Comprehensive treatment method for hydrogen peroxide hydrogenation tail gas

Abstract

The invention relates to the technical field of hydrogenated tail gas treatment, in particular to a hydrogen peroxide hydrogenated tail gas comprehensive treatment method which comprises the following steps: hydrogenated tail gas separated from a hydrogenation tower is introduced into a hydrogenated tail gas condenser and then enters a hydrogenated tail gas condensate receiving tank, and an aromatic solvent is condensed and recovered; uncondensed dead steam is pressurized and then sequentially passes through a PSA adsorption tank and a hydrogen filter, and purified hydrogen is circulated back into the hydrogenation tower; the desorbed gas flowing out of the hydrogenated liquid storage tank enters an emptying condenser, and the solvent is condensed and recovered; and flowing-out uncondensed gas is introduced into an activated carbon fiber unit, and is discharged into a waste gas incinerator for incineration treatment after being adsorbed. According to the invention, the aromatic hydrocarbon solvent in the hydrogenated tail gas is removed through condensation, the hydrogenated tail gas is pressurized and then is sequentially purified by the PSA adsorption tank and the hydrogen filtering tank, the purity of the purified hydrogen reaches 99.9%, the purified hydrogen can be re-injected into the hydrogenation tower, the recovery of aromatic hydrocarbon and the recycling of the hydrogen are realized, and the cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogenation tail gas treatment, and specifically to a comprehensive treatment method for hydrogenation tail gas of hydrogen peroxide. Background Art

[0002] At present, industrial-grade hydrogen peroxide is mainly produced by the anthraquinone method. During the production of hydrogen peroxide by the anthraquinone method, an anthraquinone hydrogenation reaction needs to be carried out. The unreacted gas generally enters the flare for combustion or is discharged into the air after simple treatment, which not only causes energy waste but also poses safety risks.

[0003] With the increasing emphasis on safety and environmental protection by people, government departments have become increasingly strict with the emission standards of volatile organic gases in industrial waste gases. The comprehensive treatment of hydrogenation tail gas in the hydrogen peroxide industry has always been highly regarded. Although the tail gas emission volume is not large, the tail gas contains a large amount of unreacted hydrogen, aromatic gas, nitrogen, and carbon dioxide, which requires high safety treatment requirements. The existing traditional technologies generally directly burn with a flare or directly discharge after simple adsorption by activated carbon. The specific treatment status is as follows: ① Most of the unreacted gas in the hydrogenation tower is directly discharged to the flare for combustion; ② Most of the analytical gas in the regeneration liquid storage tank is adsorbed by simple activated carbon or directly discharged into the atmosphere. Due to the characteristics of hydrogen, such as low density, wide explosion limit, and strong diffusibility, the safety risk to the flare is slightly greater, and direct discharge will pollute the environment. Based on this, a comprehensive treatment method for hydrogenation tail gas of hydrogen peroxide is proposed. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a comprehensive treatment method for hydrogenation tail gas of hydrogen peroxide. By condensing and removing the aromatic hydrocarbons in the hydrogenation tail gas, and then passing through the PSA adsorption tank and the hydrogen filter tank for purification and injection into the hydrogenation tower, the recovery of aromatic hydrocarbons and the recycling of hydrogen are realized, taking into account economic efficiency and safety and environmental protection requirements to achieve resource treatment.

[0005] To achieve the above object, the present invention provides the following technical solution: A comprehensive treatment method for hydrogenation tail gas of hydrogen peroxide, including the following steps,

[0006] (1) The hydrogenation tail gas separated from the hydrogenation tower is introduced into the hydrogenation tail gas condenser, and the aromatic hydrocarbons are condensed into a liquid state, and then enter the hydrogenation tail gas condensate receiving tank to further condense and recover the high-boiling aromatic hydrocarbon solvent therein;

[0007] (2) The uncondensed hydrogen tail gas waste steam is pressurized by a compressor and then introduced into the PSA adsorption tank. After the hydrogen is adsorbed, it is then passed through a hydrogen filter for filtration, and the purified hydrogen is recycled back into the hydrogenation tower;

[0008] (3) The analytical gas flowing out of the hydrogenation liquid storage tank enters the vent condenser, and after condensing and recovering the solvent, it passes through a vent water seal;

[0009] (4) The uncondensed gas discharged is introduced into the activated carbon fiber unit. After adsorption, it enters the recovery tank and is discharged into the waste gas incinerator for incineration treatment after being pressurized by a blower.

[0010] Preferably, in step (1), in the tail gas condenser, the temperature of the chilled water is controlled at 5°C.

[0011] Preferably, in step (1), the air pressure in the hydrogenation tail gas condensate receiving tank is controlled at 0.12 - 0.2 MPa.

[0012] Preferably, in step (2), the air pressure after being pressurized by the compressor is 0.5 - 0.6 MPa.

[0013] Preferably, in step (3), the pressure in the hydrogenated liquid storage tank is 1 - 2.5 KPa.

[0014] Preferably, in step (4), the flow rate of the uncondensed gas is 10 - 50 Nm 3 / h.

[0015] Preferably, in step (4), the air pressure in the recovery tank is -1 KPa.

[0016] Preferably, in step (4), the air pressure after being pressurized by the blower is 50 KPa.

[0017] The present invention provides a comprehensive treatment method for hydrogen peroxide hydrogenation tail gas, which has the following beneficial effects compared with the prior art:

[0018] 1. The present invention removes aromatic solvents in the hydrogenation tail gas through condensation. After pressurization, it is purified successively through a PSA adsorption tank and a hydrogen filtration tank. The purity of the purified hydrogen reaches 99.9%, and it can be re-injected into the hydrogenation tower to achieve the recovery of aromatic hydrocarbons and the recycling of hydrogen, saving costs.

[0019] 2. The present invention realizes the recovery of solvents in the analytical gas through a vent condenser, absorbs the uncondensed gas using an activated carbon fiber unit, and finally conducts incineration to control the non-methane total hydrocarbon emission ≤ 40 mg / m 3 , meeting the requirements of safety and environmental protection. Description of the Drawings

[0020] The drawings described herein are used to provide a further understanding of the present application, form a part of the present application, and the illustrative embodiments and descriptions thereof are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0021] Figure 1 is the general flow chart of the hydrogenation tail gas treatment of the present invention;

[0022] Figure 2This is the flow chart for the recycling treatment and utilization of the separated tail gas from the hydrogenation tower of the present invention;

[0023] Figure 3 This is the flow chart for the treatment of the analytical gas from the hydrogenated liquid storage tank of the present invention. Specific embodiments

[0024] The following examples are used to illustrate in detail the implementation mode of the present application, so as to fully understand how the present application uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly.

[0025] Example 1

[0026] A comprehensive treatment method for the tail gas of hydrogen peroxide hydrogenation includes the following steps:

[0027] (1) The hydrogenation tail gas (H2 content ≥ 90%, CO2 content ≤ 200 ppm) separated from the hydrogenation tower is introduced into the hydrogenation tail gas condenser (the temperature of the chilled water is 5°C), and the aromatic hydrocarbons are condensed into a liquid state, and then enter the hydrogenation tail gas condensate receiving tank (the air pressure is 0.2 MPa) to further condense and recover the high-boiling aromatic hydrocarbon solvent therein;

[0028] (2) The uncondensed hydrogen tail gas exhaust steam is pressurized by a compressor and then introduced into the PSA adsorption tank. After the hydrogen is adsorbed, it is then introduced into a hydrogen filter for filtration, and the purified hydrogen (H2 content 99.9%, CO2 content < 2 ppm) is recycled back into the hydrogenation tower; among them, the air pressure after being pressurized by the compressor is 0.6 MPa.

[0029] (3) The analytical gas (containing nitrogen, a small amount of hydrogen and aromatic hydrocarbon gas) flowing out from the hydrogenated liquid storage tank (the pressure is 2.5 KPa) enters the vent condenser, and after condensing and recovering the solvent, it passes through the vent water seal;

[0030] (4) The uncondensed gas (hydrogen and nitrogen, flow rate is 50 Nm 3 / h) is introduced into the activated carbon fiber unit, and after adsorption, it enters the recovery tank (the air pressure is -1 KPa), and is pressurized by a Roots blower and then discharged into the waste gas incinerator for incineration treatment. Among them, the air pressure after being pressurized by the Roots blower is 50 KPa.

[0031] Adopting the comprehensive treatment method for the tail gas of hydrogen peroxide hydrogenation in this example can achieve cost savings, safety and environmental protection, as follows:

[0032] ① By recycling and reusing the hydrogenation tail gas separated from the hydrogenation tower, 200 Nm of hydrogen can be saved 3 / h, among which it is recycled and reused in the PSA pressure swing adsorption, saving a cost of 200×8000×2 = 3.2 million yuan; among them, 8000 (h), 2 (the price of each standard cubic meter of hydrogen, yuan).

[0033] ② The hydrogenation storage tank vent analytical gas goes to incineration: 30 × 12870 / 2676 = 0.144 × 260 × 8000 = 300,000 yuan;

[0034] Among them, 30 × 12870 / 2676 (30 Nm 3 / h conversion heat energy), 0.144 (steam, tons), 260 (yuan / ton), yuan; 8000 (8000 h).

[0035] ③ The tail gas adsorption unit recovers aromatics and reduces: 0.05 × 450000 / 1000 × 6000 = 135,000 yuan;

[0036] 0.05 (unit consumption reduction); 450000 / 1000 (plant scale, tons); 6000 (yuan / ton). 1000 (kg converted to tons).

[0037] ④ The total non-methane hydrocarbon emission ≤ 40 mg / m 3 , and the safety and environmental protection requirements reach the resource treatment application effect.

[0038] Example 2

[0039] A comprehensive treatment method for hydrogen peroxide hydrogenation tail gas, including the following steps:

[0040] (1) The hydrogenation tail gas (H2 content ≥ 90%, CO2 content ≤ 200 ppm) separated from the hydrogenation tower is introduced into the hydrogenation tail gas condenser (the temperature of the chilled water is 5°C), and the aromatics are condensed into a liquid state, and then enter the hydrogenation tail gas condensate receiving tank (the air pressure is 0.12 MPa) to further condense and recover the high-boiling aromatic solvent therein;

[0041] (2) The uncondensed hydrogen tail gas waste steam is pressurized by a compressor and then introduced into the PSA adsorption tank. After the hydrogen is adsorbed, it is filtered through a hydrogen filter, and the purified hydrogen (H2 content 99.9%, CO2 content < 2 ppm) is recycled back into the hydrogenation tower; among them, the air pressure after being pressurized by the compressor is 0.5 MPa.

[0042] (3) The analytical gas (containing nitrogen, a small amount of hydrogen and aromatic gas) flowing out from the hydrogenation liquid storage tank (the pressure is 1 KPa) enters the vent condenser, and after condensing and recovering the solvent, it passes through the vent water seal;

[0043] (4) The uncondensed gas flowing out (hydrogen and nitrogen, the flow rate is 10 Nm 3 / h) is introduced into the activated carbon fiber unit, and after adsorption, it enters the recovery tank (the air pressure is -1 KPa), and is pressurized by a Roots blower and then discharged into the waste gas incinerator for incineration treatment. Among them, the air pressure after being pressurized by the Roots blower is 50 KPa.

[0044] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and permutations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A comprehensive treatment method for hydrogen peroxide hydrogenation tail gas, characterized in that: The following steps are involved: (1) The hydrogenated tail gas separated from the hydrogenation tower is passed into a hydrogenated tail gas condenser, where aromatic hydrocarbons are condensed into liquid form, and then enters a hydrogenated tail gas condensate receiving tank, where the high-boiling point aromatic hydrocarbon solvent is further condensed and recovered; (2) The uncondensed hydrogen tail gas exhaust steam is pressurized by the compressor and then passed into the PSA adsorption tank. After adsorption, the hydrogen is passed into the hydrogen filter for filtration. The purified hydrogen is circulated back into the hydrogenation tower; (3) The desorption gas flowing out of the hydrogenation liquid storage tank enters the vent condenser, condenses and recovers the solvent, and then passes through the vent water seal; (4) The uncondensed gas flows out into the activated carbon fiber unit, enters the recovery tank after adsorption, and is pressurized by the fan and discharged into the waste gas incinerator for incineration.

2. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (1), in the tail gas condenser, the temperature of the chilled water is controlled to be 5°C.

3. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (1), the gas pressure in the hydrogenated tail gas condensate receiving tank is controlled to be 0.12-0.2 MPa.

4. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (2), the air pressure after pressurization by the compressor is 0.5-0.6 MPa.

5. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (3), the pressure in the hydrogenated liquid storage tank is 1-2.5 KPa.

6. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (4), the flow rate of the uncondensed gas is 10-50 Nm 3 / h.

7. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (4), the air pressure in the recovery tank is -1 KPa.

8. The comprehensive treatment method for hydrogen peroxide hydrogenation tail gas according to claim 1, characterized in that: In step (4), the air pressure after pressurization by the fan is 50 KPa.

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