bis 15;
   4. d) einem Verhältnis von iso- zu n-Alkanen von 1 : 5 bis 1 : 11
2. B. Verwendung eines Katalysators, vorzugsweise in Form von Extrudaten, Kugeln, Tabletten, Granulaten oder Pulvern, zweckmäßigerweise auf der Basis von
   1. a) 0,1 bis 2,0, insbesondere 0,4 bis 1,0 MA.-%, bezogen auf den bei 800°C geglühten Katalysator, an hydrierendem Metall der achten Nebengruppe, insbesondere Platin, sowie
   2. b) eines Trägermaterials aus einem Zeolithen vom Typ Beta bis 60 bis 95 Masse%, bezogen auf die bei 800°C geglühte Kombination aller Komponenten,
3. C. Anwendung einer Prozess-Temperatur von mehr als 200, insbesondere von 220 bis 270°C,
4. D. Anwendung eines Drucks von 0,5 bis 20,0, vorzugsweise 2 bis 18, insbesondere von ca. 3 bis 8 MPa in Gegenwart von Wasserstoff und einem Verhältnis von Wasserstoff zu FT-Paraffin von 100 : 1 bis 2000 : 1, insbesondere etwa 250 : 1 bis 600 : 1 Nm³/m³.
5. E. E Einer Katalysatorbelastung mit FT-Paraffin im Bereich von 0,1 bis 2,0, insbesondere mit 0,2 bis 0,8 v/v. h (Volumen FT-Paraffin pro Volumen des Katalysators innerhalb einer Stunde).

The microcrystalline paraffin can be prepared by catalytic isomerization according to the process aspect of the invention as follows:

1. A. Use of FT paraffin as starting material
   1. a) having a C chain length in the range of C ₂₀ to C ₁₀₅ ,
   2. b) preferably with a solidification point in the range of 70 to 105 ° C, in particular about 70, 80, 95 or 105 ° C according to DIN ISO 2207,
   3. c) a penetration at 25 ° C from 1 to 15;
   4. d) a ratio of iso to n-alkanes of 1: 5 to 1: 11
2. B. Use of a catalyst, preferably in the form of extrudates, spheres, tablets, granules or powders, advantageously based on
   1. a) 0.1 to 2.0, in particular 0.4 to 1.0 MA .-%, based on the annealed at 800 ° C catalyst, to hydrogenating metal of the eighth subgroup, in particular platinum, and
   2. b) a support material of a zeolite beta type to 60 to 95 mass%, based on the annealed at 800 ° C combination of all components,
3. C. application of a process temperature of more than 200, in particular 220 to 270 ° C,
4. D. Application of a pressure of 0.5 to 20.0, preferably 2 to 18, in particular from about 3 to 8 MPa in the presence of hydrogen and a ratio of hydrogen to FT paraffin of 100: 1 to 2000: 1, in particular about 250: 1 to 600: 1 Nm ³ / m ³ .
5. E. E Catalyst loading with FT paraffin in the range of 0.1 to 2.0, especially 0.2 to 0.8 v / v. h (volume of FT paraffin per volume of catalyst within one hour).

In general, the catalyst fills the reactor volume almost completely, so that instead of catalyst volume can also be spoken of reactor volume.

The yield of each solid hydroisomerates is> 90%, in many cases between 90 and 96% by mass, based on the particular FT paraffin used. The hydroisomerates obtained with respect to low-melting alkanes still alkanes in C chain length range <= C ₂₂ up to 5% (usually 2 to 3%). These alkanes can be easily separated by stripping with steam under vacuum.

A catalyst is used which can selectively convert solid Fischer-Tropsch paraffin into microcrystalline paraffins in a single process step.

• 60 bis 95 Masse-% Zeolith vom Typ Beta, bezogen auf die bei 800°C geglühte Kombination aller Komponenten,
• 5 bis 39,8 Masse-% eines oberflächenreichen gamma-Aluminiumoxids, berechnet als Al₂O₃ und bezogen auf die bei 800° geglühte Kombination aller Komponenten,
• und ein oder mehrere Metalle der 8. Nebengruppe des Periodensystems der Elemente (PSE), insbesondere Platin, in Mengen von 0,2 bis 2,0 Masse-%, bezogen auf die bei 800°C geglühte Kombination aller Komponenten,

auf, vorzugsweise besteht er aus dieser, wobei das eine Metall oder die mehreren Metalle der 8. Nebengruppe des PSE, insbesondere Platin, mit dem Aluminiumoxid verbunden ist.The catalyst has a combination of

• 60 to 95% by mass of beta-type zeolite, based on the combination of all components annealed at 800 ° C.,
• 5 to 39.8 mass% of a surface-rich gamma-alumina, calculated as Al ₂ O ₃ and based on the combination of all components annealed at 800 °,
• and one or more metals of subgroup 8 of the Periodic Table of the Elements (PSE), in particular platinum, in amounts of from 0.2 to 2.0% by weight, based on the combination of all components, which is calcined at 800 ° C.

on, it preferably consists of this, wherein the one metal or the plurality of metals of the 8th subgroup of the PSE, in particular platinum, is connected to the alumina.

• 75 bis 90 Masse-% Zeolith vom Typ Beta, bezogen auf die bei 800°C geglühte Kombination aller Komponenten,
• 10 bis 25 Masse-% eines oberflächenreichen gamma-Aluminiumoxids, berechnet als Al₂O₃, und bezogen auf die bei 800° geglühte Kombination aller Komponenten,
  und ein oder mehrere Metalle der 8. Nebengruppe des Periodensytems der Elemente (PSE), insbesondere Platin in Mengen von 0,4 bis 1,0 Masse-%, bezogen auf die bei 800°C geglühte Kombination aller Komponenten,

wobei das eine oder die mehreren Metalle der 8. Nebengruppe des Periodensystems des PSE, insbesondere Platin, mit dem Aluminiumoxid verbunden ist. Der Katalysator besteht bevorzugt aus diesen vorgenannten Komponenten in den vorgenannten Masse-Verhältnissen.A preferred catalyst composition for the preparation of microcrystalline paraffins from Fischer-Tropsch paraffins, especially having C numbers of about 20 to 105

• 75 to 90% by mass of beta-type zeolite, based on the combination of all components annealed at 800 ° C,
• 10 to 25% by mass of a surface-rich gamma-alumina, calculated as Al ₂ O ₃ , and based on the combination of all components annealed at 800 °,
  and one or more metals of subgroup 8 of the Periodic Table of the Elements (PSE), in particular platinum in amounts of from 0.4 to 1.0% by weight, based on the combination of all components, which is calcined at 800 ° C.,

wherein the one or more metals of the 8th subgroup of the periodic table of the PSE, in particular platinum, is bonded to the aluminum oxide. The catalyst preferably consists of these abovementioned components in the abovementioned mass ratios.

The surface-rich gamma-alumina has a specific surface area of 15-350 m ² / g, based on γ-Al ₂ O ₃ .

The calcined at 800 ° C combination of all catalyst components is free of water and ammonium.

• mit einem SiO₂:Al₂O₃-Molverhältnis von 19, 3:1 bis 100:1
• und einem Restalkaligehalt von max. 0,05 Masse-% (bezogen auf bei 800°C kalzinierten Zeolith)

mit 5 bis 39,8 Masse-%, insbesondere 10 bis 25 Masse-%, bezogen auf die bei 800°C geglühte Kombination aller Komponenten eines, vorzugsweise pulverförmigen, gamma-Aluminiumoxidvorläufers, insbesondere einem Aluminiumhydroxid, vorzugsweise Böhmit oder Pseudoböhmit, vermischt wird, die Mischung unter Zugabe von Wasser und Säure als Peptisationsmittel verknetet, extrudiert, bei Temperaturen von 80°C bis 200°C, insbesondere 100°C bis 200°C geglüht wird, und die erhaltenen Formlinge mit einer Verbindung eines Metalls oder mehrerer Metalle der 8. Nebengruppe des PSE, insbesondere Platin, in der das Edelmetall in anionischer Form enthalten ist, imprägniert und anschließend an der Luft thermisch nachbehandelt, insbesondere getrocknet und geglüht, werden, so dass 0,2 bis 2 Masse-% Edelmetall, bezogen auf die bei 800°C geglühte Kombination, enthalten sind, und das oder die Metalle der 8. Nebengruppe des PSE, insbesondere Platin, mittels durchströmenden Wasserstoff bei erhöhter Temperatur zum Metall reduziert wird.The catalyst is preferably prepared by adding 60 to 95% by weight, in particular 75 to 90% by weight, based on the combination of all components calcined at 800 ° C., preferably powdered zeolite of the beta type (BEA-type according to US Pat HH Olson & Ch. Bärlocher: Atlas aof zeolite structure types, Fourth ed., Elsevier London, Boston, Singapore, Sidney, Toronto, Wellington 1996 )

• with a SiO ₂ : Al ₂ O ₃ molar ratio of 19, 3: 1 to 100: 1
• and a residual alkali content of max. 0.05 mass% (based on calcined at 800 ° C zeolite)

with 5 to 39.8% by mass, in particular 10 to 25% by mass, based on the combination of all components of a preferably pulverulent gamma-alumina precursor, in particular an aluminum hydroxide, preferably boehmite or pseudo-boehmite, annealed at 800 ° C., the mixture is kneaded with the addition of water and acid as a peptizer, extruded, annealed at temperatures of 80 ° C to 200 ° C, in particular 100 ° C to 200 ° C, and the resulting moldings with a compound of one or more metals of the 8 Subgroup of PSE, in particular platinum, in which the noble metal is contained in anionic form, impregnated and then thermally treated in the air, in particular dried and calcined, so that 0.2 to 2 mass% of noble metal, based on at 800 ° C annealed combination, are included, and the or the metals of the 8th subgroup of the PSE, in particular platinum, by means of flowing hydrogen at elevated Temperature is reduced to the metal.

In this way, catalyst moldings are obtained, which can be used in a heterogeneous process, wherein the catalyst is preferably used as a fixed bed, and the liquefied wax together with hydrogen at temperatures between preferably 200 and 270 ° C in trickle phase over it. This combination of catalysts achieves such high isomerization activity that a Fischer-Tropsch paraffin solid at normal ambient temperature can be used directly to obtain a microcrystalline wax in a single step. The properties of the microcrystalline wax can even be varied to a limited extent by choosing suitable reaction parameters.

Beta zeolite is a commercially available product. It is preferably used as a crystalline aluminosilicate powder in a composition Na _n [Al _n Si _64-n O ₁₂₈ ] with n <7 according to the invention. In place of aluminum can also Boron or gallium isomorphously entering the spatial silicate structure. As a result of its high content of SiO ₂ can also expose it to an acid medium, without losing its crystalline structure, wherein a portion of the aluminum tetrahedra may be removed from the crystalline lattice. The beta zeolite is preferably used as a fine powder having a particle size of in particular 0.5 to about 200 microns, as measured by laser particle size analyzer. The zeolite has pores with diameters of about 0.5 to 0.8 nm. The structural 12-ring openings have a width of 0.55 nm in [001] direction and a width of 0.64 and 0, respectively, 76 nm in the [100] direction of the crystal lattice. As a result of this expansion of the apertures, the long, normally paraffinic paraffins are apparently capable of entering, at least in part, the internal structure of the zeolite with its acidic centers.

In order for the catalyst to be particularly capable of isomerization, any alkali cations still present after the synthesis can be exchanged as quantitatively as possible by protons. The replacement of the alkali cations by protons is carried out according to methods known per se, for example by exchange with water-soluble ammonium salts and subsequent calcination at 500 ° C. The introduction of protons can also be carried out directly with dilute acids. After calcination, the zeolites are present in the carbonyl ion reactions active Brönstedt and Lewis acids form (acidic centers).

In the preparation of the catalyst, the zeolite in a preferred embodiment, in particular as a powder with a γ-aluminum oxide A100H, which serves as a binder for the zeolite and as a carrier for a hydra-metal component, or contains these in substantial proportions. Both powders are combined together and simultaneously or thereafter dilute acid, for example mineral acid, preferably nitric acid, or organic Acid, such as formic acid or acetic acid, as Peötisationsmittel and added so much water that during the intensive processing of the mass by kneading, a plasticizable, moldable mass is formed. In order to increase plasticity, in a preferred embodiment, plasticizers, in particular organic auxiliaries, for example water-soluble cellulose ethers, are added in small amounts of up to about 5% by weight, based on the powder substances. This mass is extruded, for example, by means of a screw extruder through dies, through which moldings are produced in strand form with an optional diameter and profile. The extrudates are then at temperatures of 80 ° C to 200 ° C, in particular 100 ° C to 200 ° C, dried, optionally still broken to a certain length, and in a further step thermally at temperatures of about 400 ° C to 600 ° C treated, in particular calcined, so that all or substantially all organic components, water and optionally present nitrate and ammonium ions escape from the moldings.

The alumina precursor is calcined at temperatures above about 350 ° C. in gamma-alumina over a specific surface of 150 to 350m ² / g, based on Al ₂ O ₃ , and a pore volume of 0.3 to about 1.0 cm ³ / g, based on Al ₂ O ₃ possesses , The pores of the alumina preferably have diameters of 3 to 59 nm, by which the alumina is capable of taking up large molecules and transporting them to the zeolite crystals.

The calcined shaped articles are impregnated with a solution containing the compound of the metal or the metals of the 8th subgroup of the PSE, in particular of the platinum. Particularly suitable for this purpose are H ₂ [PtCl ₆ ] and H ₂ [PdCl ₄ ]. But other suitable compounds containing the noble metals in anionic form may also be used. The compounds of precious metals are advantageously used in a preferred embodiment in aqueous solution. Advantageously, the concentration of noble metals in the solution is adjusted so that their desired final concentration in the catalyst is adjusted after receiving the solution according to simple pore filling of the moldings with the solution.

After impregnation of the moldings with the solution of the noble metal-containing compounds, the moldings are preferably dried in a device to remove water. Subsequently, the moldings are annealed, in a dry air stream with removal of the liberated volatile compounds in the exhaust gas. If necessary, the resulting nitrous gases are to be destroyed.

The precious metals are then present in fine distribution as metal oxy, in particular Platinoyverbindungen, while the zeolite crystals themselves contain no hydrogenation metal component. The catalyst is reduced prior to startup in the hydrogen-containing gas stream, in particular heated to temperatures of 100 to 480 ° C, to deposit the noble metal in finely divided metallic form on the alumina. The metal agglomerates are advantageously and in a preferred embodiment of the invention then present in such a form that at least 30% and at most about 70% of all metal atoms are capable of adsorbing a CO molecule.

The metal components act as hydrogenation-effective portions of the catalyst capable of activating the long-chain paraffins to carbonium ions. The latter react at the acidic centers in the catalyst with displacement of CH ₃ groups on the long chains. From the zeolitic pore openings occur after conversion primarily in 2-, 3-, 4- and / or 5-beta zeolite is a commercially available product. It is preferably used as a crystalline aluminosilicate powder in a composition Nan [AlnSi _64-n O ₁₂₈ ] with n <7 according to the invention. Instead of aluminum, boron or gallium can also enter the spatial silicate structure isomorphically. Due to its high content of SiO ₂ , it can also be exposed to an acidic environment without losing its crystalline structure, whereby part of the aluminum tetrahedra can be removed from the crystalline lattice. The beta zeolite is preferably used as a fine powder having a particle size of in particular 0.5 to about 200 microns, as measured by laser particle size analyzer. The zeolite has pores with diameters of about 0.5 to 0.8 nm. The structural 12-ring openings have a width of 0.55 nm in [001] direction and a width of 0.64 and 0, respectively, 76 nm in the [100] direction of the crystal lattice. As a result of this expansion of the apertures, the long, normally paraffinic paraffins are apparently capable of entering, at least in part, the internal structure of the zeolite with its acidic centers.

In order for the catalyst to be particularly capable of isomerization, any alkali cations still present after the synthesis can be exchanged as quantitatively as possible by protons. The exchange of the alkali metal ions by protons is carried out according to methods known per se, for example by exchange with water-soluble ammonium salts and subsequent calcination at 500 ° C. The introduction of protons can also be carried out directly with dilute acids. After calcination, the zeolites are present in the carbonyl reactions active Brönstedt or respectively Lewis acids form (acidic centers).

In the preparation of the catalyst, the zeolite in a preferred embodiment, in particular as a powder with a γ-aluminum oxide A100H, which at the same time as a binder for the zeolite and as a carrier for a hydro-metallic component serves, or contains these in substantial proportions. Both powders are combined, and simultaneously or thereafter, dilute acid, for example, mineral acid, preferably nitric acid, or organic acid, such as formic acid or acetic acid, is added as a peptizer and enough water to form, by plasticizing, a plasticizable, plasticized material Mass arises. In order to increase plasticity, in a preferred embodiment, plasticizers, in particular organic auxiliaries, for example water-soluble cellulose ethers, are added in small amounts of up to about 5% by weight, based on the powder substances. This mass is extruded, for example, by means of a screw extruder through dies, through which moldings are produced in strand form with an optional diameter and profile. The extrudates are then at temperatures of 80 ° C to 200 ° C, in particular 100 ° C to 200 ° C, dried, optionally still broken to a certain length, and in a further step thermally at temperatures of about 400 ° C to 600 ° C treated, in particular calcined, so that all or substantially all organic components, water and optionally present nitrate and ammonium ions escape from the moldings.

The alumina precursor is calcined at temperatures above about 350 ° C. in gamma-alumina over a specific surface of 150 to 350m ² / g, based on Al ₂ O ₃ , and a pore volume of 0.3 to about 1.0 cm ³ / g, based on Al ₂ O ₃ possesses , The pores of the alumina preferably have diameters of 3 to 59 nm, by which the alumina is capable of taking up large molecules and transporting them to the zeolite crystals.

The calcined shaped articles are mixed with a solution, the compound of the metal or of the metals of the 8th subgroup of the PSE, in particular of the platinum, contains, impregnated. Particularly suitable for this purpose are H ₂ [PtCl ₆ ] and H ₂ [PdCl ₄ ]. But other suitable compounds containing the noble metals in anionic form may also be used. The compound of the noble metals are advantageously used in a preferred embodiment in aqueous solution. Advantageously, the concentration of noble metals in the solution is adjusted so that their desired final concentration in the catalyst is adjusted after receiving the solution according to simple pore filling of the moldings with the solution.

After impregnation of the moldings with the solution of the noble metal-containing compounds, the moldings are preferably dried in a device to remove water. Subsequently, the moldings are annealed, in a dry air stream with removal of the liberated volatile compounds in the exhaust gas. If necessary, the resulting nitrous gases are to be destroyed.

The precious metals are then present in fine distribution as metal oxy, in particular Platinoyverbindungen, while the zeolite crystals themselves contain no hydrogenation metal component. The catalyst is reduced prior to startup in the hydrogen-containing gas stream, in particular heated to temperatures of 100 to 480 ° C, to deposit the noble metal in finely divided metallic form on the alumina. The metal agglomerates are advantageously and in a preferred embodiment of the invention then present in such a form that at least 30% and at most about 70% of all metal seeds are capable of adsorbing a CO molecule.

The metal components act as hydrogenation-effective portions of the catalyst capable of activating the long-chain paraffins to carbonium ions. The latter react at the acidic centers in the catalyst under displacement of CH ₃ groups on the long chains. From the zeolitic pore openings, simple methyl-group-branched paraffins emerge after conversion primarily to the 2, 3, 4 and / or 5 position on the C chain. The catalyst can be used, for example, in the form of extrudates, cylinders, granules, spheres, tablets or powders.

The catalyst can preferably be used in the presence of hydrogen at an H ₂ partial pressure of from 5 to 180 bar.

More preferably, the catalyst can be used at a H ₂ : feed ratio of 100: 1 to 2000: 1 Nm ³ / m ³ feed.

More preferably, the catalyst may be used at a loading of 0.1 to 1 volume feed / volume of catalyst per hour.

More preferably, the catalyst can be used at a temperature of 200 ° to 270 °.

The catalyst may be further suspended in the form of small particles suspended in the feed at temperatures of preferably 200 ° C to 270 ° C and elevated pressure in the presence of hydrogen to convert Fischer-Tropsch paraffin to microcrystalline wax. Optionally occurring slight fractions can be aborted by means of steam distillation (stripping).

Advantageously, the catalyst is incorporated as a fixed bed in a reactor through which the feed can flow slowly together with hydrogen at temperatures of preferably 200 ° C to 270 ° C. The catalyst can be used in a continuous, semi-continuous or batchwise procedure.

The catalyst will be explained in more detail with reference to the following example.

example Preparation of a catalyst

300 g of commercially available zeolite beta with a SiO ₂ : Al ₂ O ₃ molar ratio of 23.3 in the metal cation-free form (alkali contains less than 0.05% by mass based on 800 ° C calcined zeolite) as a powder having a particle size of 0 , 5 to about 50 μm, 62.8 g of commercially available alumina hydroxide as a fine powder and 8.4 g of water-soluble cellulose ether are intimately mixed. Then 30 ml of dilute nitric acid with 128 g of HNO ₃ / l and 350 ml of deionized water are added and kneaded intensively for one hour. The result is a malleable, kneadable mass. This mass thus obtained is pressed by means of a screw extruder through nozzles with cylindrical openings of 1.5 mm diameter, so that strand-shaped extrudates arise. These are dried for six hours in a drying cabinet at 120 ° C. The moldings are crushed to a length of 3-5 mm and calcined at 550 ° C on a sheet in a thin layer in an electric muffle furnace with a slight passage of air for three hours. There are obtained solid moldings with a bulk density of 400g / l.

From the moldings, the ingestible amount of water is determined at room temperature, which corresponds to the pore volume (= 110% based on the catalyst mass). A solution of 1.636 g of H ₂ PcCl ₆ in 242 ml of water is sprayed onto 220 g of the moldings with agitation. After a contact time of 10 minutes, the moldings are dried with agitation until the bulk of liquid has evaporated and the individual moldings are not stick more together. Thereafter, the impregnated moldings are dried at 120 ° C in a drying oven in air. The dried moldings are heated in a vertical oven at 100 ° C / h to 450 ° C in the stream of dry air and held at 450 ° C for one hour.

Subsequently, the moldings are cooled in the oven to ambient temperature, the air flow is replaced by pure nitrogen until the oxygen content in the outflowing gas is less than 0.5 vol .-% and then switched from nitrogen to hydrogen. The furnace is again heated at 100 ° C / h to 450 ° C, and the catalyst is treated for three hours at this temperature in the flowing hydrogen, that is reduced. Thereafter, the catalyst is allowed to cool in a nitrogen stream and can be removed. The resulting catalyst A according to the invention is stable in air. The platinum content is 0.8% by weight, based on the combination of all components annealed at 800 °.

Catalytic test

The catalyst A prepared above was comminuted to a particle size of 160 to 315 μm and 4 g of this comminuted catalyst were stirred into 180 g of a Fischer-Tropsch-prefin ("feed") at a temperature of 120 ° C. The mixture was poured into an autoclave. After completion of the autoclave, a hydrogen pressure of 50 bar was pressed and with stirring, the mixture was heated to 250 ° C and further treated with stirring for seven hours. Thereafter, the autoclave was again cooled to 120 ° C, and the product was taken out of the autoclave, the catalyst was separated and examined. The product characteristics were compared with those of the feed (see table). Table: Characteristics of the feed and the hydroisomerate feed hydroisomerizate C number (> 90%) 30 to 100 about 25 to 100 Freezing point in ° C 97 86.5 Enthalpy of fusion ΔH > 200 125 Penetration at 25 ° C 1-2 42 Viscosity at 120 ° C in cSt -12 15.4 Isomerate part in mass% ~12 47 <C 22 in% by weight 0 2-3

The hydroisomerizate clearly shows different properties from the starting material, which correspond to a microcrystalline wax. The proportion of I-paraffins is significantly increased compared to the feed.

Preferably, the catalytic hydroisomerization of the FT paraffins is carried out continuously in a flow-through reactor with a fixed catalyst, in particular in the form of extrudates, spheres or tablets, the reactor, when it is, as preferred, oriented vertically both from top to bottom and from bottom to top can be flowed through. However, the process can also be carried out batchwise or semi-continuously in, for example, a stirred autoclave in a batch process, the catalyst being contained in a permeable network or being finely divided is used as granules or powder in FT paraffin. The process parameters of the continuous as well as the discontinuous process are the same.

The solid microcrystalline paraffins obtained according to the invention have the following properties:

Compared with the FT paraffins used, they have somewhat lower solidification points and, in addition to n-alkanes, contain a high, in particular higher, weight fraction of iso compared to or as to n-alkanes. The proportion of n- or iso-alkanes is determined by gas chromatography. The increased degree of isomerization achieved by the hydroisomerization finds expression in increased penetration values, a reduced degree of crystallization and a reduced enthalpy of fusion. The products were firm, white, pak and sticky in consistency. The strength was in any case given at ambient temperature (20 ° C).

The degree of crystallinity is determined by an X-ray diffraction analysis. It denotes the crystalline content in the product obtained relative to the amorphous content. The amorphous portions lead to a different diffraction of the X-rays than the crystalline portions. The needle penetration at 25 ° C in the products of the invention is in the range of 20 to 100, measured according to DIN 51579.

The crystalline fraction is reduced in particular as follows: While the starting material, a crystalline content in a range of 60 to 75% occurs, is observed in the hydroisomerizate such from 30 to 45%. Especially in the range of 35 to 40%. This crystalline fraction then lies midway between the petroleum-based microcrystalline paraffin and that of the starting product, the FT paraffins. the crystalline proportion of these synthetic microparaffins accordingly also closes a gap in the performance properties of such products. For the physical and material properties of such products are usually an expression of crystallinity.

The crystalline fractions and the amorphous fractions are indicated by the aforementioned X-ray diffraction analysis in each case in MA.%.

• Nadelpenetration: von 1 x 10^-1 bis 7 x 10^-1, insbesondere 3 x 10^-1 bis 6 x 10^-1 mm, bestimmt nach DIN 51579,
• MBK-lösliches:1,0 bis 2 Gew.-% insbesondere 1,2 bis 1,6 Gew.-%, bestimmt nach MIBK nach modifizierter ASTM D 721/87
• Erstarrungspunkt: ca. 60 bis ca. 95°C, insbesondere 70 bis 85 °C ,bestimmt nach DIN ISO 2207.

The microcrystalline paraffins produced by catalytic hydroisomerization can also be deoiled with a solvent. However, this does not say that the hydroisomerization products described have a content of oily components in the conventional sense. In any case, however, short-chain n- or iso-alkanes are removed. When using a solvent mixture of dichloroethane: toluene of 95: 5 parts by volume and a product-solvent ratio of 1: 3.6 parts at 22 ° C, a deoiled microcrystalline paraffin in a yield of 80 to 90 wt .-%, based on the Hydroisomerate, obtained. It has the following properties:

• Needle penetration: from 1 × 10 ^-1 to 7 × 10 ^-1 , in particular 3 × 10 ^-1 to 6 × 10 ^-1 mm, determined to DIN 51579,
• MBK-soluble: 1.0 to 2 wt.%, In particular 1.2 to 1.6 wt.%, Determined according to MIBK according to modified ASTM D 721/87
• Freezing point: about 60 to about 95 ° C, especially 70 to 85 ° C, determined according to DIN ISO 2207.

Thus, by removing the short chain portions, the medium hard product became a very hard product when compared to the petroleum type. Then the de-oiled hydroisomerate is the hardest type comparable to petroleum.

Because of its properties, the microcrystalline hydroisomerate prepared according to the invention and the corresponding deoiled microcrystalline hydroisomerizate, such as a microwax, can be used (see introduction). In particular, the resulting hydroisomerizate can also be oxidized. There are obtained oxidized products that can be different by melting range and degree of oxidation and are used mainly as a base for corrosion inhibitors and as a cavity and underbody protection for motor vehicles. They are also used in emulsions as care and release agents and as an additive for printing and carbon paper colorants.

The acid and ester groups, which are statistically distributed over hydrocarbon chains, can be reacted with inorganic or organic bases to form water-dispersible formulations (emulsifying waxes) and lead to products with very good metal adhesion.

Further areas of application are the production of impregnating, coating and laminating waxes for the packaging and textile industry. Heat sealants and hot melt adhesives as blend component in candles and other wax goods in wax mixtures for malting agents, floor and car care products as well as for dental technology and pyrochemistry.

They are also part of sunscreen waxes for the tire industry electrical insulation materials scaffolding and model waxes for the investment casting industry and wax formulation for the explosives, ammunition and propellant technology.

Furthermore, such products are suitable as release agents in the pressing of wood, chipboard and fibreboard in the manufacture of ceramic parts and because of their retention capacity for the preparation of solvent-based care products, grinding and polishing pastes and matting agents for paints.

Furthermore, these products can be used for the formulation of adhesive waxes, cheese waxes, cosmetic preparations, chewing gum bases, cast and cable compounds, sprayable pesticides, vaselines, artificial chimney logs, lubricants and hot melt adhesives.

The synthetic microwaxes are food safe. The test is carried out according to FDA, § 175. 250.

The invention will now be explained in detail by way of examples.

Example 1:

An FT paraffin with a solidification point at 97 ° C was catalytically isomerized in the flow reactor with hydrogen at a pressure of 5 MPa (50 bar), a temperature of 270 ° C and a v / vh ratio of 0.3. The hydroisomerization that has occurred is substantiated by the figures in Table 1.

The catalyst had 0.8 MA% platinum on β- zeolite and a SIO ₂ to Al ₂ O ₃ mole ratio of 23: 1 and a high surface area alumina. The catalyst was in acid form. It contained less than 0.02% alkali oxide based on dry matter.

The resulting hydroisomerate was solid, white-opaque, odorless, slightly sticky and thus differed significantly from the brittle-hard feedstock. The isoalkane content was increased by about 5-fold, which is evidenced by the increased penetration value, the reduced crystalline content and the reduced enthalpy of fusion. The synthetic, microcrystalline paraffin thus prepared is classified according to its characteristics between a plastic and a hard microwax based on petroleum. With the hydroisimerizate thus a paraffin was obtained with pronounced microcrystalline structure whose C-chain length distribution on the basis of carbon atoms with 23 to 91 in about that of the starting material with 27 to 95, thus slightly shifted towards smaller chain lengths out. The chain length was determined by gas chromatography. a corresponding gas chromatogram is attached as FIG.

Example 2:

An FT paraffin having a solidification point of 71.5 ° C was catalytically isomerized in an autoclave under a hydrogen pressure of 5 MPa (50 bar) and a temperature of 250 ° C. The structural transformation that has occurred is substantiated by the key figures in the table.

The same catalyst was used as in Example 1.

The obtained hydroisomerizate was solid, white-opaque and odorless as well as pasty and slightly sticky. The isoalkane content was increased approximately 5-fold. The high degree of isomerization finds expression in the significantly increased penetration value, the reduced crystalline content and the reduced enthalpy of fusion. The microcrystalline paraffin thus obtained has a similar but slightly reduced C chain length as the FT paraffin, which is clear from the carbon atoms: 23 to 42 in the hydroisomerate and 25 to 48 in FT paraffin. The resulting synthetic microcrystalline paraffin is comparable to a petroleum based soft plastic microcrystalline paraffin according to its characteristics.

Examples 1 and 2 show that the FT-paraffins, which consist predominantly of n-alkanes and have a finely crystalline structure and a brittle-hard consistency, have been converted into non-flowing, pasty or solid paraffins by the process according to the invention, the lower melting temperatures as the feedstock. These paraffins are characterized by a high content of branched alkanes and consequently have a microcrystalline structure with a significantly reduced degree of crystallization (compared to the starting material) and a plastic to slightly sticky consistency. The branched alkanes are predominantly methylalkanes, with the methyl groups preferably occurring in the 2, 3, 4 or 5 position. To a lesser extent methyl branched alkanes were formed several times.

The results of Examples 1 and 2, compared with the starting material are summarized in the attached Table 1.

An example 2 corresponding gas chromatogram is in FIG. 2 shown.

Example 3:

The starting material of Example 2 was then isomerized in a flow reactor again with the same catalyst, and a hydroisomerate with somewhat different but comparable parameters (cf. also Table 1) was obtained as in the autoclave experiment (Example 2) clear lowered process temperature of 220 ° C. A reactor experiment is a large-scale one Carrying out the hydroisomerization much closer than an autoclave experiment. The thus proven possible reduction of the process temperature in comparison to the autoclave experiment can be expected the same in the case of Example 1, but at least in large-scale implementation.

The lowering of the process temperature is also associated with the significant advantage that the concurrently cracking reaction occurring in such a hydroisomerization is decisively suppressed (see FIGS. 1 to 3 ).

A gas chromatograph corresponding to Example 3 is known as FIG. 3 attached.

In contrast to the microcrystalline paraffins obtained from petroleum, the fully synthetic microcrystalline paraffins produced by the hydroisomerization according to the invention contain no strongly branched isoalkanes, no cyclic hydrocarbons (naphthenes) and in particular no aromatics and also sulfur compounds. They therefore meet the highest purity requirements for microcrystalline paraffins, making them ideally suited for use in the cosmetics and pharmaceutical industries as well as for packaging and preservation in the food industry. Table 1: Characteristics of starting materials and reaction products unit Measurement Method example 1 Example 2 Example 3 FT paraffin (H8) Hydroisomerate (HDI-8) FT paraffin (FT 70) Hydroisomerate (HDI 70-A) FT paraffin (FT70) Hydroisome-risat (HDI 70-R) Freezing point ° C DIN ISO 2207 97.0 86.5 71.5 61.5 71.5 64.5 Penetration N at 25 ° C 0.1 mm DIN 51579 2 42 13 98 13 79 melting enthalpy J / g ASTM D4419 221 127 195 120 195 142 crystalline parts MA .-% X-ray diffraction analysis 70.7 43.5 62.4 38.8 62.4 41.2 isoalkanes % gas chromatography 12 47 9 47 9 40 MIBK-soluble MA .-% ASTM D721-87 (modified) 0.66 14.6 0.4 23.1 0.4 15.0 Viscosity (100 ° C) cSt 12 (120 ° C) 15.4 (120 ° C) 6.5 5.2 6.5 5.1

Claims (13)

1. Microcrystalline paraffin as solid product, which can be prepared by catalytic hydroisomerization of FT paraffins having a carbon chain length distribution in the range from 20 to 105 at temperatures above 200°C, using a catalyst based on a β-zeolite, having a pore size between 0.50 and 0.80 nm, the catalyst further comprising a hydrogenation metal component of transition group VIII of the Periodic Table and the hydrogenation metal content of the catalyst being 0.1 to 2.0% by mass, based on the catalyst fired at 800°C, the microcrystalline paraffin produced not being liquid at 25°C, but being at least paste-like to solid with a needle penetration value of less than 100 x 10^-1 mm, measured in accordance with DIN 51579.
2. Microcrystalline paraffin according to Claim 1, characterized in that the proportion by weight of isoalkanes is greater than that of n-alkanes.
3. A process for preparing a microcrystalline paraffin, by catalytic hydroisomerization, which is not liquid at 25°C, but is at least paste-like to solid with a needle penetration value of less than 100 x 10^-1 mm, measured in accordance with DIN 51579, using as starting material, FT paraffins having carbon atoms in the range from 20 to 105, using a catalyst based on a β-zeolite, having a pore size between 0.50 and 0.80 nm, the catalyst further comprising a hydrogenation metal component of transition group VIII of the Periodic Table and the hydrogenation metal content of the catalyst being 0.1 to 2.0% by mass, in the case of platinum preferably 0.4 to 1.0% by mass, based on the catalyst fired at 800°C, using a process temperature above 200°C, and under the action of pressure in the presence of hydrogen.
4. A process according to Claim 3, characterized in that the process temperature is from 200 to 270°C.
5. A process according to either of Claims 3 and 4, characterized in that the pressure is 2 to 20 MPa.
6. A process according to Claim 5, characterized in that the pressure is 3 to 8 MPa.
7. A process according to Claim 6, characterized by a process temperature of 230 to 270°C.
8. A process according to any of Claims 3 to 7, characterized by a feed ratio of hydrogen to FT paraffin from 100:1 to 2000:1 standard m³ per m³.
9. A process according to any of Claims 3 to 8, characterized by a feed ratio of hydrogen to FT paraffin from 250:1 to 600:1 standard m³ per m³.
10. A process according to any of Claims 3 to 9, characterized in that it is carried out at a loading from 0.1 to 2.0 v/vh, preferably 0.2 to 0.8 v/vh.
11. A process according to any of Claims 3 to 10, characterized in that the catalyst has a pore size between 0.55 to 0.76 nm.
12. A process according to any of Claims 3 to 11, characterized in that the FT paraffin is used in a solidification point range from 70 to 105°C, preferably with solidification points of 70, 80, 95 or 105°C.
13. A process according to any of Claims 3 to 12, characterized in that the microcrystalline paraffins are prepared from the FT paraffins in a single process step, optionally additionally with removal of the short-chain constituents.

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