Low-pressure separated gas recovery system of coal tar hydrogenation device for chemical industry

Abstract

The utility model relates to the technical field of chemical engineering, and discloses a low-pressure separated gas recovery system of a coal tar hydrogenation device for chemical engineering. The system comprises a liquid-phase hydrogenation cold low-pressure separation tank, a hydrofining cold low-pressure separation tank, a hydrofining cold high-pressure separation tank, a low-pressure separation gas desulfurization tower and the like. The upper part of the desulfurization tower is connected with a desulfurization barren liquor solvent pump, and the bottom of the desulfurization tower is connected with a desulfurization pregnant solution desorption regeneration system and is connected with the desulfurization barren liquor solvent pump and the desulfurization pregnant solution desorption regeneration system. The top of the desulfurization tower is connected with a low-pressure gas vapor-liquid separator, and is subsequently connected with a series of equipment such as a low-pressure gas hydrogen extraction adsorption tower. According to the system, sulfides in low-pressure gas are removed by using a desulfurization barren solution, and a desulfurization pregnant solution is subjected to desorption regeneration and then is recycled. The desulfurized low-pressure separated gas is subjected to the steps of gas-liquid separation, hydrogen extraction adsorption and the like, and the purity of gas hydrogen at the outlet of the top of the hydrogen extraction adsorption tower can be controlled to be greater than 95%, so that the effective utilization of energy is realized, the coal tar hydrogenation and hydrogen cost is reduced, the energy waste, environmental pollution and potential safety hazards are reduced, the ecological environment is improved, and the production safety is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a chemical industry field, especially a coal tar hydrogenation device low fraction gas recovery system for chemical industry. BACKGROUND

[0002] The low fraction gas generated in coal tar processing contains valuable chemical substances such as hydrogen and methane, but also contains harmful substances such as sulfides. The traditional treatment method is limited to simple combustion or venting, and its potential value is not fully utilized. SUMMARY

[0003] In view of the above technical problems, the utility model provides a coal tar hydrogenation device low fraction gas recovery system for chemical industry for solving the problem that the low fraction gas generated in coal tar processing is simply combusted or vented, and its potential value is not fully utilized.

[0004] In order to realize the above purpose, the technical scheme of the utility model is as follows:

[0005] A coal tar hydrogenation device low fraction gas recovery system for chemical industry, comprising a liquid-phase hydrogenation cold low fraction tank, a hydrogenation refining cold low fraction tank and a hydrogenation refining cold high fraction tank, further comprising a low fraction gas desulfurization tower, the output pipelines of the liquid-phase hydrogenation cold low fraction tank, the hydrogenation refining cold low fraction tank and the hydrogenation refining cold high fraction tank are connected to the lower part of the low fraction gas desulfurization tower after being converged, the upper part of the low fraction gas desulfurization tower is connected with a desulfurization lean liquid solvent pump, the bottom of the low fraction gas desulfurization tower is connected with a desulfurization rich liquid resolution regeneration system, and the desulfurization rich liquid resolution regeneration system is connected with the desulfurization lean liquid solvent pump.

[0006] Further, the top of the low fraction gas desulfurization tower is connected with a low fraction gas vapor-liquid separator, the low fraction gas vapor-liquid separator is connected with a low fraction gas hydrogen extraction adsorption tower through a low fraction gas adsorption inlet adsorption program control valve, the top of the low fraction gas hydrogen extraction adsorption tower is connected with a low fraction gas hydrogen extraction output pipeline, a hydrogen-rich gas output pipeline is connected to the low fraction gas hydrogen extraction output pipeline, and a low fraction gas adsorption outlet adsorption program control valve and a hydrogen-rich gas outlet valve are sequentially installed on the hydrogen-rich gas output pipeline, and a hydrogen-rich gas hydrogen extraction adsorption tower is connected after the hydrogen-rich gas outlet valve.

[0007] Further, the low fraction gas hydrogen extraction output pipeline is further connected with a lifting pipeline, a lifting program control valve and a lifting control valve are sequentially installed on the lifting pipeline, and a low fraction gas buffer tank is connected after the lifting control valve, and the low fraction gas buffer tank is connected with a benzene removal and desulfurization adsorption tower through a purging pipeline.

[0008] Further, the low fraction gas hydrogen extraction output pipeline is further connected with a purging gas pipeline, a purging gas program control valve and a purging gas control valve are sequentially installed on the purging gas pipeline, and a hydrogen-rich gas hydrogen extraction adsorption unit purging gas buffer tank is connected after the purging gas control valve.

[0009] Further, the low fraction gas desorption gas buffer tank is connected with the low fraction gas desorption gas tank outlet valve and the coal gas compressor, and the coal gas compressor is connected with the coal gas purification device through the coal compressor outlet valve.

[0010] Further, the pressure regulating valve is installed on the output pipeline of the liquid phase hydrogenation cold low fraction tank and the hydrogenation refining cold low fraction tank, and the pressure reducing valve is installed on the output pipeline of the hydrogenation refining high fraction tank.

[0011] Further, the desulfurization lean liquid solvent pump outlet regulating valve is installed between the desulfurization lean liquid solvent pump and the low fraction gas desulfurization tower.

[0012] Further, the low fraction gas desulfurization tower top regulating valve is installed between the low fraction gas desulfurization tower and the low fraction gas vapor-liquid separator.

[0013] Further, the liquid level regulating valve is installed between the low fraction gas desulfurization tower and the desulfurization rich liquid desorption regeneration system.

[0014] Compared with the prior art, the low fraction gas desulfurization tower is provided, the sulfides in the low fraction gas are removed by the desulfurization lean liquid, the desulfurization rich liquid passes through the desulfurization liquid desorption regeneration system, the generated desulfurization lean liquid is sent into the low fraction gas desulfurization tower by the desulfurization lean liquid solvent pump, and desulfurization is performed again, and the desulfurization liquid can be recycled. The low fraction gas desulfurization tower is provided, the sulfides in the low fraction gas are removed by the desulfurization lean liquid, the desulfurization rich liquid passes through the desulfurization liquid desorption regeneration system, the generated desulfurization lean liquid is sent into the low fraction gas desulfurization tower by the desulfurization lean liquid solvent pump, and desulfurization is performed again, and the desulfurization liquid can be recycled. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural schematic view of the utility model;

[0016] In the drawing:

[0017] 1, liquid phase hydrogenation cold low tank; 2, pressure regulating valve; 3, hydrogenation refining cold low tank; 5, hydrogenation refining cold high tank; 6, pressure reducing valve; 7, desulfurization lean liquid solvent pump; 8, desulfurization lean liquid solvent pump outlet regulating valve; 9, low gas desulfurization tower; 10, tray; 11, liquid level regulating valve; 12, desulfurization rich liquid desorption regeneration system; 13, low gas desulfurization tower top regulating valve; 14, low gas vapor-liquid separator; 15, reverse blowdown program control valve; 16, low gas desorption gas buffer tank; 17, low gas desorption gas tank outlet valve; 18, coal gas compressor; 19, coal compressor outlet valve; 20, coal gas purification device; 22, low gas adsorption inlet adsorption program control valve; 23, low gas hydrogen extraction adsorption tower; 24, low gas hydrogen extraction adsorption tower adsorbent; 25, low gas hydrogen extraction output pipeline; 26, purge gas program control valve; 27, purge gas pipeline; 28, purge gas control valve; 29, hydrogen-rich gas hydrogen extraction adsorption unit purge gas buffer tank; 30, lifting program control valve; 31, lifting pipeline; 32, lifting control valve; 33, low gas buffer tank; 34, purge pipeline; 35, benzene and sulfur removal adsorption tower purge control valve; 36, benzene and sulfur removal adsorption tower; 37, low gas adsorption outlet adsorption program control valve; 38, hydrogen-rich gas output pipeline; 39, hydrogen-rich gas outlet valve; 40, hydrogen-rich gas hydrogen extraction adsorption tower. DETAILED DESCRIPTION

[0018] To make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is explained in further detail below in combination with specific implementation manners and with reference to the drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0019] A low gas recovery system of a coal tar hydrogenation device for chemical industry, comprising a liquid phase hydrogenation cold low tank 1, a hydrogenation refining cold low tank 3 and a hydrogenation refining cold high tank 5, further comprising a low gas desulfurization tower 9, the output pipelines of the liquid phase hydrogenation cold low tank 1, the hydrogenation refining cold low tank 3 and the hydrogenation refining cold high tank 5 are connected to the lower part of the low gas desulfurization tower 9 after being converged, the upper part of the low gas desulfurization tower 9 is connected with a desulfurization lean liquid solvent pump 7, the bottom of the low gas desulfurization tower 9 is connected with a desulfurization rich liquid desorption regeneration system 12, and the desulfurization rich liquid desorption regeneration system 12 is connected with the desulfurization lean liquid solvent pump 7.

[0020] The top of the low-gas desulfurization tower 9 is connected with a low-gas vapor-liquid separator 14, the low-gas vapor-liquid separator 14 is connected with a low-gas hydrogen extraction adsorption tower 23 through a low-gas adsorption inlet adsorption program control valve 22, the top of the low-gas hydrogen extraction adsorption tower 23 is connected with a low-gas hydrogen extraction output pipeline 25, the low-gas hydrogen extraction output pipeline 25 is connected with a hydrogen-rich gas output pipeline 38, the hydrogen-rich gas output pipeline 38 is connected with a hydrogen-rich gas hydrogen extraction adsorption tower 40 after being sequentially installed with a low-gas adsorption outlet adsorption program control valve 37 and a hydrogen-rich gas outlet valve 39.

[0021] The low-gas hydrogen extraction output pipeline 25 is also connected with a lifting pipeline 31, the lifting pipeline 31 is connected with a low-gas buffer tank 33 after being sequentially installed with a lifting program control valve 30 and a lifting control valve 32.

[0022] The low-gas hydrogen extraction output pipeline 25 is also connected with a purge gas pipeline 27, the purge gas pipeline 27 is connected with a hydrogen-rich gas hydrogen extraction adsorption unit purge gas buffer tank 29 after being sequentially installed with a purge gas program control valve 26 and a purge gas control valve 28.

[0023] The bottom of the low-gas hydrogen extraction adsorption tower 23 is connected with a low-gas desorption gas buffer tank 16 through a reverse discharge program control valve 15, the low-gas desorption gas buffer tank 16 is connected with a coal gas compressor 18 through a low-gas desorption gas tank outlet valve 17, the coal gas compressor 18 is connected with a coal gas purification device 20 through a coal compressor outlet valve 19.

[0024] The output pipelines of the liquid-phase hydrogenation cold low-temperature tank 1 and the hydrogenation refining cold low-temperature tank 3 are both installed with pressure regulating valves 2, and the output pipeline of the hydrogenation refining cold high-temperature tank 5 is installed with a pressure reducing valve 6.

[0025] A desulfurization lean liquid solvent pump outlet regulating valve 8 is installed between the desulfurization lean liquid solvent pump 7 and the low-gas desulfurization tower 9.

[0026] A low-gas desulfurization tower top regulating valve 13 is installed between the low-gas desulfurization tower 9 and the low-gas vapor-liquid separator 14.

[0027] A liquid level regulating valve 11 is installed between the low-gas desulfurization tower 9 and the desulfurization rich liquid desorption regeneration system 12.

[0028] The utility model discloses a hydrogenation process, which comprises a liquid-phase hydrogenation cold low-temperature separation tank 1, a hydrogenation refining cold low-temperature separation tank 3, a hydrogenation refining cold high-temperature separation tank 5, a low-temperature separation gas desulfurization tower 9, a desulfurization lean liquid solvent pump 7, a desulfurization rich liquid resolution and regeneration system 12, a low-temperature separation gas hydrogenation adsorption tower 23, a low-temperature separation gas hydrogenation adsorption tower adsorbent 24, a hydrogen-rich gas hydrogenation adsorption tower 40, a low-temperature separation gas desulfurization tower top adjusting valve 13, a low-temperature separation gas hydrogenation adsorption inlet adsorption program control valve 22 and a hydrogen-rich gas hydrogenation adsorption outlet adsorption program control valve 37.

[0029] The solvent that has absorbed H2S, i.e., the rich liquid solvent, is discharged from the desulfurization tower bottom liquid level adjusting valve 11 and enters the desulfurization rich liquid resolution and regeneration system 12 for resolution and regeneration, becoming the desulfurization lean liquid solvent, which can be sent again into the low-temperature separation gas desulfurization tower 9 by the desulfurization lean liquid solvent pump 7 to remove H2S, achieving the purpose of recycling.

[0030] The low-temperature separation gas from which H2S has been removed is discharged from the top of the low-temperature separation gas desulfurization tower 9 and sent into a low-temperature separation gas vapor-liquid separator 14 of a hydrogen production device through a low-temperature separation gas desulfurization tower top adjusting valve 13 to remove moisture in the low-temperature separation gas, enters a low-temperature separation gas hydrogenation adsorption tower 23 through a low-temperature separation gas hydrogenation adsorption inlet adsorption program control valve 22, removes impurities such as methane and ethane in the low-temperature separation gas through the low-temperature separation gas hydrogenation adsorption tower adsorbent 24 in the low-temperature separation gas hydrogenation adsorption tower 23, controls the purity of hydrogen in the outlet gas at the top of the hydrogenation adsorption tower 23 to be greater than 95%, and finally sends the hydrogen-rich gas to a rear-end hydrogen-rich gas hydrogenation adsorption tower 40.

[0031] The hydrogen-rich gas hydrogenation adsorption tower 40 adopts the principle of high-pressure adsorption and low-pressure desorption, and a three-tower adsorption and twice-pressure equalization purging process, i.e., one adsorption tower is in a high-pressure adsorption state, two adsorption towers are in a low-pressure desorption state, the low-temperature separation gas enters the low-temperature separation gas hydrogenation adsorption tower 23 through the low-temperature separation gas hydrogenation adsorption inlet adsorption program control valve 22, passes through the low-temperature separation gas hydrogenation adsorption outlet adsorption program control valve 37, the hydrogen-rich gas output pipeline 38 and the hydrogen-rich gas outlet valve 39, and is sent into the hydrogen-rich gas hydrogenation adsorption tower 40 at the rear end of the hydrogenation tower.

[0032] After the adsorption step sequence of the low-gas hydrogen extraction adsorption tower 23 is stopped, a uniform pressure reduction step sequence is started, the pressure is reduced through the lifting and lowering program control valve 30, the lifting and lowering pipeline 31 and the lifting and lowering control valve 32, the low-gas is sent into the low-gas buffer tank 33 for buffering, finally the gas is sent into the benzole and sulfur removal unit through the purge pipeline 34 and the benzole and sulfur removal adsorption tower purge control valve 35, the benzole and sulfur removal adsorption tower 36 is purged and desorbed. After the uniform pressure reduction step sequence of the low-gas hydrogen extraction adsorption tower 23 is stopped, a reverse pressure reduction step sequence is started, the reverse gas is sent into the low-gas desorption gas buffer tank 16 through the reverse discharge program control valve 15, the low-gas desorption gas enters the coal gas compressor 18 for pressurization to 0.43Mpa through the low-gas desorption gas tank outlet valve 17, and finally is sent into the coal gas purification device 20 as hydrogen production raw material.

[0033] After the reverse pressure reduction step sequence of the low-gas hydrogen extraction adsorption tower 23 is stopped, a purge step sequence is started, the desorption gas of the hydrogen extraction adsorption unit purge gas buffer tank 29 enters the low-gas hydrogen extraction adsorption tower 23 from the top for purging and desorption through the purge gas control valve 28, the purge gas pipeline 27 and the purge gas program control valve 26, the desorption gas is the same as that in the reverse pressure reduction step sequence, is pressurized to 0.43Mpa through the coal gas compressor 18 and is sent into the coal gas purification device 20 as hydrogen production raw material.

[0034] After the purge step sequence of the low-gas hydrogen extraction adsorption tower 23 is stopped, a uniform pressure increase step sequence is started, the pressure is increased through the lifting and lowering program control valve 30, the lifting and lowering pipeline 31 and the lifting and lowering control valve 32 by using the tank body pressure in the low-gas buffer tank 33, and the pressure of the low-gas hydrogen extraction adsorption tower 23 is increased to be close to the tank body pressure in the low-gas buffer tank 33.

[0035] After the uniform pressure increase step sequence of the low-gas hydrogen extraction adsorption tower 23 is stopped, the low-gas hydrogen extraction adsorption tower 23 in the adsorption state enters the low-gas hydrogen extraction adsorption tower 23 in which the uniform pressure increase step sequence is completed through the low-gas adsorption outlet adsorption program control valve 37 for final pressure increase, the low-gas hydrogen extraction adsorption tower 23 is increased to 2.6Mpa, and the low-gas hydrogen extraction adsorption tower 23 starts the adsorption step sequence. Thus the whole coal tar hydrogenation low-gas recycling process is completed.

[0036] The desulfurization rich liquid solvent which absorbs H2S is analyzed and regenerated by the desulfurization rich liquid analysis regeneration system 12, becomes a desulfurization lean liquid solvent, is sent into the low-gas desulfurization tower 9 by the desulfurization lean liquid solvent pump 7 to remove H2S, and achieves the purpose of recycling.

[0037] The low-gas hydrogen extraction adsorption tower 23 is adsorbed by the low-gas hydrogen extraction adsorption tower adsorbent 24 in the tower, removes the impurities such as methane and ethane in the low-gas, and through the uniform pressure reduction, the reverse discharge, the uniform pressure increase and the final pressure increase, the desorption and regeneration of the low-gas hydrogen extraction adsorption tower adsorbent 24 in the low-gas hydrogen extraction adsorption tower 23 are completed, and the low-gas hydrogen extraction adsorption tower 23 realizes recycling.

[0038] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low-segment gas recovery system for a coal tar hydrogenation unit for chemical applications, comprising a liquid-phase hydrogenation cooling low-segment tank (1), a hydrogenation refining cooling low-segment tank (3), and a hydrogenation refining cooling high-segment tank (5), characterized in that: It also includes a low-saturation gas desulfurization tower (9), a liquid phase hydrogenation cooling low-saturation tank (1), a hydrogenation fine cooling low-saturation tank (3), and a hydrogenation fine cooling high-saturation tank (5). The output pipes of these are connected to the lower part of the low-saturation gas desulfurization tower (9). The upper part of the low-saturation gas desulfurization tower (9) is connected to a desulfurization lean liquid solvent pump (7). The bottom of the low-saturation gas desulfurization tower (9) is connected to a desulfurization rich liquid analysis and regeneration system (12). The desulfurization rich liquid analysis and regeneration system (12) is connected to the desulfurization lean liquid solvent pump (7).

2. The low-gas recovery system for a chemical coal tar hydrogenation unit according to claim 1, characterized in that: The top of the low-saturation gas desulfurization tower (9) is connected to a low-saturation gas vapor-liquid separator (14). The low-saturation gas vapor-liquid separator (14) is connected to a low-saturation gas hydrogen extraction adsorption tower (23) through a low-saturation gas adsorption inlet adsorption control valve (22). The top of the low-saturation gas hydrogen extraction adsorption tower (23) is connected to a low-saturation gas hydrogen extraction output pipeline (25). A hydrogen-rich gas output pipeline (38) is connected to the low-saturation gas hydrogen extraction output pipeline (25). A low-saturation gas adsorption outlet adsorption control valve (37) and a hydrogen-rich gas outlet valve (39) are installed sequentially on the hydrogen-rich gas output pipeline (38), and then connected to a hydrogen-rich gas hydrogen extraction adsorption tower (40).

3. The low-gas recovery system for a chemical coal tar hydrogenation unit according to claim 2, characterized in that: The low-separation gas hydrogen output pipeline (25) is also connected to a lifting pipeline (31). The lifting pipeline (31) is connected to a low-separation gas buffer tank (33) after the lifting control valve (30) and lifting control valve (32) are installed in sequence. The low-separation gas buffer tank (33) is connected to a benzene removal and desulfurization adsorption tower (36) through a purging pipeline (34).

4. The low-gas recovery system for a chemical coal tar hydrogenation unit according to claim 3, characterized in that: The low-splitting gas hydrogen extraction output pipeline (25) is also connected to a purge gas pipeline (27). The purge gas pipeline (27) is installed with a purge gas programmable valve (26) and a purge gas control valve (28) in sequence, and then connected to a purge gas buffer tank (29) of the hydrogen-rich gas extraction adsorption unit.

5. A low-gas recovery system for a chemical coal tar hydrogenation unit according to claim 4, characterized in that: The bottom of the low-splitting gas hydrogen extraction adsorption tower (23) is connected to a low-splitting gas desorption buffer tank (16) via a reverse release programmable valve (15). The low-splitting gas desorption buffer tank (16) is connected to a gas compressor (18) via a low-splitting gas desorption tank outlet valve (17). The gas compressor (18) is connected to a gas purification device (20) via a gas compressor outlet valve (19).

6. The low-gas recovery system for a chemical coal tar hydrogenation unit according to claim 5, characterized in that: Pressure regulating valves (2, 4) are installed on the output pipes of the liquid phase hydrogenation cooling low-temperature tank (1) and the hydrogenation fine refrigeration low-temperature tank (3), and pressure reducing valves (6) are installed on the output pipe of the hydrogenation fine refrigeration high-temperature tank (5).

7. A low-gas recovery system for a coal tar hydrogenation unit for chemical applications according to claim 6, characterized in that: A desulfurization lean liquor solvent pump outlet regulating valve (8) is installed between the desulfurization lean liquor solvent pump (7) and the low-saturation gas desulfurization tower (9).

8. A low-gas recovery system for a coal tar hydrogenation unit for chemical applications according to claim 7, characterized in that: A regulating valve (13) at the top of the low-saturation gas desulfurization tower is installed between the low-saturation gas desulfurization tower (9) and the low-saturation gas vapor-liquid separator (14).

9. A low-gas recovery system for a coal tar hydrogenation unit for chemical applications according to claim 8, characterized in that: A liquid level regulating valve (11) is installed between the low-saturation gas desulfurization tower (9) and the desulfurization rich liquid analysis and regeneration system (12).

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