JPH01228923A - Method for isomerizing paraffin - Google Patents

Abstract

PURPOSE:To carry out reaction in a high conversion rate and selectivity under relatively mild conditions by using an H type mordenite carrying a rare earth element oxide and platinum group metal as a catalyst in isomerizing a paraffin in the presence of hydrogen and the catalyst. CONSTITUTION:A paraffin is isomerized to provide other paraffins having a higher added value (e.g., of a higher octane number). In the process, an H type mordenite carrying a rare earth element oxide (especially Ce oxide) in in an amount of 0.0042-1.27g atoms (preferably 0.0042-0.85g atom) rare earth element based on 1mol H type mordenite expressed in terms of Al2O3 and a platinum group metal in an amount of 0.1-1.5wt.% based on the H type mordenite is used as the catalyst to carry out reaction at 230-280 deg.C under 6-50kg/cm<2>G. The catalyst is prepared by treating mordenite with an aqueous solution of hydrochloric acid, etc., converting the mordenite into the H type, reacting an aqueous solution of the platinum group metal salt through ion exchange treatment, etc., reducing the platinum group metal salt containing the platinum group metal, adding the rare earth element oxide and calcining the resultant substance.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for isomerizing paraffins to obtain higher value-added paraffins, such as high-octane paraffins.

[Conventional technology]

As a method for isomerizing paraffin in the presence of a mordenite catalyst supporting a platinum group metal and hydrogen, the following method is known. (l> (U.S. Patent No. 3,190,939) A method using Pt group/H type mordenite in which a platinum group metal is supported on H type mordenite. The reaction temperature is 302 to 329°C.
However, it is said that the reaction pressure is preferably a total pressure of 21 to 53 kg/cJG. (2) (U.S. Patent No. 3,842.114) Platinum group metal is supported on mordenite substituted with ammonium ions, and then almost all ammonium ions are removed by firing at a temperature of 500°C or higher. Group/H type mordenite is used. The reaction temperature is 200
~300°C, and the reaction pressure is a hydrogen partial pressure of 3 to 70 kg/c, preferably 5 to 50 g/eJ. (3) (U.S. Pat. No. 3,551,353) Adding platinum group metal to dealuminated mordenite
,'j using Pt/dealuminated mordenite. Reaction part rx 31G°C and 343°C. Reaction pressure Two examples are shown in which the total pressure is 21 Kg/cJ G.

[Problem to be solved by the invention]

In any of these methods, as mentioned above, the reaction must be carried out at extremely high temperature or pressure. An object of the present invention is to provide a method capable of isomerizing paraffins under conditions that are milder than those of conventional methods.

[Means to solve the problem]

That is, the present invention provides a method for isomerizing paraffin in the presence of hydrogen and a catalyst, with a rare earth element of 0.0042 to 1.
This is a process for isomerizing paraffins, characterized in that H-type mordenite supported with 27 gram atoms of rare earth oxide and 0.1 to 1.5 vt% of platinum group metal per H-type mordenite is used as a catalyst. Catalyst> Catalyst used in the present invention (hereinafter referred to as "catalyst of the present invention")
is a H-type mordenite in which substantially all cations are hydrogen, on which a rare earth oxide and a platinum group metal are supported. The rare earths include scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium. Gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, etc. can be used. In particular, when cerium is used, its activity as a catalyst for paraffin isomerization is high. Moreover, the number of rare earth oxides to be supported may be one or two or more. The amount of rare earth oxide supported in the catalyst of the present invention is Al2O
, 0.0042 to 1.27 g atoms, preferably 0.0042 to 1.27 g atoms in terms of rare earth element, per 1 mole of H-type mordenite in terms of .
The proportion should be between 0.021 and 0.85 gram atoms. When the amount of rare earth oxide is less than 0.0042 gram atom, the catalyst activity is low, and when it is more than 1.27 gram atom, the effect is small compared to the supported amount. Further, as the platinum group metal, any of platinum, rhodium, palladium, ruthenium, osmium, and iridium can be used. Particularly preferred as a catalyst component is platinum. The supported amount of platinum group metal is 0 for H-type mordenite.
．． It is 1 to 1.5 vt%. 0.1vt% platinum group metal
If it is less than 1.5 νt%, the catalyst activity is too small.
This is because if the amount exceeds the amount supported, the effect is small compared to the amount supported. Method for producing the catalyst> The method for producing the catalyst of the present invention is basically based on the following method: When mordenite containing a metal such as sodium as a cation is used as a starting material, the mordenite may be either natural or synthetic. , consisting of the following processing steps: (a) Ion exchange to H type AH type or B a Ion exchange to NH4 type (b) Firing port for NH4 type Addition of platinum group metal salt (8) Reduction of platinum group metal salt (2) Addition of rare earth substance (e) Firing usually A Alternatively, Ba treatment is performed first. Naturally, the processing of ``ha'' must be processed after the processing of ``mouth'', and the processing of ``gaho'' must be processed after the processing of ``2''. The processing in E can also serve as the processing in Bb in A. Further, since the process (e) is usually carried out in an oxidizing atmosphere, the process (c) should be performed after the process (e), and is usually the last of the entire process. The treatment of the mouth may be before or after 2 and e, or between 2 and e. (H-type formation) H-type mordenite may be produced by a conventionally known method. That is, to prepare H-type mordenite, cations in natural or synthetic mordenite are replaced with hydrogen ions by treating the mordenite with an aqueous solution of an acid, such as hydrochloric acid. Alternatively, by treating with an aqueous solution of an ammonium salt, such as an aqueous ammonium chloride solution, an aqueous ammonia solution, or an aqueous amine solution, the cations are replaced with ammonium ions, and NH4 type mordenite is obtained. By firing this so that the nitrogen base present as a cation decomposes, H-type mordenite becomes j'? It will be done. (Compatibility of platinum group metal) Compatibility of platinum group metal consisting of the above-mentioned treatments (a) and (b) may also be carried out by a conventionally well-known method. That is, first, an aqueous solution of one or more platinum group metal salts is added to H-type or NH4-type mordenite or rare earth ion-containing mordenite, and the mordenite is then subjected to treatment, extraction treatment, ion exchange treatment, etc. to form platinum. It is contained in an amount of 0.1 to 1.5 vt% in terms of group metal. Among these, ion exchange treatment is particularly preferred for making mordenite contain the metal. Ion exchange methods include compounds in which the metal is present as a cation, such as ammonia. Alkylamine, hydroquinruamino. Ion exchange treatment with a metal complex such as hydrazine is preferred. After drying the product containing the platinum group metal salt in this way, a reducing agent such as ammonia, hydrogen, etc.
Preferably, the platinum group metal is reduced to its metallic form by heat treatment in the presence of hydrogen. (Supporting Rare Earth Oxide) A rare earth oxide is supported on mordenite or mordenite containing a platinum group metal salt by the above-mentioned treatments 2 and 5. Specifically, for example, the following two methods can be adopted. 1 Ion exchange calcination method First, the material to be treated (H-type or NH4-type mordenite or platinum group metal salt-containing mordenite) is treated with a compound in which a rare earth element exists as a cation in an aqueous solution, such as nitrate, chloride, acetate, or A portion of the hydrogen ions in the object to be treated are exchanged with rare earth ions by contacting with an aqueous solution of an acid salt, carbonate, or the like. As mentioned above, this exchange amount is
0.0042 to 127 g atoms in terms of rare earth elements, especially 0.021 per mole of p mordenite in terms of 2O,
The ratio may be set to ~0.85 grams It', if-. As described above, after this ion exchange treatment, a treatment for impregnating a platinum group metal can be performed before the next firing. The -r ion exchange treated material is dried and then the rare earth ions are converted to oxides, which are converted into mordenite.
In order to maintain the temperature, firing is performed at 1000° C. or lower in an oxygen atmosphere. This oxygen atmosphere does not need to have a high oxygen content; air is sufficient. Naturally, this firing must be carried out at a temperature long enough for the rare earth ions to convert into oxides, and the temperature for 1 g of firing is selected from the range of 400 to 1000°C (if it is in this 745 range, mordenite responsibilities are fulfilled). The upper limit of firing temperature is 1
The reason why the temperature is set at 000°C is that if the temperature exceeds this temperature, the crystal structure of mordenite will be destroyed. The reason why the upper limit of the firing temperature is set at 1000° C. in all the manufacturing methods of the present invention is for the same reason. Through this firing process, the areas where rare earth ions were present become H
Becomes a mold. This is the OHM that was coordinated to the rare earth ion.
It is presumed that this is due to the decomposition of hydrogen ions to generate hydrogen ions. Conversion of rare earth ions to their oxides is confirmed by X-ray diffraction. That is, the 2θ-6,5" and 13.9" peaks of Mordenite Special H disappear due to the exchange of rare earth ions, but when the rare earth ions are converted to oxides, these two peaks 11) appear. However,
If the color changes due to the above conversion, it can be easily confirmed by the change in color. For example, cerium oxide is pale yellow, neodymium oxide is dark red, and europium oxide is light pink. When firing H-type or NH4-type mordenite made of platinum group metal salts, it can be fired as is, but natural clays (e.g. kaolin, halloysite, montmorillonite tongue) and/or inorganic oxides (e.g. silica) can be fired. :Silica-alumina, licar-zirconia, silica-magnesia. Binary gels such as aluminum phosphate; ternary gels such as silica-magnesia-alumina, alumina, titania, zirconia, etc.) and then fired. You can also. 1i. Mixing firing method First, H type or N Ha type mordenite or platinum group metal salt-containing mordenite and a rare earth oxide and/or rare earth salt are mixed. This mixing method may be either a dry mixing method or a wet mixing method as long as the mixture is uniformly mixed. Rare earth salts are nitrates. Halides, acetates, oxalates, carbonates, oxohalides, thiosulfates, selenate, hydroxides, chromates, phosphates, borates, silicates. One type or two or more types of cyanide, formate, ethyl sulfate, dimethyl phosphate, malonate, glycolate, sebacate, cacodylate, etc. may be used. After this mixing, a treatment for impregnating a platinum group metal salt can be performed before the next firing. Next, it is fired at 1000° C. or lower in an oxygen atmosphere. This atmosphere is 1. As in the ion exchange calcination method, it is not necessary to use a material with a high oxygen content, and air is sufficient. When using rare earth oxides, the 7R degree of firing is 20
The temperature is 0 to 1000°C. If the temperature is less than 200"C, the rare earth oxide remains in a mixed state with H-type mordenite and is not supported, so it cannot be used as a highly active catalyst. This change in state can be detected by X-ray diffraction. 20-6.5° of chart
This can be confirmed by looking at the intensity of peaks such as 13.9" and 13.9". When using rare earth salts, the temperature must naturally be high enough to convert the rare earth salts into oxides. The firing temperature is selected from the range of 2° to 1000°C. (As is clear from the above explanation, in this temperature range, the rare earth oxide will be supported on H-type mordenite.) Platinum group metal When baking a mixture containing salt, i,
As in the case of the ion exchange calcination method, the granules can be fired as they are, or they can be granulated using a binder and then fired. Isomerization Reaction> In the present invention, paraffin is isomerized in a mixed state with hydrogen using the above catalyst of the present invention as a catalyst. As a paraffin, it is advantageously applied to the isomerization of C4 to C6 paraffinic hydrocarbons. The hydrogen/raw material paraffin vol ratio supplied to the catalyst bed is 0.5 to 1O1, preferably 1 to 3
, the weight hourly space velocity may be 0.5 to 1 Ohr''.The reaction temperature may be 230 to 280°C. From a thermodynamic point of view, it is advantageous to lower this temperature. Although it has a high activity, if it is too low, the reaction rate will be too low, so it is best to keep it within the above range.The higher the reaction pressure, the higher the reaction rate, but it puts a greater burden on the equipment. In the case of the present invention, it is also effective to carry out the reaction at 5 to 50 Kg/cj G, but as shown in the examples, considerably high conversion and selectivity can be achieved even at normal pressure.

【Effect of the invention】

According to the present invention, paraffins, particularly paraffins having 4 to B carbon atoms, can be isomerized with high conversion and selectivity even under relatively mild conditions.

【Example】

EXAMPLES In order to explain the present invention more specifically, Examples are shown below, but the present invention is not limited to the following Examples. Catalyst production example 1 Synthetic Na type mordenite 30g (S i02 /Al
2O, molar ratio -14.9) was dispersed in 300 ml of ammonium chloride aqueous solution with a concentration of 2.0 mol/l, and then heated at 60°C.
Ammonium ion exchange was performed by stirring for 3 hours. This operation was repeated twice. The contents were then separated by suction filtration and washed repeatedly until no chloride ions were detected. The amount of residual Na in the obtained NH4 type mordenite was determined by atomic absorption spectrometry, and it was found that O, lvt
%. An X-ray diffraction chart of this NH4 type mordenite is shown in FIG. This NH4 type mordenite,
Cerous nitrate aqueous solution with a concentration of 0.1 mol/1 1000
After dispersing the solution in 100ml, the mixture was stirred at 80°C for 5 hours to perform cerium ion exchange. The amount of ion exchange was determined by titrating the cerous nitrate aqueous solution before and after ion exchange with EDTA. CeO, converted to 8. It was OvL%. The X-ray diffraction chart of the obtained CeNH4 type mordenite is shown in Figure 2.
Cerium ions were converted into oxides by firing in air at 0° C. for 2 hours. The fired product contains the generated CeO2
Therefore, it was pale yellow to blue. The X-ray diffraction chart is shown in FIG. ? 1; Platinum (platinum reagent: Pt (NH9) 4 Cl
2) was ion-exchanged by an ion-exchange method. After ion exchange, washing was repeated until chloride ions were no longer detected, and then dried in a hot air dryer at 110° C. all day and night. The CeO2-supported Pt-H type mordenite thus obtained was pressure-molded, crushed, sieved to collect 16 to 32 mesh pieces, and fired in air at 500°C for 2 hours. Subsequently, the mixture was filled into a quartz reaction tube and subjected to hydrogen reduction at 300° C. for 3 hours. Catalyst production example 2 Synthetic Na type mo/l, Denite 30g (S i 02
/ AI, 0) - El ratio - 14,9), concentration 2.0 (
The mixture was dispersed in 300 ml of an ammonium chloride aqueous solution of -1/l and stirred at 60° C. for 3 hours to complete ammonium ion exchange. This operation was repeated twice. The contents were then separated by suction filtration and the wash was repeated until no chloride ions were detected. The residual Nam of the obtained NH, type mordenite was determined by chemical formula 1 by atomic absorption spectrometry and was found to be less than 0.1 vL%. This NH4 type mordenite was dispersed in a 10,100O aqueous solution of lanthanum nitrate with a concentration of 0.1 mol/1, and then stirred at 80"C for 5 hours to perform lanthanum ion exchange. The amount of ion exchange was determined before and after ion exchange. Calculated by titrating an aqueous solution of lanthanum nitrate with EDTA. 9.0v in terms of La20i.
It was t96. The obtained LaNH4 type mordenite was calcined in air at 650° C. for 2 hours to convert lanthanum ions into oxides. The obtained La20. Carrying H
Platinum (platinum reagent: Pt
NHI (4Cl2) was ion-exchanged by an ion-exchange method. After ion exchange, the washing was repeated until no chloride ions were detected, and then dried in a hot air dryer at 110° C. overnight. The obtained Pt-H type mordenite with La20iJL1 was pressure-molded, crushed, sieved to collect 16 to 32 mesh pieces, and heated at 500°C for 2 hours.
Baked in air for an hour. Subsequently, the mixture was filled into a quartz reaction tube and subjected to hydrogen reduction at 300° C. for 3 hours. Catalyst production example 3 Synthetic Na type mordenite 30g (S i 02 /A
After dispersing 12O, molar ratio -14.9) in 300 ml of ammonium chloride aqueous solution with a concentration of 2.0 mol/l, 6
Stir at 0°C for 3 hours to perform ammonium ion exchange.
became. This operation was repeated twice. The contents were then separated by suction aspiration and washing was repeated until no chloride ions were detected. 11) The residual NaQ of the NH, type mordenite was determined by atomic absorption spectrometry and was found to be less than 0.1 vt%. This NH4 type mordenite was mixed with 10% of an aqueous solution of cerous nitrate having a concentration of 0.1 mol/l.
After dispersing in 00 ml, the mixture was stirred at 80° C. for 5 hours to perform cerium ion exchange. The amount of ion exchange is calculated using the cerous nitrate aqueous solution before and after ion exchange.
Calculated by titration. It was 7.9vt% in terms of CeO2. 0.5νt% (
Ce N H4 type mordenite) was ion-exchanged with platinum (platinum reagent: Pt(NH3)4C12) by an ion exchange method. After ion exchange, washing was repeated until no chloride ions were detected, and then dried in a hot air dryer at 110"C overnight. The obtained Pt・CeNH4
After pressure-molding the mold mordenite, it was crushed, sieved, 16 to 32 mesh pieces were collected, and heated at 500℃ for 2 hours.
Baked in air for an hour. The obtained calcined product was filled into a quartz reaction tube and subjected to hydrogen reduction at 300"C for 3 hours. Catalyst production comparative example 1 Synthetic Na type (-/I, bunite 30g (S i 02
/AI, 0. (-ratio-14.9), concentration 2.0
After dispersing in 300 ml of a mol/1(7) ammonium chloride aqueous solution, the mixture was stirred at 60° C. for 3 hours to perform ammonium ion exchange. This operation was repeated twice. The contents were then separated by suction filtration and washed repeatedly until no chloride ions were detected. The residual Na of the obtained NH, type mordenite was determined by atomic absorption method to 11?1
As a result, it was less than O,lvt%. Obtained NH
, Platinum reagent: Pt(N
Hi)4C1z) was ion-exchanged by an ion exchange method. After ion exchange, the washing was repeated until no chloride ions were detected, and then dried in a hot air dryer at 110° C. overnight. The resulting PT/H type mordenite was pressure-molded, crushed, sieved, and 16 to 32 mesh pieces were collected and fired in air at 500°C for 2 hours. Next, it was filled into a quartz reaction tube and hydrogen reduction was performed at 300°C for 3 hours. Catalyst Production Example 4 S i O2 / Al2 whose synthesis was completed by hydrothermal synthesis
Crystallization slurry (solid content concentration 1
2.9wt%) 1000g was suction filtered using a porcelain Buchner funnel. After the filtration was completed, it was washed with 400 ml of warm water. Approximately 10 ml of 0.8N hydrochloric acid at a temperature of 35°C was poured into the cake layer thus formed while suctioning.
The liquid was passed for a minute. It was thoroughly washed by dipping in hydrochloric acid and dried. The composition of the obtained crystal was determined by chemical analysis, and the SIO2/AI203 moAt ratio was 2.
5.3, and the Na2O content is 0.05 below the detection limit.
It was less than wt%. The obtained H-type dealuminated mordenite was calcined in air at 700° C. for 1 hour. This H-type dealuminated mordenite contains 0.5νt% (
H-type dealuminated mordenite) was ion-exchanged with platinum (platinum reagent: P t (NH3) 4Cl 2 ) by an ion exchange method. After ion exchange, washing was repeated until chloride ions were no longer detected, and then dried in a hot air dryer at 110° C. all day and night. 10 g of the obtained Pt-H type membrane aluminum mordenite, CeO, and Ig were thoroughly mixed, pressure-molded, crushed, sieved to collect 16 to 32 mesh pieces, and heated in air at 500°C for 2 hours. Fired. X-ray diffraction charts of the material before and after firing are shown in FIGS. 4 and 5, respectively. Subsequently, the mixture was filled into a quartz reaction tube and subjected to hydrogen reduction at 300° C. for 3 hours. Comparative Example 2 of Catalyst Production A pt-containing H-type dealuminated mordenite was prepared in the same manner as in Catalyst Production Example 3, except that the calcining and reduction were performed without mixing CeO2. Isomerization Example Catalyst Production Example (referred to as “Example” in the table below) 1.2.3
and 4 and catalyst production comparative example (referred to as "comparative example" in the table below) using the products prepared in 1 and 2 as catalysts, reaction temperature 230°C reaction pressure atmospheric pressure hydrogen/n-hexane vol ratio 2.5 ffi amount The isomerization reaction of n-hexane was carried out at a space velocity of 1 h-', and the performance of the catalyst was evaluated. The conversion rate of raw hexane and the selectivity of its skeletal isomer after 5 hours of passing n-hexane through the oil are shown in the table below. Note) n-Cb: n-hexane 1 to C6: skeletal isomer of n-hexane

[Brief explanation of the drawing]

Figures 1.2 and 3 are X-ray diffraction charts of NH4 type mordenite, CeNH4 type mordenite, and the calcined product thereof in Catalyst Production Example 11, respectively. Figures 4 and 5
These are X-ray diffraction charts of a mixture of Pt-H type dealuminated mordenite and Cen2 before and after calcination in Catalyst Production Example 4, respectively.

Claims (1)

[Claims] (1) In a method of isomerizing paraffin in the presence of hydrogen and a catalyst, a rare earth oxide of 0.0042 to 1.27 g atoms of a rare earth element per 1 mole of H-type mordenite calculated as Al_2O_3 and 0.1 g atom per H-type mordenite are used.
A method for isomerizing paraffins, characterized in that H-type mordenite supporting ~1.5 wt% of a platinum group metal is used as a catalyst.