JPH04224539A - Process for producing tert-amyl methyl ether from c5 olefin fraction - Google Patents

Abstract

PURPOSE: To prepare tert-amyl methyl ether(TAME) which is effectively used as an oil manufacture agent and an octane number improving agent by utilizing C5 raffinate fraction obtained when butadiene and light olefin are prepared.

CONSTITUTION: Methanol and 5C olefin are reacted on a catalyst of acidic smectite clay [preferably acidic montmorillonite-silica-alumina clay of the formula (M is cation of balancing sodium or lithium between lamellas; x, y and n are number; acidity of clay is 3-20 mgKOH/g)] modified by palladium or heteropoly acid (preferably 12-phosphorus tungstic acid, 12-phosphorus molybdic acid, silicotungstic acid, or 12-silicomolybdic acid) at 20-250°C and at 0.1-7.0 MPa of pressure, to prepare TAME with high concentration of, e.g. 53%. The TAME can be isolated by the fractional distillation with 99% concentration in maximum.

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides methanol and C5
C5 hydrocarbons containing olefins and an acidic clay catalyst,
In particular, it relates to an improved method of synthesizing tert-amyl methyl ether by reaction in the presence of a modified montmorillonite acidic silica-alumina catalyst. This reaction is based on tert-amyl methyl ether (TAM
E) can be produced continuously, for example in concentrations as high as 53%, and TAME can be produced up to 99% by fractional distillation.
It is particularly advantageous in that it can be isolated at a concentration of .

Recently, there has been interest in using smectite clays as catalysts. It is known that its unique structure allows for modification that provides useful catalytic properties.

0003

BACKGROUND OF THE INVENTION Some of the unique properties that make smectite clays interesting as catalysts are described in Chem. Sy
stems Report 94-3, 239-24
9 of 3.4320 copies, “Catalysis: Sel.
It is mentioned in the article titled ``Active Developments''. These compositions are layered and exhibit a 2:1 relationship between tetrahedral and octahedral loci. In addition, the combination of cation exchange, interlayer intercalation, and the fact that the interlayer distance can be adjusted offers interesting possibilities. Moreover, by simple ion exchange techniques, the cations between the lamellar faces (Ca+2 or Na+) can be replaced with almost any desired cation.

[0004] Various factors affect clay catalysts. C
atal. Rev. Sci. Eng. ,30(3)
, 457-499 (1988).
The article titled ``Clays as Catalysts'' provides a review of the factors that influence the properties of pillared clays, including methods by which thermal stability can be improved in the range 480-800°C. It has been found that the method used to dry the agglomerated clay appears to be more important than the choice of pillaring agent and the charge of the clay layer in determining the porosity of the final product. For example, adsorption is one property that changes depending on the drying method. Also, certain chemicals, such as Al2O3, can be fixed to the clay to change its pore size distribution and increase its thermal stability, thereby increasing its surface area.

The article also describes the acidity of the pillared clay as well as the manner in which differences in processing affect Lewis or Brønsted loci to different extents. Since pillared clays do not necessarily behave in the same way as zeolites, it seems necessary to seek the presence of some type of acid locus.

``Progress in Inorga''
nic Chemistry”, Vol. 35, p.
41 (1987) discusses clay mineral catalysts including acidic montmorillonite clay catalysts. Methods for pillaring catalysts of this type have been described. Pillaring is made from lamellar solids of clay, a material that disintegrates when heated to temperatures of only a few hundred degrees Celsius.
It can be converted into a more heat-resistant two-dimensional zeolite-type material that can withstand heat treatment in a humid atmosphere far exceeding 00°C.

US Pat. Nos. 4,176,090 and 4
, 248,739 discloses a method for adding silicate to an aluminum chlorohydral solution to significantly increase the surface area of the clay. The best hydrothermal stability reported to date in the art is, in part, related to clays in which hydroxysilica-aluminum ions are intercalated.

[0008]J. Adams, Applied C
Ray Science, 2, 309 (1987), the use of cation-exchanged and acid-treated pillared montmorillonite as a catalyst for reactions that can be carried out on a laboratory or industrial scale. We are considering. These catalysts are known to exhibit Brønsted and Lewis acid activity, but may also be effective in Diels-Alder reactions. The ability of clays to act as Brønsted and Lewis acids has also been described by J. of Inclusion Pheno
Mena, 5, 663 (1987), J. M.
Adams and K. “Cla
ys as Selective Catalysts
in Organic Synthesis”. After reviewing the activity of Brønsted acids in such clays, Adams et al. state that utilizing cation-exchanged clays, if they involve tertiary or allylic carbonium ion intermediates, the reaction is 100℃
It was discovered that the process progresses even at temperatures below . At 150-180°C, reactions involving primary and secondary carbonium ions are possible.

This author also states that potential Lewis acid centers are present in smectite clays. A
The l3+ and Fe3+ ions are usually associated with the octahedral faces of montmorillonite. Page 668 describes the reaction of alcohols with isobutane in the presence of montmorillonite catalysts. This reaction gives tertiary ethers in high yields even at low temperatures according to the following equation.

0010

[Case 2]

It has been found that in this reaction, the reaction rate is proportional to the concentration of isobutene. Possible reaction equations are:

0012

[Chemical formula 3]

The rate-limiting step is the protonation of the alkene (K4
). Obviously, the effect of the solvent is large;
Using 1,4-dioxane increases the speed by a factor of 6 and promotes miscibility of all reagents. In contrast, the reaction of alcohols with linear 1-alkenes is slow and gives a mixture of 2-alkoxyalkanes and 3-alkoxyalkanes.

[0014] The use of phosphates of metals of group IV of the periodic table has been
emistry; Molecular Approa
chess to surface catalyst
, 231, 271 (1988), A. Cle
“Recent Advance” by arfield
es in Pillared Clays and
Group IV Metal Phosphates
”. Smectite clay swells with water and forms giant ions such as [Al13O4(OH)].
24・12H2O]7+ and [Zr(OH)2・4H2
It is known that O]48+ can be exchanged. These giant cations then act as pillars that open and support the clay layers. This property allows the production of catalytic materials with larger pores than found in zeolites. In particular, the potential use of α-phosphorus zirconates, which are layered compounds that are pillared by crosslinking the layers with aryl diphosphonic acids, is disclosed. It is clear that if the clay is pillared, the spacing of the pillars is determined by the radius of the incoming cation.

Smectites are characterized by alumina octahedra sandwiched between layers of silicate tetrahedra. In smectites, substitution of Al+3 by Mg2+ and substitution of Mg2+ by Li+ can occur in octahedral loci, or M3+ ions can replace Si4+ in tetrahedral loci.

[0016]J. Am. Chem. Soc. ，
101, 6891 (1979), Pinnav
aia et al. reported that the rapid collapse of simple ions sandwiched between layers, such as hydrated Cu2+ and Mn2+, and the movement of free solvent between the clay layers lead to reactions catalyzed by metal complexes in the crystalline space of the mineral. He pointed out that it shows the possibility of implementing

[0017]J. Mol. Catal. ,49,8
5 (1988), “Synthesis de
L'Ether Methyl Ter-Amilyq
ue (TAME) En Catalyse Asi
de: Cinetiques Et Equilib
Methoxylation
du Methyl-2-Butene-2'', S. et al. The article by Randriamahefa et al. describes a method for producing tert-amyl methyl ether by methoxylating pure C5 isoolefins using a catalyst consisting of a polymer-supported sulfonic acid.

[0018] J. Mol. Catal. ,49,L
Y. 47 (1989). V. The article by Subba et al. describes the synthesis and characterization of interlamellar montmorillonite-3-aminopropyltriethoxysilane (IA) and its palladium(II) complex, and the conversion of aromatic carbonyls to the corresponding carbinols at room temperature and atmospheric pressure. first describes a method for selectively reducing nitrobenzene to aniline. Selectivity of carbonyl hydrogenation was demonstrated and attributed to changes in the electronic and coordination environment of the complex introduced between the layers of montmorillonite. Tests have shown that the palladium used in the catalyst remains divalent. The catalyst exhibited less than 1% of its original hydrogenation activity after the extraction process, demonstrating that no hydrogenation was carried out by the process involving metallic Pd particles. .

``A Novel Anchored P
alladium(II) Phosphinated
Montmorillonite: theFisr
st Example in the Interla
Mellers of Smectite Clay,” by J. Chem. Soc. Chem. C
ommun. , 931, (1985), B. M. Choudary et al. disclose that montmorillonite containing PdCl2 in the interlamellar zone, fixed by attached phosphonate groups, selectively hydrogenates terminal alkenes and alkynes. This article suggests that by appropriately controlling the interlayer extension, sterically hindered double and triple bonds can be selectively reduced.

Methyl-tert- using a clay catalyst
A method for synthesizing butyl ether from methanol and isobutene is described in Clay and Clay Minera
J. ls, 30, 129 (1982). M. A
Covered in another article by Dams et al.

US Pat. Nos. 4,605,806 and 4
, 665,220 discloses that layered clays such as montmorillonite are useful as catalysts in the etherification of olefins with, for example, alkanols.

[0022]

It would be of considerable commercial value if tert-amyl methyl ether could be synthesized by rapid conversion of methanol and C5 olefins over a modified acidic catalyst. It will be. Methyl-tert-butyl ether (MT
Such a process would be particularly effective if TAME could be produced as a primary or secondary product from the typical C5 raffinates obtained in the production of BE), butadiene and light olefins. It will be. Furthermore, the acidic clay catalysts described are particularly effective and thermally stable.

[0023]

SUMMARY OF THE INVENTION The present invention provides a method for converting methanol and C5 olefins onto acidic smectite clay catalysts, particularly montmorillonite-silica-alumina clays, which have been modified with palladium or heteropolyacids.
A method for producing tert-amyl methyl ether by reaction at a temperature of ~250<0>C and a pressure of 0.1-7.0 MPa.

In various embodiments of the present invention, the clay is prepared by (i) having a heteropolyacid attached to the clay, (ii) modifying the clay with platinum or palladium, (iii) modifying the clay by:
Modified by mixing with supported platinum or palladium catalysts.

The catalyst preferably consists of a montmorillonite acidic silica-alumina clay in powdered, granular or extruded form.

A distinctive advantage of the present invention over the prior art is that the C5 raffinate fraction obtained in the production of MTBE, butadiene and light olefins can be used to produce TAMs useful as refining agents and gasoline octane improvers.
E can be produced. TAME can be isolated with a purity of up to 99% by fractional distillation.

This reaction can be expressed by the following equation.

[0028]

[C4]

This process is very useful in the reaction of C5 olefins, especially those containing significant amounts of isoamylene. This same method can be applied to other C5
It may also be applied to olefin reactions. For example, the method may be applied to reacting low molecular weight alkanols with 2-methyl-1-butene, 2-methyl-2-butene or 3-methyl-1-butene.

The reforming catalyst used for carrying out this reaction is preferably obtained by modifying a montmorillonite acidic clay catalyst rich in silica and alumina. A variety of clay catalysts containing aluminum and silica are effective for this reaction (Equation 1), but the alumina or silica must be acidic under normal operating conditions. Chemically, clay consists primarily of silicon, aluminum and oxygen, with occasional small amounts of magnesium and iron. Changes in the proportions of these constituents and changes in their crystal lattice shapes create approximately 50 different clays, each with unique properties.

Particularly effective for the reaction of Equation 1 are the smectite clays used according to the invention. Smectite clays are described in Chem. Systems Report
It is featured in the article described in T, 84-3. These clays have small particle sizes and unique intercalation properties that result in large surface areas. These are aluminosilicates that exhibit a unique structure that allows modification to yield useful catalysts. These consist of layered planes in which octahedral loci are arranged between faces of tetrahedral loci. The interlayer distance can be adjusted by treatment with a suitable solvent or by swelling by treatment with pillaring or Lewis acid reagents or the like. What makes smectites particularly interesting among clay minerals is that they have a combination of cation exchange, intercalation, and expansion properties.

Three-layered smectite clays include montmorillonite, vermiculite, and some types of mica.
All of these can be expanded between layers by appropriate processing. The ideal basic structure of this type of clay is that of pyrophyllite, with the formula: Si8Al4O20(OH)4.

The structure of montmorillonite is generally represented by the formula:

embedded image where M is an interlamellar balancing cation, usually sodium or lithium, and x, y and n are numbers.
Indicated by

[0034] These montmorillonite clays are best utilized in acidic form for this application. The acid activates montmorillonite by attacking and solubilizing the structural cations in the octahedral layers. This opens up the clay structure and increases the surface area. These acid-treated clays act as strong Bronsted acids.

Acidic montmorillonite clay is the preferred form of smectite clay used in this invention. These may be acidified by pretreatment with mineral acids, such as sulfuric acid or phosphoric acid. Preferably, these acids are
3 to 20 by titration to the phenolphthalein end point.
It should exhibit an acidity of mg KOH/g, but may have a higher acidity. The surface area of these is 3
More than 0 m2/g, preferably 200 to 1000 m2/g
It should be g. Their moisture content should also be limited, preferably less than 20% weight loss when heated to 99-100°C.

A representative example of a suitable acidic montmorillonite clay is Engelhard's 10mg KOH/
Clay-113 in powder form exhibiting a residual acidity of 300 m2/g, a surface area of 300 m2/g, and a water content of 4% by weight.
; shows acidity of 16mg KOH/g, 300m2/
Cla having a surface area of g and containing 16% water by weight.
y-13; 20/60 mesh (0.25-0.84
Granular Clay-24 with a particle size of 10/20 mesh (0.84 mm), an acidity of 16 mg KOH/g, a surface area of 300 m2/g, and a water content of 10% by weight; 2.0mm) and 16mg
Granular Clay- exhibiting an acidity of KOH/g, a surface area of 400 m2/g, and a water content of 12% by weight.
25; 20/60 mesh (0.25-0.84mm
), exhibiting an acidity of 3.0 mg KOH/g, having a surface area of 350 m/g, and containing less than 1% water by weight; and e.g. 1/16 inch diameter (1.59mm) or 3/16 inch (
4.76 mm), exhibits an acidity of approximately 3.0 mg KOH/g, has a surface area of 275 m2/g, and contains less than 1% moisture.

In one embodiment of the invention, palladium catalysts, such as palladium salts, palladium oxide or palladium complexes, are exchanged into the clay or chemically bonded to the structure of the inorganic support to improve selectivity. , the target te
rt-amyl methyl ether can be obtained in particular from a C5 olefin mixed feed. Suitable palladium derivatives include palladium salts such as palladium chloride, palladium acetylacetone and palladium acetate. Palladium salts may be introduced into the clay by ion-exchange methods, or may be introduced into the clay by ion-exchange methods, such as those described in J. I., which describes the preparation of functionalized clays, such as lamellar montmorillonite-silylamine-palladium(II) catalysts. Mol. Catal. ,49,L47(19
It may also be chemically bonded to aminosilylated clays such as Engelhard's aminosilylated Clay-24 prepared according to the method by Choudary et al., 89).

Another possibility is to use acidic clays of the above-mentioned class in combination with another heterogeneous palladium catalyst. In particular, the acidic clay catalyst can be used in combination with another supported palladium catalyst, such as a palladium on carbon catalyst. In this case, the carrier may be carbon, alumina, silica, titanium oxide, zirconia, magnesium oxide, or combinations thereof. The amount of palladium is 0.1 to 20
It should be expressed as % by weight. A suitable example is Enge
Clay-24 granules from lhard in combination with 5% by weight of palladium on carbon are used. Combinations of these catalysts may be intimately mixed or used separately. The clay:palladium catalyst weight ratio can be from 100:1 to 1:100.

In another embodiment of the invention, a heteropolyacid can be attached to a clay catalyst to improve selectivity and obtain the desired tert-amyl methyl ether, particularly from a C5 olefin blend feed. Suitable heteropolyacids that can be attached to the clay include the types of acids formed by the condensation of two or more inorganic oxyacids. For example, when phosphate and tungstate ions are reacted in an acidic medium, they condense according to Equation 2 to form 12-phosphotungstic acid, a typical heteropolyacid (HPA).

[0040]

[C6]

A variety of elements ranging from Groups I to VIII of the Periodic Table can serve as the central atom of the HPA anion, the so-called heteroatom (P in Formula 2). The nature of the heteroatoms is the dominant factor determining both the fused structure and physical properties of HPA.

The atom coordinated to the heteroatom via oxygen is called a polyatom (W in the case of formula 2), and in most cases,
Any one of a limited number of species such as molybdenum, tungsten, niobium or vanadium. The properties of the heteroatoms, condensation ratios and corresponding HPA anion chemical formulas are summarized below for the case of molybdenum (Mo) polyatoms.

An anion having a so-called Keggin structure is
It has a condensation ratio of 1:12 and is the most typical HPA anion. Heteropolyacids with the Keggin structure and their congeners are generally the most easily obtained and most commonly used in catalytic reactions. The synthesis of these heteropolyacids has been described in the literature (e.g. U.S. Pat.
No. 47,332).

[0044]

[Table 1]

Suitable heteropolyacid catalysts for use in accordance with the invention may contain molybdenum, tungsten, niobium or vanadium as polyatoms and phosphorus, silicon, germanium or arsenic as heteroatoms. Preferably the heteroatom is phosphorus or silicon. These heteropolyacids probably have the Keggin structure: H8-n
[XM12O40] (wherein, X is P or Si,
M is Mo or W and n is 4 or 5).

Preferred heteropolyacids for practicing the invention include 12-phosphomolybdic acid: M3PMo12O
40,12-phosphotungstic acid, silicomolybdic acid:
H4SiMo12O40 and 12-silicotungstic acid. These acids are generally used as hydrates. These may be used as such, partially or completely dissolved in the raw material, or preferably as a heterogeneous catalyst bound to a suitable clay support.

The weight percent concentration of polyatoms M in the formulated heteropolyacid-supported clay catalyst should generally be between 0.1 and 20 weight percent.

Catalysts of the type mentioned above are also suitable for MTBE, TA
It can also be used to co-produce ME and higher analogs. Two other results obtained using these classes of catalysts are that a) the diolefins contained in the feedstock are hydrogenated to monoolefins, and b) the double bonds in the monoolefin fraction of the feedstock are hydrogenated. Become isomerized.

The preparation of tert-amyl methyl ether can be carried out batchwise in a continuous slurry bed reactor or a fixed bed continuous flow reactor. For practical reasons fixed bed methods are preferred. The catalyst or catalyst combination is effective in the form of powder, extrudates or granules. In all cases, the amount of catalyst should be sufficient to provide the desired catalytic effect.

[0050] The production of TAME generally takes between 20 and 250
C (or 20 to 200 C when using a catalyst modified with a heteropolyacid). The preferred range is 60-180°C. The operating pressure is 0.
It can be between 0 and 1,000 psig (1 to 7.0 MPa) or higher. The preferred pressure range is 0.8
~2.9 MPa (100-400 psig).

[0051] Usually, TAME is 53% by weight in the crude product liquid.
or higher concentrations. TAME can be isolated in up to 99% purity by fractional distillation. The olefin feedstock components include pure isoamylene, a mixture of C5 olefins (e.g. 2-methyl-1-butene, 2
- mixtures of C5 olefins and C5 alkanes, including n-pentane and isopentane (2, 3, 4, 5 per molecule) , a C5 cut consisting of hydrocarbons having 6 or more carbon atoms. The C5 fraction contains saturated hydrocarbons such as isobutane, n-butane, isopentane, hexane, etc., olefins such as 1-butene, cis- and trans-2-butene, isobutylene, isoamylene, 3-methyl-1-butene, and 2-methyl-1-butene may also be included in combination with polyenes such as 1,3-butadiene and isoprene. Typical feedstocks include the C5 raffinate fraction from the MTBE unit and the C5 fraction from the light olefin unit. Such raw materials may contain 1 to 50% by weight of isoamylene.

The alcohol/C5 olefin feedstock can also be diluted with a suitable solvent before being fed to the reaction vessel. Suitable diluents include saturated hydrocarbons such as n-pentane and ethereal solvents such as p-dioxane.

The molar ratio of alcohol:C5 olefin raw material can be from 100:1 to 1:100,
Generally, a slight excess of alcohol is used. The preferred molar ratio of methanol:isoamylene raw material is 1:1 to 1.
The ratio is 0:1.

In general, methanol and C5 olefin conversions are good, and TAME selectivity is often 93-99 mole percent or more, based on either converted methanol or isoamylene. . If the C5 feedstock is a mixture of C5 olefins, T
The selectivity of AME is 10 based on isoamylene.
It may exceed 0%. The reason for this is that other C5 olefin fractions, especially 2-methyl-1-butene, are isomerized and reacted with methanol to form the desired product. These selectivities are achieved with total liquid hourly space velocities of 1 to 10 or more. liquid hourly space velocity (
LHSV) is defined as follows.

[0055]

[Math 1]

The following examples show that TAME was combined with methanol and a C5 raffinate fraction containing various C5 olefins including a) pure isoamylene, b) isoamylene diluted with n-pentane, and c) isoamylene. An example of a method for manufacturing from T explained below
Catalysts suitable for the synthesis of AME include: 1) acidic montmorillonite clay; 2) acidic montmorillonite clay containing ion-exchanged palladium salts; 3) montmorillonite-silylamine-palladium (I).
I) Catalysts 4) Physical mixtures of montmorillonite clay and supported palladium catalysts, and 5) Acidic silica-alumina clays to which a heteropolyacid, such as 12-phosphotungstic acid, is bound.

TA of methanol, ie isoamylene
In the following examples, the conversion rate to ME is estimated using the following formula.

[0058]

[Math 2]

The selectivity to TAME is generally estimated from the following equation.

[0060]

[Math 3]

[0061]

EXAMPLES Each example, including the data in the table, illustrates a one-step synthesis of TAME from a C5 olefin and methanol. The following points should be noted in the following examples.

a) Example 1 was carried out using an Engelhard Clay-24 catalyst at an LHSV of 1 to 10 and a temperature of 80 to 140° C., yielding TAME in concentrations up to 27%. The raw material mixture contains pure methanol and isoamylene in a weight ratio of approximately 2:1 (molar ratio 4.8:1).
It was included in the

b) In Example 2, when the raw material molar ratio of methanol:isoamylene is 1.2:1, the formed T
AME accounted for 53% of the product solution, and the yield was 93-99 mol% (based on converted methanol and isoamylene, respectively). TAME is produced by fractional distillation.
It could be isolated with a purity of 98%.

c) When the same methanol/isoamylene molar ratio 1.2:1 mixture was diluted with n-pentane, TAME was again produced in good yield (see Example 3).

d) TAME production was also demonstrated when the feedstock was a C5 raffinate fraction containing 6.9% isoamylene (see Example 4).

e) TAME production was similarly demonstrated when the feedstock was a C5 cut from a light olefin unit containing 14.3% isoamylene (see Example 5). In this example, the selectivity of TAME is 1
00 mol%, indicating that other C5 olefin components in the feed mixture are etherified to produce TAME.

f) TAME production was also demonstrated using palladium-modified montmorillonite clay. The selectivity to TAME was very good (Example 6).

g) The catalyst is acidic montmorillonite clay and 5
% palladium on carbon, TA
The selectivity to ME was further improved and reached 264 mol% (based on the apparent conversion of isoamylene) (comparison with Example 7 and Example 5). This result indicates that more of the other C5 olefin components in the feedstock are etherified to produce the desired TAME.

h) Even when a mixture of methanol and isoamylene in a molar ratio of 1.2:1 was diluted with n-pentane (Example 8), the palladium-supported aminosilanized clay was
was generated.

i) In Example 9, the TAME selectivity is significantly greater than 100 mol %, based on the converted isoamylene, and other C5 olefin components in the feed mixture are etherified to form TAME. It is shown that. ,

j) When the catalyst is a clay extrudate modified with 12-phosphotungstic acid, the selectivity to TAME is further increased to 261 mol% (based on the apparent conversion of isoamylene). (See Example 10). This result indicates that more of the other C5 olefin components in this feed are etherified to produce the desired TAME.

Example 1 (Comparative Example) Synthesis of TAME from isoamylene and methanol using an acidic clay catalyst.
It was carried out in a tubular reaction vessel. This reaction vessel has an inner diameter of 14
．． 3 mm x 25.4 mm long, made of 316 stainless steel, operated in rising mode, attached to the furnace for control over a range of ±1.0°C, and equipped with a pump. It was possible to control the flow rate within a range of less than 1 cc/h. The reaction vessel was also equipped with a pressure regulator and a device for monitoring temperature, pressure and flow.

[0073] In the reaction vessel, Engelhard's C
25cc of lay-24 granules were charged. A screen of glass beads was placed above and below the reaction vessel so that the clay granules remained in the middle region.

The catalyst bed was prepared using methanol/isoamylene (2
:1) A temperature of 100 °C by washing with the mixture;
2.17 MPa (300 psi) back pressure and 25 cc
Conditioning was carried out overnight at a flow rate of /h. Then, this methanol + isoamylene solution (weight ratio 2:1) was passed through the catalyst bed at 25 cc/h by a pump, while the reaction vessel was heated at 100 °C and 2.17 MPa (300 ps).
The total pressure of i) was maintained. Samples of the product were taken periodically during the flow by collection in a 316 stainless steel pressure bomb. Typical results from analyzes of samples taken under these conditions are summarized in Table I.

[0075] After reaching the equilibrium state, a certain range of temperature (80~140°C) and flow rate (25~250cc/
The performance of the catalyst was measured using h, LHSV1-10). The results of these six additional experiments are also summarized in Table I.

A sample of this mixed reaction solution (1,744 g)
was fractionally distilled at atmospheric pressure. The distillate (233 g) boiling at 85-86°C contained more than 96% tert-amyl methyl ether (TAME).

[0077]

[Table 2]

Example 2 (Comparative) Following the procedure of Example 1, a fresh sample of Clay-24 granular catalyst was added to 25 cc.
The mixture was treated with a mixture of methanol (768 g) and isoamylene (1,402 g) in a molar ratio of 1.2:1 at a temperature of 100° C. using a flow rate of /h. Samples of the product liquid were taken periodically during the flow and analyzed by GLC (gas liquid chromatography). The results are summarized in Table II.

Similarly, a certain range of temperature (80 to 140
℃) and flow rate (25-100 cc/h). The results of these additional experiments are also summarized in Table II.

A sample (989 g) of this mixed reaction solution was fractionally distilled at atmospheric pressure. Distillate boiling at about 85°C (12
7g) contained 98% TAME.

Analysis of the data from sample 4 shows that isoamylene conversion is 57%, methanol conversion is 48%, and TAME selectivity (based on isoamylene) is >99 mol%.
The TAME selectivity (based on methanol) was found to be 93 mol%.

[0082]

[Table 3]

Example 3 (Comparative) A fresh sample (40 cc) of Clay-24 granular catalyst was prepared according to the procedure of Example 1.
at a temperature of 80°C using a flow rate of 80cc/h,
Treated with a 2:1 molar mixture of methanol/isoamylene diluted with n-pentane. Samples of the product liquor were taken periodically mid-stream and analyzed by GLC. The results are summarized in Table III.

Similarly, a certain range of temperature (60 to 120
The performance of the catalyst was measured at The results of these additional experiments are also summarized in Table III.

Analysis of the data from Sample 5 revealed that the isoamylene conversion rate was 51%, the methanol conversion rate was 39%, and the TAME selectivity (based on methanol) was 95 mol%.

[0086]

[Table 4]

Example 4 (Comparative Example) A fresh sample (40 cc) of Clay-24 granular catalyst was prepared according to the procedure of Example 1.
C5 raffinate (3,000 g) and methanol (320 g) from the MTBE unit containing approximately 6.9% isoamylene were added at 80° C. using a flow rate of 80 cc/h.
). Samples of the product liquor were taken periodically midstream and analyzed by GLC for C5 and TAME content. The results are summarized in Table IV.

[0088] Working temperature within a certain range (80~120°C)
The performance of the catalyst was measured at the flow rate (40 to 80 cc/h). The results of these additional experiments are also summarized in Table IV.

[0089]

[Table 5]

Example 5 (Comparative) Following the procedure of Example 1, a fresh sample (40 cc.
) was mixed with a C5 fraction (3,000 g) from a light olefin unit containing about 14.3% of isoamylene and methanol (
640 g). Samples of the product liquid were taken periodically during the flow, and C5 and TAME
The content was analyzed by GLC, GLC-infrared spectroscopy and GLC-mass spectroscopy. The results are summarized in Table V.

Similarly, a certain range of working temperatures (80 to 1
The performance of the catalyst was measured at 20° C.) and flow rate (40-80 cc/h).

Analysis of the data from Sample 3 shows an apparent conversion of isoamylene of 43% methanol conversion.
51% TAME selectivity (isoamylene standard) 124 mol%
It turned out to be.

[0093]

[Table 6]

Examples A and B below illustrate the preparation of palladium reforming catalysts used in Examples 6 and 8 in accordance with the present invention.

Example A A 50 g sample of Engelhard Clay-24 granules was treated with acetylacetone palladium (1
．． 5 g, 5 mmol) of absolute ethanol (200 cc
) solution was added. The mixture was slowly stirred at 55° C. for 6 hours and filtered. Wash the solids with ethanol,
Dry in vacuo at 40° C. overnight.

The gray solid (48 g) recovered was P
It was found that it contained 0.2% of d.

Example B In a 1 liter flask, 11.5 g of dichlorobis(benzonitrile)palladium(II) (30 mmol)
, 100 g of aminosilanized Clay-24 (prepared by the method described above) and 500 g of dry toluene.
g was added. The mixture was stirred at atmospheric pressure for 24 hours and filtered. The solids were first washed with dry toluene and then extracted with toluene for 8 hours. The filtered solids were washed again with toluene and dried in vacuo at 40°C.

The recovered gray solid (108 g) was
It was found that it contained 2.7% Pd and 1.2% N.

Example 6 A sample of palladium-modified montmorillonite clay (25c) prepared according to the procedure of Example A was prepared according to the procedure of Example 1.
c) at a constant working temperature (80-120°C) and flow rate (
25-200 cc/h, LHSV=1-8) with a mixture of methanol and isoamylene. Samples of the product liquor were taken periodically mid-stream and analyzed by GLC. The results are summarized in Table VI.

Analysis of the data from Sample 2 revealed that the concentration of TAME in the crude product solution was: 53% TAME selectivity (based on methanol) 90 mol% TAME selectivity (based on isoamylene) >90 mol%.

[0101]

[Table 7]

Example 7 Following the procedure of Example 1, Engelhard's Cl
40 cc of a physical mixture of ay-24 granules (30 g) and palladium-supported carbon granules (10 g) was charged into a reaction vessel, and 13.1 weight of isoamylene was prepared at a certain temperature range (80 to 180°C). %
and a liquid feedstock (3,000 g) of C5 fraction containing 48.3% by weight of a mixture of 3-methyl-1-butene, 2-methyl-2-butene and 2-methyl-1-butene.
and 640 g of methanol. Samples of the product liquid are periodically taken during the flow and analyzed for GLC and GL.
Analyzed by C-infrared spectroscopy. The results are summarized in Table VII.

Analysis of the data from Sample 6 revealed that the concentration of TAME in the crude product solution was 8.9%, the apparent conversion of isoamylene was 22%, and the TAME selectivity (based on isoamylene) was 264 mol%.

[0104]

[Table 8]

Example 8 Following the procedure of Example 1, a sample of palladium-supported aminosilylated montmorillonite clay (40 cc) prepared according to the procedure of Example B was heated over a range of temperatures (60-140 cc).
C) with a mixture of methanol and isoamylene diluted with n-pentane. A sample of the product liquid was taken midstream and analyzed by GLC. The results are summarized in Table VIII.

Analysis of the data from Sample 7 revealed that the isoamylene conversion was 41% and the TAME selectivity (based on isoamylene) was 79%.

[0107]

[Table 9]

Example C This example describes the synthesis of the 12-phosphotungstic acid supported montmorillonite clay catalyst used in Examples 9 and 10.

[0109] Engelhard Grade-2
To a sample of 4 granules (100 g) was added 1 liter of an aqueous solution containing 288 g of 12-phosphotungstic acid. This mixture was mechanically stirred for 2 days at ambient temperature. The solid content was collected by filtration, washed with distilled water until no tungsten was detected in the filtrate, and heated at 40°C in vacuo.
It was dried for 1 to 2 hours.

The final clay (99 g) was found to contain 1.1% tungsten.

Example 9 The synthesis was carried out in the reaction vessel described in Example 1.

At the beginning of the experiment, the reaction vessel was charged with 40 cc of the 12-phosphotungstic acid supported montmorillonite clay catalyst described in Example C. Glass bead screens were placed above and below the reaction vessel to keep the granules in the middle. And methanol (640g,
20 moles) and about 11.5% (4.9% by weight) of isoamylene.
mol) and 3-methyl-1-pentene, 2-methyl-2-pentene and 2-methyl-1-pentene, totaling about 40
A reactant solution consisting of a C5 cut (3,000 g) obtained from a light olefin unit containing A total pressure of 300 psi was maintained. Samples of the product were taken periodically during the flow by collection in a stainless steel pressure bomb. Typical results from GLC analysis of samples taken under these conditions are summarized in Table IX. For sample 4, 2-methyl-2-butene conversion per catalyst bed pass
Methanol conversion per 35% catalyst bed passage 44%T
AME selectivity (based on converted isoamylene) 23
Approximately, it was found to be 2 mol%.

[0113] After reaching the equilibrium state, a certain range of temperature (80 to 120°C) and flow rate (40 to 80 cc/h)
The performance of the catalyst was measured. The results of these additional experiments are also summarized in Table IX.

TAME could be isolated from the typical product solution with greater than 99% purity by fractional distillation.

[0115]

[Table 10]

Example 10 Following the procedure of Example 9 and described in Example C, W0.9
40 cc of 12-phosphotungstic acid supported montmorillonite clay catalyst containing about 11.9 wt % of isoamylene (5.
1 mol) and 3-methyl-1-pentene, 2-methyl-2-pentene and 2-methyl-1-pentene total 41
% C5 fraction (3,000 g) and methanol (640 g). Samples of the product were taken periodically during the stream and analyzed by GLC for C5 fraction and TAME/methanol content. The results are summarized in Table X.

The performance of the catalyst was measured over a range of operating temperatures (80-140°C). The results of these additional experiments are also summarized in Table X. For sample 5 at 120°C, the 2-methyl-2-butene conversion per catalyst bed passage is 1
4% Methanol conversion per catalyst bed passage 14%TAME
The selectivity (based on converted isoamylene) was found to be 261 mol%.

[0118]

[Table 11]

Claims (15)

[Claims] [Claim 1] Methanol and C5 olefin,
A process for the production of tert-amyl methyl ether, comprising reaction over an acidic smectite clay catalyst at a temperature of 20 to 250°C and a pressure of 0.1 to 7.0 MPa, the catalyst being modified by palladium or a heteropolyacid. A method characterized by: 2. The smectite clay has the formula: [Image Omitted] where M is an interlamellar balanced sodium or lithium cation, x, y, and n are numbers, and the acidity of the clay is 2. The method of claim 1, wherein the acidic montmorillonite-silica-alumina clay has a concentration of 3 to 20 mg KOH/g. 3. The method according to claim 1, wherein the acidic smectite clay is pretreated with a mineral acid. 4. The method of claim 3, wherein the heteropolyacid is bonded to the acidic montmorillonite-silica-alumina clay. 5. The method according to claim 4, wherein the heteropolyacid is 12-phosphotungstic acid, 12-phosphomolybdic acid, silicotungstic acid or 12-silimolybdic acid. 6. A method according to claim 4, wherein the concentration of polyatoms in the formulated catalyst is from 0.1 to 20% by weight. 7. The method according to claim 1, wherein the acidic smectite clay is modified with palladium. 8. The method of claim 7, wherein the palladium-modified smectite clay is prepared by ion exchange of palladium salts and smectite clay. 9. The method of claim 7, wherein the palladium-modified clay is prepared by adding a palladium salt to an aminosilylated smectite clay. 10. A method according to claim 1, wherein the acidic clay catalyst is physically mixed with the supported palladium catalyst. 11. A process according to claim 1, wherein the C5 olefin is isoamylene. 12. C5 olefin is 3-methyl-
1-butene, 2-methyl-2-butene and 2-methyl-
11. Process according to any one of claims 1 to 10, characterized in that it is a mixture of 1-butenes. 13. C5 olefin is methyl-te
The method according to any one of claims 1 to 10, which is obtained from a raffinate fraction from an rt-butyl ether manufacturing unit. 14. A process according to claim 1, wherein the C5 olefin is a C5 cut from a light olefin unit. 15. A process according to claim 1, wherein a saturated hydrocarbon or ether diluent is used.