HU196351B - Process for producing tert-butylalkyl ether in presence of butadiene - Google Patents

Description

The present invention relates to a process for the preparation of tertiary-butyl-alkyl ether by reacting isobutylene containing from 20 to 70% by weight of butadiene from hydrocarbon cracking using an aliphatic alcohol, preferably methanol, in one or more reactors suitably arranged in a macroporous acidic ion exchange resin. are charged.

The addition reaction of an alcohol with a tertiary olefin such as isobutylene to form a tertiary butyl alkyl ether is an acid catalyzed exotherm.

In the presence of suitable catalysts, such as macroporous acidic ion-exchange resins, the reaction equilibrium, even at relatively low temperatures (4050 ° C), sets up rapidly enough to be of industrial interest.

It is known that it is not necessary to work with high purity isobutylene, any fraction containing isobutylene can be used because alcohol is selectively added at the tertiary carbon double bond. Particularly useful are the fractions from catalytic cracking and steam cracking, both before and after the butadiene extraction.

If you are an olefin the catalytic cracker! or by using a C ₄ fraction from the gőzkrakkolásból butadiene after extraction, the alcohol is methanol or ethanol, as catalyst is Amberlyst 15 or Lewalit SPC 108 type macroporous sulfonic, the reaction industrially can be conducted within a wide variety of reactor types and wide variety of operating conditions which are set so that the optimize the transformation of one or the other raw material. In such cases, good selectivity is always achieved and the catalyst performs well in terms of both catalytic activity and lifetime.

When working with high butadiene olefínfrakcióval - such as C ₄ fraction resulting from gőzkrakkolásból before extracting it to the operating conditions to be specified in the butadiene, which allows recovery of more than 98-99% of butadiene. It is particularly important that there be a close relationship between temperature and volume velocity as described in U.S. Patent 4,039,590.

We found that if isobutylene etherification Transformation and pressure drop in reactors time reaction in the presence of butadiene, a macroporous acid as follows: in a tube reactor containing ion exchange resin, and the starting materials in a conventional manner from top to bottom time, hour 24 500 2000 we introduce it, the pressure increases with time, RO ΔΡ in Reactor 1, Pa 1.96 IO ⁴ 1.9610 ⁴ 1.96 IO ⁴ falling in the reactor and slightly decreasing ΔΡ in Reactor 2, Pa 1.96 10 ⁴ 1.96 10 ⁴ 1.96 10 ⁴ conversion (conversion), even when the circumstances are methyl tert-butyl ether,% by weight 38.1 38 38 which are 99% butadiene dynamics cs co-dimcrck, mass% 0.05 0.05 0.05 the greater their recovery. butcnyl ethers,% by weight 0.2 0.15 0.2 However, in a similar study 55 isobutylene-átalakidás 96.6 96.4 96.4 without fraction, no pressure drop butadiene recovery > 99 > 99 > 99 no increase in transformation, nor reduction in transformation ΔΡ represents the pressure drop

detected. On the other hand, and it is an object of the present invention, it has been found that when the butadiene-containing feedstock is introduced from the bottom up, with only a slight loosening of the catalyst bed, the pressure drop remains constant over time.

The process according to the invention is thus intended for the preparation of tertiary butyl alkyl ether by reacting the isobutylene content of a hydrocarbon feedstock containing from 10 to 70% by weight of butane60 diene with an aliphatic alcohol, preferably methanol, in one or two reactors, preferably in series. , characterized in that the starting materials (butadiene-containing hydrocarbon feedstock and alcohols or alcohols) and reaction products flow from the bottom up through the macroporous acid ion exchange resin catalyst reactor or reactors.

In addition to what is said for upstream flow of starting materials and reaction products, it is important that the linear flow rate of the starting materials through the reactor or reactors varies between 0.5 and 2 cm / s and the temperature in the reactors 50. -60 ° C, preferably 50-55 ° C.

For a better understanding of the invention, some examples are described below, but are not to be construed as limiting the invention in any way.

In the process of the examples, the pressure is chosen such that the reactants are in the liquid phase; 15,198 10 ⁵ Pa-20,265 10 ^s Pa.

Example 1

C ₄ fractions having the following composition:

propylene isobutane n-butane α-butylene isobutylene β-butylene cis-β-butylene butadiene

0.46

6.87

11.80

11.39

30.19

3.25

1.55

34.43% w / w% w / w% w / w methanol so that the molar ratio of isobutylene to methanol is 0.85 and the mixture is passed at 14 1 / h at 50 ° C. two reactors connected in series, each with a capacity of 4.5 liters and 4 liters of catalyst. The catalyst is a macroporous sulfone resin with an ion exchange capacity of 4.8 milliequivalents of hydrogen ion / g of dry matter.

Starting materials flow from the bottom up,

The linear velocity is 1 cm / s.

Pressure: 18.24 10® Pa.

Example 2 (Comparative)

The starting materials described in the previous example were introduced into the two reactors in series at the same temperature, pressure, and volume, but with the starting materials flowing from top to bottom.

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At the beginning of the experiment, the results are similar to those obtained in the previous example, but over time the pressure drop gradually increases and the conversion decreases slightly.

time, hour 24 500 2000 ΔΡ in Reactor 1, Pa 2.94 10 ⁴ 3.92-10 ⁴ 14.71-10 ⁴ ΔΡ in Reactor 2, Pa 2.94 10 ⁴ 4.90 10 ⁴ 17.65-10 ⁴ methyl tertiary butyl ether,% by weight 38 37.9 36 dimers and co-dimers,% by weight 0.1 0.1 0.05 butenyl ethers,% by weight 0.2 0.2 0.2 isobutylene-átalakulés 96.4 96.1 91.3 butadiene recovery 99 99 99 Example 3

To an olefin fraction containing (comparative) wt.% isobutylene and 0.2 wt.

The mixture is introduced into 14 liters / hour at a volumetric rate of 50 C of ^these two sorbakapcsoít reactor, flow direction: top to bottom, pressure. 18.24 to 10 ⁵ Pa butadiene in the absence of any pressure ~, drop growth, either the transformation of does not decrease over time:

volatile. ORN 24 500 2000 ΔΡ tz 1, in reactor, Pa 2.94-10 ⁴ 2.94-10 ⁴ 2.94-10 ⁴ ΔΡ in Reactor 2, Pa 2.94-10 ⁴ 2.94-10 ⁴ 2.94-10 ⁴ methyl tert-butyl ether,% by weight 43.1 42.9 43 dimers and co-dimers,% by weight 0.3 0.3 0.2 izobitilén at-development 96.8 96.6 96.6

A patent claim

Claims (1)

Process for the preparation of tert-butyl alkyl ether by reacting isobutylene containing 10-70% by weight of butadiene with hydrocarbon cracking and an aliphatic alcohol, preferably methanol, in one or more reactors, preferably serially coupled, with a macroporous ion exchange resin, characterized in that flow at a linear rate of 0.5 to 2 cm / s and feed the starting materials and reaction products from the bottom up into the reactor or reactors at 15 · 10 ^{s at} -21 to 10 · ⁵ Pa, while the reactor or reactors the temperature is maintained at 50-60 ° C.