Tail gas acid mist removal device for chlorosulfonic acid production

Abstract

The utility model relates to the technical field of chlorosulfonic acid production, and provides a tail gas acid mist removal device for chlorosulfonic acid production, which comprises a chlorosulfonic acid synthesis tower, a hydrogen chloride preheater, a chlorosulfonic acid cooling tower, a sulfuric acid washing tower and a washing acid cooler which are sequentially communicated, the hydrogen chloride preheater is provided with a synthesis gas outlet, the chlorosulfonic acid cooling tower is provided with a tail gas outlet and a heat exchanger, the heat exchanger is used for performing heat exchange on tail gas discharged from the tail gas outlet and synthesis gas discharged from the synthesis gas outlet, and the hydrogen chloride preheater is communicated with the chlorosulfonic acid cooling tower through a cooling pipe, the heat exchanger and a cooling pipe; the tail gas fan is provided with an exhaust end and an exhaust end, and the exhaust end is communicated with the tail gas outlet; the chlorosulfonic acid cooling tower is communicated with the sulfuric acid washing tower through a tail gas fan, a heating pipe, a heat exchanger and a washing pipe. According to the technical scheme, the problems that the temperature of gas discharged from the chlorosulfonic acid cooling tower is low, the gas easily reaches a dew point to form acid mist, and tail gas emission does not reach the standard are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of chlorosulfonic acid production, in particular to an acid mist removal device for tail gas in chlorosulfonic acid production. Background Art

[0002] In the chlorosulfonic acid production process, a process production line consisting of a chlorosulfonic acid synthesis tower, a hydrogen chloride preheater, a chlorosulfonic acid cooling tower, a sulfuric acid scrubbing tower and a scrubbing acid cooler is required to produce chlorosulfonic acid and treat the tail gas at the same time.

[0003] In the existing production technology, the synthesis gas of the chlorosulfonic acid synthesis tower preheats the hydrogen chloride gas sent from the drying tower in the hydrogen chloride preheater. After passing through the hydrogen chloride preheater, the hydrogen chloride gas is mixed with sulfur trioxide gas and enters the chlorosulfonic acid synthesis tower. The cooled synthesis gas coming out of the hydrogen chloride preheater enters the chlorosulfonic acid cooling tower and is sprayed and cooled with liquid chlorosulfonic acid. The gas coming out of the chlorosulfonic acid cooling tower contains a small amount of gases such as chlorosulfonic acid, hydrogen chloride and sulfur trioxide, and is sent to the sulfuric acid scrubbing tower for scrubbing by a tail gas fan. During this process, since the gas coming out of the chlorosulfonic acid cooling tower has a low temperature, it is easy to reach the dew point to form acid mist; the scrubbing acid in the scrubbing tower has a low temperature, which also easily causes the gas to reach the dew point to form acid mist, resulting in unqualified tail gas emissions. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide an acid mist removal device for tail gas in chlorosulfonic acid production aiming at the above existing technical deficiencies, which solves the problem that the gas coming out of the chlorosulfonic acid cooling tower has a low temperature and is easy to reach the dew point to form acid mist, resulting in unqualified tail gas emissions.

[0005] The technical solution adopted by the utility model is: to provide an acid mist removal device for tail gas in chlorosulfonic acid production, including a chlorosulfonic acid synthesis tower, a hydrogen chloride preheater, a chlorosulfonic acid cooling tower, a sulfuric acid scrubbing tower, and a scrubbing acid cooler that are connected in sequence; the hydrogen chloride preheater has a synthesis gas outlet, and the chlorosulfonic acid cooling tower has a tail gas outlet, and further includes:

[0006] A heat exchanger for heat exchange between the tail gas discharged from the tail gas outlet and the synthesis gas discharged from the synthesis gas outlet, and the heat exchanger has two heating interfaces and two cooling interfaces;

[0007] A cooling pipe, one end of which is connected to the synthesis gas outlet, and the other end is connected to one of the cooling interfaces;

[0008] A cooling tube, one end of which is connected to the other cooling interface, and the other end is connected to the chlorosulfonic acid cooling tower. The hydrogen chloride preheater and the chlorosulfonic acid cooling tower are connected through the cooling pipe, the heat exchanger and the cooling tube;

[0009] The tail gas fan has an air extraction end and an exhaust end, and the air extraction end is communicated with the tail gas outlet;

[0010] The heating pipe has one end communicated with the exhaust end and the other end communicated with the one heating interface;

[0011] The washing pipe has one end communicated with the other heating interface and the other end communicated with the sulfuric acid washing tower. The chlorosulfonic acid cooling tower and the sulfuric acid washing tower are communicated through the tail gas fan, the heating pipe, the heat exchanger and the washing pipe.

[0012] To further optimize this technical solution, the washing acid cooler has a water inlet pipe and a water return pipe, and further includes:

[0013] The steam pipe is communicated with the water inlet pipe and is used to supply heating steam to the water inlet pipe.

[0014] To further optimize this technical solution, it further includes:

[0015] The tail gas direct pipe has one end communicated with the exhaust end and the other end communicated with the sulfuric acid washing tower. The heating pipe is communicated with the exhaust end through the tail gas direct pipe, and the washing pipe is communicated with the sulfuric acid washing tower through the tail gas direct pipe. A first valve is arranged on the heating pipe, and a second valve is arranged on the tail gas direct pipe.

[0016] To further optimize this technical solution, it further includes a spray circulation system, and the spray circulation system includes:

[0017] The chlorosulfonic acid condenser is communicated with circulating water;

[0018] The chlorosulfonic acid circulating pump has a liquid extraction end and a liquid discharge end. The liquid extraction end is communicated with the inner bottom of the chlorosulfonic acid cooling tower, and the liquid discharge end is communicated with the spray device in the chlorosulfonic acid cooling tower through the chlorosulfonic acid condenser, and is used for spray absorption of the syngas entering the chlorosulfonic acid cooling tower.

[0019] The beneficial effects of the present utility model are as follows:

[0020] 1. An additional heat exchanger is added to exchange heat between the syngas cooled by the hydrogen chloride preheater and the tail gas coming out of the chlorosulfonic acid cooling tower through the heat exchanger, so as to further reduce the temperature of the syngas cooled by the hydrogen chloride preheater, so that the absorption effect in the chlorosulfonic acid cooling tower is better;

[0021] 2. The tail gas coming out of the chlorosulfonic acid cooling tower is heated to make the gas temperature above the dew point to avoid the formation of acid mist, so as to meet the discharge standard after subsequent tail gas treatment. Description of the Drawings

[0022] Figure 1It is a schematic structural diagram of the present utility model;

[0023] Figures 2 - 5 It is a schematic structural diagram of the disassembled marking of the present utility model;

[0024] Description of the marks in the figure: 101, chlorosulfonic acid synthesis tower; 102, hydrogen chloride preheater; 1021, synthesis gas outlet; 103, chlorosulfonic acid cooling tower; 1031, tail gas outlet; 104, sulfuric acid scrubbing tower; 105, scrubbing acid cooler; 1051, water inlet pipe; 1052, return water pipe; 106, sulfuric acid circulation pump; 2, heat exchanger; 201, heating interface; 202, cooling interface; 301, cooling pipe; 302, cooling tube; 4, tail gas fan; 501, heating pipe; 5011, first valve; 502, scrubbing pipe; 6, steam pipe; 7, tail gas direct pipe; 701, second valve; 8, spray circulation system; 801, chlorosulfonic acid condenser; 802, chlorosulfonic acid circulation pump. Specific embodiments

[0025] The present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] For the sake of simplicity of the drawings, only the parts related to the utility model are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, for the sake of simplicity and easy understanding of the drawings, in some figures, for the components with the same structure or function, only one of them is schematically shown, or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation, and "several" includes "two" and "more than two".

[0027] In this article, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0028] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0029] Such as Figures 1 - 5As shown in the figure, an acid mist removal device for chlorosulfonic acid production, which is successively connected to a chlorosulfonic acid synthesis tower 101, a hydrogen chloride preheater 102, a chlorosulfonic acid cooling tower 103, a sulfuric acid scrubbing tower 104, and a scrubbing acid cooler 105; the hydrogen chloride preheater 102 has a synthesis gas outlet 1021, and the chlorosulfonic acid cooling tower 103 has a tail gas outlet 1031, and further includes:

[0030] A heat exchanger 2, which is used for heat exchange between the tail gas discharged from the tail gas outlet 1031 and the synthesis gas discharged from the synthesis gas outlet 1021. The heat exchanger 2 has two heating interfaces 201 and two cooling interfaces 202;

[0031] A cooling pipe 301, one end of which is connected to the synthesis gas outlet 1021, and the other end is connected to a cooling interface 202;

[0032] A cooling tube 302, one end of which is connected to the other cooling interface 202, and the other end is connected to the chlorosulfonic acid cooling tower 103. The hydrogen chloride preheater 102 and the chlorosulfonic acid cooling tower 103 are connected through the cooling pipe 301, the heat exchanger 2, and the cooling tube 302;

[0033] A tail gas fan 4, which has a suction end and an exhaust end, and the suction end is connected to the tail gas outlet 1031;

[0034] A heating pipe 501, one end of which is connected to the exhaust end, and the other end is connected to a heating interface 201;

[0035] A washing pipe 502, one end of which is connected to the other heating interface 201, and the other end is connected to the sulfuric acid scrubbing tower 104. The chlorosulfonic acid cooling tower 103 and the sulfuric acid scrubbing tower 104 are connected through the tail gas fan 4, the heating pipe 501, the heat exchanger 2, and the washing pipe 502.

[0036] During use, the synthesis gas of the chlorosulfonic acid synthesis tower 101 preheats the hydrogen chloride gas sent from the drying tower in the hydrogen chloride preheater 102. After passing through the hydrogen chloride preheater 102, the hydrogen chloride gas is mixed with sulfur trioxide gas and enters the chlorosulfonic acid synthesis tower 101. The cooled synthesis gas discharged from the hydrogen chloride preheater 102 enters the chlorosulfonic acid cooling tower 103 and is sprayed and cooled with liquid chlorosulfonic acid. The gas coming out of the chlorosulfonic acid cooling tower 103 contains a small amount of gases such as chlorosulfonic acid, hydrogen chloride, and sulfur trioxide, and is sent to the sulfuric acid scrubbing tower 104 for washing by the tail gas fan 4. The sulfuric acid scrubbing tower 104 and the scrubbing acid cooler 105 can be connected by a sulfuric acid circulation pump 106 to realize the recycling of the scrubbing acid.

[0037] After the syngas is preliminarily cooled by the hydrogen chloride preheater 102, it enters the heat exchanger 2 through the cooling pipe 301. The tail gas fan 4 supplies the tail gas discharged from the upper tail gas outlet 1031 of the chlorosulfonic acid cooling tower 103 into the heat exchanger 2. The syngas and the tail gas exchange heat in the heat exchanger 2 (the two do not mix, and the temperature of the syngas is higher than that of the tail gas. The two heating interfaces 201 are connected, and the two cooling interfaces 202 are connected). After the syngas is preliminarily cooled by the heat exchanger 2, it enters the chlorosulfonic acid cooling tower 103 through the cooling pipe 302. The chlorosulfonic acid cooling tower 103 uses the spraying device to spray the syngas with liquid chlorosulfonic acid for cooling and temperature reduction.

[0038] After the tail gas discharged from the upper tail gas outlet 1031 of the chlorosulfonic acid cooling tower 103 is heated up in the heat exchanger 2, it enters the sulfuric acid scrubbing tower 104 through the scrubbing pipe 502 for scrubbing. Heating up the tail gas before scrubbing is beneficial to reducing the formation of acid mist.

[0039] The syngas enters the chlorosulfonic acid cooling tower 103 through the cooling pipe 301, the heat exchanger 2, and the cooling pipe 302. The gas path can be a single path. It can also be set with multiple paths. By adding a gas path, the syngas discharged from the hydrogen chloride preheater 102 is directly connected to the chlorosulfonic acid cooling tower 103 through a gas path (i.e., the connection scheme of the prior art). The coexistence of the two paths facilitates the transformation of existing equipment, improves the safety of production, and avoids affecting normal production due to the damage of the heat exchanger 2.

[0040] Valves such as on-off valves and flow valves can be set on each pipeline according to actual on-off requirements, which is the prior art and will not be elaborated in this article.

[0041] Furthermore, the scrubbing acid cooler 105 has a water inlet pipe 1051 and a water return pipe 1052, and further includes: a steam pipe 6, and the steam pipe 6 is connected to the water inlet pipe 1051 for supplying heating steam to the water inlet pipe 1051.

[0042] During use, the scrubbing acid cooler 105 can adjust the temperature of the scrubbing acid in the sulfuric acid scrubbing tower 104. After the scrubbing acid scrubs the tail gas, the scrubbing acid heats up and needs to be cooled down. Cooling is carried out through the water inlet pipe 1051 and the water return pipe 1052 of the scrubbing acid cooler 105. However, when the temperature of the scrubbing acid is too low, the scrubbing effect will be reduced, and the single cooling temperature regulation is relatively weak. By connecting the steam pipe 6 to the water inlet pipe 1051, heat can be provided to avoid the temperature of the scrubbing acid being too low. A low temperature of the scrubbing acid in the scrubbing tower can also cause the gas to reach the dew point and form acid mist. Therefore, by adding a steam pipe 6 to the water inlet pipe 1051 of the scrubbing acid cooler 105 of the scrubbing acid to heat the scrubbing acid, the gas temperature can also be raised above the dew point to reduce the formation of acid mist and play a role in removing acid mist from the tail gas.

[0043] Further, it further includes: an exhaust gas direct pipe 7, one end of which is communicated with the exhaust end, and the other end of which is communicated with the sulfuric acid scrubbing tower 104. The heating pipe 501 is communicated with the exhaust end through the exhaust gas direct pipe 7, and the washing pipe 502 is communicated with the sulfuric acid scrubbing tower 104 through the exhaust gas direct pipe 7. A first valve 5011 is arranged on the heating pipe 501, and a second valve 701 is arranged on the exhaust gas direct pipe 7.

[0044] During use, the exhaust gas direct pipe 7 enables the exhaust gas to directly pass through the sulfuric acid scrubbing tower 104 (i.e., the connection scheme of the prior art), so that the exhaust gas temperature rise adjustment coexists with the prior art scheme, which is convenient for the transformation of existing equipment. The second valve 701 can be located on the exhaust gas direct pipe 7 and between the connection position of the heating pipe 501 and the exhaust gas direct pipe 7 and the connection position of the washing pipe 502 and the exhaust gas direct pipe 7. When the second valve 701 is closed and the first valve 5011 is opened, the exhaust gas is heated through the heat exchanger 2. When the second valve 701 is opened and the first valve 5011 is closed, the exhaust gas is directly discharged into the sulfuric acid scrubbing tower 104 for washing. It can be selected according to the actual processing capacity, and at the same time, it is convenient for the whole production line to still operate normally when the heat exchanger 2 has problems.

[0045] Further, it further includes a spray circulation system 8. The spray circulation system 8 includes: a chlorosulfonic acid condenser 801, which is communicated with circulating water; a chlorosulfonic acid circulation pump 802, which has a liquid suction end and a liquid discharge end. The liquid suction end is communicated with the bottom inside the chlorosulfonic acid cooling tower 103, and the liquid discharge end is communicated with the spray device inside the chlorosulfonic acid cooling tower 103 through the chlorosulfonic acid condenser 801, and is used for spraying and absorbing the syngas entering the chlorosulfonic acid cooling tower 103.

[0046] During use, the chlorosulfonic acid cooling tower 103 can spray and absorb the syngas with liquid chlorosulfonic acid, and the spray circulation system 8 can recycle chlorosulfonic acid. The chlorosulfonic acid condenser 801 is communicated with circulating water for cooling, which is the prior art.

[0047] Two groups of spray circulation systems 8 can be set to ensure the cooling capacity.

[0048] It can be understood that the present utility model is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present utility model, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. A tail gas acid mist removal device for chlorosulfonic acid production, comprising a chlorosulfonic acid synthesis tower (101), a hydrogen chloride preheater (102), a chlorosulfonic acid cooling tower (103), a sulfuric acid washing tower (104), and a washing acid cooler (105) which are connected in sequence; characterized in that: The hydrogen chloride preheater (102) has a synthesis gas outlet (1021), the chlorosulfonic acid cooling tower (103) has a tail gas outlet (1031), and further comprises: A heat exchanger (2) for heat exchange between tail gas discharged from the tail gas outlet (1031) and synthesis gas discharged from the synthesis gas outlet (1021), wherein the heat exchanger (2) has two temperature increasing interfaces (201) and two temperature decreasing interfaces (202); A cooling pipe (301), one end of which is in communication with the synthesis gas outlet (1021), and the other end of which is in communication with one of the cooling interfaces (202); A cooling pipe (302), one end of which is in communication with another of the cooling interfaces (202), and the other end of which is in communication with the chlorosulfonic acid cooling tower (103); the hydrogen chloride preheater (102) and the chlorosulfonic acid cooling tower (103) are in communication with each other via the cooling pipe (301), the heat exchanger (2) and the cooling pipe (302); An exhaust fan (4) having an exhaust end and an exhaust end, wherein the exhaust end is connected to the exhaust outlet (1031); A heating pipe (501), one end of which is connected to the exhaust end, and the other end of which is connected to one of the heating interfaces (201); A washing pipe (502) has one end connected to another of the heating interfaces (201) and the other end connected to the sulfuric acid washing tower (104); the chlorosulfonic acid cooling tower (103) and the sulfuric acid washing tower (104) are connected via the exhaust fan (4), the heating pipe (501), the heat exchanger (2) and the washing pipe (502).

2. The tail gas acid mist removal device for chlorosulfonic acid production according to claim 1, characterized in that: The washing acid cooler (105) has a water supply pipe (1051) and a water return pipe (1052), and further comprises: A steam pipe (6), the steam pipe (6) being in communication with the upper water pipe (1051) and being used for supplying hot steam to the upper water pipe (1051).

3. A tail gas acid mist removal device for chlorosulfonic acid production according to claim 1, characterized in that: Also includes: A tail gas straight pipe (7) has one end connected to the exhaust end and the other end connected to the sulfuric acid washing tower (104); the heating pipe (501) is connected to the exhaust end via the tail gas straight pipe (7); the washing pipe (502) is connected to the sulfuric acid washing tower (104) via the tail gas straight pipe (7); a first valve (5011) is provided on the heating pipe (501); and a second valve (701) is provided on the tail gas straight pipe (7).

4. The tail gas acid mist removal device for chlorosulfonic acid production according to claim 1, characterized in that: It also includes a spray circulation system (8), wherein the spray circulation system (8) includes: A chlorosulfonic acid condenser (801) is connected to circulating water; The chlorosulfonic acid circulation pump (802) has a liquid extraction end and a liquid discharge end, wherein the liquid extraction end is connected to the bottom of the chlorosulfonic acid cooling tower (103), and the liquid discharge end is connected to the spray device in the chlorosulfonic acid cooling tower (103) through the chlorosulfonic acid condenser (801), and is used for spraying and absorbing the synthesis gas entering the chlorosulfonic acid cooling tower (103).

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