Synthesis gas pretreatment tower

Abstract

An embodiment of the present invention discloses a synthesis gas pretreatment tower, comprising a tower body, a processing device, and a conversion device. The processing device comprises a water bath section, a distributor section, a tray section, and a demister section installed in the tower body from bottom to top. A synthesis gas outlet channel is installed at the top of the tower body. Cooling water is stored in the water bath section. The outlet end of the synthesis gas inlet channel is inserted into the cooling water of the water bath section. The crude synthesis gas passes through the water bath section, the distributor section, the tray section, and the demister section in sequence to obtain treated synthesis gas. The conversion device is provided with a catalyst for catalyzing the conversion reaction of CO and H2O in the synthesis gas and releasing heat, so that the treated synthesis gas absorbs heat to form superheated synthesis gas. The present invention not only has the functions of removing slag, dust, and cooling the crude synthesis gas, but also has the function of a conversion furnace. By simplifying the processing flow, the use of equipment such as separation tanks, detoxification tanks, and synthesis gas heaters is reduced, and the synthesis gas processing efficiency is effectively improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of coal chemical industry, and particularly to a synthesis gas pretreatment tower. Background Art

[0002] In traditional processes, scrubbers are used to remove slag, dust, and temperature. The syngas exiting the scrubber is at its saturation temperature at the operating pressure. Due to the long distance between the gasification and conversion stages, the syngas pipeline is excessively long. Heat loss in the pipeline causes water vapor in the syngas to condense and liquefy. In the presence of liquid water, sulfides corrode the pipeline and deactivate the catalyst in the conversion stage. Therefore, in traditional processes, before entering the conversion furnace, the syngas must first pass through a separator to separate the liquid water, then pass through a detoxification tank to remove harmful substances, and then pass through a heat exchanger to raise the syngas temperature before entering the conversion furnace for the conversion reaction. However, this process presents challenges such as a long and complex process route, suboptimal liquid water removal, and a high failure rate for the heat exchanger and conversion furnace. Summary of the Invention

[0003] To this end, an embodiment of the present invention provides a synthesis gas pretreatment tower to solve the problem of long and complicated process routes in the prior art.

[0004] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0005] According to a first aspect of an embodiment of the present invention, a synthesis gas pretreatment tower includes:

[0006] The tower body has a syngas inlet channel installed at its lower portion for connecting to an external gasifier to supply raw syngas into the tower body, and a syngas outlet channel installed at its top portion for connecting to an external shift converter to discharge treated syngas out of the tower body;

[0007] A processing device, the processing device comprising a water bath section, a distributor section, a tray section, and a demister section installed in the tower body from bottom to top, the synthesis gas inlet channel being arranged between the water bath section and the distributor section, the water bath section containing cooling water, the gas outlet end of the synthesis gas inlet channel being inserted into the cooling water in the water bath section, so that the crude synthesis gas passes through the water bath section, the distributor section, the tray section, and the demister section in sequence to obtain treated synthesis gas;

[0008] The conversion device is used to collect the treated synthesis gas, make the treated synthesis gas absorb heat to form superheated synthesis gas, and transport the superheated synthesis gas to the conversion furnace. The conversion device is provided with a catalyst for catalyzing the conversion reaction of CO and H2O in the synthesis gas and releasing heat.

[0009] Furthermore, the water bath section is a box component installed inside the tower body and with an open top. The gas outlet end of the synthesis gas inlet channel is inserted into the cooling water of the water bath section to remove fine slag in the crude synthesis gas and cool it.

[0010] Furthermore, a gray water outlet channel extending to the outside of the tower body is installed on the side wall of the water bath section, which is used to be connected to an external gasifier for washing the crude synthesis gas to obtain relatively clear gray water for circulation to the gasifier. A black water outlet channel extending to the outside of the tower body is installed at the bottom of the water bath section, which is used to be connected to an external flash evaporation system for discharging black water containing fine slag from the bottom of the water bath section to the flash evaporation system to realize slag-water separation.

[0011] Furthermore, the bottom of the water bath section is a funnel-shaped structure for discharging fine residues, and the inlet end of the black water outlet channel is connected to the conical bottom of the water bath section.

[0012] Furthermore, the tray section is provided with at least one section, and multiple tray sections are distributed from bottom to top, for washing the synthesis gas and achieving gas-liquid separation.

[0013] Furthermore, cooling water inlet channels are installed on the tower walls above the distributor section and the tray section for external equipment to supply cooling water to the tower body and then spray it from top to bottom to cool and remove dust from the synthesis gas.

[0014] Furthermore, the gas outlet end of the synthesis gas inlet channel is serrated to break foam.

[0015] Furthermore, the conversion device is a filler plate with a catalyst inside, which is installed inside the tower body and arranged between the synthesis gas outlet channel and the demister section.

[0016] Furthermore, the conversion device includes a pre-conversion furnace and a reaction plate arranged in the pre-conversion furnace. An air inlet pipe is installed at the bottom of the pre-conversion furnace for connecting to the synthesis gas outlet channel of the tower body. An air outlet pipe is installed at the top of the pre-conversion furnace for connecting to the conversion furnace.

[0017] Furthermore, a bypass pipe is provided on the outside of the pre-transformer furnace, one end of the bypass pipe is connected to the air inlet pipe, and the other end is connected to the air outlet pipe, and a regulating valve is installed on the bypass pipe.

[0018] The embodiment of the present invention has the following advantages: by providing a tower body, and sequentially arranging a water bath section, a distributor section, a tray section, a demister section and a conversion device in the tower body from bottom to top, the synthesis gas inlet channel is inserted into the cooling water in the water bath section, thereby removing fine slag entrained in the crude synthesis gas, and the washed synthesis gas passes through the distributor section, the tray section and the demister section from bottom to top, respectively, to further wash the synthesis gas, the distributor section can promote sufficient contact between the crude synthesis gas and the cooling water, the tray section can be set according to the requirements of the process conditions, thereby meeting the dust content requirements of the crude synthesis gas, the demister section is used to remove foam and droplets entrained in the synthesis gas, and finally the conversion device is used to provide conditions for the synthesis gas to undergo a conversion reaction through the conversion device equipped with a catalyst, so that the synthesis gas passing through the conversion device is superheated, so that in the process of transporting the synthesis gas to the conversion furnace section, no gaseous water condenses, thereby avoiding pipeline corrosion, and by simplifying the processing flow, reducing the use of equipment such as separation tanks, detoxification tanks, and synthesis gas heaters, effectively improving the processing efficiency of the synthesis gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0020] The structures, proportions, sizes, etc. illustrated in this specification are intended only to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall still fall within the scope of the technical contents disclosed herein.

[0021] Figure 1 This is a schematic diagram of the overall structure of a synthesis gas pretreatment tower provided in Example 1 of the present invention;

[0022] Figure 2 This is a schematic diagram of the overall structure of a synthesis gas pretreatment tower provided in Example 2 of the present invention.

[0023] In the figure: 1. Tower body; 11. Synthesis gas inlet channel; 12. Synthesis gas outlet channel; 13. Grey water outlet channel; 14. Black water outlet channel; 15. Cooling water inlet channel; 2. Treatment device; 21. Water bath section; 22. Distributor section; 23. Tray section; 24. Defoamer section; 3. Conversion device; 31. Pre-conversion furnace; 311. Air inlet pipe; 312. Air outlet pipe; 32. Reaction plate; 33. Bypass pipe; 34. Control valve. DETAILED DESCRIPTION

[0024] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, an embodiment of the present invention provides a synthesis gas pretreatment tower, including a tower body 1, a processing device 2 and a conversion device 3, and the specific configuration is as follows:

[0027] The tower body 1 is provided with a syngas inlet channel 11 at its lower portion for connecting to an external gasifier to allow crude syngas to enter the tower body 1, and a syngas outlet channel 12 is provided at its top portion for connecting to an external shift converter to allow treated syngas to be discharged outside the tower body 1;

[0028] The processing device 2 includes a water bath section 21, a distributor section 22, a tray section 23, and a demister section 24 installed from bottom to top in the tower body 1. The water bath section 21 is a box component installed inside the tower body 1 and with an open top. The synthesis gas inlet channel 11 is arranged between the water bath section 21 and the distributor section 22, and cooling water is contained in the water bath section 21 so that the cooling water in the water bath section 21 always maintains a certain liquid level. The gas outlet end of the synthesis gas inlet channel 11 is inserted into the cooling water in the water bath section 21 to perform water bath washing on the crude synthesis gas from the gasifier, remove fine slag in the crude synthesis gas and cool it. After the crude synthesis gas is washed in the water bath section 21, it passes through the distributor section 22, tray section 23, and demister section 24 from bottom to top to obtain the treated synthesis gas. The gas outlet end of the synthesis gas inlet channel 11 is serrated to remove foam. Preferably, a gray water outlet channel 13 extending to the outside of the tower body 1 is installed on the side wall of the water bath section 21, which is used to connect to an external gasifier for washing the crude synthesis gas to obtain clearer gray water for circulation to the gasifier. A black water outlet channel 14 extending to the outside of the tower body 1 is installed at the bottom of the water bath section 21, which is used to connect to an external flash evaporation system for black water containing fine slag to be discharged from the bottom of the water bath section 21 to the flash evaporation system to achieve slag-water separation. The bottom of the water bath section 21 is a funnel-shaped structure, and the inlet end of the black water outlet channel 14 is connected to the cone bottom of the water bath section 21 to facilitate the discharge of all fine slag and avoid the accumulation of fine slag in the water bath section 21. Among them, 2 to 3 black water outlet channels 14 can be set.

[0029] As described above, the distributor section 22, the tray section 23 and the demister section 24 are used to further wash the synthesis gas, respectively. The distributor section 22 is located at the upper part of the water bath section 21 and is fixed on the partition and the support ring of the tower body 1, which can promote sufficient contact between the crude synthesis gas and the cooling water; the tray section 23 is located at the upper part of the distributor section 22, and the tray section 23 is provided with at least one section, and multiple tray sections 23 are distributed from bottom to top, and each tray section can be connected to the support ring of the tower body 1, so that the synthesis gas passes through multiple tray sections 23 in sequence, realizing the washing of the synthesis gas and completing the gas-liquid separation, thereby meeting the dust content requirements of the crude synthesis gas; the demister section 24 is located at the upper part of the tray section 23 and is fixed on the tower body 1, and is used to remove foam and droplets entrained in the synthesis gas. Preferably, cooling water inlet channels 15 are installed on the tower walls above the distributor section 22 and the tower plate section 23 for external equipment to supply cooling water to the tower body 1, and then spray the synthesis gas from top to bottom to cool and remove dust. In this process, the gas flows from bottom to top, while the cooling water flows from top to bottom, and the two phases are in countercurrent contact, which helps to improve the washing effect. Among them, the cooling water inlet channel 15 in the tower plate section 23 can be set above the tower plate or below the tower plate according to process requirements.

[0030] The conversion device 3 is used to collect the treated synthesis gas, so that the treated synthesis gas absorbs heat to form superheated synthesis gas, and then transports the superheated synthesis gas to the conversion furnace. The conversion device 3 is provided with a catalyst for catalyzing the conversion reaction of CO and H2O in the synthesis gas and releasing heat. Specifically, the conversion device 3 is a filler plate with a catalyst, which is installed inside the tower body 1 and arranged between the synthesis gas outlet channel 12 and the demister section 24, so that the synthesis gas leaving the demister section 24 enters the conversion device 3, and the synthesis gas undergoes a conversion reaction in this section. The synthesis gas absorbs the heat released by the conversion reaction to increase the temperature to become superheated synthesis gas, which can be superheated by 10 to 30°C. The superheated synthesis gas leaves the tower body 1 through the synthesis gas outlet channel 12. During the process of being transported to the conversion furnace, the temperature drops slightly due to heat loss in the pipeline. However, since the temperature is higher than the saturation temperature under the operating pressure, no gaseous water condenses, thereby avoiding pipeline corrosion and reducing the use of equipment such as separation tanks, detoxification tanks, and synthesis gas heaters, and can be directly transported to the conversion furnace.

[0031] Therefore, functionally, the synthesis gas pretreatment tower of this embodiment has the functions of removing slag, dust and cooling the raw synthesis gas, and also has the function of a conversion furnace. Structurally, the slag removal, dust removal and cooling sections of the synthesis gas pretreatment tower of this embodiment can be selected from four sections, three sections, or even two sections of the water bath section 21, the distributor section 22, the tower plate section 23, and the demister section 24, so as to achieve the purpose of dust removal.

[0032] Example 2

[0033] The difference from Example 1 is that Figure 2 As shown, the conversion device 3 includes a pre-conversion furnace 31 and a reaction plate 32 disposed within the pre-conversion furnace 31. The pre-conversion furnace 31 is positioned above the tower body 1. An inlet pipe 311 is installed at the bottom of the pre-conversion furnace 31 for external connection to the syngas outlet channel 12 of the tower body 1. An outlet pipe 312 is installed at the top of the pre-conversion furnace 31 for external connection to the conversion furnace. The reaction plate 32 is a filler plate containing a catalyst. Syngas exiting the demister section 24 exits the tower body 1 through the syngas outlet channel 12. Since the syngas temperature is at the saturation temperature at the operating pressure, an excessively long delivery pipeline would cause water vapor in the syngas to condense due to heat loss, leading to pipeline corrosion. Therefore, when connecting the tower body 1 and the pre-conversion furnace 31, the length of the pipeline directly connecting the tower body 1 and the pre-conversion furnace 31 is minimized.

[0034] The synthesis gas enters the pre-conversion furnace 31, and a conversion reaction occurs in this section. The synthesis gas absorbs the heat released by the conversion reaction, causing the temperature to rise and become superheated synthesis gas. In the early stage of the device operation, due to the good activity and high efficiency of the catalyst, the synthesis gas temperature can be increased by 60°C. However, if the superheat is too high, the pipeline design temperature will increase and heat will be wasted. Taking all factors into consideration, superheating the synthesis temperature transported to the conversion furnace by 10 to 30°C can avoid the precipitation of condensed water during transportation, which is more conducive to achieving the purpose of energy saving. Therefore, a bypass pipe 33 is also provided on the outside of the pre-conversion furnace 31. One end of the bypass pipe 33 is connected to the air inlet pipe 311, and the other end is connected to the air outlet pipe 312. A regulating valve 34 is installed on the bypass pipe 33. During the initial operation, the regulating valve 34 of the bypass pipe 33 can be opened, allowing a portion of the syngas to undergo a shift reaction in the pre-conversion furnace 31, raising its temperature. The remaining portion of the syngas, after passing through the bypass pipe 33, mixes with the superheated syngas exiting the pre-conversion furnace 31. The ratio of the two syngas streams can be adjusted by adjusting the opening of the regulating valve 34 on the bypass pipe 33. The opening of the regulating valve 34 is determined by ensuring that the temperature of the mixed syngas streams is 10-30°C higher than the syngas exiting the tower body 1. As the operation time of the device increases, the catalyst activity in the pre-conversion furnace 31 decreases. The regulating valve 34 of the bypass pipe 33 can be closed to ensure that the syngas entering the shift section is superheated by 10-30°C. Because the syngas temperature is higher than the saturation temperature at the operating pressure, liquid water condensation will not occur, thus avoiding pipeline corrosion and reducing the need for equipment such as separation tanks, detoxification tanks, and syngas heaters. The syngas can be directly delivered to the shift furnace in the shift section.

[0035] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A synthesis gas pretreatment tower, characterized in that: The synthesis gas pretreatment tower comprises: A tower body (1) is provided with a synthesis gas inlet channel (11) at the bottom thereof for connecting to an external gasification furnace so as to allow crude synthesis gas to enter the tower body (1); a top portion of the tower body (1) is provided with a synthesis gas outlet channel (12) for connecting to an external shift furnace so as to allow treated synthesis gas to be discharged outside the tower body (1); A processing device (2) comprises a water bath section (21), a distributor section (22), a tray section (23) and a demister section (24) installed in a tower body (1) from bottom to top; the synthesis gas inlet channel (11) is arranged between the water bath section (21) and the distributor section (22); cooling water is contained in the water bath section (21); the gas outlet end of the synthesis gas inlet channel (11) is inserted into the cooling water in the water bath section (21), so that the crude synthesis gas passes through the water bath section (21), the distributor section (22), the tray section (23) and the demister section (24) in sequence to obtain the treated synthesis gas; the tray section (23) is provided with at least one section, and multiple tray sections (23) are distributed from bottom to top, for washing the synthesis gas and performing gas-liquid separation; A conversion device (3) is provided for collecting treated synthesis gas, causing the treated synthesis gas to absorb heat to form superheated synthesis gas, and transporting the superheated synthesis gas to a conversion furnace, wherein a catalyst is provided in the conversion device (3) for catalyzing a conversion reaction between CO and H2O in the synthesis gas and releasing heat; the conversion device (3) is a filler plate provided with a catalyst, which is installed inside the tower body (1) and is arranged between the synthesis gas outlet channel (12) and the demister section (24); The water bath section (21) is a box component installed inside the tower body (1) and with an open top. The outlet end of the synthesis gas inlet channel (11) is inserted into the cooling water of the water bath section (21) for removing fine slag in the crude synthesis gas and cooling it. A gray water outlet channel (13) extending to the outside of the tower body (1) is installed on the side wall of the water bath section (21) for external connection to a gasifier to wash the crude synthesis gas to obtain relatively clear gray water for circulation to the gasifier. A black water outlet channel (14) extending to the outside of the tower body (1) is installed at the bottom of the water bath section (21) for external connection to a flash evaporation system to discharge black water containing fine slag from the bottom of the water bath section (21) to the flash evaporation system to achieve slag-water separation.

2. A synthesis gas pretreatment tower according to claim 1, characterized in that: The bottom of the water bath section (21) is a funnel-shaped structure for discharging fine slag, and the inlet end of the black water outlet channel (14) is connected to the conical bottom of the water bath section (21).

3. The synthesis gas pretreatment tower according to claim 1, characterized in that: Cooling water inlet channels (15) are installed on the tower wall above the distributor section (22) and the tray section (23) for connecting external equipment. After cooling water enters the tower body (1), it is sprayed from top to bottom to cool and remove dust from the synthesis gas.

4. The synthesis gas pretreatment tower according to claim 1, characterized in that: The gas outlet end of the synthesis gas inlet channel (11) is serrated and is used for breaking foam.

5. The synthesis gas pretreatment tower according to claim 1, characterized in that: The conversion device (3) comprises a pre-conversion furnace (31) and a reaction plate (32) arranged in the pre-conversion furnace (31); an air inlet pipe (311) is installed at the bottom of the pre-conversion furnace (31) for externally connecting to a synthesis gas outlet channel (12) of a tower body (1); and an air outlet pipe (312) is installed at the top of the pre-conversion furnace (31) for externally connecting to the conversion furnace.

6. The synthesis gas pretreatment tower according to claim 5, characterized in that: A bypass pipe (33) is provided outside the pre-transformer furnace (31), one end of the bypass pipe (33) is connected to the air inlet pipe (311), and the other end is connected to the air outlet pipe (312), and a regulating valve (34) is installed on the bypass pipe (33).

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