CN1026580C - Prepn. of methyl tertiarybutyl ether - Google Patents

Abstract

The present invention relates to a new preparation method of methyl tertiarybutyl ether(MTBE). A conventional catalyst is adopted, and the present invention is characterized in that a reactor neither needs internal heat exchange equipment nor needs external circulation cooling equipment. The present invention has the characteristics of simple structure, low investment and convenient operation; energy consumption can be obviously reduced, conversion rate can still meet design requirements. The present invention not only is suitable for new-built MTBE equipment, but also is suitable for old plant reformation in the prior art, and is suitable for the production of cumene and tertiary butyl alcohol and other similar technological production processes.

Description

Prepn. of methyl tertiarybutyl ether

The invention belongs to a kind of new method of synthetic MTBE, MTBE is as a kind of gasoline dope that improves gasoline octane rating, and its manufacture method is widely used in the petrochemical production process.

Technical background:

By C ₄Iso-butylene and methyl alcohol react in the synthesize methyl tert-butyl ether technology of (being called for short MTBE) in the cut, the general fixed-bed reactor that adopt, under liquid phase state, react,, adopt traditional shell and tube reactor or reaction mass outer circulation refrigerative cartridge reactor more for solving the taking-up of reaction heat.The equipment complexity, throwing is inferior big, and the energy consumption height has been developed to shell and tube reactor as Italian Snam company and West Germany Huls company, pass to water coolant in the shell side of reactor, with control reaction temperature, U.S. ARCO company has been developed to cartridge type outer circulation reaction technology (U.S.P4198530), it be reaction product through the cooling after, loop back reactor inlet, control reaction temperature, but, also reduced reaction efficiency because of isobutylene concentration is recycled the material dilution.IFP has been developed liquid phase expanded bed reaction technology (being so-called IEP technology), (Fr2455019, Fr2440931) characteristics of this reaction technology are the focuses of having eliminated in the reactor, but material is back-mixing in reactor, reduced concentration of reactants, thereby reaction efficiency, the CR﹠amp of the U.S. have been reduced; It is the new technique of making MTBE that C/NC company (U.S.P.4439350) and main office of China Petrochemical Industry (Chinese patent 88109705.5) have been developed to catalytic distillation technology, but because of catalyst loading structure more complicated, so be affected in the practical application.

Purpose of the present invention:

For solving the problem of aforementioned existence, the objective of the invention is to adopt a kind of new method, change vapour, liquid two phase reaction into by homogeneous reaction, allow reaction heat be absorbed, thereby can cancel the consumption of heat exchange cooling apparatus and water coolant by the partial material vaporization, do not need simultaneously reactor outer loop part material to get back to reactor yet, thereby equipment is simple, reduced investment, and energy consumption is low, and is easy to operate, not only can be used for the design of newly-built factory, also can be used for the transformation of old technology factory.

General introduction of the present invention:

The present invention is according to the characteristics of MTBE building-up reactions, makes in the bubble point that is reflected at material and the dew-point temperature scope to carry out.The reaction heat that reaction process is emitted can make material partly vaporize and be absorbed, and carries out so that be reflected under the predetermined temperature.Therefore the present invention is different from traditional liquid phase reaction, and reaction is carried out under vapour-liquid mixed phase reaction conditions, and reactor is an insulation fix bed reactor.Use a bed when iso-butylene content is low in raw material.When iso-butylene content is higher, can be divided into two or three to four beds to catalyzer, raw material is except that mainly being entered the reactor by the reactor end, other tells the cold raw material of 1-3 thigh and enters the further temperature of reaction of adjusting between the beds by side line respectively, therefore without any need for additional heat-obtaining measure, reaction heat can utilize fully, simple in structure, reduced investment, energy consumption is low.

Technical process and explanation (seeing accompanying drawing 1)

Raw material C ₄(1) by pump (2), methyl alcohol (3) is squeezed into reactor inlet pipeline (5) by pump (4), mixes the back and through being preheated to certain temperature, enters reactor (7) at mixing tank (6), go out reactor after process macropore sulfuric acid resin beds (8) reacts, enter separation column (9).Vapor phase product is ejected by separation column, after voltage-controlled variable valve (10) and condenser (11) coagulate entirely, enters return tank (12), and part overhead condensation liquid is back to separation column (9) top, all the other C through reflux pump (13) ₄Liquid goes out device through pipeline (14).MTBE product at the bottom of the tower, part is returned separation column after reboiler (15) is heated at the bottom of, all the other products float controller valve (16) and pipeline (17) at the bottom of tower go out device.

Raw material C ₄Pass through the reactor catalyst bed with carbinol mixture, under the effect that general catalyzer macropore sulfonic acid tree refers to, iso-butylene and methyl alcohol react, and generate MTBE, and this reaction is reversible exothermic reaction.

The reaction liberated heat, absorb by partial material vaporization control reaction temperature.And use by the cold raw material that side line enters between each beds in the reactor and regulated, carry out so that be reflected under the predetermined temperature condition.This temperature of reaction is in the bubble point and dew-point temperature scope of material, and bubble point and dew point are decided by reaction pressure.Therefore adjusting working pressure gets final product control reaction temperature.

The molecular ratio of methyl alcohol and iso-butylene is 0.9～2.5 in the reaction mass, and reaction velocity was generally 1～30 o'clock ^-1Reactor inlet temperature is generally 25～80 ℃, and reaction temperature out (stable reaction temperature) is generally 60～120 ℃, and reaction outlet top temperature should be controlled within the top temperature of catalyzer permission.The optimum reaction conditions is: air speed 4～20 ^-1, temperature in 30-70 ℃, equilibrium temperature 60-90 ℃, methyl alcohol/pib molecule compares 0.9-2.

When MTBE synthesis technique and alkylation process associating, iC ₄Transformation efficiency reaches 90～92% and can meet the requirements, and in this case, general mixed phase reaction can reach requirement, as Fig. 1.

When in order to produce high-purity butene-1, or when producing the raw material of divinyl as oxydehydrogenation, iC ^- ₄Transformation efficiency require to reach more than 99%, can adopt the two-stage reaction flow process, as shown in Figure 2, promptly reach equilibrium conversion through one section mixed phase reaction after, enter the MTBE that separation column is told generation, residue C ₄Enter the second mixed phase reactor (7) after the preheating again, further react, total conversion rate is reached more than 99%, and then enter after-fractionating tower (9), tell the MTBE of generation at the bottom of tower, cat head obtains iso-butylene content and is lower than 0.5% residue C ₄Can also react the new catalytic distillation technique of inventing with my institute with mixed phase of the present invention, (its application number is a Chinese patent 88109705.5) combines, form new technical process, as Fig. 3, promptly through after one section mixed phase bed (7) reaction, product enters in the catalytic distillation reaction tower (9) of synthetic MTBE, under reacting section catalyst (8) effect, carry out secondary reaction, cat head is fragrant to containing iC ^- ₄Be less than 0.5% residue C ₄, get the MTBE product at the bottom of the tower.

The effect of invention:

Aforesaid goal of the invention all reaches, because being reflected at the vapour-liquid two-phase is to carry out under the mixed phase condition, can cancel facilities such as cooling heat-obtaining and outer circulation thermal relief, simplify structure of reactor, simplified the operation, reduced investment, reactant directly enters separation column, reaction heat is utilized fully, can cancel water coolant again, thereby can significantly cut down the consumption of energy.One section reaction conversion ratio can reach to 90～92%, meets the requirements.As required, further the degree of depth transforms, and makes iC ⁼ ₄Transformation efficiency reaches more than 99%, reaction back residue C ₄Middle iso-butylene content＜0.5% can be produced divinyl behind the separating methanol, the raw material of n-butene-1 or other products.

According to same reaction principle, the present invention also is applicable to other similar art production process such as the isopropyl benzene and the trimethyl carbinol except that being applicable to that MTBE produces.

Embodiment one:

Raw material C ₄In, iso-butylene content 40% alfin molecular ratio 1.07: 1

Table one

Reaction pressure (MPa) transformation efficiency %(is heavy)

0.50????90.88

0.71????91.05

0.91????90.94

Example two:

Raw material C ₄Middle iso-butylene content 40% alfin molecular ratio 1.07: 1

Table two

During air speed ^-1Isobutene conversion %

2.0 95.56(is heavy)

3.1????93.96

4????91.56

5????90.74

10.25????89.12

Example three:

Raw material C ₄Middle iso-butylene content 40%, alfin molecular ratio 1.07: 1, reaction pressure 0.71MPa.

Table three

℃ transformation efficiency %(is heavy for the reaction temperature in)

40????93.61

50????93.22

60????93.37

Example four:

Raw material C ₄Middle iso-butylene content 26%, alfin molecular ratio 1.1: 1.

Table four

Reaction velocity (time ^-1) transformation efficiency %(weight)

1.0????94.36

3.0????91.90

89.38

13.0????87.66

20.0????83.18

Claims (2)

1, a kind of processing method by iso-butylene in the C 4 fraction and the synthetic MTBE of methyl alcohol reaction is used catalyzer commonly used, it is characterized in that:

A. reactor is the fixed bed pattern, has 1-4 beds:

B. when iso-butylene content was higher in the raw material, catalyst reactor can be divided into 2-4 bed, and told the cold raw material of part and entered between the beds by side line:

C. conditioned reaction device pressure makes in the bubble point that is reflected at material and the dew-point temperature scope and carries out;

D. when requiring isobutene conversion to reach 99% when above, can adopt two sections mixed phase reactions and two tower fractionation process, promptly first separation column ejects after the C 4 fraction that comes mends a certain amount of methyl alcohol, enter the second mixed phase reactor, further carry out etherification reaction, the reaction product of being come out by the second mixed phase reactor enters the after-fractionating tower;

E. the molecular ratio of methyl alcohol and iso-butylene is generally 0.9-2.5;

When f. reaction velocity is generally 1-30 ^-1,

G. temperature of reaction: inlet: 25-80 ℃,

Stable: 60-120 ℃.

2, by the described method of claim 1, it is characterized in that The optimum reaction conditions: during air speed 4-20 ^-1, temperature in 30-70 ℃, equilibrium temperature 60-90 ℃, methyl alcohol/pib molecule compares 0.9-2.

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