Coke oven gas desulfurization system

Abstract

The coke oven gas desulfurization system comprises a primary desulfurization tower and a regeneration tower, the first-stage desulfurization tower is filled with filler, and a desulfurization liquid spraying device is arranged at the upper part in the first-stage desulfurization tower; the height of the regeneration tower is lower than that of the primary desulfurization tower, a gas-liquid separator for collecting barren liquor is arranged in the regeneration tower, a sulfur foam outlet is formed in the top of the regeneration tower, and a premixing nozzle for mixing compressed air and rich liquor is arranged at the bottom of the regeneration tower; the pre-mixing nozzle is vertically arranged at the bottom of the regeneration tower, the pre-mixing nozzle is provided with a pre-mixing cavity which is vertically arranged, the pre-mixing cavity upwards extends to the upper end face of the pre-mixing nozzle so as to form an upward spraying opening, the pre-mixing nozzle is further provided with a compressed air inlet and a rich liquid inlet, and the compressed air inlet and the rich liquid inlet are both communicated with the pre-mixing cavity; the system further comprises a barren liquor pump, and the barren liquor pump is connected with the gas-liquid separators and the desulfurization liquid spraying device through pipelines, so that barren liquor collected by the low-position gas-liquid separator is conveyed to the high-position desulfurization liquid spraying device.

Description

TECHNICAL FIELD

[0001] The utility model relates to a coke oven gas desulfurization system. BACKGROUND

[0002] In the coking process, about 30%-35% of sulfur in coal is converted into hydrogen sulfide and other sulfides, and the rest of the sulfur enters the coke. Hydrogen sulfide, together with ammonia and hydrogen cyanide, forms impurities in the coal gas. Their presence not only seriously endangers people's health and corrodes equipment, but also pollutes the environment; if used as synthesis gas, it will also cause poisoning of the catalyst; at the same time, various industrial furnaces and flame cutters have certain requirements for the sulfur content in coke oven gas, so coke oven gas must be desulfurized and dehydrocyanated before use. Whether coke oven gas is used as fuel or as a production raw material, it needs to be purified before use to remove H2S in the coal gas to meet environmental protection and production requirements.

[0003] The most widely used method for industrial coke oven gas desulfurization and dehydrocyanation at present is the wet oxidation method. Most coking plants in China generally use HPF desulfurization and dehydrocyanation process. HPF method is a desulfurization process developed domestically. Because this method has the characteristics of simple equipment, stable operation, high desulfurization efficiency, short process, low one-time investment, and low running cost, it has been widely applied in many coking enterprises. Most domestic manufacturers use a three-stage desulfurization process. The hydrogen sulfide index after the first-stage desulfurization tower is about 800 mg / Nm³, the hydrogen sulfide index after the second-stage desulfurization tower is below 50 mg / Nm³, and the hydrogen sulfide index after the third-stage desulfurization tower is below 20 mg / Nm³.

[0004] The desulfurization liquid can be reused after regeneration in the regeneration tower. The rich liquid at the bottom of the first-stage desulfurization tower is sent to the regeneration tower, where it is oxidized and regenerated under the catalytic action of catalyst HPF by contacting with compressed air. In the existing coke oven gas desulfurization system, a large amount of regeneration air is required for regeneration, and the height of the regeneration tower is higher than or equal to the height of the first-stage desulfurization tower. The temperature of the poor liquid for regeneration is relatively high, which affects the desulfurization effect in the first-stage desulfurization tower. SUMMARY

[0005] In order to overcome the above-mentioned shortcomings of the existing coke oven gas desulfurization system, the utility model provides a coke oven gas desulfurization system with smaller regeneration air consumption and better desulfurization effect.

[0006] The technical solution for solving the technical problems of the utility model is: a coke oven gas desulfurization system, comprising a first-stage desulfurization tower and a regeneration tower.

[0007] The first-stage desulfurization tower is filled with packing. The lower part of the first-stage desulfurization tower is provided with a gas inlet. The upper part of the first-stage desulfurization tower is provided with a desulfurization liquid spraying device. The top of the first-stage desulfurization tower is provided with a gas outlet. The bottom of the first-stage desulfurization tower is provided with a rich liquid outlet.

[0008] The height of the regeneration tower is lower than that of the primary desulfurization tower, a gas-liquid separator for collecting lean liquid is arranged in the regeneration tower, and the top of the regeneration tower is provided with a sulfur foam outlet, characterized in that a premixing nozzle for mixing compressed air and rich liquid is arranged at the bottom of the regeneration tower.

[0009] The premixing nozzle is vertically arranged at the bottom of the regeneration tower, the premixing nozzle is provided with a premixing cavity arranged vertically, the premixing cavity extends upward to the upper end surface of the premixing nozzle to form an upwardly directed spray outlet, the premixing nozzle is further provided with a compressed air inlet and a rich liquid inlet, the compressed air inlet and the rich liquid inlet are both in communication with the premixing cavity, the compressed air inlet is connected with an air compressor, and the rich liquid inlet is connected with a rich liquid outlet at the bottom of the primary desulfurization tower.

[0010] Further, the premixing cavity extends downward to the lower end surface of the premixing nozzle to form the rich liquid inlet.

[0011] Further, the premixing nozzle is provided with an inclined channel inclined downward from top to bottom and outward in communication with the premixing cavity, the inclined channel is further provided with an air inlet channel arranged transversely and in communication therewith, and the end of the air inlet channel forms the compressed air inlet.

[0012] Further, the end of the inclined channel forms a steam inlet.

[0013] Further, the end of the inclined channel forms a steam inlet.

[0014] Further, the premixing nozzle is provided with a support frame, and the inclined channel is supported on the support frame.

[0015] Further, the support frame comprises a support rod arranged on the premixing nozzle, and the end of the support rod is provided with a support sleeve, and the inclined channel is supported in the support sleeve.

[0016] Further, the premixing nozzle comprises an upper section, a middle section and a lower section from top to bottom, the diameter of the lower section is greater than that of the upper section, the upper section and the lower section are connected through the middle section, the side wall of the middle section is inclined, and the inclined channel is in communication with the premixing cavity at the middle section.

[0017] Further, a sulfur foam tank capable of receiving sulfur foam flowing out of the sulfur foam outlet is further included.

[0018] Further, a cooler is arranged on the pipeline between the lean liquid pump and the desulfurization liquid spraying device, and / or on the pipeline between the lean liquid pump and the gas-liquid separator.

[0019] Further, the system further comprises a secondary desulfurization tower and / or a tertiary desulfurization tower, wherein the gas inlet of the secondary desulfurization tower is connected with the gas outlet of the primary desulfurization tower, and the gas inlet of the tertiary desulfurization tower is connected with the gas outlet of the secondary desulfurization tower.

[0020] The beneficial effects of the present application are that the premixing nozzle is arranged in the regeneration tower, the rich liquid and compressed air are premixed by the high-efficiency premixing nozzle and then sprayed out, the amount of the regeneration air is only 45% of that of the traditional regeneration tower, meanwhile, the oxygen content in the regeneration air is controlled below 15% (Vol), which can be directly returned to the coal gas, and the operation environment is friendly.

[0021] The regeneration tower is located at a low position, and the temperature of the desulfurization liquid after being sprayed by the lean liquid pump is greatly reduced, which is beneficial to improving the desulfurization effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic view of the present application.

[0023] Figure 2 is a structural schematic view of the regeneration tower.

[0024] Figure 3 is a structural schematic view of the premixing nozzle. DETAILED DESCRIPTION

[0025] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0026] Referring to Figure 1 , Figure 2 , Figure 3 , a coke oven gas desulfurization system comprises a primary desulfurization tower 11 and a regeneration tower 1.

[0027] The primary desulfurization tower 11 is filled with a filler, the lower part of the primary desulfurization tower 11 is provided with a gas inlet, the upper part of the primary desulfurization tower 11 is provided with a desulfurization liquid spraying device 12, the top of the primary desulfurization tower 11 is provided with a gas outlet, and the bottom of the primary desulfurization tower 11 is provided with a rich liquid outlet.

[0028] The height of the regeneration tower 1 is lower than that of the primary desulfurization tower 11, the regeneration tower 1 is provided with a gas-liquid separator 13 for collecting lean liquid, the top of the regeneration tower 1 is provided with a sulfur foam outlet, and the bottom of the regeneration tower 1 is provided with a premixing nozzle 2 for mixing compressed air and rich liquid.

[0029] A lean liquid pump 14 is also included, which is connected to the gas-liquid separator 13 and the desulfurization liquid spraying device 12 respectively through pipelines, so as to transport the lean liquid collected by the low-positioned gas-liquid separator 13 to the high-positioned desulfurization liquid spraying device 12. The gas-liquid separator 13 is a mature technology in the prior art, and thus will not be described here.

[0030] The coke oven gas to be treated is first introduced into the lower part of the primary desulfurization tower 11 through a gas inlet, and is in countercurrent contact with the lean liquid sprayed by the desulfurization liquid spraying device 12 at the top of the tower, so that the H2S and HCN in the gas are absorbed, and NH3 is also partially absorbed. The rich liquid at the bottom of the tower is sent to the bottom of the regeneration tower through a rich liquid outlet, mixed with compressed air after passing through a premixing nozzle 2 at the bottom of the regeneration tower, and then introduced into the regeneration tower, where the rich liquid is oxidized and regenerated under the action of a catalyst. After regeneration, the lean liquid is collected by a gas-liquid separator 13, and is pumped to the top of the primary desulfurization tower 11 by a lean liquid pump 14 for recycling and spraying. The regenerated lean liquid is sucked and sent back to the desulfurization liquid spraying device 12, and the temperature of the lean liquid has been greatly reduced, which is beneficial to improving the desulfurization effect. The elemental sulfur generated by oxidation in the regeneration tower is floated to the top of the tower by air to form a sulfur foam.

[0031] In one embodiment, a cooler 15 is arranged on the pipeline between the lean liquid pump 14 and the desulfurization liquid spraying device 12, and / or on the pipeline between the lean liquid pump 14 and the gas-liquid separator 13. The regenerated lean liquid is cooled by the cooler 15 before being pumped back to the desulfurization liquid spraying device 12, which is beneficial to further cooling of the regenerated lean liquid. The cooler 15 can be a water cooler.

[0032] In one embodiment, the coke oven gas desulfurization system further includes a sulfur foam tank 16 capable of receiving the sulfur foam flowing out of the sulfur foam outlet. The elemental sulfur generated by oxidation in the regeneration tower 1 is floated to the top of the tower by air to form a sulfur foam, and then flows into the sulfur foam tank 16 for collection.

[0033] The premixing nozzle 2 is vertically arranged at the bottom of the regeneration tower 1, and has a premixing cavity vertically arranged therein. The premixing cavity extends upward to the upper end face of the premixing nozzle 2 to form an upwardly directed spray outlet 3. The premixing nozzle 2 is further provided with a compressed air inlet 4 and a rich liquid inlet 5, and the compressed air inlet 4 and the rich liquid inlet 5 are both in communication with the premixing cavity. The compressed air inlet is connected to an air compressor, which can be a conventional air compressor or a blower, as long as it can provide compressed air. The rich liquid inlet is connected to a rich liquid outlet at the bottom of the primary desulfurization tower 11. In one embodiment, the premixing cavity extends downward to the lower end face of the premixing nozzle 2 to form the rich liquid inlet 5, which is more convenient for the rich liquid at the bottom of the previous desulfurization tower to enter the premixing nozzle. Of course, the rich liquid inlet 5 can also be separately arranged on the side wall of the premixing nozzle 2.

[0034] The utility model discloses a premixing nozzle 2 is arranged in the regenerating tower, and the premixing nozzle 2 is used to spray out after pre-mixing of rich liquid and compressed air, and the air consumption of regeneration is only 45% of traditional regenerating tower, simultaneously, the oxygen content in the air of regeneration is controlled below 15% (Vol), can be directly back to the allocation in the coal gas, and the operation environment is friendly.

[0035] In one embodiment, the compressed air inlet 4 and the rich liquid inlet 5 are not in a straight line, so that the compressed air entering from the compressed air inlet 4 can be better mixed with the rich liquid entering from the rich liquid inlet 5.

[0036] In one embodiment, the compressed air inlet 4 is specifically provided in the following manner: the premixing nozzle 2 is provided with an inclined channel 6 inclined from top to bottom and outward, which communicates with the premixing cavity; the inclined channel 6 is further provided with an air inlet channel 7 transversely arranged and communicating with the inclined channel 6; and the end of the air inlet channel 7 forms the compressed air inlet 4, which can form a better mixing effect of compressed air and rich liquid.

[0037] In one embodiment, the premixing nozzle 2 is provided with a support frame, and the inclined channel 6 is supported on the support frame, so that the inclined channel 6 is more stable. The support frame can have the following specific structure: the support frame includes a support rod 8 arranged on the premixing nozzle 2, and the end of the support rod 8 is provided with a support sleeve 9, and the inclined channel 6 is supported in the support sleeve 9.

[0038] In one embodiment, the end of the inclined channel 6 forms a steam inlet 10, which can be used to pass steam into the inclined channel to dredge when the pipeline is blocked.

[0039] In one embodiment, the premixing nozzle 2 has an upper section 2-1, a middle section 2-2 and a lower section 2-3 from top to bottom, the diameter of the lower section 2-3 is greater than that of the upper section 2-1, the upper section 2-1 and the lower section 2-3 are connected through the middle section 2-2, the side wall of the middle section 2-2 is inclined, the inclined channel communicates with the premixing cavity at the middle section 2-2, and the variable-diameter structure can achieve better mixing of compressed air and rich liquid.

[0040] Of course, the coke oven gas desulfurization system of the utility model can further include more desulfurization towers, and generally at most three desulfurization towers, i.e., a secondary desulfurization tower and a tertiary desulfurization tower are further included, the gas inlet of the secondary desulfurization tower is connected with the gas outlet of the primary desulfurization tower, and the gas inlet of the tertiary desulfurization tower is connected with the gas outlet of the secondary desulfurization tower.

[0041] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0042] The embodiments of the present application have been described above. However, the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. A coke oven gas desulfurization system comprising a primary desulfurization tower, a regeneration tower; the primary desulfurization tower is filled with packing, the lower part of the primary desulfurization tower is provided with a gas inlet, the upper part of the primary desulfurization tower is provided with a desulfurization liquid spraying device, the top of the primary desulfurization tower is provided with a gas outlet, and the bottom of the primary desulfurization tower is provided with a rich liquid outlet; The height of the regeneration tower is lower than that of the primary desulfurization tower, a gas-liquid separator for collecting lean liquid is arranged in the regeneration tower, and the top of the regeneration tower is provided with a sulfur foam outlet. the bottom of the regeneration tower is provided with a premixing nozzle for mixing compressed air and rich liquid; the premixing nozzle is vertically arranged at the bottom of the regeneration tower, the premixing nozzle has a premixing cavity arranged vertically, the premixing cavity extends upward to the upper end face of the premixing nozzle to form an upwardly directed spray outlet, the premixing nozzle is further provided with a compressed air inlet and a rich liquid inlet, the compressed air inlet and the rich liquid inlet are in communication with the premixing cavity, the compressed air inlet is connected with an air compressor, and the rich liquid inlet is connected with the rich liquid outlet at the bottom of the primary desulfurization tower; a lean liquid pump is further included, the lean liquid pump is connected with the gas-liquid separator and the desulfurization liquid spraying device through pipelines respectively, so that the lean liquid collected by the low-positioned gas-liquid separator is delivered to the high-positioned desulfurization liquid spraying device.

2. The coke oven gas desulphurization system as claimed in claim 1, wherein: the premixing cavity extends downward to the lower end face of the premixing nozzle to form the rich liquid inlet.

3. The coke oven gas desulfurization system as claimed in claim 2, wherein: the premixing nozzle is provided with an inclined channel inclined outward from top to bottom in communication with the premixing cavity, the inclined channel is further provided with an air inlet channel arranged transversely in communication therewith, and the end of the air inlet channel forms the compressed air inlet.

4. The coke oven gas desulfurization system as claimed in claim 3, wherein: the end of the inclined channel forms a steam inlet.

5. The coke oven gas desulfurization system as claimed in claim 3, wherein: the premixing nozzle is provided with a support frame, and the inclined channel is supported on the support frame.

6. The coke oven gas desulfurization system as claimed in claim 5, wherein: the support frame comprises a support rod arranged on the premixing nozzle, and the end of the support rod is provided with a support sleeve, and the inclined channel is supported in the support sleeve.

7. The coke oven gas desulphurization system as claimed in claim 3 wherein: the premixing nozzle comprises an upper segment, a middle segment and a lower segment from top to bottom, the diameter of the lower segment is greater than that of the upper segment, the upper segment and the lower segment are connected through the middle segment, and the sidewall of the middle segment is inclined. the inclined channel is in communication with the premixing cavity at the middle segment.

8. The coke oven gas desulphurization system as claimed in any one of claims 1 to 7, wherein: a sulfur foam tank capable of receiving sulfur foam flowing out of the sulfur foam outlet is further included.

9. The coke oven gas desulphurization system as claimed in any one of claims 1 to 7, wherein: coolers are arranged on the pipelines between the lean liquid pump and the desulfurization liquid spraying device, and / or on the pipelines between the lean liquid pump and the gas-liquid separator.

10. The coke oven gas desulphurization system as claimed in any one of claims 1 to 7, wherein: a secondary desulfurization tower and / or a tertiary desulfurization tower are further included, the gas inlet of the secondary desulfurization tower is connected with the gas outlet of the primary desulfurization tower, and the gas inlet of the tertiary desulfurization tower is connected with the gas outlet of the secondary desulfurization tower.

Images