Hydrogenation reaction system for reducing activated carbon regenerated acid gas to prepare sulfur

Abstract

The utility model provides a hydrogenation reaction system for producing sulfur by reducing acid gas regenerated by activated carbon, which comprises an acid gas pretreatment system, a first-stage hydrogenation system, a second-stage hydrogenation system, a tail gas treatment system and a liquid sulfur tank, the acid gas generated by regeneration of desulfurized activated carbon is pretreated and then is subjected to hydrogenation reduction to produce sulfur, the hydrogenation is divided into two stages, wherein the primary hydrogenation is divided into a plurality of sections according to different SO2 contents, a sectional hydrogenation method is adopted, gas subjected to the primary hydrogenation enters the secondary hydrogenation, air is introduced into the gas subjected to the secondary hydrogenation, and after side reaction products generated by hydrogenation are oxidized into sulfur and SO2, residual tail gas is sent back to an inlet of the activated carbon desulfurization device. Through first-stage hydrogenation and second-stage hydrogenation, the temperature rise of the hydrogenation reaction is reduced, side reactions are reduced, and the SO2 conversion rate is improved; oxidation-method tail gas treatment is adopted to directly return to activated carbon for desulfurization, and no waste gas is discharged on the whole.

Description

Technical Field

[0001] The utility model belongs to the field of comprehensive treatment and resource utilization of flue gas in air pollution control, and relates to a hydrogenation reaction system for regenerating activated carbon to reduce acid gas to produce sulfur. Background Art

[0002] With the increasingly strict national control of air pollution, the integrated desulfurization and denitrification technology of activated carbon has been widely applied and developed in the comprehensive treatment of flue gas. Most of the regeneration methods of activated carbon adsorbed with pollutants are mainly thermal regeneration. The acid gas rich in SO2 generated is prepared into concentrated sulfuric acid through purification, conversion and absorption, thus realizing the conversion of pollutants into valuable industrial products and the resource utilization of pollutants.

[0003] However, concentrated sulfuric acid is a dangerous chemical and a precursor chemical for drug manufacturing. There are great safety risks in production, transportation and storage. Secondly, the use of concentrated sulfuric acid has strong regional limitations. In some places, users of concentrated sulfuric acid cannot be found locally, which limits the application of the sulfuric acid production route. In addition, sulfuric acid production is limited by scale and equipment and is not suitable for applications with small flue gas volume or low sulfur content.

[0004] Sulfur is a solid with much lower danger than concentrated sulfuric acid, and is easy to store and transport, with less limitation on production scale. Therefore, reducing the regenerated acid gas to produce sulfur can be used as an alternative process to the sulfuric acid production process for some enterprises not suitable for sulfuric acid production, especially in some non-ferrous metal smelting enterprises and some special regions.

[0005] The reduction of sulfur dioxide to elemental sulfur can be divided into gas-phase reduction method and liquid-phase reduction method. The gas-phase reduction method refers to directly or indirectly reducing sulfur dioxide in the gas phase with a reducing agent to form elemental sulfur. Common reducing agents include carbon monoxide (CO), hydrogen (H2), coke (C), methane (CH4), ammonia (NH3), etc. The liquid-phase reduction method means that sulfur dioxide is absorbed in the liquid phase and then reduced and converted into sulfur, such as electro-reduction method, biological reduction method, etc. The disadvantage of the liquid-phase reduction method is that it will produce secondary pollution such as wastewater. In the gas-phase reduction method, when using carbon monoxide, carbon, methane, etc. as reducing agents, side reactions will generate COS, the selectivity of the reduction reaction is relatively low, and the reaction requires a relatively high temperature. When using hydrogen as a reducing agent, the catalytic reduction reaction can be carried out at a lower temperature. At present, with the continuous development of green energy in China and the significant reduction of the cost of green electricity, the production of hydrogen from green electricity has been practically applied in some regions, and the cost of hydrogen has decreased a lot. In this case, the cost of hydrogenating SO2 produced by activated carbon regeneration to produce sulfur has also decreased significantly, making industrialization possible.

[0006] However, current research on sulfur production from SO2 hydrogenation is mostly limited to the study of hydrogenation catalysts and laboratory research. In particular, the acid gas generated from activated carbon regeneration has characteristics such as high water content, high SO2 concentration with a large concentration variation range, high dust content, and complex composition. How to produce sulfur through hydrogenation reaction and ensure that the hydrogenation reaction can be realized at the industrial level is a problem to be solved. At the same time, since the hydrogenation reaction is an exothermic reaction, the temperature rises significantly during the hydrogenation of high-concentration SO2. Too high a temperature affects the service life of the catalyst and will also cause a large number of side reactions, reducing the efficiency of conversion into sulfur. Therefore, reducing the reaction temperature and increasing the conversion rate are the keys to sulfur production by hydrogenation reduction. Summary of the Invention

[0007] The present invention provides a hydrogenation reaction system for sulfur production by reducing acid gas from activated carbon regeneration. Through primary staged hydrogenation and secondary hydrogenation, the temperature rise of the hydrogenation reaction is reduced, side reactions are reduced, and the SO2 conversion rate is increased; the tail gas treatment by the oxidation method is directly returned to activated carbon desulfurization, and there is no waste gas emission as a whole.

[0008] The technical solution adopted by the present invention to solve its technical problems is:

[0009] A hydrogenation reaction system for sulfur production by reducing acid gas from activated carbon regeneration, comprising:

[0010] An acid gas pretreatment system, connected to the activated carbon desulfurization device, for receiving the acid gas from activated carbon regeneration and removing the activated carbon dust in the regenerated acid gas;

[0011] A primary hydrogenation system, composed of n successively connected hydrogenation reaction sections, each hydrogenation reaction section is connected to the acid gas pretreatment system and the external hydrogen gas pipeline, for hydrogenation reduction of a part of SO2; the first hydrogenation reaction section is also connected to the external nitrogen gas pipeline;

[0012] A secondary hydrogenation system, connected to the nth hydrogenation reaction section and the external hydrogen gas pipeline, for hydrogenation reduction of the remaining SO2 and reduction of the by-products generated;

[0013] A tail gas treatment system, connected to the secondary hydrogenation system and the external air pipeline, for oxidizing the gas generated by reducing the by-products of the secondary hydrogenation system; the tail gas treatment system is also connected to the inlet of the activated carbon desulfurization device through a tail gas fan, for returning the SO2 generated by the oxidation treatment to the activated carbon desulfurization;

[0014] A liquid sulfur tank, connected to the outlets of each hydrogenation reaction section of the primary hydrogenation system, the secondary hydrogenation system, and the tail gas treatment system, for receiving and storing the sulfur generated by the reactions of each system.

[0015] Further, the acid gas pretreatment system includes a high-temperature dust collector and a dust collector. The regenerated acid gas is introduced into the high-temperature dust collector to remove activated carbon dust, and the dust collector is connected to the high-temperature dust collector to recover the dust obtained by dust removal in the high-temperature dust collector.

[0016] Further, the structures of the hydrogenation reaction sections of the primary hydrogenation system are the same, and each includes a primary hydrogenation heater, a primary hydrogenation reactor, and a primary hydrogenation cooler connected in sequence. The primary hydrogenation cooler of the previous section is communicated with the primary hydrogenation heater of the next section, and the primary hydrogenation cooler of the nth section is communicated with the secondary hydrogenation system; the primary hydrogenation coolers of each section are all communicated with the liquid sulfur tank.

[0017] Further, the secondary hydrogenation system includes a secondary hydrogenation heater, a secondary hydrogenation reactor, and a secondary hydrogenation cooler connected in sequence; the secondary hydrogenation heater is communicated with the primary hydrogenation cooler of the nth hydrogenation reaction section, and the secondary hydrogenation cooler is respectively communicated with the liquid sulfur tank and the tail gas treatment system.

[0018] Further, the tail gas treatment system includes an oxygen heater, an oxidation reactor, and an oxidation cooler connected in sequence; the oxygen heater is communicated with the secondary hydrogenation system, and the oxidation cooler is respectively communicated with the liquid sulfur tank and the tail gas fan.

[0019] Further, a liquid sulfur pump is provided in the liquid sulfur tank to pump the sulfur in the liquid sulfur tank to the forming section.

[0020] Further, an acid gas SO2 concentration detector and an acid gas flow detector are provided on the gas transmission pipeline of the high-temperature dust collector to the primary hydrogenation system.

[0021] Further, a primary acid gas flow detector and a primary acid gas regulating valve are provided on the connecting pipeline between the primary hydrogenation heater of each hydrogenation reaction section and the acid gas pretreatment system; a primary hydrogen gas flow detector and a primary hydrogenation regulating valve are provided on the connecting pipeline between each primary hydrogenation heater and the external hydrogen gas pipeline; a nitrogen gas flow detector and a nitrogen gas regulating valve are provided on the connecting pipeline between the primary hydrogenation heater of the first hydrogenation reaction section and the external nitrogen gas pipeline; a primary pre-hydrogenation temperature detector and a primary pre-hydrogenation SO2 concentration detector are provided on the connecting pipeline between the primary hydrogenation heater and the primary hydrogenation reactor of each hydrogenation reaction section; a primary post-hydrogenation temperature detector and a primary post-hydrogenation SO2 concentration detector are provided on the connecting pipeline between the primary hydrogenation reactor and the primary hydrogenation cooler of each hydrogenation reaction section.

[0022] Further, a secondary hydrogen flow detector and a secondary hydrogenation regulating valve are provided on the connecting pipeline between the secondary hydrogenation heater and the external hydrogen pipeline; a pre-secondary hydrogenation temperature detector and a pre-secondary hydrogenation SO2 concentration detector are provided on the connecting pipeline between the secondary hydrogenation heater and the secondary hydrogenation reactor; a post-secondary hydrogenation temperature detector and post-secondary hydrogenation H2 and SO2 concentration detectors are provided on the connecting pipeline between the secondary hydrogenation reactor and the secondary hydrogenation cooler.

[0023] Further, an air flow detector and an oxidation air regulating valve are provided on the connecting pipeline between the oxygen heater and the external air pipeline; a pre-oxidation temperature detector and pre-oxidation H2S and SO2 concentration detectors are provided on the connecting pipeline between the oxygen heater and the oxidation reactor; a post-oxidation temperature detector and post-oxidation H2S and SO2 concentration detectors are provided on the connecting pipeline between the oxidation reactor and the oxidation cooler.

[0024] The beneficial effects of the present utility model include:

[0025] The system pre-treats the acidic gas generated by the regeneration of the desulfurization activated carbon and then conducts hydrogenation reduction to produce sulfur. The hydrogenation is divided into two stages. Among them, the first-stage hydrogenation is divided into several segments according to different SO2 contents, and the method of segmented hydrogenation is adopted. The gas after the first-stage hydrogenation enters the second-stage hydrogenation. The gas after the second-stage hydrogenation is introduced into the air. After the side reaction products generated by the hydrogenation are oxidized into sulfur and SO2, the remaining tail gas is sent back to the inlet of the activated carbon desulfurization device; through this system, high-concentration SO2 is hydrogenated and reduced to sulfur for recycling, realizing the resource utilization of pollutants; through the first-stage segmented hydrogenation and the second-stage hydrogenation, the temperature rise of the hydrogenation reaction is reduced, side reactions are reduced, and the SO2 conversion rate is increased; the oxidation method is used for tail gas treatment and directly returns to the activated carbon desulfurization, and there is no waste gas emission as a whole. Description of the Drawings

[0026] Figure 1 Schematic Flow Diagram of the Hydrogenation Reaction System for the Reduction of Acidic Gas from Activated Carbon Regeneration to Sulfur

[0027] In the figure: 1 - High-temperature dust collector; 21 - First-stage first-section hydrogenation heater; 22 - First-stage second-section hydrogenation heater; 2n - First-stage n-section hydrogenation heater; 3 - Second-stage hydrogenation heater; 31 - First-stage first-section hydrogenation reactor; 32 - First-stage second-section hydrogenation reactor; 3n - First-stage n-section hydrogenation reactor; 4 - Second-stage hydrogenation reactor; 41 - First-stage first-section hydrogenation cooler; 42 - First-stage second-section hydrogenation cooler; 4n - First-stage n-section hydrogenation cooler; 5 - Second-stage hydrogenation cooler; 6 - Oxidation heater; 7 - Oxidation reactor; 8 - Oxidation cooler; 9 - Liquid sulfur tank; 10 - Liquid sulfur pump; 11 - Tail gas fan; 12 - Dust collector; 101 - First-stage first-section acid gas regulating valve; 102 - First-stage second-section acid gas regulating valve; 10n - First-stage n-section acid gas regulating valve; 201 - First-stage first-section hydrogenation regulating valve; 202 - First-stage second-section hydrogenation regulating valve; 20n - First-stage n-section hydrogenation regulating valve; 301 - Nitrogen regulating valve; 401 - Second-stage hydrogenation regulating valve; 501 - Oxidation air regulating valve; A0 - Acid gas SO2 concentration detector; A11 - SO2 concentration detector before first-stage first-section hydrogenation; A12 - SO2 concentration detector before first-stage second-section hydrogenation; A1n - SO2 concentration detector before first-stage n-section hydrogenation; A21 - SO2 concentration detector after first-stage first-section hydrogenation; A22 - SO2 concentration detector after first-stage second-section hydrogenation; A2n - SO2 concentration detector after first-stage n-section hydrogenation; A3 - SO2 concentration detector before second-stage hydrogenation; A4 - H2 and SO2 concentration detector after second-stage hydrogenation; A5 - H2S and SO2 concentration detector before oxidation; A6 - H2S and SO2 concentration detector after oxidation; F0 - Acid gas flow detector; F11 - First-stage first-section acid gas flow detector; F12 - First-stage second-section acid gas flow detector; F1n - First-stage n-section acid gas flow detector; F21 - First-stage first-section hydrogen flow detector; F22 - First-stage second-section hydrogen flow detector; F2n - First-stage n-section hydrogen flow detector; F3 - Second-stage hydrogen flow detector; F4 - Air flow detector; FN - Nitrogen flow detector; T11 - Temperature detector before first-stage first-section hydrogenation; T12 - Temperature detector before first-stage second-section hydrogenation; T1n - Temperature detector before first-stage n-section hydrogenation; T21 - Temperature detector after first-stage first-section hydrogenation; T22 - Temperature detector after first-stage second-section hydrogenation; T2n - Temperature detector after first-stage n-section hydrogenation; T3 - Temperature detector before second-stage hydrogenation; T4 - Temperature detector after second-stage hydrogenation; T5 - Temperature detector before oxidation; T6 - Temperature detector after oxidation;

[0028] Wherein: n is the number of hydrogenation reaction sections in the first-stage hydrogenation system. Detailed implementation mode

[0029] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative work fall within the scope of protection of the present utility model.

[0030] In addition, the technical features involved in different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] Embodiment 1

[0032] This embodiment provides a hydrogenation reaction system for regenerating activated carbon to reduce sour gas to sulfur, as Figure 1 shown, mainly including: a sour gas pretreatment system, a primary hydrogenation system, a secondary hydrogenation system, a tail gas treatment system, and a liquid sulfur tank 9.

[0033] The sour gas pretreatment system includes a high-temperature dust collector 1 and a dust collector 12. The high-temperature dust collector 1 is connected to an activated carbon desulfurization device to introduce regenerated sour gas of activated carbon to remove activated carbon dust in the regenerated sour gas. The dust collector 12 is connected to the high-temperature dust collector 1 to recover the dust obtained by dust removal by the high-temperature dust collector 1. An SO2 concentration detector A0 and a sour gas flow detector F0 are provided on the gas pipeline of the high-temperature dust collector 1 leading to the primary hydrogenation system. The sour gas pretreatment system is required to have a temperature resistance of not less than 450 °C and a dust removal efficiency of not less than 99.5%. Based on this requirement, the high-temperature dust collector 1 is preferably a pulse back-blow high-temperature ceramic tube dust collector.

[0034] The primary hydrogenation system is composed of n successively connected hydrogenation reaction sections. Each section includes a primary hydrogenation heater, a primary hydrogenation reactor, and a primary hydrogenation cooler, as well as relevant regulating valves, flow detectors, SO2 concentration detectors, and temperature detectors. The total number of sections n of the primary hydrogenation system is comprehensively determined according to the flow rate and SO2 content of the regenerated sour gas, and the value range is 2 ≤ n ≤ 6.

[0035] Specifically, in the first-stage single-section hydrogenation reaction section, the flow rate of acid gas entering the first-stage single-section hydrogenation heater 21 (i.e., the reading of the first-stage single-section acid gas flow meter F11) is adjusted by the first-stage single-section acid gas regulating valve 101 to account for no less than 1 / n of the total acid gas flow rate (i.e., the reading of the acid gas flow meter F0); the hydrogen addition amount (i.e., the reading of the first-stage single-section hydrogen gas flow meter F21) is adjusted by the first-stage single-section hydrogenation regulating valve 201 to be 95% - 100% of the molar number of SO2 in the acid gas entering the first-stage single-section hydrogenation heater 21; the nitrogen flow rate (i.e., the reading of the nitrogen flow meter FN) is adjusted by the nitrogen regulating valve 301 so that the SO2 content in the gas after heating in the first-stage single-section hydrogenation heater 21 (i.e., the reading of the SO2 concentration detector A11 before the first-stage single-section hydrogenation) is no more than 5% (V / V). After the mixed gas enters the first-stage single-section hydrogenation heater 21 and is heated, it enters the first-stage single-section hydrogenation reactor 31 for hydrogenation reduction reaction. The gas after the reaction in the first-stage single-section hydrogenation reactor 31 is cooled by the first-stage single-section hydrogenation cooler 41 to recover sulfur to the liquid sulfur tank 9, and the remaining gas enters the first-stage second-section hydrogenation reaction section.

[0036] In the first-stage second-section hydrogenation reaction section, the hydrogen addition amount (i.e., the reading of the first-stage second-section hydrogen gas flow meter F22) is adjusted by the first-stage second-section hydrogenation regulating valve 202 to be 95% - 100% of the molar number of SO2 in the acid gas entering the first-stage second-section hydrogenation heater 22; the flow rate of acid gas entering the first-stage second-section hydrogenation heater 22 (i.e., the reading of the first-stage second-section acid gas flow meter F12) is adjusted by the first-stage second-section acid gas regulating valve 102 so that the SO2 content in the gas after heating in the first-stage second-section hydrogenation heater 22 (i.e., the reading of the SO2 concentration detector A12 before the first-stage second-section hydrogenation) is no more than 5% (V / V). It is mixed with the gas after sulfur recovery by the first-stage single-section hydrogenation cooler 41 and enters the first-stage second-section hydrogenation reactor 32 for hydrogenation reduction reaction. The gas after the hydrogenation reaction in the first-stage second-section hydrogenation reactor 32 is cooled by the first-stage second-section hydrogenation cooler 42 to recover sulfur to the liquid sulfur tank 9, and the remaining gas enters the first-stage third-section hydrogenation reaction section. Other first-stage hydrogenation reaction sections of each stage are the same as the first-stage second-section hydrogenation reaction section. The gas after sulfur recovery in the first-stage n-section hydrogenation reaction section enters the second-stage hydrogenation system.

[0037] The secondary hydrogenation system includes a secondary hydrogenation heater 3, a secondary hydrogenation reactor 4, a secondary hydrogenation cooler 5, a secondary hydrogenation regulating valve 401, a secondary hydrogen flow detector F3, a SO2 concentration detector A3 before secondary hydrogenation, an H2 and SO2 concentration detector A4 after secondary hydrogenation, a temperature detector T3 before secondary hydrogenation, and a temperature detector T4 after secondary hydrogenation. The gas coming from the first-stage n-section hydrogenation cooler 4n is mixed with hydrogen and then enters the secondary hydrogenation heater 3 for heating, and then enters the secondary hydrogenation reactor 4 for hydrogenation reduction. After the reaction, the gas enters the secondary hydrogenation cooler 5 for cooling to recover sulfur to the liquid sulfur tank 9, and the remaining gas enters the tail gas treatment system. The secondary hydrogen flow (i.e., the reading of the secondary hydrogen flow detector F3) is adjusted through the secondary hydrogenation regulating valve 401 to make the SO2 concentration at the outlet of the secondary hydrogenation reactor 4 less than 0.5% (V / V), and at the same time, the hydrogen concentration after the reaction in the secondary hydrogenation reactor 4 is controlled to be less than 0.5% (V / V) (i.e., the reading of the H2 and SO2 concentration detector A4 after secondary hydrogenation).

[0038] The tail gas treatment system includes an oxidation heater 6, an oxidation reactor 7, an oxidation cooler 8, an oxidation air regulating valve 501, an air flow detector F4, an H2S and SO2 concentration detector A5 before oxidation, an H2S and SO2 concentration detector A6 after oxidation, a temperature detector T5 before oxidation, and a temperature detector T6 after oxidation. The gas coming from the secondary hydrogenation cooler 5 is mixed with air and then enters the oxidation heater 6 for heating and then enters the oxidation reactor 7 for oxidation reaction. After the reaction, the gas enters the oxidation cooler 8 for cooling to recover sulfur to the liquid sulfur tank 9, and the cooled gas is sent back to the inlet of the activated carbon desulfurization device through the tail gas fan 11. The air flow (i.e., the reading of the air flow detector F4) is adjusted through the oxidation air regulating valve 501 to make the H2S concentration detected by the H2S and SO2 concentration detector A6 after oxidation less than 0.3% (V / V).

[0039] The first-stage first-section hydrogenation heater 21, the first-stage second-section hydrogenation heater 22, the first-stage n-section hydrogenation heater 2n, the secondary hydrogenation heater 3, and the oxidation heater 6 are all preferably shell-and-tube heat exchangers, and the heating medium can be high-temperature steam, hot flue gas from a hot blast stove, etc. The heated temperature is determined by the requirements of the hydrogenation catalyst or the oxidation catalyst. Preferably, the temperature after heating in each stage of the first stage is controlled at 200 - 220 °C.

[0040] The first-stage first-section hydrogenation cooler 41, the first-stage second-section hydrogenation cooler 42, the first-stage n-section hydrogenation cooler 4n, the secondary hydrogenation cooler 5, and the oxidation cooler 8 are all shell-and-tube heat exchangers. Each cooler can be set independently or a multi-tube-pass single-shell heat exchanger can be used.

[0041] The first-stage one-section hydrogenation reactor 31, the first-stage two-section hydrogenation reactor 32, the first-stage n-section hydrogenation reactor 3n, and the second-stage hydrogenation reactor 4 are all preferably horizontal or vertical reactors; the gas temperature (T21 to T2n, T4) after the reaction in the hydrogenation reactor shall not be higher than the allowable temperature of the hydrogenation catalyst, and the temperature rise before and after the hydrogenation reaction shall not be greater than 200 °C.

[0042] Example 2

[0043] Taking the flue gas treatment of a 300 MW power plant boiler as an example. The boiler flue gas parameters are shown in the following table:

[0044] Table 1 Boiler flue gas parameters (300 MW)

[0045]

[0046] Activated carbon desulfurization and denitrification are adopted, and the composition of the acid gas produced during reproduction is shown in Table 2:

[0047] Table 2 Reproduced acid gas parameters

[0048]

[0049]

[0050] The acid gas produced during the reproduction of activated carbon is hydrogenated and reduced by this system to produce sulfur. The high-temperature acid gas enters the acid gas pretreatment system, and the activated carbon dust contained in the acid gas is removed by the high-temperature dust collector 1. This dust will affect the color of the product sulfur. The dust obtained by dust removal is cooled and recovered by the dust collector 12 and recycled as fuel.

[0051] The pretreated acid gas enters the first-stage hydrogenation system, and the first-stage hydrogenation system has 4 hydrogenation reaction sections. Among them, 1200 Nm 3 / h of acid gas is added to the first hydrogenation reaction section, and 700 Nm 3 / h is added to each of the second, third, and fourth sections. The flow rate of the acid gas in each section is adjusted by the acid gas regulating valves (101 to 104) in each stage of the first stage.

[0052] In the first hydrogenation reaction section, nitrogen is added to dilute the acid gas to less than 5%, and the nitrogen addition amount is 2500 Nm 3 / h. The hydrogenation amount in the first hydrogenation reaction section is 360 Nm 3 / h, and the molar ratio H2 / SO2 = 1 is controlled. The mixed temperature is about 140 °C.

[0053] Using hot flue gas for heating, in the first-stage and first-section hydrogenation heater 21, the mixed gas in the first section is heated to 200 - 220 °C (the reading of the temperature detector T11 before the first-stage and first-section hydrogenation) and then enters the first-stage and first-section hydrogenation reactor 31 for reaction. The catalyst used is a sulfur-tolerant Ru / Al2O3 hydrogenation catalyst. The temperature after reaction (the reading of the temperature detector T21 after the first-stage and first-section hydrogenation) is 350 - 370 °C, with an increase of approximately 150 °C. The gas after reaction enters the first-stage and first-section hydrogenation cooler 41 for cooling, and the elemental sulfur generated condenses into a liquid and enters the liquid sulfur tank 9 for collection.

[0054] The gas cooled in the first stage and first section is approximately 160 °C and enters the first-stage and second-section hydrogenation reaction section, where it is mixed with the second-section acid gas and hydrogenated by 200 Nm 3 / h, and the molar ratio of H2 / SO2 is controlled to be 0.95. The mixed second-section mixed gas is heated to 200 - 220 °C (the reading of the temperature detector T12 before the first-stage and second-section hydrogenation) by the first-stage and second-section hydrogenation heater 22 and then enters the first-stage and second-section hydrogenation reactor 32 for reaction. The catalyst used is a sulfur-tolerant Ru / Al2O3 hydrogenation catalyst. The temperature after reaction (the reading of the temperature detector T22 after the first-stage and second-section hydrogenation) is 350 - 370 °C, with an increase of approximately 150 °C. The gas after reaction enters the first-stage and second-section hydrogenation cooler 42 for cooling, and the elemental sulfur generated condenses into a liquid and enters the liquid sulfur tank 9 for collection. The cooled gas enters the first-stage and third-section hydrogenation reaction section.

[0055] The first-stage and third-section hydrogenation reaction section and the first-stage and fourth-section hydrogenation reaction section are the same as the first-stage and second-section hydrogenation reaction section.

[0056] The main chemical reactions occurring in the first-stage hydrogenation system are as follows:

[0057] SO2 + 2H2 = 1 / xS x + 2H2O

[0058] SO2 + 2CO = 1 / xS x + 2CO2

[0059] 1 / xS x + CO = COS

[0060] Through the first-stage hydrogenation reaction, most of the SO2 in the acid gas is reduced to sulfur for recovery. The conversion rate of SO2 in the first-stage hydrogenation is approximately 95%, and the conversion rate of sulfur is approximately 91%.

[0061] The gas cooled after the first-stage four-section hydrogenation reaction section enters the second-stage hydrogenation system and mixes with the second-stage hydrogenation hydrogen. The second-stage hydrogenation regulating valve 401 regulates the second-stage hydrogen flow rate (the reading of the second-stage hydrogen flow detector F3) to make the SO2 concentration at the outlet of the second-stage hydrogenation reactor 4 less than 0.5% (V / V). To ensure safety, the hydrogen concentration after the reaction in the second-stage hydrogenation reactor 4 is also controlled to be less than 0.5%. The second-stage mixed gas enters the second-stage hydrogenation reactor 4 for hydrogenation reaction after being heated by the second-stage hydrogenation heater 3, and the temperature after heating is controlled at 240 - 280 °C. The second-stage hydrogenation uses a composite catalyst, with a SO2 hydrogenation catalyst in the upper layer and a Claus catalyst in the lower layer. The gas temperature after hydrogenation reduction (the reading of the second-stage hydrogenation post-temperature detector T4) is about 300 °C and enters the second-stage hydrogenation cooler 5 for cooling to recover sulfur.

[0062] The main purpose of the second-stage hydrogenation is to hydrogenate and reduce the remaining SO2, and at the same time reduce the by-product COS generated, and generate sulfur through the Claus reaction for the reduced H2S. The main chemical reactions occurring in the second-stage hydrogenation are:

[0063] SO2 + 2H2 = 1 / xS x + 2H2O

[0064] COS + 2H2 = H2S + CO

[0065] SO2 + 2H2S = 3 / xS x + 2H2O

[0066] The gas with a temperature of about 160 °C after the second-stage hydrogenation cooling enters the tail gas treatment system, mixes with air and then enters the oxidation heater 6 to be heated to 210 - 230 °C. The air addition amount is controlled by the oxidation air regulating valve 501 to make the H2S concentration at the outlet of the oxidation reactor 7 (the reading of the post-oxidation H2S and SO2 concentration detector A6) less than 0.3%, and the SO2 concentration is also detected. The gas temperature after the oxidation reaction (the reading of the post-oxidation temperature detector T6) is about 250 °C, and after being cooled to 120 °C by the oxidation cooler 8 to recover sulfur, it is sent back to the inlet of the activated carbon desulfurization device by the tail gas fan 11 to ensure that there is no waste gas emission in the whole system. The main chemical reactions occurring in the tail gas system are:

[0067] 2H2S + O2 = 2 / xS x + 2H2O

[0068] 2H2S + 2O2 = SO2 + 2H2O

[0069] The sulfur recovery rate of the whole system is about 95%, and the sulfur output is about 673 Kg / h.

[0070] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. An activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system, characterized in that: include: The acid gas pretreatment system is connected to the activated carbon desulfurization device to receive the activated carbon regenerated acid gas and remove the activated carbon dust in the regenerated acid gas; The primary hydrogenation system is composed of n hydrogenation reaction sections connected in sequence, each of which is connected to the acid gas pretreatment system and an external hydrogen pipeline to hydrogenate and reduce a portion of SO2; the first hydrogenation reaction section is also connected to an external nitrogen pipeline; A secondary hydrogenation system is connected to the nth hydrogenation reaction section and an external hydrogen pipeline to hydrogenate and reduce the remaining SO2 and the generated by-products; The tail gas treatment system is connected to the secondary hydrogenation system and the external air pipeline, and is used to oxidize the gas generated by the reduction of the by-products of the secondary hydrogenation system; the tail gas treatment system is also connected to the inlet of the activated carbon desulfurization device through the tail gas fan (11), and is used to return the SO2 generated by the oxidation treatment to the activated carbon desulfurization; The liquid sulfur tank (9) is connected to the outlets of each hydrogenation reaction section of the primary hydrogenation system, the secondary hydrogenation system, and the tail gas treatment system, and is used to receive and store sulfur produced by the reactions of each system.

2. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 1 is characterized in that: The acid gas pretreatment system comprises a high-temperature dust collector (1) and a dust collector (12). Regenerated acid gas is introduced into the high-temperature dust collector (1) to remove activated carbon dust. The dust collector (12) is connected to the high-temperature dust collector (1) to recover dust removed by the high-temperature dust collector (1).

3. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 1, characterized in that: The hydrogenation reaction sections of the first-stage hydrogenation system have the same structure, and all include a first-stage hydrogenation heater, a first-stage hydrogenation reactor and a first-stage hydrogenation cooler connected in sequence. The first-stage hydrogenation cooler of the first stage is connected to the first-stage hydrogenation heater of the second stage, and the first-stage hydrogenation cooler of the nth stage is connected to the second-stage hydrogenation system; and the first-stage hydrogenation coolers of each stage are connected to the liquid sulfur tank (9).

4. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 3 is characterized in that: The secondary hydrogenation system comprises a secondary hydrogenation heater (3), a secondary hydrogenation reactor (4) and a secondary hydrogenation cooler (5) which are connected in sequence; the secondary hydrogenation heater (3) is connected to the primary hydrogenation cooler of the nth hydrogenation reaction section, and the secondary hydrogenation cooler (5) is connected to the liquid sulfur tank (9) and the tail gas treatment system respectively.

5. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 1 or 4, characterized in that: The tail gas treatment system comprises an oxygen heater (6), an oxidation reactor (7) and an oxidation cooler (8) which are connected in sequence; the oxygen heater (6) is connected to the secondary hydrogenation system, and the oxidation cooler (8) is connected to the liquid sulfur tank (9) and the tail gas fan (11) respectively.

6. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 1, characterized in that: A liquid sulfur pump (10) is provided in the liquid sulfur tank (9) for pumping the sulfur in the liquid sulfur tank (9) out to the molding section.

7. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 2, characterized in that: An acid gas SO2 concentration detector (A0) and an acid gas flow detector (F0) are provided on the gas transmission pipeline from the high-temperature dust collector (1) to the primary hydrogenation system.

8. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 3, characterized in that: A first-level acid gas flow detector and a first-level acid gas regulating valve are provided on the connecting pipeline between the first-level hydrogenation heater of each hydrogenation reaction section and the acid gas pretreatment system; a first-level hydrogen flow detector and a first-level hydrogenation regulating valve are provided on the connecting pipeline between each first-level hydrogenation heater and the external hydrogen pipeline; a nitrogen flow detector (FN) and a nitrogen regulating valve (301) are provided on the connecting pipeline between the first-level hydrogenation heater of the first hydrogenation reaction section and the external nitrogen pipeline; a first-level pre-hydrogenation temperature detector and a first-level pre-hydrogenation SO2 concentration detector are provided on the connecting pipeline between the first-level hydrogenation heater of each hydrogenation reaction section and the first-level hydrogenation reactor; a first-level post-hydrogenation temperature detector and a first-level post-hydrogenation SO2 concentration detector are provided on the connecting pipeline between the first-level hydrogenation reactor of each hydrogenation reaction section and the first-level hydrogenation cooler.

9. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 4, characterized in that: A secondary hydrogen flow detector (F3) and a secondary hydrogenation regulating valve (401) are provided on the connecting pipeline between the secondary hydrogenation heater (3) and the external hydrogen pipeline; a secondary pre-hydrogenation temperature detector (T3) and a secondary pre-hydrogenation SO2 concentration detector (A3) are provided on the connecting pipeline between the secondary hydrogenation heater (3) and the secondary hydrogenation reactor (4); a secondary post-hydrogenation temperature detector (T4) and a post-hydrogenation H2 and SO2 concentration detector (A4) are provided on the connecting pipeline between the secondary hydrogenation reactor (4) and the secondary hydrogenation cooler (5).

10. The activated carbon regeneration acid gas reduction sulfur hydrogenation reaction system according to claim 5, characterized in that: An air flow detector (F4) and an oxidation air regulating valve (501) are provided on the connecting pipeline between the oxygen heater (6) and the external air pipeline; a pre-oxidation temperature detector (T5) and a pre-oxidation H2S and SO2 concentration detector (A5) are provided on the connecting pipeline between the oxygen heater (6) and the oxidation reactor (7); and a post-oxidation temperature detector (T6) and a post-oxidation H2S and SO2 concentration detector (A6) are provided on the connecting pipeline between the oxidation reactor (7) and the oxidation cooler (8).

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