Heat exchange system for avoiding freezing of water in CO2 feed gas

Abstract

The utility model provides a heat exchange system for preventing water in CO2 feed gas from being frozen and congealed. The heat exchange system comprises a feed gas heater, a desulfurizing tower, a dealkylation preheater and a dealkylation tower, the raw material gas heater is connected with the desulfurization tower and is used for removing sulfur elements in raw material gas; and the desulfurization tower is connected with the dealkylation preheater and the dealkylation tower and is used for removing hydrocarbon substances in the raw material gas. According to the utility model, a large amount of heat generated by dealkylation is recovered to the previous process for heat exchange, the use of energy is reduced, so that carbon emission generated by energy production is indirectly reduced, and water condensed by carbon dioxide feed gas can be discharged by arranging the guide spraying pipeline on the shell pass of the heat exchanger, so that the water is prevented from being frozen and congealed in winter.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of carbon dioxide refining device, specifically, especially involves a kind of heat exchange system to avoid water freeze of CO2 raw material gas. BACKGROUND

[0002] The existing carbon dioxide refining device plays a vital role in industrial production. The device mainly includes desulfurization, dehydrocarbonization, drying and rectification and other key processes. The process flow of carbon dioxide refining device is as follows: first, the raw material gas enters the desulfurization process, and the sulfur compounds in the gas are removed by a specific desulfurization technology to provide a relatively pure gas environment for the subsequent process. Then, the gas enters the dehydrocarbonization process, in which a large amount of heat is generated due to chemical reactions and other factors. The dehydrocarbonization process itself requires a certain initial temperature at the beginning of operation to ensure efficient and stable operation. After that, the gas treated by dehydrocarbonization enters the drying process to remove water and other impurities, ensuring that the dryness of the gas meets the requirements. Finally, in the rectification process, the carbon dioxide is purified by precise temperature and pressure control to obtain high-purity carbon dioxide products. SUMMARY

[0003] According to the above-mentioned problem that the dehydrocarbonization process itself requires a certain initial temperature and dehydrocarbonization generates a large amount of heat, a heat exchange system is provided to avoid water freeze in CO2 raw material gas. The heat generated by dehydrocarbonization is recovered to the previous process for heat exchange, and a guide pipe is provided in the shell side of the heat exchanger to discharge the water condensed from the carbon dioxide raw material gas, avoiding its freezing in winter.

[0004] The technical means adopted by the utility model are as follows:

[0005] A heat exchange system to avoid water freeze in CO2 raw material gas, comprising: a raw material gas heater, a desulfurization tower, a dehydrocarbonization preheater and a dehydrocarbonization tower.

[0006] The raw material gas heater is connected to the desulfurization tower and is used to remove sulfur elements from the raw material gas. The desulfurization tower is connected to the dehydrocarbonization preheater and the dehydrocarbonization tower and is used to remove hydrocarbon substances from the raw material gas.

[0007] Further, an electric heater is provided at the front end of the dehydrocarbonization tower, which heats the raw material gas entering the dehydrocarbonization tower during the early stage of operation to ensure smooth startup of the system.

[0008] Further, the high-temperature carbon dioxide gas generated by the dehydrocarbonization tower can enter the tube side of the dehydrocarbonization preheater and the raw material gas heater to provide heat for the raw material gas, realizing recycling of heat and making the raw material gas meet the process gas requirements.

[0009] Further, the shell side of the dehydrocarbon preheater and the raw material gas heater is provided with a guide valve capable of discharging the condensed water in the raw material gas, preventing freezing phenomenon in winter, and ensuring stable operation of the system.

[0010] Due to the adoption of the above technical scheme, compared with the prior art, the heat exchange system has the following advantages:

[0011] 1. The heat exchange system for avoiding water freezing in CO2 raw material gas provided by the utility model recycles and utilizes the heat generated by dehydrocarbon to heat the raw material gas, so that the raw material gas meets the process air requirement, and the demand for external energy is reduced.

[0012] 2. The heat exchange system for avoiding water freezing in CO2 raw material gas provided by the utility model reduces the production cost directly due to the reduction of energy consumption.

[0013] 3. The heat exchange system for avoiding water freezing in CO2 raw material gas provided by the utility model reduces the use of energy, thereby indirectly reducing the carbon emission caused by energy production, and truly practices the national energy-saving and carbon-reducing slogan to the extreme.

[0014] 4. The heat exchange system for avoiding water freezing in CO2 raw material gas provided by the utility model makes the temperature of each process more stable during the heat exchange process, and reduces the damage to the equipment caused by temperature fluctuation.

[0015] Based on the above reasons, the utility model can be widely popularized in the field of carbon dioxide refining devices. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be simply introduced below, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without paying creative labor.

[0017] Figure 1 It is a kind of heat exchange system flow chart for avoiding water freezing in CO2 raw material gas described in the utility model.

[0018] In the drawing: 1, raw material gas heater;2, desulfurization tower;3, dehydrocarbon preheater;4, electric heater;5, dehydrocarbon tower;6, heater guide valve;7, preheater guide valve. DETAILED DESCRIPTION

[0019] It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict. The utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme of the embodiments of the utility model will be described clearly and completely below in combination with the drawings of the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, not as any limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0021] It should be noted that the terms used herein are only for describing specific embodiments, not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or their combination.

[0022] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the embodiments are not intended to limit the scope of the utility model. At the same time, it should be clear that in order to facilitate description, the size of each part shown in the drawings is not drawn according to the actual proportion relationship. The technology, method and equipment known to those skilled in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as part of the authorized specification. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0023] In the description of the utility model, it needs to be understood that the orientation words such as '' front, back, top, bottom, left, right '' '' horizontal, vertical, perpendicular, horizontal '' and '' top, bottom '' and the like indicated orientation or positional relationship usually based on the orientation or positional relationship shown in the drawing, just for the convenience of describing the utility model and simplifying the description, in the case where no contrary statement is made, these orientation words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore it can not be understood as the limitation of the protection scope of the utility model: the orientation words '' inside, outside '' refer to the inside and outside relative to the contour of each component.

[0024] For the convenience of description, spatial relative terms such as '' above'', '' above'', '' upper surface'', '' upper '' and the like can be used here to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawing. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawing. For example, if the device in the drawing is inverted, the device described as '' above '' or '' above '' other devices or structures will be positioned '' below '' or '' below '' other devices or structures. Thus, the exemplary term '' above '' can include both '' above '' and '' below ''. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative description used here is interpreted accordingly.

[0025] In addition, it should be noted that the use of '' first'', '' second '' and the like to limit parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore it can not be understood as the limitation of the protection scope of the utility model.

[0026] As shown in Figure 1 The utility model provides a kind of heat exchange system for avoiding water freeze in CO2 raw gas, comprising: raw gas heater 1, desulfurization tower 2, dehydrocarbon preheater 3, dehydrocarbon tower 5;

[0027] The raw gas heater 1 is connected with the desulfurization tower 2, for removing sulfur element in raw gas;The desulfurization tower 2 is connected with the dehydrocarbon preheater 3, dehydrocarbon tower 5, for removing hydrocarbon substances in raw gas.

[0028] Further, carbon dioxide raw gas first enters raw gas heater 1, and here raw gas is preliminarily heated, prepares for subsequent desulfurization process.Raw gas heater 1 shell is equipped with heater guide valve 6, for removing water condensed in heating process of raw gas.

[0029] The carbon dioxide raw material gas heated by the raw material gas heater 1 enters the desulfurization tower 2 to perform desulfurization treatment to remove sulfur impurities in the raw material gas.

[0030] The raw material gas from the desulfurization tower 2 enters the dealkylation preheater 3 to exchange heat with high-temperature carbon dioxide generated after the dealkylation tower 5, so that the raw material gas is further heated to meet the process gas requirement for entering the dealkylation tower 5. The dealkylation preheater 3 is also provided with a preheater drain valve 7 to drain the condensed water in the raw material gas.

[0031] In the early stage of starting, the raw material gas needs to be heated by the electric heater 4 before entering the dealkylation tower 5. When the dealkylation reaction is heated, the electric heater 4 is no longer used.

[0032] The raw material gas after the heating treatment enters the dealkylation tower 5 to perform dealkylation treatment. The dealkylation process generates a large amount of heat, which is recycled and utilized subsequently.

[0033] The high-temperature carbon dioxide gas after the dealkylation tower 5 enters the tube side of the dealkylation preheater 3 and the raw material gas heater 1 to heat the raw material gas, so that the heat is recycled and utilized to achieve the purpose of energy saving and consumption reduction.

[0034] Further, the electric heater 4 is arranged at the front end of the dealkylation tower 5 to heat the raw material gas entering the dealkylation tower 5 in the early stage of starting to ensure the smooth start of the system.

[0035] Further, the high-temperature carbon dioxide gas generated by the dealkylation tower 5 can enter the tube side of the dealkylation preheater 3 and the raw material gas heater 1 to provide heat for the raw material gas, so that the heat is recycled and utilized to make the raw material gas meet the process gas requirement.

[0036] Further, the shell side of the dealkylation preheater 3 and the raw material gas heater 1 is provided with a drain valve, which can drain the condensed water in the raw material gas to prevent freezing in winter and ensure the stable operation of the system.

[0037] Further, when the dealkylation reaction is heated, the electric heater 4 is no longer used. At this time, the raw material gas is directly heated by the dealkylation preheater 3 after the raw material gas heater 1 and the desulfurization tower 2 to exchange heat with the high-temperature carbon dioxide after the dealkylation, and then enters the dealkylation tower 5. In the whole process, the raw material gas heater 1 and the dealkylation preheater drain valve 7 will continue to work to drain the condensed water in the raw material gas in time to avoid freezing in winter.

[0038] It should be finally pointed out that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application examples.

Claims

1. A heat exchange system for avoiding water freezing in a CO2 feed gas, characterized by, It comprises: a raw material gas heater (1), a desulfurization tower (2), a dehydrocarbon preheater (3), and a dehydrocarbon tower (5); the raw material gas heater (1) is connected with the desulfurization tower (2) and used for removing sulfur elements in the raw material gas; the desulfurization tower (2) is connected with the dehydrocarbon preheater (3) and the dehydrocarbon tower (5) and used for removing hydrocarbon substances in the raw material gas.

2. The heat exchange system of claim 1, wherein, An electric heater (4) is arranged at the front end of the dehydrocarbon tower (5) and used for heating the raw material gas entering the dehydrocarbon tower (5) in the early stage of starting to ensure the smooth start of the system.

3. The heat exchange system of claim 1, wherein the heat exchange system further comprises a water trap. The high-temperature carbon dioxide gas generated by the dehydrocarbon tower (5) can enter the tube side of the dehydrocarbon preheater (3) and the raw material gas heater (1) to provide heat for the raw material gas, realize the recycling of heat, and make the raw material gas meet the process gas requirement.

4. The heat exchange system of claim 1, wherein, The shell side of the dehydrocarbon preheater (3) and the raw material gas heater (1) is provided with a guide valve, the guide valve can discharge the condensed water in the raw material gas, prevent the freezing phenomenon in winter, and ensure the stable operation of the system.

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