CN211035759U

CN211035759U - Equipment for degrading polytetrahydrofuran and recycling tetrahydrofuran

Info

Publication number: CN211035759U
Application number: CN201921737089.4U
Authority: CN
Inventors: 唐元; 周代红; 宋锋; 吴航宇; 张敏
Original assignee: Sinopec Great Wall Energy Chemical Ningxia Co Ltd
Current assignee: Sinopec Great Wall Energy Chemical Ningxia Co Ltd
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-07-17
Anticipated expiration: 2029-10-16

Abstract

The utility model provides an equipment that degradation polytetrahydrofuran and recovery tetrahydrofuran, this equipment raw materials storage tank links to each other with degradation reactor through the pipeline, and degradation reactor links to each other with the atmospheric tower through gaseous extraction pipeline, and the atmospheric tower passes through the pipeline and links to each other with the pressurized column, and the pressurized column passes through the pipeline and links to each other with qualified tetrahydrofuran storage tank. The normal pressure tower is respectively connected with a normal pressure tower condenser, a normal pressure tower condensing tank and a normal pressure tower top reflux pump in series through pipelines; the pressurizing tower is respectively connected with a pressurizing tower top condenser, a pressurizing tower condensing tank and a pressurizing tower top reflux pump in series through pipelines. The utility model discloses increase a degradation reactor outside current tetrahydrofuran production system, increase a tetrahydrofuran basin, increase a gaseous phase and adopt the pipeline, increase a cooler, original atmospheric tower and pressurized column are refine to the tetrahydrofuran separation and utilize, optimize the equipment that the combination formed one set of degradation polytetrahydrofuran and retrieved tetrahydrofuran with above-mentioned newly-increased equipment and former plant equipment. The utility model discloses do not need newly-built rectification system, the small investment, the benefit is high.

Description

Equipment for degrading polytetrahydrofuran and recycling tetrahydrofuran

Technical Field

The utility model belongs to the fine chemical industry field in coal chemical industry low reaches, concretely relates to equipment of tetrahydrofuran is retrieved in degradation polytetrahydrofuran.

Background

The industrial production of Polytetrahydrofuran (PTMEG) is mainly prepared by cationic ring-opening polymerization of Tetrahydrofuran (THF). During the original driving of the polytetrahydrofuran device, due to the fact that the pipeline and equipment have more impurities, operation and the like, unqualified PTMEG products of about 1500t-3000t can be produced. In normal production, the PTMEG device can generate 2-3% PTMEG oligomer in the SPD (narrow distillation) process, the average molecular weight is generally 250-400, and the annual low molecular weight polytetrahydrofuran is about 2000 tons according to 9.2 ten thousand tons/year device calculation. These oligomers are sold at low prices, with a sales revenue of about 800 ten thousand yuan assuming a market price of substantially about 4000 yuan per ton, whereas a market price of about 10000 yuan per ton of tetrahydrofuran, self-depolymerization produces a yield of about 2000 ten thousand yuan.

In order to recover the unqualified products, the unqualified PTMEG is required to be sent into a tetrahydrofuran reactor for depolymerization according to the Envida equipment, and the generated tetrahydrofuran is recycled. The tetrahydrofuran reactor is not provided with stirring, forced circulation stirring is carried out by a tetrahydrofuran bottom pump, due to the characteristics of strong oxidizing property of sulfuric acid and high viscosity of polytetrahydrofuran, partial high-temperature carbonization of PTMEG and tar generation coaction are carried out, the circulation flow of the bottom pump of the tetrahydrofuran reactor is low, the tube of a heat exchanger is blocked, a filter screen at the inlet of the pump is blocked, and the reaction cannot be carried out. Because the tetrahydrofuran reactor is used for simultaneously carrying out two works of preparing tetrahydrofuran by BDO dehydration and degrading polytetrahydrofuran during degradation, once the problems occur, a tetrahydrofuran device cannot be used for production, and larger economic loss can be caused. However, if a set of technological process for degrading and recovering tetrahydrofuran is separately established, the investment is very huge. The present invention is therefore directed to solving this problem with minimal investment.

Disclosure of Invention

The utility model aims at providing a new equipment for degrading polytetrahydrofuran and recycling tetrahydrofuran aiming at the defects of the existing equipment for degrading polytetrahydrofuran and recycling tetrahydrofuran.

Realize the utility model discloses the technical scheme of purpose does: a raw material storage tank for storing low-molecular polytetrahydrofuran or unqualified polytetrahydrofuran is connected with a degradation reactor through a pipeline, the degradation reactor is connected with an atmospheric tower through a gas-phase extraction pipeline and a cooler, the atmospheric tower is connected with a pressurizing tower through a pressurizing tower feeding pipeline, and the pressurizing tower is connected with a qualified tetrahydrofuran storage tank through a qualified tetrahydrofuran discharging pipeline at the bottom of the pressurizing tower. The top end of the degradation reactor is provided with a mechanical stirrer, and a steam pipeline, a tar outlet, a pipeline, a steam condensate discharge pipeline and a nitrogen pipeline which are used for providing steam are respectively connected with the degradation reactor. The normal pressure tower is respectively connected with a normal pressure tower condenser, a normal pressure tower condensing tank and a normal pressure tower top reflux pump in series through pipelines; the pressurizing tower is respectively connected with a pressurizing tower top condenser, a pressurizing tower condensing tank and a pressurizing tower top reflux pump in series through pipelines. A reject tetrahydrofuran return line is connected from the pressurized column to the atmospheric column. And a qualified tetrahydrofuran discharge pipeline at the bottom of the pressurizing tower is connected to a qualified tetrahydrofuran storage tank from the pressurizing tower. Adding a solid acid catalyst into a degradation reactor through a catalyst feeding port, adding low molecular weight polytetrahydrofuran or non-molecular polytetrahydrofuran into the degradation reactor through a raw material storage tank, and connecting the degradation reactor with a normal pressure tower through a nitrogen pipeline to protect the degradation reactor. The degradation reactor, the tetrahydrofuran storage tank, the gas phase feed pipeline and the heat exchanger in the tetrahydrofuran production system are newly added equipment, and the tetrahydrofuran separation and refining system formed by the newly added equipment utilizes the normal pressure tower and the pressurizing tower of the original device to optimize and combine the newly added equipment and the original device to form a set of equipment for degrading polytetrahydrofuran and recovering tetrahydrofuran.

The utility model discloses have as follows and show the effect:

the utility model discloses under the minimum investment condition, newly-increased degradation reactor in original flow one, increase tetrahydrofuran storage tank one, increase gaseous phase extraction pipeline one, increase 1 of heat exchanger to utilize the refined flow of original tetrahydrofuran, degrade polytetrahydrofuran and retrieve. The price of the newly added stainless steel solid acid degradation reactor is 20-30 ten thousand yuan, and compared with a 1000 ten thousand yuan Hastelloy alloy reactor adopting the existing tetrahydrofuran reactor degradation equipment, the investment is saved by about 20-30 times. The newly added gas phase pipeline enters the stripping section of the atmospheric tower, so that a heat source can be provided for the atmospheric tower, the purpose of rectification is realized, and the original rectification system is not influenced. The newly-added heat exchanger can adopt different heat exchange media according to the gas phase temperature, and the temperature control of entering the atmospheric tower is realized. The utility model discloses utilize original device refining system to realize that tetrahydrofuran is refined, need not newly-built rectification system, the small investment, the benefit is high. If the device is degraded and recycled according to full load, the production cost is removed, 1800 tons of tetrahydrofuran can be recycled every year, and the economic benefit is about 1000 ten thousand yuan compared with the economic benefit created by directly selling low molecular weight polytetrahydrofuran.

Drawings

FIG. 1 is a schematic diagram showing the structure and connection relationship of an apparatus for degrading polytetrahydrofuran and recovering tetrahydrofuran.

As shown in the figure: 1-a raw material storage tank; 2-a degradation reactor; 3-atmospheric tower; 4-a pressurized column; 5-a mechanical stirrer; 6-tar discharge port and pipeline; 7-a steam line; 8-a vapor condensate discharge line; 9-off-spec tetrahydrofuran return line; 10-atmospheric tower condensing tank; 11-atmospheric tower condenser; 12-atmospheric overhead reflux pump; 13-a column bottom heater; 14-a water discharge line; 15-a pressurized column feed line; 16-pressurized tower condensing tank; 17-a pressurized column overhead condenser; 18-pressurized overhead impurity removal line; 19-pressurized overhead reflux pump; 20-a pressurized tower bottom heater; 21-qualified tetrahydrofuran discharge line at the bottom of the pressurized tower; 22-qualified tetrahydrofuran storage tank; 23-a catalyst feed port; a 24-nitrogen line; 25-gas phase extraction line. 26-cooler

The utility model discloses equipment and pipeline function explain:

the raw material storage tank 1 is used for storing low molecular polytetrahydrofuran or unqualified polytetrahydrofuran; the degradation reactor 2 is used for degrading polytetrahydrofuran into tetrahydrofuran; the atmospheric tower 3 is used for primarily separating tetrahydrofuran F from water; the pressurizing tower 4 treats the moisture in the tetrahydrofuran to be qualified to obtain qualified tetrahydrofuran; the mechanical stirrer 5 is used for uniformly stirring the reactants and the catalyst; the device 6 is used for discharging tar generated by degradation reaction; a steam line 7 is used to supply 1.0MNPa steam to provide heat for the reaction; a vapor condensate discharge line 8 for discharging vapor condensate; the unqualified tetrahydrofuran returns to the pipeline 9, and the unqualified tetrahydrofuran returns to the normal pressure tower again for separation; the atmospheric tower condensing tank 10 is used for collecting the atmospheric tower top condensate; the atmospheric tower condenser 11 condenses the gaseous phase of the tetrahydrofuran at the top of the atmospheric tower by adopting circulating cooling water; the atmospheric tower top reflux pump 12 is a reflux pump of the atmospheric tower and is used for providing reflux for the tower top; the tower bottom heater 13 is used for providing a tower bottom heat source for the atmospheric tower; the pressurized column feed line 15 feeds the pressurized column tetrahydrofuran mixture; the pressurized tower condensing tank 16 is used for collecting pressurized tower top condensate; a condenser 17 at the top of the pressurizing tower condenses the gas phase of the tetrahydrofuran mixture at the top of the pressurizing tower by adopting circulating cooling water; a pressurized overhead impurities discharge line 18 provides discharge for pressurized overhead impurities; a pressurizing column top reflux pump 19 for pressurizing the column top to supply a reflux liquid; a pressurized tower bottom heater 20 provides a heat source for the pressurized tower bottom; the catalyst feed port 23 is used for feeding solid catalyst required by degradation reaction; a nitrogen line 24 is used to provide the necessary nitrogen blanket for the reaction. The gas phase extraction pipeline 25 is used for a pipeline for producing gas phase products through degradation reaction and entering the atmospheric tower. The cooler 26 is used to cool the degradation reaction to produce a gas phase.

Detailed Description

As shown in fig. 1: a raw material storage tank 1 for storing low-molecular polytetrahydrofuran or unqualified polytetrahydrofuran is connected with a degradation reactor 2 through a pipeline, the degradation reactor 2 is connected with an atmospheric tower 3 through a gas phase extraction pipeline 25, the atmospheric tower 3 is connected with a pressurizing tower 4 through a pressurizing tower feeding pipeline 15, and the pressurizing tower 4 is connected with a qualified tetrahydrofuran storage tank 22 through a qualified tetrahydrofuran discharging pipeline 21 at the bottom of the pressurizing tower. The top end of the degradation reactor 2 is provided with a mechanical stirrer 5, and a steam pipeline 7, a tar discharge port and pipeline 6, a steam condensate discharge pipeline 8 and a nitrogen pipeline 24 which are used for providing steam are respectively connected with the degradation reactor 2. The atmospheric tower 3 is respectively connected with an atmospheric tower condenser 11, an atmospheric tower condensing tank 10 and an atmospheric tower top reflux pump 12 in series through pipelines; the pressurizing tower 4 is connected in series with a pressurizing tower overhead condenser 17, a pressurizing tower condensing tank 16 and a pressurizing tower overhead reflux pump 19 through pipelines, respectively. A reject tetrahydrofuran return line 9 is connected from the pressurized column 4 to the atmospheric column 3. A qualified tetrahydrofuran discharge line 21 at the bottom of the pressurized column is connected from the pressurized column 4 to a qualified tetrahydrofuran storage tank 22. 15 is the pressurized column feed line. The degradation reactor 2 is independently arranged and made of 304 or 316SS materials, the qualified tetrahydrofuran storage tank 22 is made of carbon steel, and the degradation reactor 2 is provided with a matched catalyst filling port, a mechanical stirrer, a jacket, a gas phase extraction pipeline, a nitrogen pipeline and a tar oil discharge port of the degradation reactor.

Use the utility model discloses the time: starting a mechanical stirrer 5 to adjust the rotation speed to 200r/min, heating the mixture to 170 ℃, introducing 2.5Mpa steam through a steam pipeline 7 to provide the temperature required by degradation, discharging steam condensate through a steam condensate discharge pipeline 8, directly feeding the generated tetrahydrofuran gas phase into an atmospheric tower for rough refining, wherein the heat source of the atmospheric tower 3 is mainly provided by a tower bottom heater, the tetrahydrofuran gas phase can also provide a part of heat source, most of water in the tetrahydrofuran in the atmospheric tower is removed through a water discharge pipeline 14, the tetrahydrofuran with a small water content at the top of the atmospheric tower is condensed by a tower top condenser 11 and then enters an atmospheric condensate tank 10, a part of condensate is used for providing reflux for the atmospheric tower 3 through an atmospheric tower top reflux pump 12, a part of tetrahydrofuran with a small water content enters a pressurizing tower 4 through a pressurizing tower feeding pipeline 15 for rectification treatment, and a pressurizing tower bottom heater 20 is used for providing the heat source for the pressurizing tower, refined tetrahydrofuran produced at the bottom of the tower enters a qualified tetrahydrofuran storage tank 22 through a qualified tetrahydrofuran discharge pipeline 21 at the bottom of the pressurized tower; if the tetrahydrofuran at the bottom of the tower is unqualified, the unqualified tetrahydrofuran is returned to the atmospheric tower 3 through an unqualified tetrahydrofuran return line 9, the pressurized tower top gas-phase tetrahydrofuran mixture is condensed by a pressurized tower top condenser 17 and then enters a pressurized tower condensing tank 16, a part of the tetrahydrofuran mixture enters the pressurized tower 4 through a pressurized tower top reflux pump 19 to provide reflux for the pressurized tower, and a small part of the tetrahydrofuran mixture is discharged system impurities through a pressurized tower top impurity discharge line 18. A small amount of tar generated in the degradation process is periodically discharged through a tar discharge port of the degradation reactor and a pipeline 6. The utility model discloses use low molecular weight polytetrahydrofuran or unqualified polytetrahydrofuran as the raw materials, adopt solid acid catalyst, carry out degradation reaction under the uniform temperature, the degradation produces the tetrahydrofuran and enters into atmospheric tower and pressurized column with the state of gaseous phase or liquid phase and refines, obtains the tetrahydrofuran that accords with the national standard superior grade article. The method is characterized in that a solid acid catalyst is adopted for degrading polytetrahydrofuran, and a pipeline for producing tetrahydrofuran gas phase after degradation directly enters a tetrahydrofuran separation system of the existing device after being modified.

The above description is only the preferred embodiment of the present invention, the protection scope of the present invention is not limited thereto, and any person skilled in the art can obviously obtain the simple changes or equivalent replacements of the technical solutions within the technical scope of the present invention.

Claims

1. A device for degrading polytetrahydrofuran and recycling tetrahydrofuran is characterized in that a raw material storage tank (1) for storing low molecular polytetrahydrofuran or unqualified polytetrahydrofuran is connected with a degradation reactor (2) through a pipeline, the degradation reactor (2) is connected with an atmospheric tower (3) through a gas phase extraction pipeline (25) and a cooler (26), the atmospheric tower (3) is connected with a pressurizing tower (4) through a pressurizing tower feeding pipeline (15), the pressurizing tower (4) is connected with a qualified tetrahydrofuran storage tank (22) through a qualified tetrahydrofuran discharging pipeline (21) at the bottom of the pressurizing tower, a mechanical stirrer (5) is arranged at the top end of the degradation reactor (2), a steam pipeline (7) for providing steam, a tar discharging port and pipeline (6), a steam condensate discharging pipeline (8) and a nitrogen pipeline (24) are respectively connected with the degradation reactor (2), the atmospheric tower (3) is respectively connected with an atmospheric tower condenser (11), an atmospheric tower condensing tank (10) and an atmospheric tower top reflux pump (12) in series through pipelines; the pressurizing tower (4) is respectively connected with a pressurizing tower top condenser (17), a pressurizing tower condensing tank (16) and a pressurizing tower top reflux pump (19) in series through pipelines, an unqualified THF return pipeline (9) is connected to the atmospheric tower (3) from the pressurizing tower (4), and a pressurizing tower bottom qualified tetrahydrofuran discharge pipeline (21) is connected to a qualified tetrahydrofuran storage tank (22) from the pressurizing tower (4).

2. The apparatus for degrading polytetrahydrofuran and recovering tetrahydrofuran according to claim 1, wherein the degradation reactor (2) is separately arranged and made of 304 or 316SS material, the qualified tetrahydrofuran storage tank (22) is made of carbon steel, and the degradation reactor (2) is provided with a matched catalyst filling port, a mechanical stirrer, a jacket, a gas phase outlet pipeline, a nitrogen pipeline and a degradation reactor tar discharging port; the gas phase production line (25) and the cooler (26) are made of 304 stainless steel, and the feeding position of the gas phase line is positioned at the stripping section of the atmospheric tower (3) and can provide a heat source for the refining separation of THF and water.