CN101381287B

CN101381287B - Method for producing MTBE from four-carbon compounds and methanol

Info

Publication number: CN101381287B
Application number: CN2008101433796A
Authority: CN
Inventors: 谷益忠; 袁红星; 李建良
Original assignee: YUEYANG HUAKE CHEMICAL CO Ltd
Current assignee: Sinopec Hunan Petrochemical Co.,Ltd.
Priority date: 2008-10-18
Filing date: 2008-10-18
Publication date: 2011-08-24
Anticipated expiration: 2028-10-18
Also published as: CN101381287A

Abstract

The invention discloses a method for producing MTBE (methyl tert-butyl ether) from C4 and methanol. The method is characterized by comprising the following: (1) a step of raw materials pretreatment, which is to fully mix the C4 containing isobutene and the methanol through a static mixer, then to heat up raw materials to the temperature of between 30 and 60 DEG C through a raw material preheater, and to perform etherification reaction initially in a purifier; and (2) a step of reaction and product separation, during which, the mixed raw materials from the purifier are cooled to the temperature of between 30 DEG C and 70 DEG C through a cooler and then enter a reactor to perform the etherification reaction, the mixture after reaction enters a catalytical distillation tower to carry out the etherification reaction, and the MTBE coming out from the bottom of the catalytical distillation tower is cooled by the cooler to obtain the MTBE finished product. The method effectively reduces the concentration of the isobutene of the raw materials in the reactor, better protects catalysts in the reactor, greatly prolongs the service cycle of the catalysts, and prolongs the equipment operation cycle simultaneously.

Description

A kind of by the method for carbon four with methanol production MTBE

Technical field

The present invention relates to a kind of is raw material with the carbon four that contains iso-butylene, produces the method for MTBE through etherification reaction.

Background technology

At present the main method of domestic production methyl tertiary butyl ether (MTBE) be the carbon four that contains iso-butylene with methyl alcohol through the static mixer thorough mixing, mixing raw material enters cleaner and removes wherein alkali and alkalimetal ion, heat up through raw material interchanger and 1.0MPa steam heat-exchanging then, enter reactor and carry out etherification reaction, separate through catalytic distillation tower limit coronite at last, obtain the process mode of product MTBE.

From technical process, MTBE production mainly comprises following step: 1. raw materials pretreatment: the carbon four, the methyl alcohol that contain iso-butylene pressurize through pump respectively, by entering the cleaner of dress resin catalyst behind the static mixer thorough mixing; 2. react and the product separation part: the mixing raw material that comes from cleaner passes through the preheater pre-heating temperature elevation, enter reactor then, under the effect of resin catalyst, etherification reaction takes place generate MTBE, the post reaction mixture material enters catalytic distillation tower with the gas-liquid mixed phase and continues to take place etherification reaction, methyl alcohol and unreacted carbon four distillate from cat head with the azeotrope form, overhead product enters return tank after the overhead condenser condensation, wherein a part is as the backflow of tower, another part is as the charging of extraction tower, the MTBE that comes out from the catalytic distillation tower bottom delivers to the tank field and stores after the water cooler cooling.This flow scheme design also comes with some shortcomings, mainly show the following aspects: 1, cleaner does not have surveillance and control measure intuitively to the decontamination effect improving of raw material, especially in temperature lower winter, cleaner charging and discharging temperature does not have the temperature difference, add and do not have the alkali content analysis means, even catalyzer complete deactivation can not in time be found in the cleaner, so just may cause great impact to reactor catalyst.In case reactor catalyst is poisoned, be fatal to the influence of MTBE device, this is because the iso-butylene in the raw material has more than 90% to transform in reactor.In addition, the significantly downslide of transformation efficiency in the reactor also can cause a large amount of iso-butylene autohemagglutinations in the catalytic distillation tower, and a large amount of heats that the iso-butylene autohemagglutination is emitted will cause the beds overtemperature, thereby burn out catalyzer.Like this, whole device will be forced to stop work completely.2, the device cycle of operation is too short.As guaranteeing iso-butylene total conversion rate 〉=99%, reach the index request of " chemical industry type ", then install the cycle of operation and can only keep six months, do not reach the target in 1 year far away.3, the catalyzer in the cleaner is not fully used.

Technical scheme

The object of the present invention is to provide a kind of method by carbon four and methanol production MTBE that can prolong the life cycle of catalyzer and install the cycle of operation.

The technical solution used in the present invention is as follows: a kind of by the method for carbon four with methanol production MTBE, its feature: include following steps: 1. raw materials pretreatment: the carbon four, the methyl alcohol that contain iso-butylene pressurize through pump respectively, by raw material being heated to cleaner and the preliminary etherification reaction that takes place that enters the dress resin catalyst after 30 ℃～60 ℃ by feed preheater behind the static mixer thorough mixing; 2. react and product separation: the mixing raw material that comes from cleaner is cooled to 30 ℃～70 ℃ by water cooler, enter reactor then, under the effect of resin catalyst, etherification reaction takes place, the post reaction mixture material enters catalytic distillation tower with the gas-liquid mixed phase and continues to take place etherification reaction, methyl alcohol and unreacted carbon four distillate from cat head with the azeotrope form, overhead product enters return tank after the overhead condenser condensation, wherein a part is as the backflow of tower, another part is as the charging of extraction tower, the MTBE that comes out from the catalytic distillation tower bottom after the water cooler cooling, the MTBE finished product.

The thermal source of described feed preheater is the condensed water of steam or recovery.

The present invention is newly-increased feed preheater before cleaner, improve cleaner feed(raw material)inlet temperature, make raw material in cleaner, just begin reaction, with the reach of partial reaction load, brought into play the effect of cleaner to greatest extent, alleviated the burden of reactor greatly, this compares with transforming the preceding single purification raw material of cleaner function, and its effect is further improved; Exothermic heat of reaction rises cleaner outlet material temperature simultaneously, size variation by the temperature difference can be judged activity of such catalysts changing conditions in the cleaner very intuitively, so that can be in time catalyst changeout more, thereby reached the purpose of catalyzer in the guard reactor better; Because the part iso-butylene transforms in cleaner, reduced the concentration of iso-butylene in the reactor feed effectively, make exothermic heat of reaction minimizing in the reactor, more help realizing cold operation, slow down coming off of catalyzer sulfonate ion, prolonged life cycle, the device cycle of operation of catalyzer greatly.

The present invention with the reactor in the original technology before former preheater change water cooler into, owing to before cleaner, set up feed preheater, feeding temperature rises, the part iso-butylene is reacted in cleaner, exothermic heat of reaction rises the cleaner temperature out, reach as high as more than 75 ℃, and reactor is when raw catalyst just comes into operation, its temperature in reaches 30 ℃ and gets final product, temperature in is high more, reactor batch temperature is just high more, and by product is uncontrollable, and can produce a very large impact the life cycle of catalyzer, therefore, a water cooler is set before reactor,, guarantees quality product and on-stream time with the temperature in of controlling reactor.

The present invention effectively reduces the concentration of iso-butylene in the reactor feed, and has protected the catalyzer in the reactor better, and the life cycle that has prolonged catalyzer has greatly prolonged the device cycle of operation simultaneously.

Description of drawings

Fig. 1 is the process flow sheet before transforming;

Fig. 2 is a process flow sheet of the present invention.

Embodiment

Further the present invention will be described by the following examples:

Embodiment:

Under the effect of D006 type etherificate resin catalyst or D005 type etherificate resin catalyst, working pressure is 0.75MPa, is the contrast experiment by technology before transforming and technology of the present invention respectively with the carbon four that contains iso-butylene and methyl alcohol, and its experimental data is as follows respectively:

1, iso-butylene, the contrast of MTBE content:

Table 1 cleaner outlet iso-butylene, MTBE content contrast table

As can be seen from Table 1, cleaner outlet MTBE content of the present invention obviously rises, and iso-butylene content obviously descends, proved absolutely that raw material process cleaner under the effect of catalyzer, etherification reaction has taken place, generated a spot of MTBE, iso-butylene content reduces in the raw material of reaction back, alleviated the reaction load of reactor effectively, this compares with the single purification raw material function of transforming preceding technology cleaner, and the effect of cleaner is further improved.

2, reactor hot(test)-spot temperature contrast:

Reactor batch temperature of the present invention changes more obvious, and particularly the control of the hot(test)-spot temperature of reactor catalyst is lower, and the low-temp reaction phase has prolonged nearly four months relatively.

The reactor hot(test)-spot temperature distributed and contrasts before and after table 2 was transformed

As known from Table 2; when the present invention produces at different catalyzer on probation; reactor batch temperature with transform before compare; the low temperature reaction phase of catalyzer holds time long and more stable; the active centre sulfonate ion that more helps guard catalyst; can slow down the exfoliation rates of sulfonate ion effectively, prolong the work-ing life of catalyzer, protection equipment is avoided the corrosion of strong acid better.

3, service temperature and working pressure contrast:

Table 3 service temperature, pressure changing

	Temperature ℃ in the reactor middle and lower part	Temperature ℃ in the reactor middle part	Temperature ℃ in the reactor middle and upper part	Temperature ℃ in the reactor top	Reactor outlet pressure KPa	Catalytic distillation tower top pressure KPa
							Operation mean value before transforming	68.1	71.3	72.4	72.4	755.7	673.2
The present invention operates mean value	57.2	61.7	62.7	62.7	577.6	526.7
							The variation of operating parameters amplitude	△10.9↓	△9.7↓	△9.7↓	△9.7↓	△178.1↓	△146.5↓

From table 3 data; very big variation has taken place in device operating parameters of the present invention; reactor batch temperature is the highest has as can be seen descended 10.9 ℃ by contrasting; the working pressure of the reactor 178KPa that descended; the working pressure of the catalytic distillation tower T1101 146KPa that descended; thereby prolonged the low-temp reaction cycle of reactor effectively, protected catalyzer.

The macropore strong acid resin catalyst in use can produce the sulfonate ion obscission, it is documented, reaction bed temperature is about 60 ℃, and its sulfonate ion exfoliation rates is 9～20 * 10 ^-8Mmol/g.h; high more its exfoliation rates of temperature is fast more; and sulfonate ion activity of such catalysts center just; therefore the catalyzer cold operation time is long more; just can slow down coming off of catalyzer sulfonate ion effectively more; favourable to the guard catalyst active centre, favourable to the life cycle that prolongs catalyzer.Simultaneously because after the decline of reactor catalyst focus, the corrosion of protection equipment being avoided sulfonate ion has great importance.

4, reactive system isobutene conversion contrast:

The present invention is because part isobutene reaction reach, so the reactor outlet conversion for isobutene obtained effective control, and table 4 data are reactor outlet isobutene conversion data calculateds before and after transforming.

Reactor outlet isobutene conversion contrast before and after table 4 is transformed

From table 4 data, the reactor outlet isobutene conversion is not only stable and keep higher level, and in catalyst activity late period, isobutene conversion can be stabilized in about 90% especially, to the operation in stopping reaction later stage, it all is favourable prolonging the catalyzer life cycle.

5, cleaner temperature out contrast:

By improving raw material preheating temperature, impel part iso-butylene antedating response in cleaner, so the temperature out of cleaner also there is sizable variation thereupon.

Cleaner and water cooler out temperature changing conditions before and after table 5 is transformed

As known from Table 5, cleaner has been realized the part etherification reaction among the present invention, temperature out is greatly improved, effect after implement, we not only can change the activity change trend of in time grasping the cleaner inner catalyst according to the temperature out of cleaner, and when the cleaner import and export do not have the temperature difference, can judge the interior catalyzer of cleaner inactivation, can in time change.Simultaneously, can also be according to the feeding temperature of the flexible controlling reactor of the active situation of reactor catalyst, thus the catalyzer in the reactor has been played the better protection effect.

6, reactor cycle of operation contrast:

Table 6 catalyst in reactor cycle of operation cartogram

After adopting the present invention as known from Table 6, the cycle of operation of catalyst in reactor prolongs.

7, catalyst consumption contrast:

MTBE output contrast table before and after table 7 is transformed

After adopting the present invention as known from Table 7, because the reactive system conversion for isobutene improves and the cycle of operation prolongs, MTBE output also rises synchronously.

Claims

1. one kind by carbon four method with the methanol production methyl tertiary butyl ether, it is characterized in that: include following steps:

1. raw materials pretreatment: the carbon four, the methyl alcohol that contain iso-butylene pressurize through pump respectively, by raw material being heated to cleaner and the preliminary etherification reaction that takes place that enters dress D006 type etherificate resin catalyst or D005 type etherificate resin catalyst after 30 ℃～60 ℃ by feed preheater behind the static mixer thorough mixing;

2. react and product separation: the mixing raw material that comes from cleaner is cooled to 30 ℃～70 ℃ by water cooler, enter reactor then, under the effect of D006 type etherificate resin catalyst or D005 type etherificate resin catalyst, etherification reaction takes place, the post reaction mixture material enters catalytic distillation tower with the gas-liquid mixed phase and continues to take place etherification reaction, methyl alcohol and unreacted carbon four distillate from cat head with the azeotrope form, overhead product enters return tank after the overhead condenser condensation, wherein a part is as the backflow of tower, another part is as the charging of extraction tower, the methyl tertiary butyl ether that comes out from the catalytic distillation tower bottom after the water cooler cooling, the methyl tertiary butyl ether finished product.

2. method according to claim 1 is characterized in that: the thermal source of described feed preheater is the condensed water of steam or recovery.