CA1244479A - Production of ethers - Google Patents

Abstract

ABSTRACT

A process for the production of an ether by contacting an olefin and an alcohol with a catalyst comprising a zeolite having an XO2/Y2O3 ratio equal to or greater than 10, wherein X is silicon and/or germanium and Y is one or more of aluminium, iron, chromium, vanadium, molybdenum, arsenic, manganese, gallium or boron, the zeolite being predominantly in the hydrogen form.
The process is particularly suitable for the production of methyl t-butyl ether from isobutene and methanol.

Description

Production of Ethers _______ ___-The present invention relates to the production of ethers; especially tertiary alkyl ethers. - -- -It is known to produce ethers by reacting ole-fins-and alcohols in the presence of suitable catalysts. For example, tertiary alkyl ethers may be prepared by reacting a tertiary olefin and an alcohol, e.g. isobutene and methanol to give methyl t-butyl ether, in the presence of catalysts such as mineral acids, e.g. sulphuric acid, and-a range of solid catalysts such as heteropolytungstic or molybdic acids doped with phosphorus or boron, acidified alumina, and various acidified ion-exchange resins.
The use of mineral acid catalysts can give rise to corrosion problems which make it difficult to-apply such catalysts on a commercial scale. Commercial pro cesses are known using acidified ion-exchange catalysts, especially for the production of methyl t butyl ether, which is particularly useful as a gasoline additive with high octane properties, but such catalysts often have poor thermal stability and this limits the reaction temperature which can be used, eOg. in many 7~

cases reaction temperatures not in excess of 80C. The use of lower reaction temperatures can in turn result in long reaction times and low throughput per unit volume of reaction vessel.
Another problem which can arise with known pro-cesses is the formation of dialkyl ether by-products deriving from the alcohol used.
Polish Patent No. 103379 describes a method of making methyl t-butyl ether by reacting methanol and isobutene in the presence of a catalyst comprising zeolite X or Y or a partially dealuminated, modified or ion-exchanged form thereo, the process being carried out in a vapour or liquid phase. Using zeolite Y in a vapour phase process at 120C, a liquid product is obtained con-sisting of 8.1% methyl t-butyl ether and 91.8~ methanol.
The same zeolite is used in a liquid phase process at 160C and a pressure of 31 atmospheres and a partially dealuminated zeolite Y is used at 125C and a pressure of 23 atmospheres.
According to US Patent No. 2882244, zeolite X has a silica/alumina ratio in the range 2-3 and according to US Patent No 3130007, zeolite Y has a silica/alumina ratio in the range 3-6.
We have now ound that tertiary alkyl ethers may be prepared from tertiary olefins and alcohols in the presence of certain zeolite catalysts under milder con ditions than are described in the Polish patent, con-ditions which allow the production of the tertiary alkyl ethers at high selectivity and in good yield, with low yields of undesirable by-product dialkyl ethers and oliyomers of the olefin.
According to the present invention we provide a process for the production of an ether which comprises contacting an olefin and an alcohol wlth a catalyst com-prising a zeolite having an X02/Y203 ratio equal to or greater than 10, wherein X is siliccn and/or germanium, and Y is one or more o aluminium, iron, chxomium, vanadium, molybdenum, arsenic, manganese, gallium ox boron, the zeolite being predominantly in the hydrogen form.
The said zeolites have acid sites within zeolite pore systems active i~ the catalysi~ of tertiary alkyl ether formation. The entry poxt size in the preferred zeolites is such that reactants and products can move into and out of the pore systems, i.e. with a Len~ard Jones diameter a (A) of from about 5.0 to 8.0 ~? (the Lennard Jones diameter a (A) is defined by D W Breck in "Zeolite Molecular Sieves", Wiley Intersclence, 1947, page 636).
The preferred zeolites for use as catalyst are 15 based on X02 as silica (SiO2) and Y203 a~ alumina tA1~03~.
Suitable zeolites which may be employed as catalysts in the process of the invention include:
Zeolite beta (US 3308069) ZSM-5 (US 3702886; EPA 0011362) 20 ZSM-8 (German OLS 2049755) ZSM-ll (US 3709979 ZSM-12 (US 3832449; EPA 0013630 ZSM-23 (US 4076842) ZSM-35 (US 4016245) 25 ZSM-43 (EPA 0001695) ZSM-48 (EPA 0015132) FU-l (UK 1563346) Nu-5 (Cdn. Appln. Ser. No. 392585) Nu-6(2) (Cdn. Appln. Ser. No. 391473) 30 Nu-10 (Cdn. Appln. Ser. No. 403309) Eu-l (European 42226) Eu-2 (UK 2077709A) . , .

Zeolite omega (UK 1178186) Zeolite phi (German OLS 2513682) The zeolites may be converted to their hydrogen form by methods which have been fully described in the prior art, for example by calcination of the as-made zeolite and subsequent acid exchange. If desired, the zeolites may be ion-exchanged or impregnated so as to comprise cations or oxides selected from the ollowing, - Cu, Ag, Mg, Ca, Sr, Zn, Cd, B, A1, Sn, Pbr V, P, Sbj Cr, Mo, W, Mn, Re, Fe, Co, Ni, noble metals and lanthanides.
The formation of olefin oligomers may be further inhibited by treating ths zeolite with a bulky-organic base, for example phenanthridine. It is believed that the base neutralises the surface acidic sites whilst being unable, because of its bulk, to enter the pore system of the zeolite.
Suitable olefins for use in the process of the invention include mono- or di-olefins containing from 4-16 carbon atoms, especially 4 to 9 carbon atoms, e.g.
isobutene, 2~methylbut-1-ene, 2-methylbut-2-ene,

2-methylpent l-ene, 2-methylpent-2-ene, 3-methylpent-2- - -ene, 2-methylhex-1-ene, 2-methylhept-1-ene and 2-methyloct-1-ene, or mixtures thereof. -- -Suitable alcohols for use in the process of the invention include primary and secondary alkanols con-taining from 1 to 12 carbon atoms t more preferably con-taining from 1 to 4 carbon atoms, e.g. methanol, ethanol, n-propanol, iso-propanol, and n-butanol. Also included are ether alcohols, e.g. RO(CH2CH20)nH where R is H or hydrocarbyl and n is 1-20, e.g. 2-methoxyethanol.
The process of the invention is particularly applicable to the production of tertiary alkyl ethers containing a total of 5 to 10 carbon atoms from the corresponding tertiary oleins and alcohols, and especially to the production of methyl t-butyl ether ~;~4~47~

from isobutene and methanol. The preferred zeolite catalysts for use in the production of MTBE are zeolites Nu-2, Nu-4, Nu-10 and beta.
The etherification reaction may be carried out in the vapour or liquid phase. The liquid phase reaction is typically carried out in a stirred and heated pressure vessel containing the reactants and catalyst. In the gas phase, the reactants may conveniently be passed through a heated tubular reactor containing the catalyst. This process readily lends itself to continuous production of the ethex product.
The liquid phase and vapour phase processes may suitably be carried out at a temperature in the range from 0C to 200C, preferably in the range from 50C to 110Cr for example70C to 100C. The reaction is normally conducted under atmospheric or superatmospheric pressure, e.g. at a pressure in the range 1 to 100 bars.
The molar ratio of the olefin to alcohol may vary widely but is suitably in the range from 0.5 to 5.0 moles of alkanol per mole of olefin.
For the liquid phase process, the proportion of catalyst in the reaction mixture may vary within very broad limits, but is suitably ~7ithin the range from about 0.1 to about 5~ by weight.
Under conditions suitable for the reaction of an alkanol and an olefin to yield tertiary alkyl ethers selectively, the zeolite catalyst is remarkably stable and doe not ltself suffer damage from degradation reactions which give materials having poor catalytic activity. By virtue of its nature,a zeolite can be rapidly recovered from the reaction mixture in liquid phase processes and c~n be reused in further batch operations.
Zeolites for use in the process of the invention, and methods for their preparation, have been described in the patent specifications referred to above. Inasmuch as some of these patent specifications are as yet unpub-lished, further details of zeolites Nu-2, Nu-4, Nu-5, Nu-6, Nu-10, EU-l, EU-2 and FU-9 are provided below.
Zeolite Nu-2 has a molar composition expressed by the formula:
0.5 to 1.8 R20 : ~23 : at least 10 X02 : 0 to 100 H20 wherein R is a monovalent cation or l/n of a cation of valency n, X is silicon and/or germanium, Y is one or more of aluminium, iron, chromium, vanadium, molybdenum, arsenic, manganese, gallium or boron, and H20 is water of hydration additional to water notionally present when R is H, and has a~ X-ray pattern substantially as set out in Tables 1 and 2 (as determined by standard technique using copper K~ radiation). Table 1 shows X-ray data for zeolite Nu-2 as prepared, and Table 2 shows X~ray data for zeolite Nu-2 in the calcined Na-H form.
Within the above definition of chemical composition, the number of moles of X02 is typically in the range 10 to 100 and zeolite Nu-2 appears to be most readily formed in a state of high purity when the number of moles of X02 is in the range 25 to 50.
Zeolite Nu-2 may be prepared by reacting an aqueous mixture containing at least one oxide X02, at least one oxide Y203, and at least one alkylated or part~ally alkylated quaternary ammonium or phosphonium or ternary sulphonium compound i.e. (RlR~R3R4N)~ or (RlR2R3R4P)-~ or tRlR2R3S)+ hereinafter referred to as Q~. Rl~ R2, R3 and R4 can be from two to four ethyl groups, the remainder can be H, CH3 or C3H7. Alternatively precursors of the quaternary compound can be used e.g. triethylamine plus ethanol, or an ethyl halide or sulphate, in which case the precursor is preferably preheated in a solvent e.g.
methyl ethyl ketone, prior to the addition of other reactants.
The reaction mixtures preferably have the fol-lowing molar composition.
X02/Y203 ~ 10, preferably 10 to 3000 Zeolite Nu-2 as made . _ . . . _ . . _ __ 1133 904 756 6.61--5037 14.51 1 4.14 ~
lOOI/ 23 vb 3 4 vb 3 3 vb 5 vb 2 ¦ 23 vb* ¦ 12 L~J

_ . .. _ _ .. . . .. . _ d~ 3.38 30 -31 3.10 ¦ 3.02 2.9 ;3 2.91 2.68 2.59 .. .. _ . _~
100/1 2 21 7vb 21 8 S vb 6 3 Vb = very broad di~ractlon peak Vb* = very broad base but terminating ln a very sharp peak TA~LE 2 Calcined sodium hydrogen Nu-2 d~11.33 9.04 ?.56 6.61 6.03 5.37 4.51 4.1a 3.96 ¦ 3-51 3.46 .... , . . _ __ _ ~ ...
.~ .. lOOI/ 22vb 17. 5 47b 3 3vb O 2 12 1 3 - - --. . . _ _ . _ . _ . . . _ . _ _ ¦ dA¦ 3.38 ¦ 3.31 ¦ 3.10 ¦ 3.02 ¦ 2.93 ¦ 2.91 ¦ 2.68 ¦ 2.59 ¦
¦ IV ¦ 2 ¦ lS ¦ 7vb ¦ 12 L 3 ¦ 5vb ¦ 6 1 2 J

Ak+/Q~ = 0.15 to 2.0 H20/Q = 30 75 OH-/X02 = Ool to 2.0 T~20/Ak~ 3 15 QZ/X2 = 0.02 to 0.4 wherein X and Y are as above, Ak+ is an alkali metal ion, or mixtures of such ions, which can include ammonium, and refers to free alkali, OH includes ree alkali and free quaternary ammonium hydroxide and Z is OH or any acid radical. When Z is an acid radical an equivalent excess of free Ak~ must be added as hydroxide in order to maintain the alkalinity of the reaction mixture. Q+
is a quaternary ion of N, P or S.
The preferred quaternary compound is tetra-ethylammonium hydroxide.
Zeolite Nu-4 has a molar composition expressed by the formula:
5 to 15 M10 : O to 10 Y203 : 100 X02 : O to 50 H20 wherein Ml is a monovalent cation or l/n of a cation of valency n, X is silicon or germanium, Y is aluminium, iron, chromium, vanadium, molybdenum, arsenic, antimony, manganese, gallium or boron, and H20 is water of hydration additional to water notionally present when Ml is H~ and has an X-ray pattern substantially as set out in Table 3 (as determined by standard technique using copper K
radiation). Table 3 shows X-ray data for zeolite Nu-4 as prepared and in the calcined hydrogen form.
Within the above definition of chemical com-position, the number of moles of Y203 is typically inthe ranye O to 10 and zeolite Nu-4 appears to be most readily formed in a state of high purity when the number of moles of Y203 is in the range O to 4.
Zeolite Nu-4 may be prepared by reacting an aqueous mixture comprising at least one oxide X02, at least one oxide Y203 and at least one polyalkylene TABI.E 3 ~ 4L4~9 ., . . , ~
Z~ollte Nu-4 Z~ollt~ N11-4 (~18 ioadel ~c~lclner~ i~ lorm) dA loO ~/~0 dA loo 1~O
, . . _ .. ... .
11.3 16 .1 ao 11.07 33 10.08 15 10.07 36 s.so a 9.96 10 9.~7 6 9.79 lo _ _ 9.28 1 , 9.05 L 9.02 1.5 _ _ 3.08 7.50 2 7.45 4 7.09 1 7.Q9 2 6.7a 2 6.72 4 5.44 S - 6.33 8 6.07 4 6.08 S
6.05 5 6.02 7 5.97 1 S.99 7 ~,75 8 5.73 9 5.65 6 5.57 a 5.63 2 5.~1 2 5.38 2 5.19 2 5.15 4 5.07 1 5.04 ` 3 5.~1 4 5.00~ 5 .91~ 1 ~.agg ~.
_ _ 4.725 4,629 9 4,610 9 ~ ~ 2 4.495 2 4.Jgo L
J . 475 2 4 . 470 2 4.386 13 4.380 14 4.291 10 4.Z80 13 .12~ 13 4.103 3 4 . 104 4 4.039 6 4.022 7

3.950' 1 3.950 3 3 . 880 100 3.850 69 3.869 100 _ _ 3.a36 73 3.7~13 51 3.764 35 3.730 SO 3.735 S~l 3 . 678 z7 3 . 662 29 3.649 22 3.604 ~ ~1 3.629 S
_ _ I . 500 5 3.466 12 3.469 10 3.364 6 3.3G8 7 3 . 332 9 3 . 342 10 3 . 329 4 3.273 4 3.265 3 3.267 4 - 3.260 4 3.260 12 ~'~4~L7~

polyamine having the formula:

Rl R4 N ~ [(CH2)x N - R3]y (CH2)X

10 where x is in the range 2 to 6 and y is in the range - -from 0 to 10, an amine degradation product thereof, or a precursor thereof. In the polyamine, each of Rl to R5, independently, represents hydrogen or a Cl-C5 alkyl group. When ~ i5 from 2 to 6, the R3 substituents may be the same or different. When y = 0 then x = 2 to 5.
The reaction mixture can have the following molar ratios:
X02/Y203 ~ 10 Q/X2 = 0.01 t~ 4.0 ~10E/x02 = o to 2.0 H2/X2 = 10 to 200 M2Z/X02 = 0 to 4.0 wherein X and Y are as above, Ml is an alkali metal or ammonium or hydrogen, M is an alkali metal or ammonium or hydrogen and can be the same as Ml and Q is the aforesaid polyalkylene polyamine, amine degradation product thereof or a precursor thereof, or a related compound. Z~ is a strong acid radical present as a salt of M2 and may be added as a free acid to reduce the free MlOH level to a desired value~ However, zeolite Nu-10 can be syntheslsed from a narrow range of molar ratios which falls withln this much wider range for zeolite Nu-4 synthesis. Therefore if SiO2/A1203 ratios between 70 and 300 are chosenO then to ensure that zeolite Nu-4 is obtained free of zeolite Nu~10 it is necessar~ to employ ~2JL?k447'9 either low H20/X02 ratios or high M1OH/X02 ratios or both.
The preferred ranges for preparing zeolite Nu-4 are as follows:
Range.l X02/Y203 = 20 to 70 Q/X2 = 0.15 to 4.0 H20/X02 = 15 to 60 MlOH/X02 = 0.01 to 1.0 M2Z/X02 = 0 to 2.0 Range 2(a) Xo2/Y203 = 70 to 120 Q/X2 = 0.10 to 4.0 M2Z/X02 = 0 to 2.0 if H~0/X02 = 20 to 30 then M10H/Xo2 = 0.04 to 1.0 2(b):
if H20/X02 = 30 to 40 then M10H/Xo2 = 0.1 to 1.0 2(c):
i~ H20/X02 = 40 to 60 then MlOH/X02 = 0.18 to 1.0 Range 3 X02/Y203 = 120 to 300 Q/X2 = 0-05 to 4.0 M2Z/X02 = 0 to 2.0 H20/X02 = 20 to 60 MlOH/X02 = 0.08 to 1.0 47~3 Range 4 X02/Y2o3 = 300 to 800 Q/X2 = 0.02 to 4~0 M2Z/X02 = 0 to 2.0 H20/X02 a 10 to 70 MlOH/X02 = 0 to 1.0 Range 5 -X02/Y2o3 = 800 to infinity (i.e~ to no Y203) Q/X02 = ~ to 4.0 M2Z/X02 = 0 to 2.0 H20/X02 = 10 to 80 MlOH/X02 - 0 to 2.0 The preferred polyalkylene polyamines are tri-ethylene tetramine and tetraethylene pentamine.
Zeolite Nu~5 has a molar composition expressed by the formula:
2 : Y203 : at least 10 X02 : 0 to 2000 H 0 wherein R is a monovalent cation or l/n of a cation of - valency n, X is silicon and or germanium, Y is one or more of aluminium,iron, chromium, vanadium, molybdenum, arsenic, manganese, gallium or boron, and H20 is water of hydration additional to water notionally present when R is H, and has an X-ray pattern substantially as set out in Table 4 (as determined by standard technique using copper K~ radiation). Table 4 shows X-ray data for zeolite Nu-5.
Within the above definition of chemical com-position, the numher of moles of X02 is typically in the range 10 to 5000 and zeolite Nu-5 appears to be most readily formed in a state of high purity when the number of moles of X02 is in the range 45 to 100.
Zeolite Nu-5 may be prepared by reacting an aqueous mixture comprising at least one oxide X02, X~ra~ diffraction data for Nu-5 , . , ....
As~made Nu-5 Hydrogen Nu-5 _ _ . ~ ~ . ~ .. .
dA looI~IO dA looI/Io ~__ ~
11.11 70 ~1.12 ~5 10.02 41 10.04 51 9.96 37 9.96 45 9.74 18 9.75 20 9.00 3 8.95 3 8.04 1 .8.03 1 7.~4 6 7.43 4 7.08 3 7.08 3 6.71 7 6.71 8 6.36 14 6.37 lS
S.99 15 6.01 19 5.70 12 5.59 13 5.58 15 5.13 4 5.14 3 5.03 6 5.02 5

4.g84 ~ 4.984 8 4.623 7 4.~16 8 40371 15 4.370 14 4.266 15 4.266 lS

..

~L ~2 ~ 9L L/~ ~7 9 TABLE 4 ( contd ) ~ , - . - ~ - . . . . ...
As-made Nu-5 Hydrogen Nu-5 , . . _ . ~ _ .
dA lOoI/IO dA lOOI/Io . . .~ _ ~ . -- - -, - .
4.095 14 4.095 9 4.014 11 4.022 12 3.859 100 3. ~59100 3.821 70 3.825 68 3.749 39 3.755 32 3.725 54 3.731 48 30643 31 3.652 28 3.598 4 3.601 4 3.484 . 7 3.484 6 3.358 10 3.355 9 3 ~ 315 12 3.315 11 3.054 12 - 3.054 12 -2.994 13 2.991 15 2.979 13 2.97g ~2 2.015 . 8 2.015 10 8 ~

at least one oxide Y203 and at lea~t one compound selected from pentaerythritol~ dipentaerythritol and tripentaery-thritol.
The reaction mixture preferably has the following molar composition:
X02/Y203 10 to 5000 preferably 50 to 200 MOH/X02 0.01 to 0.5 preferably 0.10 to 0.25 Z-/Y203 0 to 5000 preferably 10 to 100 A/Y 03 1 to 200 preferably 1 to 50 H~O/X02 10 to 500 preferably 15 to 300 wherein X and Y are as above, M is an alkali metal or ammonium, A is the aforesaid pentaerythritol compound and Z is a strong acid radical present as a salt of M
and may be added as a free acid to reduce the free OH
level to a desired value. M can be present as hydroxides or salts of inorganic or organic acids provided the MOH/X02 requirement is fulfilled.
The preferred pentaerythritol compound is penta-erythritol, itself.
Zeolite Nu-6t2) has a molar composition expressed by the formula:
. R20 : Y203 : at least 10 X02 : O to 2000 H20 wherein R is a monovalent cation or l/n of a cation of valency n, X is silicon, and/or germanium, Y is one or more of aluminium, iron, chromium, vanadium, molybdenum, antimony, arsenic, manganese, gallium or boron, and H20 is water of hydration,additional to water notionally present when R is H, and has an X-ray diffraction pattern substantially as set out in Table 5 (as determined by standard technique using copper Ka radiation).

4~

TABLE 5 - ZEOLITE Nu-6(2) dA 8.41 6.67 6009 4.61 4.33 ca 4.19 ca 4.10 , I/Io ~ r ~ -.
dA 3.94 3.76 3.65 3.4~ 3.33 3.17 3.05 . _ - _ . __ _ _ lOOI/Io ~ B Y

Within the above definition of chemical composition, the number of moles of X02 is typically in the range 10 to 5000 and zeolite Nu-6(2) appears to be most readily formed i~ a state of high purity when the number of moles of X02 is in the range 20 to 1000.
Zeolite Nu-6(2) may be prepared by heating zeolite Nu-6(1) at a temperature in the range 200C to 750C, zeolite Nu-6(1) itself being made together with some zeolite Nu-6(2) by reacting an aqueous mixture con-taining at least one oxide X02, at least one oxide Y203 and a 4,4'-bipyridyl compound.
The reaction mixture preferably has the follow-ing molar composition:
X2/~23 10 to 5000 preferably 20 to 3000 MOH/X02 0 to loO preferably 0.01 to 0.3 Z /Y~03 10 to 5000 preferably 10 to 100 Q/Y203 0.1 to 5000 pre~erably 1 to 500 H2/X2 10 to 500 preferably 15 to 300 BOH/Y203 0 to 500,000 preferably O to 1000 wherein X and Y are as above, M is an alkali metal or ammonium, Q is the aforesaid 4,4'-bipyridyl compound and Z~ i~ a strong acid ràdical present as a salt of M and may be added as a free acid to reduce the free OH level to a desired value. M and/or Q can be present as hydroxides or salts of inorganic or organic acids provided the MOH/X02 requirement is fulfilled. BOH is an aliphatic or aromatic alcohol, preferably an alkanol.
Whilst not essential, an alcohol improves crystallisation in viscous reaction mixtures~
The preferred bipyridyl compound is 4,4'-bipyridyl itself.
The preferred alcohol (BOH) is ethanol.
Zeolite Wu-lO has a molar composition expressed by the formula:
2 23 : at least 60 X02 : O to 200 H O
wherein R is amonovalent cation or /n of a cation of valency n, X is silicon, and/or germanium, Y is one or more of aluminium, iron, chromium! vanadium, molybdenum, arsenic, antimony, manganese, gallium or boron, and H20 is water of hydration additional to water notionally present when R is H, and has an X-ray pattern substantially as set out in Table 6 tas determined by standard technique uslng copper K radiation).

7~

X-Ray Data of Zeolite Nu-10 I

10.95 ~ 0.25 m~s 8.80 + 0.1~ w-~
6~99 + 0.14 w~m

5.~1 + 0.10 w 4.57 + 0.09 w 4.38 + 0.08 vs 3.69 + 0.07 vs 3.63 + 0.07 vs 3.48 + 0.06 m~s 3.36 + 0.06 w 3.31 + 0.05 w 2.78+ 0.05 w 2.53 + 0.04 m ~.44+ 0.04 w 2.37 + 0.03 w 1 1111 O 0~ w vs = 60 ~o 100 s = 40 to 60 m = 20 to 40 w = 0 to 20 - ~L Z 4 9~ L~L7 9 Within the above definition of chemical com~
position the number of moles of X02 is typically in the range 60 to 500. Zeolite Nu-10 appears to be most readily formed in a state of high purity when the number of moles of X2 is in the range 80 to 120.
Zeolite Nu-10 may be prepared by reacting an aqueous mixture containing at least one oxide X02, at least one oxide Y203 and at least one polyalkylene poly-amine having the formula:
Rl R4 N - [~CH2)x~ N - R3~y- (CH2)X N

where x is in the range 2 to 6 and y is in the range from 0 to 10, an amine degradation product thereof, or a precursor thereof. In the polyamine, each of R
to R5, independently, represents hydrogen or a Cl-C6 alkyl group. When y is from 2 to 6, the R3 substituents may be the same or different. When y - 0 then x = 2 to 5.
The reaction mixture preferably has the following molar ratios:
X02/Y203 - 60 to 500, preferably 70 to 200, most pre-ferred 80 to 150 MlOH/X02 = 10-8 to 1.0, preferably 10-6 to 0.25, rnost pr~ferred 10-4 to 0.15 ~2/X2 = 10 to 200, preferably 15 to 60, most pre-ferred 30 to 50 Q/X2 = 0 5 to 4, preferably 0.1 to loO~ most pre-ferred 0.2 to 0.5 M2Z/X02 = 0 to 4.0, preferably 0 to 1.0, most pre-ferred 0 to 0.6 wherein X and Y are as above, Ml is an alkali metal or ammonium or hydrogen, M2 is an alkali metal or ammonium ~2~79 or hydrogen and can be the same as M1 and Q is the afore-said polyalkylene polyamina, amine degradation product thereof or a precursor thereof, or a related compound.
Z is a strong acid radical present as a salt of M2 and may be added as a free acid to reduce the free M1OH
level to a desired value.
The preferred polyalkylene polyamines are tri-ethylene tetramine and tetraethylene pentamine.
Zeolite EU-l has a molar composition expressed 10- by the formula:
R20 : Y203 : at least 10 X02 : 0 to 100 H 0 wherein R is a monovalent cation or l/n of a cation of valency n, X is sillcon and/or germanium, Y is one or more of aluminium, iron, gallium or boron, and H20 is water of hydration additional to water notionally present when R is H, and has an X-ray pattern substantially as set out in Tables 7 and 8 (as determined by standard technique using copper Ka radiation). Table 7 shows X-ray data for zeolite EU-l as prepared, and Table 8 shows X-ray data for zeolite EU-l in the calcined Na-H
form.
Within the above definition of chemical composition, the number of moles of X02 is typically in the range 10 to 500 and zeolite EU-1 appears to be most readily formed in a state of high purity when the number of moles of X02 is in the range 20 to 300.
Zeolite EU-l may be prepared by reacting an aqueous mixture comprising at least one oxide X02, at least one oxide Y203 and at least one alkylated derivative of a polymethylene ~ diamine having the formula:
Rl R4 R2 ~ N - (CH2)n N ~ R5 7~

TABLE 7.
. . _ d ~A~ - I/Io ._ _ . .... _ ~ __ _ 11. 03 Very Strong 10.10 Strong .9. 72 Weak ` 6. 84 Weak 5. 86 Very Weak 4.66 ~ Very Stxong 4.31 Very Strong 4.00 Very Strong 3.82 Strong 3. 71 Strong 3. 44 Medium .. 3 . 3 8 Medi um 3.26 Strong 3.16 Very Weak : .
3.11 . Very Weak 2.96 Very Weak . .
2. 71 Very Weak 2.55 Weak 2. 48 Very Weak 2.42 Very Weak 2 . 33 Very Weak 2. 30 Very Weak 2.13 Very Weak . _ . _ _ 2~

TA~LE 8 Zeolite EU-l i~ calcined Na-H form __ __ , , ~ . . _ , _ .
d ~' I~Io 11.11 Very strong 19.03 Very strong 9.78 Weak 7.62 Weak

6.84 Medium . 6.21 Very Weak 5.73 Weak 4.87 Very weak 4.60 Very strong 4.30 Very s~rong 3~97 Very strong 3.77 Strong ~3.71 Weak 3.Ç3 Very weak 3.42 Medium 3.33 Medium 3~27 Strong 3.23 Medium 3.15 Weak 3.97 Weak 2.93 Weak 2.69 Weak 2.63 Very weak 2.57 Very weak . 2.51 , Weak 2.45 Very weak 2.41 Very weak 2.32 Very weak 2.29 Ver~ weak 2.ll Very weak an amine degradation product thereof, or a precursor thereof, wherein n is in the range from 3 to 12 and Rl to R6 which may be the same or different, can be alkyl or hydroxyalkyl groups, containing from 1 to 8 carbon atoms and up to five of the groups Rl-R6 can be hydrogen, the mixture having the molar composition:
X02/Y203 at least 10, preferably 13 to 150 OH /X02 0.1 to 6.0, preferably Ool to 1.0 (M+ +Q)/Y203 O.S to 100 Q/~M+ + Q) 0.1 to 1.0 H2/~02 1 to 100 wherein X and Y are as above, M is an alkali metal or ammonium, and Q is the aforesaid alkylated derivative of a polymethylene diamine, an amine degradation product thereof, or a precursor thereo, or a related compound.
M and/or Q can be present as hydroxides or salts of inorganic or organic acids provided the OH /X02 re-quire~ent is fulfilled.
Preferred alkylated polymethylene diamine starting materials include alkylated hexamethylene diamines, especially methylated hexamethylene diamines, for example 1:6-N,N,N,Nl,Nl,Nl-hexamethyl hexamethylene diammonium salts (e.g. halide, hydroxide, sulphate, silicate, aluminate).
Zeolite EU-2 has a molar composition expressed by the formula:
2 23 : at least 70 X02 : O to 100 H O
wherein R is a monovalent cation or /n of a cation of valency n, X is silicon and/or germanium, Y is one or more of aluminium, iron, gallium, or boron, and H20 is water of hydration additional to water notionally present when a is H, and has an X-ray pattern substantially as set out in Table 9 (as determined.by standard techni.que using copper K~ radiation).

4~9 Zeolite EU-2 _ _ Interplanar Relative Intensity Spacings d(~) 100 I/Io _ ____ 11.74 17 10.13 14 6.33 7 5.85 7 4.33 5 4~18 86 3.~9 100 3.6~ 7 3.37 7 3.0~ 5 `:
2.85 18 2.09 __ .5 _ ~

Within the above definition of chemical composition, the number of moles of X0~ is typically in the range 100 :to 5000 and zeolite EU-2 appears to be most readily formed in a state of hig~ purity when the number of moles of X02 is in the range 150 to 3000.
Zeolite EU-2 may be prepared by reacting an aqueous mixture cumprlsing at least one oxide X92, at least one oxide Y203 and at lPast one alkylated derivative of a polymethylene a-~ diamine having the formula:

4~g R2 ~ N+ (CH2)n N+ ~ R5 which by our definition is Q2+ an amine degradation product thereof, or a precursor thereof, wherein n is in the range from 3 to 12, R1 to R6 which may be the same or different, can be alkyl or hydroxyalkyl groups con~
~ 10 taining from 1 to 8 carbon atoms and up to five of the groups Rl-R6 can be hydrogen, the mixture having the molar composition:
X02/Y203 at least 70, preferably at least 150 OH-/X02 0.1 to 6.0 preferably 0.1 to 1.0 15 (M+ ~Q)/Y203 0-5 to 100 Q/(M~ + Q) 0.1 to 1.0 H2/X2 1 to 100 wherein X and Y are as above, M is an alkali metal or ammonium and Q is the aforesaid alkylated derivative of a polymethylene diamine, an amine degradation product thereof, or a precursor thereof, or a related compound.
M and/or Q can be present as hydroxides or salts of inorganic or organic acids provided that OH-/X02 requirement is fulfilled.
Pref~rred alkylated polymethylene diamine starting materials include alkylated hexamethylene diamines, especially methylated hexamethylene diamines, for example 1:6-N,N,N,Nl,Nl,Nl-hexamethyl hexane-1,6-diammonium salts (e.g. halide, hydroxide, sulphate, silicate, aluminate).
Zeolite FU-9 has a molar composition expressed by the formula:
0.5 to 1.5 R20 : Y203 : 15 to 30 X02 : 0 to 500 H20 wherein R is a monovalent cation or l/n of a cation of valency n, X is silicon and/or germanium, Y is one or more of aluminium, iron, chromium, vanadium, molybdenum, arsenic, manganese, gallium or boron~ and H20 is water of hydration additional to water notionally present when R is H, and having an X-ray pattern substantially as set out in Table 10 (as determined by standard technique using copper K~ radiation)~ Table 10 shows X-ray data for zeolite FU9 as prepared;
zeolite FU9 may be prepared by reacting an aqueous mixture comprising at least one oxide X02, at least one oxide Y203 and at least one tetramethylammonium compound.
- 10 The reaction mixture preferably has the following molar compositiono X02/Y203 5 to S0 preferably 10 to 30 free Mo2/xo2 Ool to 1.0 preferably 0.1 to 0~5 Z-/Y203 0 to 5000 preferably 10 to 100 Q/Y203 0.1 to 150 preferably 1 to 50 H2/X2 5 to 200 preferably 10 to 30 Q = (TMA)2 + xA
wherein X and Y are as above, M is an alkali metal or ammonium, and Q is a mixture of TMA the tetramethylammonium compound, amine degradation product thereof or a precursor thereof, or a related compound, and A which is a trialkyl-amine and/or an alkanolamine or salt thereo, where x is equal to 0.2 to 2.0 moles and A preferably contains 1 to 12 carbon atoms Z~ is a strong acid radical present as a salt of M and may be added as a free acld to reduce the free M20 level to a desired value. M and/or Q can be present as hydroxides or salts of inorganic acids provided the M20/X02 requirement is fulfilled.
The preferred quaternary compound is a tetra-methyl ammonium hydroxide.
For the efficient use of the reactants in methylt-butyl ether produc-tion, it is important that any catalyst for the vapour phase reaction does not promote by-product ~ormation. By virtue of its unique crystal structure, the channel system in our preferred zeolite, ~Z~7~

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Nu-10, limits the formation of oligomers of isobutene.
Thus, a very high proportion of isobutene is converted to metyl t-butyl ether.
The invention is illustrated by the following Examples.

These examples illustrate the preparation of zeolite Nu-2 and its use as a catalyst in the production of methyl t-butyl ether (MTBE) from isobutene and methanol.
The synthesis mixture for the preparation of zeolite Nu-2 had the following molar composition:
1.35 Na20~ 3-14 Q2' A1203~ 29 SiO2~ 311 H20

8.7g solid sodium hydroxide were dissolved in 250y tetra ethyl ammonium hydroxide ~40% aqueous solution) followed by 16.4g Kaiser SA alumina powder. Next 649g colloidal silica were added with stirring. The resulting gel/slurry was crystallised to zeolite Nu-2 in a stirred-autoclave after 6 days at 150C. The washed dried product had the molar composition: -0-6 Na2~ 2-2 Q2~ A1203, 20sio2, 6 H20 The product thus obtained was calcined at 450C
for 48 hours, followed by treating with normal hydro~
chloric acid for 24 hours, washing thoroughly with deionised water and calcined for 24 hours at 450C. The product was zeolite H-Nu~20 20 ml of methanol (0.5 mole) and lg of Nu-2 zeolite (prepared as above) were added to a glass flask in a stream of nitrogen. 20 ml (0.21 mole) of isobutene was condensed into the cooled flask. The mixture was put into an autoclave then heated with stirring at 90C
for one hour. After the reaction the autoclave was cooled to 0C and the reaction mixture was analysed by gas chromatography.
The results are shown as Example 1 in Table 11 are as follows:

~J~'~479 Mole % conversion of isobutene 92.3 Mole % conversion of methanol 39.4 5electivity to M T B E 98.0 The procedure described for Example 1 was S used in Examples 2-7. The results are also shown in Table 11.

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`~ ~2~ 9 Referring to Table 11, Examples 1-7 illustrate the use of zeolite Nu-2 as catalyst for the production of MTBE from isobutene and methanol.
Example 1 shows the high conversion and select-ivity to MTBE in a short reaction time (1 hour) and at 90C.
Example 2 demonstrates that a lower concentration of catalyst can be used without adversely affecting con-version and selectivity.
Example 3 shows that the reaction can be carried out under high pressure in the presence of an inert diluent (carbon dioxide), with only slight reduction in conversion and selectivity.
Example 4 shows that the reaction can be carrled out in the presence of an inert solvent ~hexane) with only slight reduction in conversion and select1vity.
Examples 5-7 show the reaction can be carried out at much lower temperature, although the rea~tion time is increased.
Examples__8-18 These examples illustrate the productlon of methyl t-butyl ether (MTBE) from isobutene and methanol u~lng a range of zeolites as catalysts. The preparation of the zeolites is described in the releva~t patent sp~cification~
(to which reference has already been made). The as-made zeolites were calcined and exchanged and calcined as described in Example 1.
The results, shown in Table 11, illustrate that zeolite beta (Example 16) and zeolite Nu-(23 (Examples 1-7) are the most effective catalysts, Ex~mple 19 This example illustrates the production of ethyl t-butyl ether ~EIBE) from isobutene and ethanol.
20 ml of ethanol (O.S mole) and lg of Nu-2 zeolite were added to ~ glass flask in a stream of nitrogen. 20 ml (0.21 mole) of isobutene was condensed ~nto the cooled flask. The mixture was put into an autoclave then heated ~2~479 with stirring at 90C for one hour. After the reaction the autoclave was cooled to 0C and the reaction mixture was analysed by gas chromatography.
The results were as follows:-s Mole % conversion of isobutene 65.5 Mole % conversion of ethanol 43.3 Selectivity to ETBE 97.0 This example illustrates the production of methyl 3-methylpentyl ether (M3MPE~ from 3-methylpent-2-ene and methanol using zeolite Nu-2 as catalyst.
10 ml of methanol (0.25 mole), 10 ml of 3-methylpent-2-ene (0.082 mole) and lg Nu-2 zeolite were added to a glass 1ask in a stream of nitrogen.
The mixture was put into an autoclave then heated to 90C for one hour. After the reaction the autoclave was cooled to 20C and the reaction mixture was analysed by gas chromatography.
The results were as follows:-Mole % conversion of 3-methyl-2-pentene 21.2 Mole ~ conversion of methanol 7.7 Selectivity to M3MPE 94.5 _Example 21 ... . .
This example illustrates the production of ethylene glycol methyl t-butyl ether (EGMTBE) from isobutene and 2-methoxyethanol using zeolite Nu-2 as catalyst.
20 ml of 2-methoxyethanol (0.25 mole), 20 ml of isobutene (0.21 mole) and 0.25 g Nu-2 zeolite were added to a glass flask in a stream of nitrogen. The mixture was put into an autoclave then heated to 90C
for one hour. After the reaction, the mixture was analysed by gas chromatography.
The results were as follows:
Mole % conversion of isobutene 42.3 Mole % conversion of 2-methoxyethanol 36.6 Selectivity to EGMTBE 96.5 Examples 22-24 1 gm of Nu-2 zeolite was powdered and packed into a glass tube~ The tube and contents were heated by a furnace to 90C wh~lst passing a continuous stream of methanol vapoux and isobutene over the zeolite bed (mole ratio 2:1). The products from the reaction were collected at hourly intervals and analysed by gas chromatography.
The results, sho~n as Example 22 in Table 12, are as follows:-Selectivity to MTBE ~5-80%
Selectivity to Di-isobutene 20-30 Catalytic activity (g MTBE/g catalyst~hr) 0.06-0.12 The procedure described for Example 22 was used in Examples 23 and 24 except that the temperature was lowered to 70C then 50C as shown in Table 12. Examples 22-24 demonstrate that selectivity to MTBE increases as th~
temperature is lowered.
ExamE~e 25 .
lg of zeolite Nu-2 prepared as described in Example 1 was soaked in the bulky amine phenanthridine (20 ml) for 24 hours then filtered, washed well with hexane and dried on a vacuum line at 100C. The amine treated zeolite was then packed into a glass tube as described in Example 22 and evaluated for the synth~sis of MTBE
in a flow reactor at 90C.
The results are shown in Table 12 and demonstrata that at 90C the bulky amine ion-exchanged onto the surface of the zeolite inhibits the formation of di-isobutene and improves the overall selectivity to MTBE without loss in catalyst activity.
Examples 26-30 These examples illustrate the production of methyl tertiary butyl ether from isobutene and methanol using a range of zeolites in the flow reactor. The 1;~ 7~

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preparation of the zeolites is described in the relevant patent specification (to which reference has already been made). The as-made zeolites were calcined and exchanged and calcined as described in Example 1.
The results, as shown in Table 12, illustrate that zeolites Nu-4 and Nu-10 are particularly effective catalysts.

What we claim is:

Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the production of an ether which comprises contacting an olefin and an alcohol with a catalyst comprising a zeolite having an XO2/Y2O3 ratio equal to or greater than 10, wherein X is silicon and/or germanium and Y
is one or more of aluminium, iron, chromium, vanadium, molybdenum, arsenic, manganese, gallium or boron, the zeolite being predominantly in the hydrogen form.

2. A process according to Claim 1 wherein the zeolite has been treated with a bulky organic base.

3. A process according to Claim 1 wherein the olefin is a mono- or di-olefin containing from 4 to 16 carbon atoms.

4. A process according to Claim 3 wherein the olefin contains 4 to 9 carbon atoms.

5. A process according to Claim 1 wherein the alcohol is a primary or secondary alkanol containing from 1 to 12 carbon atoms.

6. A process according to Claim 5 wherein the alcohol contains from 1 to 4 carbon atoms.

7. A process according to any one of Claims 1 to 3 wherein the alcohol is an ether alcohol of the formula:
RO(CH2CH2O)nH
wherein R is H or hydrocarbyl and n is 1-20.

8. A process according to any one of Claims 4 to 6 wherein the alcohol is an ether alcohol of the formula:
RO(CH2CH2O)nH
wherein R is H or hydrocarbyl and n is 1-20.

9. A process according to any one of Claims 1 to 3 wherein isobutene and methanol are reacted to form methyl t-butyl ether.

10. A process according to any one of Claims 1 to 3 wherein the zeolite is selected from zeolites Nu-2, Nu-4, Nu-10 and beta.

11. A process according to any one of Claims 4 to 6 wherein isobutene and methanol are reacted to form methyl t-butyl ether.