MTBE production heat recovery system

Abstract

The utility model relates to an MTBE (methyl tert-butyl ether) production heat recovery system which comprises an etherification reaction device, a catalytic distillation device and a reboiler arranged at the bottom of the catalytic distillation device. A first heat exchange device and a second heat exchange device are sequentially arranged on a pipeline for connecting a discharge port of the etherification reaction device and a feed port of the catalytic distillation device, and an outlet in the bottom of the catalytic distillation device is connected with a hot side inlet of the first heat exchange device through a pipeline; and a shell pass outlet of the reboiler is connected with a hot side inlet of the second heat exchange device through a pipeline. According to the MTBE production heat recovery system, the energy consumption of the catalytic distillation tower can be reduced, the production cost is reduced, and the economic benefit is improved.

Description

Technical Field

[0001] This utility model relates to the field of MTBE production technology, and in particular to an MTBE production heat recovery system. Background Technology

[0002] Methyl tert-butyl ether (MTBE) is a transparent, colorless organic liquid with an ether-like odor. It is a good gasoline additive and also has wide applications in bioanalytical techniques. Currently, the main process for synthesizing MTBE is etherification. Isobutylene and methanol undergo an etherification reaction under specific temperature, pressure, and acidic catalyst conditions. Under the action of an acidic catalyst, isobutylene and methanol can undergo etherification to synthesize MTBE. This etherification reaction is a reversible exothermic reaction, and it is difficult to completely convert isobutylene in a standalone etherification reactor. Catalytic distillation removes the high-boiling-point MTBE from the bottom of the column during the reaction, ensuring complete conversion of isobutylene in the mixed C4. In the catalytic distillation column, the MTBE generated from the isobutylene etherification is collected as the heavy component from the bottom of the column, while the unreacted C4 components are collected as the light component from the top. In MTBE production plants, the reboiler at the bottom of the catalytic distillation column requires a large amount of heat to separate the C4 and MTBE products. The high energy consumption of the catalytic distillation column has always been a problem in MTBE production. Utility Model Content

[0003] To address the aforementioned problems, the purpose of this invention is to design a heat recovery system for MTBE production to reduce energy consumption in the catalytic distillation column.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] Design a heat recovery system for MTBE production, including an etherification reaction unit, a catalytic distillation unit, and a reboiler located at the bottom of the catalytic distillation unit. The outlet of the etherification reaction unit is connected to the inlet of the catalytic distillation unit via a pipeline. A first heat exchanger and a second heat exchanger are sequentially installed on the pipeline connecting the outlet of the etherification reaction unit and the inlet of the catalytic distillation unit. The outlet at the bottom of the catalytic distillation unit is connected to the hot-side inlet of the first heat exchanger via a pipeline. The shell-side outlet of the reboiler is connected to the hot-side inlet of the second heat exchanger via a pipeline.

[0006] The MTBE production heat recovery system designed in this scheme reduces the heat required for the vaporization of the etherification reaction products by increasing the temperature of the products entering the catalytic distillation unit, thereby reducing the steam consumption of the reboiler and decreasing energy consumption. Specifically, the outlet of the etherification reaction unit is connected to the inlet of the catalytic distillation unit via a pipeline. A first heat exchanger and a second heat exchanger are sequentially installed on the pipeline to heat the etherification reaction products, thereby increasing the temperature of the etherification reaction products entering the catalytic distillation unit. The liquid-phase outlet at the bottom of the catalytic distillation unit is connected to the hot-side inlet of the first heat exchanger via a pipeline. MTBE product is discharged from the liquid-phase outlet at the bottom of the catalytic distillation unit, undergoes a first heat exchange with the etherification reaction product in the first heat exchanger, and is then cooled and sent to a storage tank. The etherification reaction product, heated by the first heat exchange, enters the second heat exchanger. The shell-side outlet of the reboiler is connected to the hot-side inlet of the second heat exchanger via a pipeline. High-temperature condensate is discharged from the shell-side outlet of the reboiler and enters the second heat exchanger, undergoing a second heat exchange with the etherification reaction product. The etherification reaction product, heated by the second heat exchange, enters the catalytic distillation unit and is circulated back to the reboiler for heating and vaporization. By setting up two heat exchangers, heat from the MTBE production process is recovered and utilized. The feed temperature of the etherification reaction product entering the catalytic distillation unit is increased through two heat exchange processes, thereby reducing the steam consumption of the reboiler, lowering the energy consumption of the catalytic distillation unit, reducing production costs, and improving economic efficiency.

[0007] Furthermore, a first condensate storage tank is provided on the pipeline connecting the shell-side outlet of the reboiler to the hot-side inlet of the second heat exchanger. The first condensate storage tank includes a first outlet, which is connected to the hot-side inlet of the second heat exchanger.

[0008] The first condensate storage tank acts as an intermediate buffer device, temporarily storing the high-temperature condensate discharged from the shell side of the reboiler before stably supplying it to the hot-side inlet of the second heat exchanger. The first condensate storage tank regulates the flow rate and temperature fluctuations of the condensate through its buffering effect, preventing a decrease in heat exchange efficiency in the second heat exchanger due to sudden high temperatures or flow rate changes, thus ensuring a stable heat exchange process.

[0009] Furthermore, it also includes a second condensate storage tank, wherein the first condensate storage tank includes a second outlet, and the second outlet is connected to the second condensate storage tank.

[0010] The high-temperature condensate from the first condensate storage tank is preferentially supplied to the second heat exchange device through the first outlet for high waste heat recovery. When there is excess high-temperature condensate in the first condensate storage tank, the remaining condensate enters the second condensate storage tank through the second outlet. The second condensate storage tank is connected to other heat exchange devices for heat exchange heating.

[0011] Furthermore, it also includes a third heat exchange device, wherein the heat-side outlet of the second heat exchange device is connected to the heat-side inlet of the third heat exchange device via a pipeline.

[0012] The residual heat temperature of the condensate after heat exchange in the second heat exchanger remains relatively high. This condensate can then be further used for low-grade heat demands, achieving graded utilization of thermal energy and avoiding underutilization of high-energy resources. Therefore, a third heat exchanger is installed. The heat-side outlet of the second heat exchanger is connected to the heat-side inlet of the third heat exchanger via pipelines. The material outlet of the third heat exchanger is connected to the light-weight material removal tower to heat the material entering the tower.

[0013] Furthermore, the outlet of the second condensate storage tank is connected to the heat-side inlet of the third heat exchange device via a pipeline.

[0014] The second condensate storage tank is directly connected to the third heat exchange device, providing a higher temperature heat source directly to the third heat exchange device. There are three modes for selecting the heat source of the third heat exchange device: the first is the condensate after heat exchange by the second heat exchange device, the second is the condensate from the second condensate storage tank, and the third is the condensate from the second heat exchange device and the second condensate storage tank. Different modes can be selected by controlling the valve according to the actual usage requirements.

[0015] Furthermore, it also includes a third condensate storage tank, and the hot-side outlet of the third heat exchange device is connected to the inlet of the third condensate storage tank via a pipeline.

[0016] The third condensate storage tank is used to collect the condensate after heat exchange by the third heat exchanger. The collected condensate is pumped to a centralized treatment facility.

[0017] Furthermore, the first condensate storage tank also includes a control valve device, which is used to control the opening and closing of the first outlet and the second outlet.

[0018] The opening of the first outlet (connected to the second heat exchanger) and the second outlet (connected to the second condensate storage tank) are adjusted in real time by a control valve device to achieve free distribution of condensate flow. The control valve device buffers sudden changes in flow rate at the reboiler shell-side outlet through throttling, preventing seal failure or tube bundle damage to the second heat exchanger due to instantaneous high-pressure impact. When the internal pressure of the first condensate storage tank is abnormal, the outlet can be closed and the pressure relief valve can be activated in conjunction, forming a dual protection mechanism of "tank buffering + valve shut-off".

[0019] Furthermore, it also includes a low-pressure steam device connected to the shell-side inlet of the reboiler.

[0020] Low-pressure steam is supplied to the shell side of the reboiler through a low-pressure steam unit, while the etherification reaction products enter the tube side of the reboiler, thus avoiding cross-contamination. The low-pressure steam also provides heat to the catalytic distillation unit, thereby achieving the separation of C4 components and MTBE products.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] The MTBE production heat recovery system designed in this scheme reduces the heat required for the vaporization of the etherification reaction products by increasing the temperature of the products entering the catalytic distillation unit, thereby reducing the steam consumption of the reboiler and decreasing energy consumption. Specifically, the outlet of the etherification reaction unit is connected to the inlet of the catalytic distillation unit via a pipeline. A first heat exchanger and a second heat exchanger are sequentially installed on the pipeline to heat the etherification reaction products, thereby increasing the temperature of the etherification reaction products entering the catalytic distillation unit. The liquid-phase outlet at the bottom of the catalytic distillation unit is connected to the hot-side inlet of the first heat exchanger via a pipeline. MTBE product is discharged from the liquid-phase outlet at the bottom of the catalytic distillation unit, undergoes a first heat exchange with the etherification reaction product in the first heat exchanger, and is then cooled and sent to a storage tank. The etherification reaction product, heated by the first heat exchange, enters the second heat exchanger. The shell-side outlet of the reboiler is connected to the hot-side inlet of the second heat exchanger via a pipeline. High-temperature condensate is discharged from the shell-side outlet of the reboiler and enters the second heat exchanger, undergoing a second heat exchange with the etherification reaction product. The etherification reaction product, heated by the second heat exchange, enters the catalytic distillation unit and is circulated back to the reboiler for heating and vaporization. By setting up two heat exchangers, heat from the MTBE production process is recovered and utilized. The feed temperature of the etherification reaction product entering the catalytic distillation unit is increased through two heat exchange processes, thereby reducing the steam consumption of the reboiler, lowering the energy consumption of the catalytic distillation unit, reducing production costs, and improving economic efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an MTBE production heat recovery system according to an embodiment of the present invention.

[0024] Illustrations: 1. Etherification reaction apparatus; 2. Catalytic distillation apparatus; 3. Reboiler; 4. First heat exchanger; 5. Second heat exchanger; 6. First condensate storage tank; 61. First outlet; 62. Second outlet; 63. Control valve device; 7. Second condensate storage tank; 8. Third heat exchanger; 9. Third condensate storage tank; 10. Low-pressure steam apparatus. Detailed Implementation

[0025] To facilitate understanding of this invention, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0026] like Figure 1 As shown, this embodiment provides a heat recovery system for MTBE production, including an etherification reaction unit 1, a catalytic distillation unit 2, and a reboiler 3 located at the bottom of the catalytic distillation unit 2. The shell-side inlet of the reboiler 3 is connected to an external low-pressure steam unit 10. The outlet of the etherification reaction unit 1 is connected to the inlet of the catalytic distillation unit 2 via a pipeline. A first heat exchanger 4 and a second heat exchanger 5 are sequentially installed on the pipeline connecting the outlet of the etherification reaction unit 1 and the inlet of the catalytic distillation unit 2. The outlet at the bottom of the catalytic distillation unit 2 is connected to the hot-side inlet of the first heat exchanger 4 via a pipeline, and the shell-side outlet of the reboiler 3 is connected to the hot-side inlet of the second heat exchanger 5 via a pipeline. Low-pressure steam is provided by the low-pressure steam unit 10 into the shell side of the reboiler 3, and the etherification reaction products enter the tube side of the reboiler 3, avoiding cross-contamination. The low-pressure steam provides heat to the catalytic distillation unit 2, thereby achieving the separation of C4 components and MTBE products.

[0027] A first condensate storage tank 6 is installed on the pipeline connecting the shell-side outlet of the reboiler 3 to the hot-side inlet of the second heat exchanger 5. The first condensate storage tank 6 includes a first outlet 61 and a second outlet 62, with the first outlet 61 connected to the hot-side inlet of the second heat exchanger 5. The system also includes a second condensate storage tank 7, with the second outlet 62 connected to it. The first condensate storage tank 6 acts as an intermediate buffer device, temporarily storing the high-temperature condensate discharged from the shell side of the reboiler 3 before stably delivering it to the hot-side inlet of the second heat exchanger 5. The first condensate storage tank 6, through its buffering effect, regulates the flow rate and temperature fluctuations of the condensate, preventing a decrease in heat exchange efficiency of the second heat exchanger 5 due to instantaneous high temperatures or sudden changes in flow rate, thus ensuring a stable heat exchange process. The high-temperature condensate from the first condensate storage tank 6 is preferentially supplied to the second heat exchange device 5 through the first outlet 61 for high-temperature waste heat recovery. When there is excess high-temperature condensate in the first condensate storage tank 6, the remaining condensate enters the second condensate storage tank 7 through the second outlet 62. The second condensate storage tank 7 is connected to other heat exchange devices for heat exchange heating. The first condensate storage tank 6 also includes a control valve device 63, which controls the opening and closing of the first outlet 61 and the second outlet 62. By adjusting the opening of the first outlet 61 (connected to the second heat exchange device) and the second outlet 62 (connected to the second condensate storage tank) in real time through the control valve device 63, the free distribution of condensate flow direction can be achieved. The control valve device 63 buffers the sudden flow change at the shell-side outlet of the reboiler 3 through throttling, preventing the second heat exchange device 5 from sealing failure or tube bundle damage due to instantaneous high-pressure impact. When the internal pressure of the first condensate storage tank 6 is abnormal, the outlet can be closed and the pressure relief valve can be activated in conjunction, forming a dual protection mechanism of "tank buffering + valve cut-off".

[0028] This system also includes a third heat exchanger 8 and a third condensate storage tank 9. The hot-side outlet of the second heat exchanger 5 is connected to the hot-side inlet of the third heat exchanger 8 via pipelines, and the hot-side outlet of the third heat exchanger 8 is connected to the third condensate storage tank 9 via pipelines. The second condensate storage tank 7 is connected to the hot-side inlet of the third heat exchanger 8 via pipelines. The waste heat temperature of the cooled condensate after heat exchange in the second heat exchanger 5 is still relatively high. The cooled condensate can be further used for low-grade heat demand, realizing graded utilization of heat energy and avoiding high-energy underutilization. Therefore, a third heat exchanger 8 is set up. The hot-side outlet of the second heat exchanger 5 is connected to the hot-side inlet of the third heat exchanger 8 via pipelines. The material outlet of the third heat exchanger 8 is connected to the light-weight material removal tower to heat the material entering the light-weight material removal tower. The second condensate storage tank 7 is directly connected to the third heat exchanger 8, providing it with a higher-temperature heat source. The third heat exchanger 8 has three heat source selection modes: the first is the condensate from the second heat exchanger 5, the second is the condensate from the second condensate storage tank 7, and the third is the condensate from both the second heat exchanger 5 and the second condensate storage tank 7. Different modes can be selected by controlling the valves according to actual usage requirements. The third condensate storage tank 9 is used to collect the condensate from the third heat exchanger 8. The collected condensate is pumped to a centralized treatment facility.

[0029] In this embodiment, the first heat exchange device 4, the second heat exchange device 5, and the third heat exchange device 8 can be plate heat exchangers or tubular heat exchangers. In other possible embodiments, the first heat exchange device 4, the second heat exchange device 5, and the third heat exchange device 8 can also be other types of heat exchangers, which are not specifically limited here.

[0030] The MTBE production heat recovery system in this embodiment reduces the heat required for the vaporization of the etherification reaction products by increasing the temperature of the products entering the catalytic distillation unit 2, thereby reducing the energy consumption of the reboiler 3. Specifically, the outlet of the etherification reaction unit 1 is connected to the inlet of the catalytic distillation unit 2 via a pipeline. A first heat exchanger 4 and a second heat exchanger 5 are sequentially installed on the pipeline to heat the etherification reaction products, thereby increasing the temperature of the etherification reaction products entering the catalytic distillation unit 2. The liquid-phase outlet at the bottom of the catalytic distillation unit 2 is connected to the hot-side inlet of the first heat exchanger 4 via a pipeline. MTBE product is discharged from the liquid-phase outlet at the bottom of the catalytic distillation unit 2, undergoes a first heat exchange with the etherification reaction product in the first heat exchanger 4, and is then cooled and sent to a storage tank. The etherification reaction product, heated by the first heat exchange, enters the second heat exchanger 5. The shell-side outlet of the reboiler 3 is connected to the hot-side inlet of the second heat exchanger 5 via a pipeline. High-temperature condensate is discharged from the shell-side outlet of the reboiler 3 and enters the second heat exchanger 5, undergoing a second heat exchange with the etherification reaction product. The etherification reaction product, heated by the second heat exchange, enters the catalytic distillation unit 2 and is circulated back to the reboiler 3 for heating and vaporization. By setting up two heat exchangers, heat generated during the MTBE production process is recovered and utilized. The feed temperature of the etherification reaction product entering the catalytic distillation unit 2 is increased through two heat exchange processes, thereby reducing the steam consumption of the reboiler 3, lowering the energy consumption of the catalytic distillation unit 2, reducing production costs, and improving economic efficiency.

[0031] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, the inclusion of "first," "second," etc., in a feature may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat recovery system for MTBE production, comprising an etherification reaction unit, a catalytic distillation unit, and a reboiler disposed at the bottom of the catalytic distillation unit, characterized in that, The outlet of the etherification reaction device is connected to the inlet of the catalytic distillation device via a pipeline. A first heat exchanger and a second heat exchanger are sequentially installed on the pipeline connecting the outlet of the etherification reaction device and the inlet of the catalytic distillation device. The outlet at the bottom of the catalytic distillation device is connected to the hot-side inlet of the first heat exchanger via a pipeline. The shell-side outlet of the reboiler is connected to the hot-side inlet of the second heat exchanger via a pipeline.

2. The MTBE production heat recovery system according to claim 1, characterized in that, A first condensate storage tank is provided on the pipeline connecting the shell-side outlet of the reboiler to the hot-side inlet of the second heat exchanger. The first condensate storage tank includes a first outlet, which is connected to the hot-side inlet of the second heat exchanger.

3. The MTBE production heat recovery system according to claim 2, characterized in that, It also includes a second condensate storage tank, and the first condensate storage tank includes a second outlet, which is connected to the second condensate storage tank.

4. The MTBE production heat recovery system according to claim 3, characterized in that, It also includes a third heat exchange device, wherein the heat-side outlet of the second heat exchange device is connected to the heat-side inlet of the third heat exchange device via a pipeline.

5. The MTBE production heat recovery system according to claim 4, characterized in that, The outlet of the second condensate storage tank is connected to the heat-side inlet of the third heat exchanger via a pipeline.

6. The MTBE production heat recovery system according to claim 5, characterized in that, It also includes a third condensate storage tank, and the heat-side outlet of the third heat exchange device is connected to the inlet of the third condensate storage tank via a pipeline.

7. The MTBE production heat recovery system according to claim 3, characterized in that, The first condensate storage tank also includes a control valve device, which is used to control the opening and closing of the first outlet and the second outlet.

8. The MTBE production heat recovery system according to claim 1, characterized in that, It also includes a low-pressure steam unit connected to the shell-side inlet of the reboiler.

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