CN217809225U

CN217809225U - Energy-saving system for preparing olefin from methanol

Info

Publication number: CN217809225U
Application number: CN202222119608.9U
Authority: CN
Inventors: 李晓东; 仇海文; 其他发明人请求不公开姓名
Original assignee: Inner Mongolia Imk System Technology Co ltd
Current assignee: Inner Mongolia Imk System Technology Co ltd
Priority date: 2022-08-11
Filing date: 2022-08-11
Publication date: 2022-11-15
Anticipated expiration: 2032-08-11

Abstract

The utility model provides an economizer system of methyl alcohol system alkene belongs to methyl alcohol system alkene technical field, including methyl alcohol storage tank, methyl alcohol heating unit, MTO reaction unit, methyl alcohol heating unit includes the reaction gas heat exchanger, MTO reaction unit includes MTO reactor, triple-spiral separator, the discharge gate of methyl alcohol storage tank with the shell side entry linkage of reaction gas heat exchanger, the shell side export of reaction gas heat exchanger with the entry linkage of MTO reactor, the export of MTO reactor with the entry linkage of triple-spiral separator, the export of triple-spiral separator with the tube side entry linkage of reaction gas heat exchanger, so the reaction gas after through the methyl alcohol reaction heats feeding methyl alcohol for the used energy consumption of methyl alcohol by the heating gasification reduces; and the temperature of the reaction gas is reduced through the heat exchange between the reaction gas and the methanol, so that the cooling water required by the subsequent cooling process is greatly reduced, and the discharge of sewage is reduced.

Description

Energy-saving system for preparing olefin from methanol

Technical Field

The utility model relates to a methanol-to-olefin technical field, concretely relates to economizer system of methanol-to-olefin.

Background

The methanol-to-olefin (MTO) device is a process for producing olefins such as ethylene, propylene and the like by using methanol as a raw material. The methanol-to-olefin (MTO) device first preheats and vaporizes methanol, the methanol enters a reactor, the methanol in the reactor reacts under the action of a catalyst to generate reaction gas such as ethylene, propylene and the like, the catalyst and the reaction gas are separated by a cyclone separator and then return to the reactor, the reaction gas is washed and cooled and then sent to a product compressor unit to be compressed, condensed and removed with oxide, an olefin product is purified, and finally the reaction gas passes through an alkaline washing drying system to remove acid gas and moisture in the reaction gas.

In the prior art, the application numbers are as follows: 202123080150.2's chinese utility model discloses a device that MTO low pressure lime set heat was recycled, including lime set collection tank, desalted water heat exchanger, circulating water heat exchanger, the lime set that the lime set collection tank was collected arrange outside after desalted water heat exchanger and circulating water heat exchanger recovery part heat, the device still includes steam stripping water heat exchanger and the methyl alcohol charge pump that feeding methyl alcohol preheated, raw materials methyl alcohol sets up pipe connection through methyl alcohol charge pump to circulating water heat exchanger's circulating water inlet that goes up, circulating water heat exchanger's return water export sets up pipe connection to steam stripping water heat exchanger. The utility model discloses a device with feeding methyl alcohol through with the lime set heat transfer, can effectively reduce the required steam quantity of heating methyl alcohol, improve lime set heat recovery utilization ratio, this utility model though through lime set and feeding methyl alcohol heat transfer for the temperature of methyl alcohol risees, but this utility model's feeding methyl alcohol still need can be carried the methyl alcohol heating to the MTO reactor with a large amount of steam and lead to energy consumption big.

Disclosure of Invention

In view of this, the utility model provides an economizer system of methyl alcohol system alkene that can reduce the steam quantity.

The utility model provides a technical scheme that its technical problem adopted is:

the utility model provides an economizer system of methyl alcohol system alkene, includes methyl alcohol storage tank, methyl alcohol heating unit, MTO reaction unit, methyl alcohol heating unit includes reaction gas heat exchanger, steam heat exchanger, MTO reaction unit includes MTO reactor, reaction heat transfer device, the export of methyl alcohol storage tank with steam heat exchanger's tube side entry linkage, steam heat exchanger's tube side export with the shell side entry linkage of reaction gas heat exchanger, the shell side export of reaction gas heat exchanger with the entry linkage of MTO reactor, the export of MTO reactor with the entry linkage of reaction heat transfer device, the export of heat transfer reaction device with the tube side entry linkage of reaction gas heat exchanger to preheat earlier through steam, rethread reaction heat transfer device will take reaction hot reaction gas to carry out the heat transfer to crude methyl alcohol in the reaction gas heat exchanger, make crude methyl alcohol reach reaction temperature when getting into the MTO reactor.

Preferably, the outlet of the methanol storage tank is further connected with the shell side inlet of the reaction gas heat exchanger and provided with a first valve, and the pipeline connecting the outlet of the methanol storage tank with the tube side inlet of the steam heat exchanger is provided with a second valve.

Preferably, the energy-saving system for preparing olefin from methanol further comprises a quenching unit, wherein the quenching unit comprises a quenching tower, and an inlet of the quenching tower is connected with a tube-side outlet of the reaction gas heat exchanger.

Preferably, the quenching unit comprises a steam generator, the methanol heating unit further comprises a low-pressure boiler water pipeline, a shell-side inlet of the steam generator is connected with a tube-side outlet of the reaction gas heat exchanger, a shell-side outlet of the steam generator is connected with an inlet of the quenching tower, and a tube-side inlet of the steam generator is connected with an outlet of the low-pressure boiler water pipeline.

Preferably, the methanol heating unit further comprises a low-pressure vapor condensation liquid pipeline, an inlet of the low-pressure vapor condensation liquid pipeline is connected with an inlet of a tube side outlet of the steam generator, and an outlet of the low-pressure vapor condensation liquid pipeline is connected with a shell side inlet of the steam heat exchanger

Preferably, the methanol heating unit further comprises a condensed water heat exchanger and a condensed water pipeline, wherein a tube pass inlet of the condensed water heat exchanger is connected with an outlet of the methanol storage tank, a tube pass outlet of the condensed water heat exchanger is connected with a tube pass inlet of the steam heat exchanger, and a shell pass inlet of the condensed water heat exchanger is connected with an outlet of the condensed water pipeline.

Preferably, the inlet of the condensed water pipeline of the device is connected with the shell side outlet of the steam heat exchanger.

Preferably, the methanol heating unit further comprises a condensed water air cooler, and an inlet of the condensed water air cooler is connected with a shell side outlet of the condensed water heat exchanger.

Preferably, the methanol heating unit further comprises a purified water heat exchanger, a tube pass inlet of the purified water heat exchanger is connected with an outlet of the methanol storage tank, and a tube pass outlet of the purified water heat exchanger is connected with a shell pass outlet of the condensed water heat exchanger.

Compared with the prior art, the beneficial effects of the utility model reside in that:

the utility model provides an among the economizer system of methyl alcohol system alkene, methyl alcohol gets into earlier from the methyl alcohol storage tank steam heat exchanger, follows again steam heat exchanger gets into the reaction gas heat exchanger, methyl alcohol only needs through preheating of steam heat exchanger, and the rethread reaction heat transfer device will take the reaction gas of reaction heat to transmit to the reaction gas heat exchanger, the tube side of reaction gas heat exchanger lets in the reaction gas that takes the reaction heat and heats the methyl alcohol of reaction gas heat exchanger inner shell side to the required temperature of reaction to guarantee the continuous operation of production, and has carried out the heat transfer to raw materials methyl alcohol through the high temperature reaction gas that follows the separation of reaction heat transfer device, makes the methyl alcohol heat to the energy consumption that uses when reacting required temperature reduce; and the temperature of the reaction gas is reduced through the heat exchange between the reaction gas and the methanol, so that the cooling water required by the subsequent cooling process is greatly reduced, and the discharge of sewage is reduced.

Drawings

FIG. 1 is a process flow diagram of an energy-saving system for producing olefins from methanol.

In the figure: the system comprises a methanol-to-olefin energy saving system 10, a methanol storage tank 100, a first valve 110, a second valve 120, a methanol heating unit 200, a reaction gas heat exchanger 210, a low-pressure boiler water pipeline 220, a steam heat exchanger 230, a low-pressure steam condensate pipeline 240, a condensed water heat exchanger 250, a device condensed water pipeline 260, a condensed water air cooler 270, a purified water heat exchanger 280, an MTO reaction unit 300, an MTO reactor 310, a reaction heat transfer device 320, a quenching unit 400, a quenching tower 410 and a steam generator 420.

Detailed Description

The following combines the utility model discloses an attached drawing is right the technical scheme and the technological effect of the embodiment of the utility model are further elaborated.

Referring to fig. 1, an energy saving system 10 for preparing olefins from methanol includes a methanol storage tank 100, a methanol heating unit 200, and an MTO reaction unit 300, where the methanol heating unit 200 includes a reaction gas heat exchanger 210, the MTO reaction unit 300 includes an MTO reactor 310 and a reaction heat transfer device 320, an outlet of the methanol storage tank 100 is connected to a shell-side inlet of the reaction gas heat exchanger 210, a shell-side outlet of the reaction gas heat exchanger 210 is connected to an inlet of the MTO reactor 310, an outlet of the MTO reactor 310 is connected to an inlet of the reaction heat transfer device 320, and an outlet of the heat transfer device 320 is connected to a tube-side inlet of the reaction gas heat exchanger 210.

The reaction gas heat exchanger 210 is a heat exchanger.

The reaction heat transport device 320 is a triple-cyclone separator, and the reaction heat transport device 320 separates the reaction gas from the impurities and transports the reaction gas with the reaction heat to the reaction gas heat exchanger 210 for heat utilization.

the utility model provides an among the economizer system 10 of methanol-to-olefin, methanol is advanced from methanol storage tank 100 and is gone into steam heat exchanger 230, follows again steam heat exchanger 230 gets into reaction gas heat exchanger 210, methanol only need heat to 109 ℃ through preheating of steam heat exchanger 230, rethread reaction heat transfer device 320 will take reaction gas of reaction heat to transmit to reaction gas heat exchanger 210, reaction gas heat exchanger 210's tube side lets in reaction gas with reaction heat and heats the methanol of reaction gas heat exchanger 210 inner shell side to 249 ℃, with the high temperature reaction gas through following reaction heat transfer device 320 separates out carries out the heat transfer to raw materials methanol for methanol is heated to 249 ℃, makes the steam energy consumption that used when methanol heats to the required temperature of reaction reduce; and the temperature of the reaction gas is reduced through the heat exchange between the reaction gas and the methanol, so that the cooling water required by the subsequent cooling process is greatly reduced, and the discharge of sewage is reduced.

Further, the outlet of the methanol storage tank 100 is further connected to the shell-side inlet of the reaction gas heat exchanger 210 and provided with a first valve 110, a pipeline connecting the outlet of the methanol storage tank and the tube-side inlet of the steam heat exchanger is provided with a second valve 120, when the entire energy-saving system for producing olefins from methanol 10 is in large-scale operation, the first valve 110 is closed, the second valve 120 is opened, methanol is preheated by 109 ℃ through the steam heat exchanger 230, reaction gas with reaction heat is transmitted to the reaction gas heat exchanger 210 through the reaction heat transmission device 320, reaction gas with reaction heat is introduced into the tube-side of the reaction gas heat exchanger 210 with reaction heat, and the reaction gas with reaction heat is heated to 249 ℃ in the shell-side of the reaction gas heat exchanger 210, so that heat exchange is performed on raw material methanol through high-temperature reaction gas separated from the reaction heat transmission device 320, and the methanol is heated to 249 ℃. When the whole energy-saving system 10 for preparing olefin from methanol is put into operation for a short time or is in a pilot plant, the second valve 120 can be closed, the first valve 110 is opened, the temperature in the methanol storage tank is the same as that of methanol in a large amount of production, part of methanol can be heated to the required temperature at the beginning and then enters the MTO reactor 310 to generate reaction gas, after the reaction gas is normally produced, the methanol directly enters the shell side of the reaction gas heat exchanger 210, the methanol is heated to 249 ℃ through the reaction gas, and the production amount of the reaction gas is smaller than the feeding amount of the methanol, so that the production can be carried out for a short time, and if the reaction gas is used for a long time, the reaction gas can not continuously exchange heat with the methanol, and the normal operation can not be ensured.

Further, the energy-saving system for preparing olefin from methanol further comprises a quenching unit 400, wherein the quenching unit 400 comprises a quenching tower 410, an inlet of the quenching tower 410 is connected with a tube side outlet of the reaction gas heat exchanger 210, the reaction gas is subjected to primary cooling by the reaction gas heat exchanger 210 to be cooled to 261 ℃, and then the reaction gas enters the quenching tower 410 to be cooled, so that the amount of water is reduced, and the amount of sewage is reduced.

Further, the quenching unit 400 comprises a steam generator 420, the methanol heating unit 200 further comprises a low-pressure boiler water pipeline 220, a shell-side inlet of the steam generator 420 is connected with a shell-side outlet of the reaction gas heat exchanger 210, a shell-side outlet of the steam generator 420 is connected with an inlet of the quenching tower 410, and a tube-side inlet of the steam generator 420 is connected with an outlet of the low-pressure boiler water pipeline 220; when the reaction gas is primarily cooled to 261 ℃ by the reaction gas heat exchanger 210, the temperature of the reaction gas is further cooled to 200 ℃ by the steam generator 420, and then the reaction gas enters the quenching tower 410 for cooling, so that the amount of water is reduced, and the amount of sewage is reduced.

Further, the methanol heating unit 200 further includes a low-pressure condensate line 240, an inlet of the low-pressure condensate line 240 is connected to an inlet of a tube-side outlet of the steam generator 420, an outlet of the low-pressure condensate line 240 is connected to a shell-side inlet of the steam heat exchanger 230, a pressure of the low-pressure condensate line 240 is 0.46MPa, when the temperature of the reaction gas is further lowered to 200 ℃ by the steam generator 420, heat of the reaction gas is again transferred to water in the low-pressure boiler water line 220, so that the water in the low-pressure boiler water line 220 is heated to low-pressure steam, and the low-pressure steam is used to heat the feed methanol, so that the methanol is heated from 100 ℃ to 105 ℃.

Further, the methanol heating unit 200 further includes a condensed water heat exchanger 250 and a device condensed water pipeline 260, wherein a tube-side inlet of the condensed water heat exchanger 250 is connected to an outlet of the second valve 120, an inlet of the second valve 120 is connected to an outlet of the methanol storage tank 100, a tube-side outlet of the condensed water heat exchanger 250 is connected to a tube-side inlet of the steam heat exchanger 230, a shell-side inlet of the condensed water heat exchanger 250 is connected to an outlet of the device condensed water pipeline 260, and the methanol is heated from 75 ℃ to 100 ℃ by the condensed water of the device.

Further, an inlet of the condensed water pipeline 260 of the device is connected to a shell side outlet of the steam heat exchanger 230, when the low-pressure steam exchanges heat of the methanol from 100 ℃ to 105 ℃, the low-pressure steam is cooled to 144 ℃ condensed water, and then the condensed water is introduced into the inlet of the condensed water pipeline 260 of the device to exchange heat of the methanol again, so as to fully utilize the waste heat.

Further, the methanol heating unit 200 further comprises a condensed water air cooler 270, an inlet of the condensed water air cooler 270 is connected with a shell pass outlet of the condensed water heat exchanger 250, when the condensed water in the condensed water pipeline 260 exchanges heat with the methanol, the temperature of the condensed water is about 80 to 90 ℃, the condensed water can be introduced into the condensed water air cooler 270, and the temperature is further reduced by utilizing the waste heat of the condensed water.

Further, the methanol heating unit 200 further comprises a purified water heat exchanger 280, a tube-side inlet of the purified water heat exchanger 280 is connected with an outlet of the second valve 120, an inlet of the second valve 120 is connected with an outlet of the methanol storage tank 100, a tube-side outlet of the purified water heat exchanger 280 is connected with a shell-side outlet of the condensed water heat exchanger 250, the methanol is subjected to heat exchange through purified water at 90 ℃, the heat exchange of the methanol is 75 ℃, and the temperature of the methanol is raised.

Specifically, for a set of 60 ten thousand tons/year MTO device, if the steam of 0.46Mpa is calculated according to 80 yuan/ton, the cost can be reduced by 640-960 ten thousand yuan. And the consumption of quenching water can be reduced by 10-15 tons/hour, and the discharged sewage can be reduced by 10-15 tons/hour.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. The energy-saving system for preparing the olefin from the methanol is characterized by comprising a methanol storage tank, a methanol heating unit and an MTO reaction unit, wherein the methanol heating unit comprises a reaction gas heat exchanger and a steam heat exchanger, the MTO reaction unit comprises an MTO reactor and a reaction heat transfer device, an outlet of the methanol storage tank is connected with a tube pass inlet of the steam heat exchanger, a tube pass outlet of the steam heat exchanger is connected with a shell pass inlet of the reaction gas heat exchanger, a shell pass outlet of the reaction gas heat exchanger is connected with an inlet of the MTO reactor, an outlet of the MTO reactor is connected with an inlet of the reaction heat transfer device, an outlet of the reaction heat transfer device is connected with a tube pass inlet of the reaction gas heat exchanger, so that the reaction gas with reaction heat is preheated through the steam, and then the reaction heat transfer device exchanges heat with the reaction heat in the reaction gas heat exchanger, so that the temperature of the crude methanol reaches the reaction temperature when the crude methanol enters the MTO reactor.

2. The energy-saving system for preparing olefin from methanol according to claim 1, wherein an outlet of the methanol storage tank is further connected with a shell-side inlet of the reaction gas heat exchanger, an outlet of the methanol storage tank is further connected with the shell-side inlet of the reaction gas heat exchanger and provided with a first valve, and a pipeline connecting the outlet of the methanol storage tank with a tube-side inlet of the steam heat exchanger is provided with a second valve.

3. The energy-saving system for preparing olefin from methanol as claimed in claim 1, further comprising a quenching unit, wherein the quenching unit comprises a quenching tower, and an inlet of the quenching tower is connected to the tube-side outlet of the reaction gas heat exchanger.

4. The energy saving system for methanol to olefin of claim 3, wherein the quenching unit comprises a steam generator, the methanol heating unit further comprises a low-pressure boiler water pipeline, a shell side inlet of the steam generator is connected with a tube side outlet of the reaction gas heat exchanger, a shell side outlet of the steam generator is connected with an inlet of the quenching tower, and a tube side inlet of the steam generator is connected with an outlet of the low-pressure boiler water pipeline.

5. The energy saving system for methanol to olefin according to claim 4, wherein the methanol heating unit further comprises a low pressure vapor condensate line, an inlet of the low pressure vapor condensate line is connected with an inlet of a tube side outlet of the steam generator, and an outlet of the low pressure vapor condensate line is connected with a shell side inlet of the steam heat exchanger.

6. The energy-saving system for preparing olefin from methanol according to claim 3, wherein the methanol heating unit further comprises a condensed water heat exchanger and a condensed water pipeline, a tube-side inlet of the condensed water heat exchanger is connected with an outlet of the methanol storage tank, a tube-side outlet of the condensed water heat exchanger is connected with a tube-side inlet of the steam heat exchanger, and a shell-side inlet of the condensed water heat exchanger is connected with an outlet of the condensed water pipeline.

7. The energy saving system for preparing olefin from methanol according to claim 6, wherein the inlet of the condensed water pipeline of the device is connected with the shell side outlet of the steam heat exchanger.

8. The energy-saving system for preparing olefin from methanol according to claim 6, wherein the methanol heating unit further comprises a condensed water air cooler, and an inlet of the condensed water air cooler is connected with a shell side outlet of the condensed water heat exchanger.

9. The energy-saving system for preparing olefin from methanol according to claim 6, wherein the methanol heating unit further comprises a purified water heat exchanger, a tube-side inlet of the purified water heat exchanger is connected with an outlet of the methanol storage tank, and a tube-side outlet of the purified water heat exchanger is connected with a shell-side outlet of the condensed water heat exchanger.