CS222886B1 - Process for producing methyl tert-butyl ether - Google Patents

Abstract

The production of methyl tert-butyl ether is carried out by highly selective addition of methanol to isobutene alone or in a mixture with other hydrocarbons, e.g. in the debutadienized pyrolysis C4 fraction, at a temperature of 30 to 200 °C (70 to 140 °C) in the gas or vapor phase on an acidic heterogeneous catalyst. This specially treated and activated Y zeolites with an NH4 exchange range of 20 to 99% (70 to 95%). Specially treated hydrothermal Y zeolites in a stream of oxygen saturated with water vapor in the range of 20 to 95 % (60 to 90 %) at a temperature of 450 to 900 degrees Celsius (540 to 800 °C) for 1 to 6 h and then hydrated. Activation is carried out before the reaction at a temperature of 300 to 600 °C (350 to 500 °C) under vacuum or reduced pressure in an inert or oxygen-containing atmosphere.

Description

The production of methyl tert-butyl ether is accomplished by high-selective addition of methanol to isobutene alone or in admixture with other hydrocarbons, e.g. in de-butadienized pyrolysis C ₄ fraction, at a temperature of 30 to 200 ° C (70 to 140 ° C) affected or in the vapor phase on an acid heterogeneous catalyst.

Thereby specially treated and activated zeolites Y with an NH ₄ exchange range of 20 to 99% (70 to 95%). The specially treated hydrothermal zeolites Y in a steam stream saturated with water in the range of 20 to 95 ° / o (60 to 90 ° / o) at 450 to 900 degrees Celsius (540 to 800 ° C) for 1 to 6 h are then hydrated. Activation is performed prior to the reaction at a temperature of 300 to 600 ° C (350 to 500 ° C) under vacuum or reduced pressure in an inert or oxygen-containing atmosphere, respectively.

The invention solves a process for the production of methyl tert-butyl ether (MTBE) from available petrochemical feedstocks on highly selective heterogeneous catalysts.

The addition of isobutene to methanol takes place under the catalytic action of acid catalysts [Kirk-Othrner: Encyclopedia of Chemical Technology, Vol. 8 (1965), Houben-Weyl: Methoden der Organtschen Chemie VI / 3, 19 (1965), US Pat. 2,480,940, 2,858,331, Germany Pat. 908,453]. acid, the solid acid catalyst BF _3, A1C1 _{3 R FeCl3.} Their disadvantage is particularly strong corrosive effect on the equipment of the device and the need for additional technical measures to remove catalyst residues from · the crude product. the drawbacks solved by the method (Ger. 868,147, US 2 480 940, 3 921 315, etc.) using organic ion exchange catalysts, however, their disadvantage is their thermal sensitivity and swellability, although acidic catalysts based on H-form zeolites or aluminosilicates solve these problems, but these catalysts (U.S. Patent 189,071, U.S. Pat. No. 3,940,450), however, do not exhibit a sufficiently high catalytic activity as compared to ion exchange catalysts.

The advantages of these known processes take advantage of and in addition the problems of relatively low catalytic activity are solved by the process of the present invention.

According to the present invention, a process for the production of methyl tert-butyl ether by reacting isobutene with methanol under the catalytic action of heterogeneous acid catalysts at a temperature of 30 to 200 ° C, preferably 70 to 140 ° C, is carried out such that isobutene or a mixture of isobutene-containing hydrocarbons. preferably the de-butadiene C ₄ fraction in the gas and / or vapor phase reacts with methanol on a solid catalyst which is zeolites Y with a (+) NH ₄ ion exchange range of 20 to 99%, preferably 70 to 95% hydrothermally treated in a stream of oxygen saturated with water vapor in the range of 20 to 95%, preferably 60 to 90%, at a temperature of 450 to 900 ° C, preferably at 540 to 800 ° C, for 1 to 6 hours, then hydrated, preferably at a temperature The modified zeolites Y are activated at a temperature of 300 to 600 ° C, preferably 350 to 500 ° C, under vacuum and at room temperature, prior to the reaction. under reduced pressure, in an inert or oxygen-containing atmosphere for 1 to 6 h.

Preferred methods for the production of MTBE of the invention can use as donor olefins, especially isobutene, straight odfoutadienizovanú pyrolysis solvent system B, and C ₄ C ₄ -fractions catalytic cracking or hydrocracking high oil fractions, the linear butenes and BUFANO CHO-Vayu inerted. Another advantage is the high catalytic activity, structural stability and durability of the hydrothermally treated zeolites, as well as high selectivity (0.01% diisobutene, 0.0 dimethyl ether) while avoiding corrosion of the device. Last but not least, the advantage of the present invention is the technologically lightly mentioned modification of the zeolites, their heat and volume stability.

Catalysts for the production of MTBE according to the invention are synthetic zeolites Y in NI-I ₄ form, hydrothermally treated in a stream of oxygen saturated to 20-95%, preferably 60-80% by steam at 450-900 ° C, preferably at 540 to 800 ° C, for 1 to Θ hours. The zeolites are then hydrated, preferably at room temperature. This hydrothermal treatment releases aluminum from the zeolite skeleton into its cavities, thereby increasing their structural stability and forming strongly acidic Lewis and Bronsted active centers. Activation of the hydrothermally treated zeolites before the catalytic reaction is carried out in an inert or oxygen-containing atmosphere, the top of the gas stream (oxygen, nitrogen, argon, air] or under vacuum at temperatures of 300 to 600 DEG C., preferably at 400 to 500 ^Q C Activation leads to dehydration of zeolite and activation of acid centers.

The process for producing MTBE according to the present invention can be carried out in a continuous, but preferably continuous, process. The sabotage catalyst may be in the air or fixed bed when the catalyst does not escape. Methyl tert-butyl ether from the crude product is isolated by known methods such as distillation, rectification, distillation under elevated pressure, particularly preferred is extractive distillation at atmospheric or near atmospheric pressure. Unconverted starting components, mainly isobutene and methanol, are recirculated.

Further details of the production process of the present invention as well as other advantages are apparent from the examples.

EXAMPLE

The stainless steel reactor is charged with 2.75 g of a zeolite NH ₄ Y 1 + catalyst (Si: Al = 2.7j, with an NH ₄ ion exchange range (RVI) of 92.8%. The catalyst is activated at 350-500 ° C. C and atmospheric pressure for 2 to 5 hours. After cooling the catalyst to the reaction temperature (95 ° C) was fed to the reactor a mixture of spray pyrolysis odbutadienizovanej C ₄ -fractions comprising 40 to 50% isobutene and methanol (mol. ratio of isobutene: methanol; 1j in an amount of 1.06 kg dm- ³ cat b- ¹ .

The product is analyzed for MTBE content, which is separated from the crude product by distillation and extractive rectification using monoethylene glycol as the extraction agent for methanol. The conversion of isobutene to MTBE is 2.5%; MTBE production is defined by 228888

As an amount of MTBE in kg per m ^{3 of} catalyst per hour it reaches 26.2 kg.m- ³ .h ^-1 .

Example 2

The procedure is similar to that of Example 1, except that the catalyst is zeolite NH ₄ Y (Si: Al = 2.9) with RVI = 95% (NH ₄ Y - 95). 1.03 kg. dm ^_3 cat. h ^_1 mixture of C ₄ -fractions pyrolysis and methanol. the conversion of isobutene to MTBE 13.5 ° / o, throughput through 140 kg. m ^_3 cat. h ^1.

Example 3

In a manner similar to Example 1 but with prior treatment of the NH ₄ Y zeolite with a mixture of oxygen and water vapor (60-90%) at 500-800 ° C for 2 to 4 h and hydration at room temperature. Upon activation of the catalyst according to Example 1 was fed to the reactor a mixture of C ₄ -fractions methanol at 0.1 kg. dm ³ cat · bh

The conversion of isobutene to MTBE is 65%; MTBE production is 31.3 kg. m ^_3 cat.

.h ^_1 .

Example 4

In a manner similar to Example 3, but with the difference that an amount of

1.8 kg. dm ³ -cat. h ^_1 mixture. The conversion of isobutene to MTBE is 18%; MTBE production is 325 kg. m ~ ³ cat. h ^_1 .

Example 5

The procedure is similar to Example 2, except that the catalyst is subjected to water vapor and oxygen (as in Example 3). The reactor was fed a mixture of C ₄ -fractions pyrolysis and methanol in an amount of 2.54 kg. dm ~ ³ cat. h ^_1 . The conversion of isobutene to MTBE is 22.5%; production 572 kg. ³ NR a, l. li'-.

Claims (5)

222886 The amount of MTBE in kg per m 3 of catalyst per hour is 26.2 kg · m · 3 · h -1. Example 2 Proceeds similar to Example 1, but with the difference that. The catalyst used is NH 4 Y zeolite (Si: Al = 2.9) with RVI = 95% (NH 4 Y - 95) Injection of 1.03 kg of dm_3kat, h_1 of a mixture of pyrolysis C4-fraction and methanol is introduced into the reactor. is 13.5 ° / o; 140 kg .m_3kat. h "1 3 In a manner similar to Example 1, or by previously treating NH 4 Y zeolite with a mixture of oxygen and aqueous vapor (60-90%) at a temperature of 500-800 ° C for 2-4 h by hydration at room temperature. feeds a mixture of C4-fraction of amethanol in an amount of 0.1 kg. The method for producing methyl tert-butyl ether by reacting isobutene with methanol under the catalytic effect of heterogeneous acid catalysts at a temperature of 30 to 200 ° C, preferably 70 to 140 ° C, characterized in that or a mixture of hydrocarbons containing isobutene, preferably butadiene C4 - the fraction in the gaseous and / or vapor phase reacts with methanol on the solid catalyst, i +), which are Y zeolites with an NH4 ion exchange range of 20 to 99%, preferably 70% up to 95% 6 Conversion of isobutene to MTBE reaches 65%; MTBE is 31.3 kg. m_3kat. .h_1. Example 4 in a manner similar to Example 3, but with the addition of a 1.8 kg feed into the reactor by means of a catalyst. dm3'kat. h_1 mixtures. The conversion of isobutene to MTBE is 18%; MTB production capacity 325 kg. m ~ 3kat. h_1. Example 5 The procedure is similar to Example 2 but with the difference that the catalyst is affected by the influence of water vapor and oxygen (such as Example 3). A 2.54 kg mixture of pyrolysis C4-fructose and methanol is fed to the reactor. dm ~ 3kat. h_1. The conversion of isobutene to MTBE is 22.5%; 572kg. m-3kat. h1 " hydrothermally treated in a stream of oxygen saturated with water vapor in the range of 20-95 ° C, preferably 60-90%, at a temperature of 450-900 ° C, preferably at 540-800 ° C, for 1 to 6 h, then hydrating, preferably room sealing, wherein the treated Y-zeolites are activated at 300 to 600 ° C, preferably 350 to 500 ° C, in a vacuum or reduced pressure, in an inert or oxygen-containing atmosphere prior to the reaction. for 1 to 6 h.