CN217549774U

CN217549774U - Methanol synthesis system

Info

Publication number: CN217549774U
Application number: CN202220290724.4U
Authority: CN
Inventors: 崔正伟
Original assignee: Guoneng Baotou Coal Chemical Co ltd; China Shenhua Coal to Liquid Chemical Co Ltd
Current assignee: Guoneng Baotou Coal Chemical Co ltd; China Shenhua Coal to Liquid Chemical Co Ltd
Priority date: 2022-01-30
Filing date: 2022-01-30
Publication date: 2022-10-11
Anticipated expiration: 2032-01-30

Abstract

The utility model relates to a methanol synthesis technical field discloses a methanol synthesis system, and the system comprises a purification tank 1, a first heat exchanger 21, a first methanol synthesis tower 22, a first air cooler 23, a first water cooler 24, a first methanol separator 25, a second heat exchanger 31, a second methanol synthesis tower 32, a second air cooler 33, a second water cooler 34 and a second methanol separator 35; the first air cooler 21 and the second air cooler 31 are identical in structure; the first air cooler 23 includes a fan 231, a water supply pipe 232, a spray head 233 and a heat exchange pipe 234, wherein the fan 231 is disposed below the heat exchange pipe 234, the water supply pipe 232 is disposed between the fan 231 and the heat exchange pipe 234, and the spray head 233 is disposed on the water supply pipe 232. The utility model provides a pair of methyl alcohol synthesis system has that the condensation is effectual in summer, adjusts convenient advantage, can improve the one-way conversion rate of methyl alcohol, the reduction system energy consumption.

Description

Methanol synthesis system

Technical Field

The utility model relates to a methyl alcohol synthesis technology field, concretely relates to can energy-conserving methyl alcohol synthesis system of increase production.

Background

The methanol synthesis process plays an important role in the coal chemical industry process and is an essential link in the modern coal-to-olefin technology. The methanol synthesis reaction belongs to an exothermic reaction, circulating synthesis gas containing gaseous methanol extracted from a methanol synthesis tower needs to be cooled and condensed so as to separate liquid methanol, and the circulating synthesis gas after the methanol is separated is returned to the methanol synthesis tower to carry out the methanol synthesis reaction again.

The traditional methanol synthesis technology generally adopts a water cooling technology, and the water cooling technology has large water consumption. Most modern coal chemical enterprises are distributed in northwest areas with abundant coal resources but relatively deficient water resources. In order to reduce water consumption, the water cooling process in the large-scale coal chemical engineering project newly built in the northwest area at present mostly adopts a form of combining an air cooler and a water cooler.

However, the cooling effect of the air cooler is affected by seasons, and particularly in summer, the cooling effect is poor. In high-temperature weather in summer, particularly when the wind speed is low, the convection air flow rate around the air cooler is low, the air temperature around the air cooler is up to 40-50 ℃, the temperature of the circulating synthesis gas cooled by the air cooler is 20-30 ℃ higher than the design value, so that the temperature of the circulating synthesis gas before entering the methanol separator is 15-20 ℃ higher than the design value, methanol cannot be fully condensed in the methanol separator, a large amount of methanol returns to the methanol synthesis tower along with the circulating synthesis gas, the one-way conversion rate of the synthesis reaction is reduced, the side reaction products are increased, the consumption of raw methanol gas per ton is increased, and the reaction efficiency is reduced. Meanwhile, the circulating gas amount is increased, the load of the compressor is large, and the energy consumption is increased.

In order to ensure the cooling effect in summer, the number of the air coolers is required to be increased, and the scale of the air coolers is increased. However, in winter, the cooling effect of the air cooler itself is significantly improved due to the low ambient temperature, and in this case, a part of the air cooler needs to be stopped compared with summer. The design mode of large consumption of air coolers in summer and small consumption of air coolers in winter ensures that the equipment investment is overlarge, the operation cost is high and the resources are wasted.

Therefore, it is highly desirable to provide a methanol synthesis system that can increase production, save energy, reduce water consumption, and reduce the number of air coolers in summer.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving and adopting the air cooler too big investment in the methyl alcohol synthesis technology, and can not overcome high temperature weather effect, reply operating mode change ability is poor, the poor methyl alcohol synthesis reaction single pass conversion rate that leads to of methyl alcohol separation effect is low in the circulating synthesis gas in summer, the side reaction aggravation, reaction efficiency descends, ton methyl alcohol feed gas consumption increases, methyl alcohol output reduces, a series of problems such as the circulating compressor load is big, a methyl alcohol synthesis system is provided, this system has that condensation in summer is effectual, adjust convenient advantage, can improve the single pass conversion rate of methyl alcohol, the lowering system energy consumption.

In order to accomplish the above object, the present invention provides a methanol synthesis system, which comprises a purification tank 1, a first heat exchanger 21, a first methanol synthesis tower 22, a first air cooler 23, a first water cooler 24, a first methanol separator 25, a second heat exchanger 31, a second methanol synthesis tower 32, a second air cooler 33, a second water cooler 34, and a second methanol separator 35;

wherein, the purification tank 1 is respectively connected with a first heat exchanger 21 and a second heat exchanger 31; wherein the first heat exchanger 21 and the first methanol synthesis tower 22 are connected with each other, and the first methanol synthesis tower 22 is further connected with the first air cooler 23, the first water cooler 24 and the first methanol separator 25 in sequence through the first heat exchanger 21; the second heat exchanger 31 is connected with the second methanol synthesis tower 32, and the second methanol synthesis tower 32 is further connected with the second air cooler 33, the second water cooler 34 and the second methanol separator 35 in sequence through the second heat exchanger 31;

wherein the first heat exchanger 21 is further connected to the second methanol separator 35, and the second heat exchanger 31 is further connected to the first methanol separator 25;

the first air cooler 21 and the second air cooler 31 have the same structure; the first air cooler 23 includes a fan 231, a water supply pipe 232, a spray head 233 and a heat exchange pipe 234, wherein the fan 231 is disposed below the heat exchange pipe 234, the water supply pipe 232 is disposed between the fan 231 and the heat exchange pipe 234, and the spray head 233 is disposed on the water supply pipe 232.

Through the technical scheme, the utility model discloses the excellent technological effect who gains as follows:

1) The utility model provides a preferred methyl alcohol synthesis system, through set up delivery pipe and shower nozzle in the air cooler, can show and improve the condensation effect, avoid increasing the quantity of the condenser in summer, can reduce investment cost and running cost;

2) The utility model provides a preferred methyl alcohol synthesis system, through setting up the shutoff valve and adjusting the spraying state of opening, can adjust the water spray volume according to ambient temperature is nimble, can reduce water consumption, it is strong to deal with the operating mode change ability;

3) The utility model provides a preferred methyl alcohol synthesis system, selects the water mist that the fine spray nozzle can spout the micron order water droplet and form, can prevent the water droplet too big to avoid because the big granule water droplet drips the trouble that causes on motor and belt;

4) The utility model provides a preferred methyl alcohol synthesis system can reduce the content of methyl alcohol in first circulating gas and the second circulating gas, can avoid methyl alcohol to return first methyl alcohol synthetic tower and second methyl alcohol synthetic tower to take place the side reaction on the one hand, can improve methyl alcohol's per pass conversion rate and methyl alcohol output; on one hand, the load of the second compressor can be reduced, the steam consumption of the steam turbine can be reduced, and the purposes of increasing production and saving energy are achieved.

Drawings

FIG. 1 is a schematic diagram of a methanol synthesis system in a preferred embodiment provided by the present invention;

fig. 2 is a schematic structural diagram of a first air cooler according to a preferred embodiment of the present invention.

Description of the reference numerals

1. A purifying tank 21, a first heat exchanger 22 and a first methanol synthesis tower

23. First air cooler 231, fan 232, delivery pipe

233. Spray head 234, heat exchange tube 24 and first water cooler

25. A first methanol separator 31, a second heat exchanger 32 and a second methanol synthesis tower

33. A second air cooler 34, a second water cooler 35 and a second methanol separator

41. First compressor 42, second compressor 43, and steam turbine

44. Air-cooled steam condenser 45 and steam condensate storage tank

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The utility model provides a methanol synthesis system, the system includes purification tank 1, first heat exchanger 21, first methanol synthesis tower 22, first air cooler 23, first water cooler 24, first methanol separator 25, second heat exchanger 31, second methanol synthesis tower 32, second air cooler 33, second water cooler 34 and second methanol separator 35;

the first air cooler 21 and the second air cooler 31 have the same structure; the first air cooler 23 includes a blower 231, a water supply pipe 232, a spray head 233 and a heat exchange pipe 234; wherein the blower 231 is disposed below the heat exchange pipe 234, the water supply pipe 232 is disposed between the blower 231 and the heat exchange pipe 234, and the spray head 233 is disposed on the water supply pipe 232.

The utility model discloses in, the feed gas falls into two strands, first strand feed gas and the second strand feed gas after purifying the tank purification desorption and containing impurity such as sulphur chlorine. The method comprises the following steps of heating a first feed gas in a first heat exchanger to 200-250 ℃, then feeding the heated first feed gas into a first methanol synthesis tower to perform a methanol synthesis reaction, feeding a circulating synthesis gas I containing gaseous methanol extracted from the first methanol synthesis tower into the first heat exchanger to cool, further cooling the circulating synthesis gas I by a first air cooler and a first water cooler, feeding the cooled circulating synthesis gas I into a first methanol separator, and separating liquid crude methanol I and gas-phase first circulating gas in the first methanol separator. The first circulating gas separated from the first methanol separator is converged with a second feed gas, then enters a second heat exchanger to be heated to 200-250 ℃ and then enters a second methanol synthesis tower to generate a methanol synthesis reaction, the circulating synthesis gas II containing gaseous methanol extracted from the second methanol synthesis tower enters the second heat exchanger to be cooled, then enters the second methanol separator to separate out liquid crude methanol II and gas phase second circulating gas after being further cooled by a second air cooler and a second water cooler, a small part of the second circulating gas separated from the second methanol separator is used as purge gas to be evacuated, and the rest part of the second circulating gas is converged with the first feed gas and then enters the first heat exchanger. The process is repeated, and crude methanol is continuously synthesized and separated.

In a preferred embodiment, the first methanol synthesis column 22 and the second methanol synthesis column 32 are the same.

Take first methyl alcohol synthetic tower as an example, in the utility model discloses in, be provided with the heat transfer tubulation of vertical distribution in first methyl alcohol synthetic tower, be provided with the steam pocket outside first methyl alcohol synthetic tower, the heat transfer tubulation is connected with the steam pocket. Wherein, the utility model discloses in, the intraductal circulation of heat transfer tubulation has boiler water, and boiler water becomes steam-water mixture after absorbing the heat that the synthesis reaction emitted, steam-water mixture gets into the steam pocket and carries out water vapor separation, can obtain the by-product steam, and the water of isolating then returns cyclic utilization.

In a preferred embodiment, the first heat exchanger 21 is used for heat exchange between the feed and the discharge of a first methanol synthesis column 22, the first methanol synthesis column 22 is used for methanol synthesis, and the first air cooler 23 and the first water cooler 24 are used for condensing the discharge of the first methanol synthesis column 22 from the first heat exchanger 21.

In a preferred embodiment, the second heat exchanger 31 is used for heat exchange of the feed and the discharge of a second methanol synthesis column 32, the second methanol synthesis column 32 is used for methanol synthesis, and the second air cooler 33 and the second water cooler 34 are used for condensing the discharge of the second methanol synthesis column 32 from the second heat exchanger 31.

In a preferred embodiment, the first air cooler 23, the first water cooler 24, the second air cooler 33, and the second water cooler 34 are provided in plural numbers. Wherein, the utility model discloses do not do special the injecing to the quantity of first air cooler, first water cooler, second air cooler, second water cooler, can select according to actual need.

In a preferred embodiment, the first air cooler 23 further includes a motor; wherein, the motor is arranged at the lower part of the first air cooler 23 and is in belt transmission with the fan 231.

In a preferred embodiment, in the first air cooler 23, the water supply pipe 232 includes a plurality of water supply branch pipes which are uniformly distributed below the heat exchange pipes 234.

In a preferred embodiment, the first air cooler 23 further comprises a spray water pump. Wherein, the utility model discloses in, what supply in the water supply pipe is the clean normal atmospheric temperature demineralized water of pumping into by spray pump, wherein, the utility model discloses do not specially injecing the demineralized water, the demineralized water commonly used in the field all can be used in the utility model discloses in. To avoid the blockage of the spray head, a filter can be arranged at the inlet of the spray water pump.

In a preferred embodiment, the pipe diameter of the water supply branch pipe is more than or equal to 100mm, and the water supply branch pipe can resist the pressure of 1-3MPa (G).

In a preferred embodiment, the spray nozzles 233 are water mist nozzles, which are arranged in a plurality and uniformly distributed on the water supply branch pipe. Wherein the water mist spray head can spray water mist formed by micron-sized water drops, so that the water drops can be prevented from being too large, and faults caused by the dropping of large-particle water drops on the motor and the belt can be avoided.

In a preferred embodiment, the water supply branch pipe is further provided with a cut-off valve for controlling the opening state of the spray head.

The utility model discloses in, use first air cooler as an example: when the temperature is high in summer, the spray water pump can be started, and the cut-off valve is opened. The opening number of the block valves can be determined according to actual requirements, and the block valves can be fully opened or only partially opened. The air flow generated by the fan and the water mist sprayed by the spray head exchange heat with the heat exchange tube of the first air cooler to take away heat, the condensation effect of the first air cooler is increased, the temperature of the circulating synthesis gas I when entering the first methanol separator is further reduced, and the methanol in the circulating synthesis gas I is fully condensed in the first methanol separator to reduce the content of the methanol in the first circulating gas.

The content of methanol in the first circulating gas is reduced, so that the methanol can be prevented from returning to the first methanol synthesis tower to generate side reaction, and the once-through conversion rate of the methanol can be improved; on one hand, the circulating energy consumption can be reduced, and the purpose of energy conservation is achieved. When the temperature is reduced to below 5 ℃ in winter, the spray auxiliary cooling is not needed to be started, the water supply pipe, the spray water pump and the spray head can be shut down and emptied at the moment, the purging is clean, the spray water supply pipe is isolated by a blind plate at a boundary area, and the spray water pipeline and equipment are prevented from being frozen.

In a preferred embodiment, the water supply pipe 232 includes 4 water supply branch pipes, each of which is provided with 5 to 7 water mist heads, and each of which is provided with a shut-off valve.

In a preferred embodiment, the system further comprises a compressor train comprising a first compressor 41, a second compressor 42, a steam turbine 43, an air cooled steam condenser 44 and a steam condensate storage tank 45; wherein the first compressor 41 is connected in series with the second compressor 42, and the steam turbine 43 is used for driving the first compressor 41 and the second compressor 42; the steam turbine 43 is also connected to the air-cooled steam condenser 44, and the air-cooled steam condenser 44 is connected to the steam condensate storage tank 45.

The utility model discloses in, the steam turbine is condensing steam turbine, and the steam turbine is done work and is discharged steam and adopt and get into the steam condensate tank behind the air-cooled steam condenser condensation, sends out boundary area or boiler plant outside condensate pump again.

In a preferred embodiment, a water supply pipe, a shower head, and a shut-off valve having the same structure as that of the first air cooler are provided in the air-cooled steam condenser.

The air-cooled steam condenser that steam turbine exhaust steam condensation used also can appear that the condensation effect is poor because temperature is high in summer, and steam turbine vacuum system vacuum degree is on the low side, and the steam consumption is big, and steam turbine jump risk increase scheduling problem through add delivery pipe and shower nozzle in air-cooled steam condenser, can improve the condensation effect, reduces air-cooled steam condenser export condensate temperature, can reduce steam turbine steam consumption, guarantees compressor unit operation stability simultaneously.

In a preferred embodiment, the first compressor 41 is connected to the purge tank 1 for pressurizing the feed gas; the first methanol separator 25 is connected to the second heat exchanger 31 through the second compressor 42, and is used for providing conveying power for the feed (the mixture of the first recycle gas and the second feed gas) entering the second methanol synthesis tower.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. In the technical idea scope of the present invention, it can be right to the technical solution of the present invention perform multiple simple modifications, including each technical feature combined in any other suitable manner, these simple modifications and combinations should be regarded as the disclosed content of the present invention, and all belong to the protection scope of the present invention.

Claims

1. A methanol synthesis system, characterized by: the system comprises a purification tank (1), a first heat exchanger (21), a first methanol synthesis tower (22), a first air cooler (23), a first water cooler (24), a first methanol separator (25), a second heat exchanger (31), a second methanol synthesis tower (32), a second air cooler (33), a second water cooler (34) and a second methanol separator (35);

wherein the purification tank (1) is respectively connected with a first heat exchanger (21) and a second heat exchanger (31); wherein the first heat exchanger (21) is connected with the first methanol synthesis tower (22), and the first methanol synthesis tower (22) is further connected with the first air cooler (23), the first water cooler (24) and the first methanol separator (25) in sequence through the first heat exchanger (21); the second heat exchanger (31) is connected with the second methanol synthesis tower (32), and the second methanol synthesis tower (32) is further connected with the second air cooler (33), the second water cooler (34) and the second methanol separator (35) in sequence through the second heat exchanger (31);

wherein the first heat exchanger (21) is further connected to the second methanol separator (35), and the second heat exchanger (31) is further connected to the first methanol separator (25);

wherein the first air cooler (23) and the second air cooler (33) are identical in structure; the first air cooler (23) comprises a fan (231), a water supply pipe (232), a spray head (233) and a heat exchange pipe (234); wherein the fan (231) is disposed below the heat exchange pipe (234), the water supply pipe (232) is disposed between the fan (231) and the heat exchange pipe (234), and the spray head (233) is disposed on the water supply pipe (232).

2. The system of claim 1, wherein the first methanol synthesis column (22) and the second methanol synthesis column (32) are the same.

3. The system of claim 1, wherein the first heat exchanger (21) is configured to exchange heat between a feed and a discharge of a first methanol synthesis column (22), wherein the first methanol synthesis column (22) is configured to synthesize methanol, and wherein the first air cooler (23) and the first water cooler (24) are configured to condense the first methanol synthesis column (22) discharge from the first heat exchanger (21).

4. The system according to claim 1, wherein the second heat exchanger (31) is configured to exchange heat between the feed and the discharge of a second methanol synthesis column (32), wherein the second methanol synthesis column (32) is configured to synthesize methanol, and wherein the second air cooler (33) and the second water cooler (34) are configured to condense the second methanol synthesis column (32) discharge from the second heat exchanger (31).

5. The system of claim 1, wherein the first air cooler (23) further comprises a motor; the motor is arranged at the lower part of the first air cooler (23) and is in transmission with the fan (231) through a belt.

6. The system as claimed in claim 1, wherein the water supply pipe (232) includes a plurality of water supply branch pipes in the first air cooler (23), the water supply branch pipes being uniformly distributed below the heat exchange pipe (234).

7. The system according to claim 6, wherein the spray heads (233) are water mist spray heads, and are arranged in a plurality and uniformly distributed on the water supply branch pipe.

8. The system according to claim 6 or 7, wherein a cut-off valve is further provided on the water supply branch pipe, and the cut-off valve is used for controlling the opening state of the spray head.

9. The system of claim 1, further comprising a compressor train comprising a first compressor (41), a second compressor (42), a steam turbine (43), an air cooled steam condenser (44), and a steam condensate storage tank (45);

wherein the first compressor (41) is connected in series with the second compressor (42), the turbine (43) being used to drive the first compressor (41) and the second compressor (42);

the steam turbine (43) is also connected to the air-cooled steam condenser (44), the air-cooled steam condenser (44) being connected to the steam condensate storage tank (45).

10. The system of claim 9, wherein the first compressor (41) is connected to the purge tank (1); the first methanol separator (25) is connected to the second heat exchanger (31) via the second compressor (42).