CN217724614U

CN217724614U - MTBE product quality optimization promotes technical transformation system

Info

Publication number: CN217724614U
Application number: CN202221436546.8U
Authority: CN
Inventors: 许肖慧; 郑德金; 赵育生; 许爱云; 郝天军; 孙昱
Original assignee: Daqing Zhonglan Petrochemical Co Ltd
Current assignee: Daqing Zhonglan Petrochemical Co Ltd
Priority date: 2022-06-09
Filing date: 2022-06-09
Publication date: 2022-11-04
Anticipated expiration: 2032-06-09

Abstract

The utility model relates to a MTBE product quality optimization promotes technical transformation system. Mainly solves the problem that the MTBE product in the prior system contains methanol, so that the purity of the product can not reach a higher level. The method is characterized in that: the catalytic distillation tower is connected with a feeding pipeline, the top of the catalytic distillation tower is connected with an air cooler and a reflux tank, and the reflux tank is connected with a reflux pump; the reflux pump extraction pipeline is connected to the upper part of the catalytic distillation tower; the suction pipeline of the reflux pump is also connected with a feed line of the water washing tower; the top pipeline of the washing tower is connected with a carbon four-buffer tank, the bottom pipeline of the carbon four-buffer tank is connected with a carbon four-non-return pump, and a carbon four-non-return pipeline is assembled between a carbon four-return pump outlet and a catalytic distillation tower incoming material pipeline. This MTBE product quality optimization promotes technical transformation system can separate out a small amount of methyl alcohol in the product, from more making MTBE purity obtain promoting.

Description

MTBE product quality optimization promotes technical transformation system

Technical Field

The utility model relates to a petrochemical technical field, in particular to MTBE product quality optimization promotes technical transformation system.

Background

Under the selected process conditions, isobutene in the raw material C4 fraction and industrial methanol are mixed and then enter a pre-etherification reactor to react and synthesize methyl tert-butyl ether (MTBE). Crude MTBE flowing out of an outlet of the pre-etherification reactor enters a catalytic distillation tower for mixture separation, pure MTBE is obtained at the bottom of the catalytic distillation tower, the mixture is sent to a distillation system for desulfurization, a mixture of methanol obtained at the top of the tower and carbon four which is not reacted is condensed by an air cooler at the top of the tower and then enters a reflux tank, a liquid phase in the reflux tank is pumped out by a reflux pump, one part of the liquid phase is sent back to the catalytic distillation tower to be used as reflux, the other part of the liquid phase is sent to a washing tower, a methanol water solution is obtained at the bottom of the washing tower, the carbon four component left at the top of the tower enters a carbon four buffer tank, and finally the carbon four component is pumped out by the carbon four which is not reacted and then is sent to a tank area after being controlled by a flow control valve.

And (3) the etherified carbon four in the pre-etherification reactor flows out from the bottom to enter a catalytic distillation tower, C4 and methanol form a low-boiling azeotrope in the catalytic distillation tower, and by means of the characteristic, the MTBE product can be separated from unreacted C4 and residual methanol in the catalytic distillation tower by adopting an azeotropic distillation method, so that a purer MTBE product is obtained at the bottom of the tower.

The problems with this system are: in the MTBE synthesis reaction, methanol and isobutylene are equimolar reactions, i.e., consumption of 1:1. In order to improve the conversion rate of isobutene and avoid the occurrence of isobutene dimerization reaction, the feeding amount of methanol is larger than a theoretical value, and the methanol is controlled between 1.0 and 1.2 at present, so that the polymerization reaction of isobutene in the C-C raw material can be caused due to too low methanol, and the product is unqualified. When the amount of the methanol is too high, a large amount of dimethyl ether is generated, and the purity of the product is also influenced. Methanol and C4 can form an azeotrope with low boiling point, and because the boiling point of methanol is 64.5 ℃, the boiling point of MTBE is 55 ℃ and the boiling point of methanol is higher than that of MTBE, the content of methanol in the azeotropic distillation tower must not be larger than the amount of the components forming the azeotrope with C4. If the amount is larger than the amount of azeotrope with C4, the excess methanol falls into MTBE when MTBE is separated, and the purity of MTBE is lowered. At present, the methanol content is 0.5-1.0%, and the methanol purity cannot reach a higher level because the MTBE product contains methanol.

Disclosure of Invention

The utility model aims to solve the technical problem that it leads to product purity can not reach higher level problem to contain methyl alcohol in overcoming the MTBE product that exists among the background art, and provides an MTBE product quality optimization promotion technique transformation system, and this MTBE product quality optimization promotion technique transformation system can separate away a small amount of methyl alcohol in the product, obtains promoting from more making MTBE purity.

The utility model provides a its problem accessible reach as follows technical scheme: the MTBE product quality optimization and improvement technical transformation system comprises a catalytic distillation tower, wherein the catalytic distillation tower is connected with a material supply pipeline, the top of the catalytic distillation tower is connected with an air cooler and a reflux tank, and the reflux tank is connected with a reflux pump; the reflux pump extraction pipeline is connected to the upper part of the catalytic distillation tower; the suction pipeline of the reflux pump is also connected with a feed line of the washing tower; the top pipeline of the washing tower is connected with a carbon four-buffer tank, the bottom pipeline of the carbon four-buffer tank is connected with a carbon four-non-return pump, and a carbon four-non-return pipeline is assembled between a carbon four-return pump outlet and a catalytic distillation tower incoming material pipeline.

Preferably, two sides of the non-carbon-reversed four-way pipeline are respectively provided with a pilot valve for purging the pipeline when the pipeline is stopped.

Preferably, valves are respectively installed at the root parts of the two sides of the non-carbon-reversed four pipelines.

Preferably, one side of the root discharge on the non-reverse carbon four-line is connected with a flowmeter for displaying the non-reverse carbon four-flow of the added catalyst.

Preferably, the rear part of the non-carbon-reversed four-pipeline upper flow meter is connected with a self-control valve group.

Preferably, the automatic control valve group comprises a control valve, and a side valve A and a side valve B on two sides.

Preferably, the incoming line is from the pre-etherification reactor discharge.

This MTBE product quality optimization promotes technical transformation system principle: the characteristic that the solubility difference of methanol in C4 fraction and water is large is utilized, and the overhead product of the catalytic distillation tower is washed by water, so that the methanol is extracted by water to obtain methanol water solution. By utilizing the density difference between the liquefied gas carbon four and the methanol water, qualified carbon four which is not reacted can be obtained at the top of the water washing tower, and the methanol water solution can be obtained at the bottom of the water washing tower.

Compared with the above background art, the utility model can have following beneficial effect:

the invention uses the non-carbon-return four-pump as power, adds a non-carbon-return four-line on the outlet line of the non-carbon-return four-pump to the inlet of the catalytic distillation tower, and the reactant enters the catalytic distillation tower along with the ether at the outlet of the reactor. Two ends of the carbon four lines which are not reversed are respectively provided with one valve; and a flowmeter is also arranged on the carbon non-return four line, so that the carbon non-return four flow rate of the added catalyst can be conveniently displayed. A self-control valve group is arranged at the rear part of the flowmeter so as to adjust the flow of the non-carbon-return four; and guide shower valves are respectively arranged on two sides of the pipeline so as to facilitate the pipeline cleaning treatment when the pipeline is stopped.

Under the condition of not influencing normal production, an unreflected carbon four-line is added to an outlet line of an unreflected carbon four-line to a catalytic distillation tower, and the unreflected carbon four-line is introduced into the catalytic distillation tower, so that redundant methanol and carbon four in the tower form a low-boiling-point azeotrope, the redundant methanol can be left from the tower top along with the carbon four, and the purity of a product MTBE at the tower bottom is further improved.

Before the MTBE product quality optimization and improvement technology transformation system is applied, the purity of MTBE reaches about 98.5%, the methanol content is 0.5-1.0%, the methanol content in MTBE is reduced from 0.5-1.0% to 0-0.5% after transformation, the product purity reaches more than 99%, and the effect is obvious. The purity of the MTBE product is effectively upgraded through optimization and transformation.

Drawings

Figure 1 is the utility model discloses MTBE product quality optimizes the technical transformation system flow chart that promotes.

In the figure: 1. A catalytic distillation column; 2. an air cooler; 3. a reflux tank; 4. a reflux pump; 5. washing the tower with water; 6. a carbon four buffer tank; 7. a carbon four pump is not reversed; 8. a valve A; 9. a pilot shower valve A; 10. a flow meter; 11. a side valve A; 12. a control valve; 13. a side valve B; 14. non-reverse carbon four-line; 15. a pilot shower valve B; 16. and a valve C.

The specific implementation mode is as follows:

the invention will be further explained with reference to the drawings:

as shown in the attached figure 1, the improved system for the MTBE product quality optimization and promotion technology comprises a catalytic distillation tower 1, wherein the catalytic distillation tower 1 is connected with an incoming material pipeline, and MTBE with pure components is obtained at the bottom of the catalytic distillation tower; the top of the catalytic distillation tower 1 is connected with an air cooler 2 and a reflux tank 3, and the reflux tank 3 is connected with a reflux pump 4; the extraction pipeline of the reflux pump 4 is connected to the upper part of the catalytic distillation tower 1; the pumping pipeline of the reflux pump 4 is also connected with a feeding line of the water washing tower 5; the top pipeline of the water scrubber 5 is connected with a carbon four-buffer tank 6, the bottom pipeline of the carbon four-buffer tank 6 is connected with a carbon four-pump 7 which is not used for returning carbon, and a carbon four-pipeline 14 which is not used for returning carbon is assembled between the extraction line of the carbon four-pump 7 which is not used for returning carbon and the incoming material pipeline of the catalytic distillation tower 1; one side of the discharge at the root part of the non-carbon-return four-pipeline 14 is sequentially connected with a valve A8, a pilot shower valve A9, a flowmeter 10 and a self-control valve group; the feeding side of the non-carbon-return four pipeline 14 is sequentially connected with a valve C16 and a pilot shower valve B15; the automatic control valve group comprises a control valve 12, and a side valve A11 and a side valve B13 on two sides.

This MTBE product quality optimization promotes technical transformation system, under the condition that does not influence normal production, take and join in marriage on 7 exit lines of non-anti-carbon four pumps and add a non-anti-carbon four-line to catalytic distillation tower, will not anti-carbon four introduce in the catalytic distillation tower, make unnecessary methanol and carbon four in the tower form low boiling azeotrope, can leave unnecessary methanol along with carbon four from the top of the tower, and then improve the purity of product MTBE at the bottom of the tower, make the purity reach more than 99%.

The invention uses the non-carbon-return four-pump as power, adds a non-carbon-return four-line on the outlet line of the non-carbon-return four-pump to the inlet of the catalytic distillation tower, and the reactant enters the catalytic distillation tower along with the ether at the outlet of the reactor. The two ends of the non-reverse carbon four-wire are respectively provided with one root valve, so that the root valves are adopted as isolating valves when the device is stopped, and the mounting of blind plates is facilitated to be thoroughly isolated; and a flowmeter is also arranged on the carbon non-return four line, so that the carbon non-return four flow rate of the added catalyst can be conveniently displayed. A self-control valve group is arranged at the rear part of the flowmeter so as to adjust the flow of the non-carbon-return four; and guide shower valves are respectively arranged on two sides of the pipeline so as to conveniently introduce steam through the guide shower valves to carry out pipeline sweeping treatment when the pipeline is stopped.

The invention solves the problem that the purity of the methanol cannot reach higher due to the methanol contained in the MTBE product, and the methanol with the purity of 0.5-1.0 percent in the product is successfully separated out by implementing the invention, so that the purity of the MTBE is further improved.

The MTBE product quality optimization and promotion technology transformation system flow is as follows: firstly, the pilot valve A9 is closed, and the pilot valve B15 is closed, so that the harm caused by leakage of carbon four in the use process is prevented. Opening a valve A8, passing through a flowmeter-10, and opening a self-control valve group side valve A11, a control valve B12, a side valve B13 and a valve C16. The non-reverse carbon four flows into a non-reverse carbon four pipeline 14 from the outlet of a non-reverse carbon four pump 7, then enters a flowmeter 10 through a configured root valve A8, then enters a control valve 12, two side valves A11 and a side valve B13, finally enters the catalytic distillation tower 1 together with the outlet material of the pre-etherification reactor through a valve C16, and mixture separation is carried out in the catalytic distillation tower. MTBE with higher purity is obtained at the bottom of the tower, and a mixture of methanol and carbon four is obtained at the top of the tower.

Claims

1. The utility model provides a MTBE product quality optimization promotes technological transformation system, includes catalytic distillation tower (1), its characterized in that: the catalytic distillation tower (1) is connected with a feeding pipeline, the top of the catalytic distillation tower (1) is connected with an air cooler (2) and a reflux tank (3), and the reflux tank (3) is connected with a reflux pump (4); the extraction pipeline of the reflux pump (4) is connected to the upper part of the catalytic distillation tower (1); the pumping pipeline of the reflux pump (4) is also connected with a feeding line of the water washing tower (5); the top pipeline of the water scrubber (5) is connected with a carbon four-buffer tank (6), the bottom pipeline of the carbon four-buffer tank (6) is connected with a carbon four-pump (7), and a carbon four-pipeline (14) which is not reversed is assembled between the extraction line of the carbon four-pump (7) and the incoming material pipeline of the catalytic distillation tower (1).

2. The improvement system of MTBE product quality optimization promotion technique of claim 1, characterized in that: and guide shower valves are respectively arranged on two sides of the four non-carbon-return pipelines (14) and used for purging the pipelines when the pipelines are not used.

3. The improvement system of MTBE product quality optimization promotion technique of claim 1, characterized in that: and valves are respectively arranged at the root parts of the two sides of the non-carbon-return four pipeline (14).

4. The improvement system of MTBE product quality optimization promotion technique of claim 1, characterized in that: and one side of the discharge of the root part of the carbon non-return four pipeline (14) is connected with a flowmeter (10) for displaying the carbon non-return four flow rate of the added catalyst.

5. The MTBE product quality optimization and promotion technology transformation system of claim 4, wherein: the rear part of the non-carbon-reversed four-pipeline upper flow meter (10) is connected with a self-control valve group.

6. The improvement system of MTBE product quality optimization promotion technique of claim 5, characterized in that: the automatic control valve group comprises a control valve (12), and a side valve A and a side valve B which are arranged on two sides.

7. The improvement system of MTBE product quality optimization promotion technique of claim 1, characterized in that: the incoming material of the incoming material pipeline of the catalytic distillation tower comes from the discharging of the pre-etherification reactor.