KR100757031B1 - Preparing method of light olefin trimer by using zeolites and production of heavy alkylates by using thereof - Google Patents

Abstract

A method for preparing a trimer by using an olefin, and a method for preparing an alkylate are provided to improve the selectivity of trimers and to increase the viscosity of an alkylate. A preparation method of a trimer comprises the step of polymerizing an olefin in the presence of a zeolite catalyst comprising a pore having 12 oxygen atoms, a pore crossing with the pore and having 12 oxygen atoms and/or having 6-10 oxygen atoms. Preferably the reaction is carried out at a temperature of 50-100 deg.C and with a space velocity of 0.5-100 h^-1. Preferably the olefin is isobutene; and the zeolite catalyst is zeolite beta, Al-rich beta, boron-containing zeolite, gallium-containing beta zeolite, titanium-containing beta zeolite, CIT-6, beta zeolite comprising silica only, or zeolite having Tschernichite structure.

Description

Preparing Method of Light Olefin Trimer by using zeolites and Production of heavy alkylates by Using Thereof}

Figure 1 shows the change in conversion and selectivity over time in the oligomerization of isobutene according to Example 1.

The present invention relates to a method for oligomerization of olefins, a process for producing trimers obtained thereby, and a method for obtaining high boiling point alkylates by hydrogenation of trimers.

More specifically, by using a zeolite as a catalyst used in oligomerization but using a zeolite having cross pore properties as a catalyst, the selectivity of the trimer is increased, thereby increasing the productivity and purity of the trimer of the olefin, It is to provide an effective production method with a very increased catalyst life.

The oligomerization of olefins is mainly carried out using acid catalysts such as supported phosphoric acid and is mainly used to produce gasoline additives through hydrogenation after the production of dimers (US 6689927, 6284938). These hydrocarbons, which have undergone hydrogenation after oligomerization, are called alkylates, and have various uses depending on the carbon number of the alkylates.

Another way of obtaining alkylates is the alkylation reaction between olefins and paraffins in the presence of sulfuric acid or hydrofluoric acid and related literature is known (Catalysis Today, 49, 193, 1999), but with environmental and corrosion problems associated with the use of liquid acids. Has always been a big stumbling block. In addition, in the alkylate production reaction described in the above-mentioned publication (Catalysis Today, 49, 193, 1999), a small amount of C ₉ or more high boiling point alkylate is obtained at about 5-10%, and is used as a high-quality solvent and as an additive for improving cetane value of diesel fuel. Although it is used, its productivity is limited, so other process development is required more.

Among the studies on oligomerization of olefins, studies of making trimers have been known in recent years. Olefin oligomerization was mainly carried out using a solid acid catalyst. The catalysts used were heteropolyacid (JP 2005015383), zirconia (JP 2005015384), zeolite named Al-TS-1 (US 6914165), sulfated-titania (J. Molecular Catalysis A, 228, 333, 2005), Ionic liquid (CN 1379005), etc., etc. are mentioned.

In addition, some examples of using a cation exchange resin as a catalyst are also known. The published patent of US 2005 / 0119111A1 claims that ion exchange resins can be used as catalysts for dimerization, and US 5789643 also shows that oligomerization reactions can be carried out using ion exchange resins. Ion exchange resins have also been used in the preparation of tetramers or pentamers by oligomerization of the dimers. The present inventors have recently invented that the selectivity of the trimer can be increased by utilizing the hydrogen-type cation exchange resin of macropore and maintaining a high conversion rate (Korean Patent Application 10-2006-0012317). In addition, an example of proceeding oligomerization of isobutene by using an ion exchange resin called Amberlyst-15 as a catalyst (Catalysis Today 100, 463, 2005) has a very low conversion rate of 40% or less, and mainly generates dimers.

In addition, some examples of using zeolite as an acid catalyst for the oligomerization reaction have been attempted (Catalysis Today 100, 463, 2005). However, in the zeolites such as H-ZSM-5, Y, beta, and mordenite, dimers are produced under the studied conditions. But after 3-4 hours there was little reactivity due to rapid deactivation.

Therefore, until now, the result obtained mainly from trimerization when using zeolite as a catalyst has not been known, and there is no further example of promoting the trimerization by selecting a zeolite having a special pore structure.

Accordingly, the present invention has attempted to develop a technology for preparing oligomerization of olefins, in particular, trimers, and has developed a novel method for easily preparing high boiling point alkylates by hydrogenation of such trimers.

In particular, it is an object of the present invention to develop oligomerization reaction technology and high boiling point alkylate production technology having high productivity and long catalyst life in addition to high selectivity of trimers.

In order to achieve the above object, the present invention is a novel method for producing olefin oligomerization and high boiling point alkylate, which uses a zeolite having mutually intersecting pores as a catalyst, thereby surprisingly increasing the selectivity of the trimer. The manufacturing method was found.

Particularly, the present invention provides remarkably high productivity by using a zeolite having 12 pore oxygen (hereinafter referred to as 12 membered ring and weakened to 12 MR) pores and zeolite having 12MR pores intersecting therewith among zeolites having cross pores. The reaction with high selectivity and high stability was carried out and the trimer was effectively prepared.

In addition, the present invention obtains a high boiling point alkylate having a high boiling point of C ₉ or more through hydrogenation using the trimer of the highly selective olefin prepared above. The hydrogenation is carried out in fine chemicals through heterogeneous catalysis, Wiley-VCH, 2001, pp. It is well known that the process proceeds relatively easily in the manner described in 351-426, and thus the description thereof will be omitted.

In the present invention, the olefin used for oligomerization may be any C ₂ or higher olefin, but C ₃ -C ₄ olefin is suitable, C ₄ olefin is more suitable, and isobutene is most suitable. Oligomerization yields C ₈ or more olefins, in particular C ₉ or more olefins being more suitable and C ₁₂ olefins being most suitable.

The temperature of the oligomerization reaction is not limited, but room temperature ~ 120 ℃ is suitable, if the temperature is too low, the reaction rate is too slow, if the temperature is too high, the reaction conversion rate is not only disadvantageous due to the exothermic reaction of the oligomerization reaction, the polymer compound is easily There is a disadvantage that the deactivation of the catalyst is increased. 50-100 degreeC of reaction temperature is more suitable.

The oligomerization reaction can be both batch and continuous and continuous processes are suitable for large scale production processes. The continuous process may be any reactor, but a continuous stirred reactor may be used, and it is suitable to proceed using a fixed bed reactor, and the reactants may flow upstream or downstream.

Since oligomerization is an exothermic reaction with a very large heat of reaction, it is very important to control the heat of reaction and to use a solvent to facilitate the transfer of raw materials and products. Solvents may be good and the hydrocarbon is C ₂ -C ₁₀ hydrocarbon paraffin components between good more isobutane, normal butane, pentane, hexane, heptane, octane, nonane, decane, etc. is more and more good use of cyclohexane. The ratio of reactant to solvent is irrelevant to any composition between 1: 100 and 100: 1 and is preferably maintained at 1:10 to 10: 1 in consideration of ease of operation and productivity. Instead of solvents, inert gases such as nitrogen, argon, carbon dioxide and helium may be used as diluents. If gas is used as a diluent, it is preferable to flow reactants and diluents downstream in a fixed bed reactor.

The catalyst of the oligomerization reaction may be any catalyst as long as it is a zeolite having pores that cross each other. The pores intersecting with 12MR may be 12 MR or / and 10-6 MR. In zeolites with 12 MR and / or 10-6 MR crossing 12MR, Beta zeolites 12ZE and 12MR crossed (Zeolites, 8, 446-452 (1988), designated BEA in IZA code) are active and catalytic Excellent stability Al-rich Beta (Microporous Materials, 5, 289-297, 1996), boron-containing Beta zeolite (Proc. 9th Int. Zeolite Conf., Pp. 425-432, 1993; J. Incl. Phenom Mol.Recogn.Chem., 20, 197-210, 1994), beta zeolite containing gallium (J. Incl. Phenom.Mol.Recogn.Chem., 20, 197-210, 1994), beta zeolite with titanium (Chem) Commun., 2367-2368, 1996), CIT-6 (Topics in Catalysis, 9, 35-42, 1999), beta zeolite consisting solely of silica (pure silica beta, Chem. Commun., 2365-2366, 1996) and Tschernichite (Am. Mineral., 78, 822-826, 1993) is also possible and can be used as a trimerization catalyst if any hydrogen cation is present and has an acid point. Zeolite catalysts can be applied to any ionic form by its acidity, but in the hydrogen form (proton form) it is more preferable because the acidity is high and the reactivity is more preferable. It is still more preferable if it is 0.5 or more.

Zeolite catalysts with intersecting pores can be used in the form of powder or granules, and can be formed in any form such as pellets, spheres, extrudates, etc. by using additional binders. The preferred form is more preferable in terms of preventing the differential pressure. The size of the catalyst is not practically limited, but the grain size is preferably 0.1 mm or more, more preferably 0.2-10 mm.

As the conversion rate of oligomerization increases as the conversion rate increases, the concentration of trimer increases so that it is irrelevant to 50% or more. If the conversion rate is too low, there is a large amount of impurities, and if the conversion rate is too high, impurities of larger molecular weight or higher than tetramers are easily mixed, so it is necessary to increase the concentration of the diluent or the solvent.

If the flow rate of the reactants is too slow, not only the productivity is low but also the by-products of large molecular weight are bound to by-products and if too fast, the conversion rate of the reaction and the selectivity of the trimer are low. 0.5-100 h ^-1 is appropriate and 1-50 h ^-1 is more suitable based on the weight hourly space velocity (WHSV) of the olefin.

The oligomers obtained by oligomerization may be used directly for industrial purposes, such as making neo-acid compounds, or may be converted to high boiling point alkylates through hydrogenation. For the hydrogenation reaction, general hydrogenation reactors and catalysts such as fixed bed reactors and continuous stirring reactors can be used.The catalysts are Pd / C, Pd / alumina, Pt / C, Pt / alumina, Ru / C, Ru / alumina, Ni / C. , Supported catalysts such as Ni / alumina, mixed catalysts thereof, and catalysts in which Pd, Pt, Ru, Ni, etc., which have a hydrogenation activity, are mixed and supported. The hydrogenation reaction can be any reaction in the liquid and gas phase, and hydrogen is irrelevant as long as it is equal to or more than the equivalent of the hydrogenation reaction.

Hereinafter, the present invention is described in more detail in the following non-limiting examples.

Example  One

Beta zeolite (NH ₄ -type, Zeolyst, CP814E, SiO ₂ / Al ₂ O ₃ = 25, surface area = 680m ² / g) was calcined at 550 ° C for 8 hours to convert to hydrogen type catalyst (H-Beta catalyst) Used as. After press-fitting a fixed pellet reactor flowing upstream with dry pellet type (diameter: distributed between 0.5-2 mm) of 2 g of the H-Beta catalyst, it was maintained at 300 ° C. for 10 hours with nitrogen, pretreated, and then cooled to reactor temperature. Was maintained at 70 ° C and n-butane and iso-butene were injected at a ratio of 1: 1 (weight ratio) using a liquid mass flow controller (MFC) to promote the oligomerization reaction. i-butene was fed such that WHSV (g-isobutene / g-catalyst / h) = 10 h ⁻¹ . As reaction heat was generated, a constant reaction temperature was maintained by using a liquid circulator to control the amount of heat injected or absorbed from the outside. After the reaction, the total flow rate of n-butane and iso-butene was measured by mass flow meter (MFM) to calculate the conversion rate, and the conversion rate was again confirmed by analyzing gaseous components by gas chromatography (GC). The liquid product was collected and analyzed by GC to analyze the composition of the product. As shown in FIG. 1, the reaction was very stable through the reaction for 60 hours, the conversion after 60 hours was 99.9%, the selectivity of the trimer was maintained at 57.9 wt%, and the selectivity of the dimer was present at a small amount of 12.9 wt%. . Detailed reaction conditions and results are summarized in Table 1.

Example  2

The reaction was performed in the same manner as in Example 1, but i-butene WHSV was increased to 50 h ⁻¹ instead of 10 h ⁻¹ to maintain a large space velocity. The i-butene conversion was 94.7%, the trimer selectivity was 57.6 wt% and the dimer selectivity was 30.7 wt% after 12 hours of reaction even at very high space velocity. Detailed reaction conditions and results are summarized in Table 1.

Example  3. Hydrogenation

After separating the trimer obtained in Example 1 by distillation, 10 g was added to the continuous stirring reactor, and 90 g of cyclohexane was added as a solvent. A catalyst basket made of stainless steel mesh was installed on the stirred shaft, and 0.5 g of Pd (5%) / C catalyst was placed therein, and the temperature was raised to 100 ° C. and maintained at 10 atm using hydrogen. The reaction was started by stirring, and the consumed hydrogen was always supplied to 10 atm using a back pressure regulator. After 1 hour of reaction, cyclohexane was distilled off and the conversion of olefin to paraffin was found to be 99.5% by gas chromatographic / mass spectrometry, indicating that high boiling point alkylate was successfully obtained.

Comparative example  One

In the same manner as in Example 1, instead of using the H-Beta catalyst, commercial ammonium mordenite (Zeocat, SiO ₂ / Al ₂ O ₃ = 25) was calcined in an electric furnace at 550 ° C. After the removal, the H-mordenite was converted to hydrogen and used as a catalyst. Mordenite catalysts do not have intersecting pores but only one-dimensional pores of 12 MR. Although the activity was high at the beginning of the reaction, the conversion rate decreased rapidly to 20.0% after 12 hours of reaction, and the selectivity of the trimer was present in a small amount of 8.7 wt%. Detailed reaction conditions and results are summarized in Table 1. Although the reaction time was short, the conversion was low and the selectivity of the trimer was very low.

Table 1 trimerization reaction conditions and results

As described above, according to the present invention, the use of a zeolite having mutually intersecting pores as a catalyst may selectively proceed with the olefin trimerization reaction. The oligomers thus obtained can be used to prepare neo-acids or can be converted to high boiling point alkylates which can be used as additives for higher solvents and gas oils by hydrogenation.

Claims (9)

The amount of olefins using a catalyst is characterized by using a zeolite composed of a zeolite composed of 12 oxygen-containing pores, 12 oxygen-containing pores, and / or 10 to 6 oxygen-containing pores. Method of making sieves. The method of claim 1, Zeolites having mutually intersecting pores are zeolite Beta, Al-rich Beta, boron-containing Beta zeolite, gallium-containing Beta zeolite, titanium-containing Beta zeolite, CIT-6, silica zeolite consisting of only beta or Tschernichite structure Method for preparing trimer. The method of claim 2, Zeolites having pores that cross each other have a zeolite Beta structure. The method of claim 1, Zeolites having pores that cross each other are hydrogen-type. The method of claim 1, The reaction temperature is 50 to 100 ℃, the space velocity is 0.5 to 100 h ^{- 1} maintaining the reaction, characterized in that the olefin trimer production method. The method of claim 1, A method for producing an olefin trimer, wherein the conversion rate of the olefin is maintained at 50% or more. The method of claim 1, The olefin is isobutene, the process for producing an olefin trimer. delete delete

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