A desulfurization agent and a desulfurization method for removing organic sulfur from industrial synthesis gas

Abstract

The application discloses a kind of desulfurizer and removal method for removing organic sulfur in industrial synthesis gas, belongs to gas separation technical field, comprising: dust removal, dehydration, humidity adjustment, preheating, into the fixed bed adsorption filled with desulfurizer and regeneration post-processing.The desulfurizer prepared in the application, in cooperation with the dust removal, dehydration, humidity adjustment and preheating of industrial synthesis gas, etc.Pretreatment process, can realize that desulfurizer maintains high-efficiency desulfurization effect after 10 times regeneration, thereby significantly prolonging the service life of desulfurizer, reducing the replacement frequency of desulfurizer, reducing the cost of consumables procurement and replacement, while reducing the production downtime caused by replacing desulfurizer, guaranteeing the continuous operation of industrial synthesis gas treatment, adapting the efficiency demand of large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas separation, in particular to a desulfurization agent and method for removing organic sulfur from industrial synthesis gas. BACKGROUND

[0002] Industrial synthesis gas is widely used in the fields of chemical industry, energy, etc. as a core raw material for the industrial processes of ammonia synthesis, methanol synthesis, Fischer-Tropsch synthesis, power generation, etc. The purity of the industrial synthesis gas directly determines the quality of downstream products and the stability of production processes. Organic sulfur (such as carbon oxysulfide, carbon disulfide, mercaptan, etc.) is a typical harmful impurity in the industrial synthesis gas, which not only seriously corrodes the production equipment and blocks the process pipelines, but also causes the poisoning and deactivation of downstream synthesis catalysts, greatly reducing the catalytic efficiency and product yield.

[0003] The fixed-bed dry desulfurization technology is a common way for removing organic sulfur from industrial synthesis gas. However, the core desulfurization agent has obvious service life defects. The traditional desulfurization agent is mostly based on a single molecular sieve or metal oxide as the core, and the carrier and active components have poor adaptability and uneven dispersion. The desulfurization capacity and selectivity are insufficient, and the agent is easily deactivated quickly by impurities when treating complex synthesis gas. The regeneration performance is poor, and the efficiency is greatly reduced after 3-5 times of regeneration. Frequent replacement not only increases the cost of consumables, but also causes production downtime, interrupts continuous production, and is difficult to adapt to large-scale demand.

[0004] Therefore, the technical personnel in the field are committed to developing a desulfurization agent and method for removing organic sulfur from industrial synthesis gas. SUMMARY

[0005] In view of the above defects of the prior art, the technical problem to be solved by the present application is that the traditional desulfurization agent is mostly based on a single molecular sieve or metal oxide as the core, and the carrier and active components have poor adaptability and uneven dispersion. The desulfurization capacity and selectivity are insufficient, and the agent is easily deactivated quickly by impurities when treating complex synthesis gas. The regeneration performance is poor.

[0006] To achieve the above-mentioned purpose, the present application provides a desulfurization agent for removing organic sulfur from industrial synthesis gas, and the preparation method of the desulfurization agent comprises the following steps:

[0007] S1. modifying ZSM-5 molecular sieve;

[0008] The ZSM-5 molecular sieve is calcined at 500-600℃, cooled, ground, and sieved. An ammonium chloride solution is prepared, and the pH is adjusted to 4.0-5.5 by adding dilute hydrochloric acid dropwise. The ZSM-5 molecular sieve is mixed with the ammonium chloride solution and stirred, and the solid phase and liquid phase are separated. The solid phase is washed to obtain modified ZSM-5 molecular sieve;

[0009] S2. preparing a carrier;

[0010] Take 60-85 parts by weight of modified ZSM-5 molecular sieve, 4-6 parts by weight of silicon carbide powder, 13-20 parts by weight of pseudo-boehmite dry mixing, grinding and sieving to obtain the carrier;

[0011] S3. Prepare an active dispersion liquid;

[0012] A mixed solution containing Ce(NO3)3, Cu(NO3)2 and Co(NO3)2 is prepared, and a graphene oxide solution accounting for 0.5-2% of the mass of the mixed solution is added dropwise, ultrasonic dispersion is performed, 4-8% of the mass of the mixed solution is added to the starch, and stirring is performed to obtain an active dispersion liquid;

[0013] The molar ratio of Ce, Cu and Co in the mixed solution is 1-3:2-5:1-4;

[0014] S4. Compound;

[0015] The carrier and the active dispersion liquid are impregnated according to the ratio of 1g:1.2-2mL, dried to constant weight, and a precursor powder is obtained;

[0016] S5. Forming;

[0017] The precursor powder is made into small balls with a particle size of 4-6mm, and the small balls are calcined at 520-550℃ for 2-4h to obtain a sulfur removal agent.

[0018] In the preferred embodiment of the present application, S1 is specifically: ZSM-5 molecular sieve is placed in a muffle furnace and calcined at 500-600℃ for 4-6h, and then ground to 80-120 mesh after cooling to room temperature;

[0019] An ammonium chloride solution with a concentration of 0.5-2mol / L is prepared, and the pH is adjusted to 4.0-5.5 by adding dilute hydrochloric acid dropwise;

[0020] The ZSM-5 molecular sieve and the ammonium chloride solution are mixed according to the ratio of 1g:5-10mL, stirred at 60-80℃ and 200-300r / min for 2-4h, the solid phase and the liquid phase are separated by vacuum filtration, and the solid phase is washed with deionized water at 80-90℃ to obtain modified ZSM-5 molecular sieve.

[0021] In the preferred embodiment of the present application, S3 is specifically: a mixed solution containing Ce(NO3)3, Cu(NO3)2 and Co(NO3)2 is prepared, the total concentration of metal ions is 1.2-1.5mol / L, a graphene oxide solution accounting for 0.5-2% of the mass of the mixed solution is added dropwise at a speed of 2-3mL / min, ultrasonic dispersion is performed for 20-40min, 4-8% of the mass of the mixed solution is added to the starch, and stirring is performed at 200-300r / min for 15-22min to obtain an active dispersion liquid.

[0022] A removal method for removing organic sulfur in industrial synthesis gas by using the sulfur removal agent, comprising the following steps:

[0023] S1. Dust removal;

[0024] The industrial synthesis gas is passed into a cyclone separator at an inlet flow rate of 12-20 m / s, and the coarse particle dust with a particle size of ≥10 μm is separated by centrifugal force;

[0025] S2. Dehydration;

[0026] S3. Humidity adjustment;

[0027] The dehydrated industrial synthesis gas is passed into a humidity adjustment tower, and deionized water is sprayed into the tower through a top atomizing nozzle to control the water content to 10-20%;

[0028] S4. Preheating;

[0029] The humidity-adjusted industrial synthesis gas is adjusted to a temperature of 300-400℃ by a preheater;

[0030] S5. Passing into a fixed bed filled with the sulfur removal agent;

[0031] S6. Post-regeneration treatment;

[0032] The sulfur removal agent is passed through inert gas, purged at 200℃-250℃ for 1-2 h, heated to 500℃-650℃, and passed through inert gas mixed gas containing 5-10% O2 by volume, oxidized and decomposed to generate SO2, and maintained for 2-3 h; switched to a reducing gas and reduced at 280-320℃ for 1-2 h to realize regeneration of the sulfur removal agent.

[0033] In a preferred embodiment of the present application, S2 is specifically: the dust-removed industrial synthesis gas is passed into a tube-type condenser, the synthesis gas passes through the tube, the cooling medium passes through the shell, the cooling temperature is 15℃-25℃, and the gas stays in the tube, and saturated water vapor in the synthesis gas is removed by condensation, enters a gas-liquid separator, and the liquid water formed by condensation is separated off.

[0034] In a preferred embodiment of the present application, in S5, the preheated industrial synthesis gas is passed into a fixed bed reactor filled with the sulfur removal agent, the outlet pressure is 2-3 MPa, the gas velocity is 1500 h -1 -3000 h -1 .

[0035] In a preferred embodiment of the present application, in S5, the bulk density of the sulfur removal agent is 0.8 g / cm 3 -1.2 g / cm 3 .

[0036] In the preferable embodiment of the present application, the SO2-containing tail gas generated in the regeneration process is introduced into the lye absorption tower for neutralization and absorption, and the tail gas is discharged.

[0037] The device provided by the present application has the following technical effects:

[0038] 1. The sulfur removal agent prepared in the present application can maintain high sulfur removal efficiency after 10 times of regeneration when combined with the pretreatment process of industrial synthesis gas, such as dust removal, dehydration, humidity adjustment, and preheating, thereby significantly prolonging the service life of the sulfur removal agent, reducing the replacement frequency of the sulfur removal agent, reducing the cost of purchasing and replacing consumables, reducing the production downtime caused by replacing the sulfur removal agent, ensuring the continuous operation of industrial synthesis gas treatment, and adapting to the efficiency requirements of large-scale production.

[0039] 2. The present application modifies ZSM-5 molecular sieve, compounding a carrier containing silicon carbide powder and pseudo-boehmite, and using specific molar ratios of Ce(NO3)3, Cu(NO3)2, and Co(NO3)2 to prepare an active dispersion liquid to form an adapted sulfur removal agent. At the same time, the industrial synthesis gas is sequentially subjected to dust removal, dehydration, humidity controllable adjustment, and preheating treatment, which can avoid the interference of dust, water vapor fluctuation in synthesis gas and performance defects of the sulfur removal agent on the removal effect, and ensure the sulfur removal stability in long-term operation. At this time, the fixed bed reactor filled with the sulfur removal agent can effectively remove organic sulfur in the synthesis gas, avoid corrosion of production equipment and blockage of process pipelines, and cause poisoning and deactivation of downstream synthesis catalysts.

[0040] The concept, technical effects of the present application will be further described below with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is the process flow chart of the preparation and removal method of the sulfur removal agent for removing organic sulfur in industrial synthesis gas in embodiment 1 of the present application;

[0042] Figure 2 is the XRD diffraction pattern of the modified ZSM-5 molecular sieve, carrier, precursor powder and sulfur removal agent in embodiment 3 of the present application;

[0043] Figure 3 is the actual picture of the sulfur removal agent prepared in embodiment 1 of the present application. DETAILED DESCRIPTION

[0044] The present application is described in detail below with reference to specific embodiments. Although the application is described with reference to the embodiments, persons of ordinary skill in the art understand that various modifications in form and details can be made without departing from the spirit of the application. It should be noted that the embodiments below and the features in the embodiments can be combined with each other without conflict.

[0045] Some exemplary embodiments of the present application are described for illustrative purposes. It should be understood that the present application can be implemented in other ways not specifically shown in the drawings.

[0046] Embodiment 1: The present embodiment provides a sulfur removal agent and a method for removing organic sulfur from industrial synthesis gas. The preparation method of the sulfur removal agent comprises the following steps:

[0047] S1. Modification of ZSM-5 molecular sieve;

[0048] The ZSM-5 molecular sieve was placed in a muffle furnace and calcined at 500℃ for 4h. After cooling to room temperature, it was ground through an 80-120 mesh sieve;

[0049] A 0.5mol / L ammonium chloride solution was prepared, and the pH was adjusted to 4.0-5.5 by adding dilute hydrochloric acid dropwise;

[0050] The ZSM-5 molecular sieve was mixed with the ammonium chloride solution at a solid-liquid ratio of 1g:5mL, stirred at 60℃ and 200r / min for 2h, and the solid and liquid phases were separated by vacuum filtration. The solid phase was washed with deionized water at 80℃ until there was no chloride ion in the washing liquid (no white precipitate was detected using 0.1mol / L silver nitrate solution), and the modified ZSM-5 molecular sieve was obtained;

[0051] S2. Preparation of carrier;

[0052] 60 parts by weight of the modified ZSM-5 molecular sieve, 4 parts by weight of silicon carbide powder, and 13 parts by weight of pseudo-boehmite were weighed into a mixer and dry mixed at 400r / min for 30min. The mixture was ground and sieved to obtain a carrier with a particle size of 200μm;

[0053] S3. Preparation of active dispersion liquid;

[0054] A mixed solution containing Ce(NO3)3, Cu(NO3)2, and Co(NO3)2 was prepared, with a total metal ion concentration of 1.2mol / L. A graphene oxide solution with a mass fraction of 0.5% in the mixed solution was added at a rate of 2mL / min, and ultrasonic dispersion was performed for 20min. Starch with a mass fraction of 4% in the mixed solution was added, and stirring was performed at 200r / min for 15min to obtain an active dispersion liquid;

[0055] The molar ratio of Ce, Cu and Co in the mixed solution is 1:2:1;

[0056] S4. Compounding;

[0057] The carrier and the active dispersion liquid are impregnated according to the ratio of 1g:1.2mL for 2h, and dried at 100℃ to constant weight to obtain a precursor powder;

[0058] S5. Shaping;

[0059] The precursor powder is made into small balls with a particle size of 4-6mm by using a disc roller ball machine, and the small balls are calcined at 520℃ for 2h to obtain a sulfur removal agent.

[0060] The ZSM-5 molecular sieve is produced by Rui Zhi New Material (Shandong) Co., Ltd. 2-3mm hydrogen type ZSM-5 molecular sieve;

[0061] The silicon carbide powder is produced by Henan Fengkai Refractory Material Co., Ltd., and the product number is FK-0930;

[0062] The pseudo-boehmite is produced by Ningbo Jiemicro Nanometer New Material Technology Co., Ltd., and the model number is JWN-AN-GN11;

[0063] The method for removing organic sulfur in industrial synthesis gas by using the sulfur removal agent is specifically:

[0064] S1. Dust removal;

[0065] The industrial synthesis gas (initial temperature ≥80℃) is passed into the CLT / A cyclone separator at an inlet flow rate of 12-15m / s, and the coarse particle dust with a particle size of ≥10μm is separated by centrifugal force;

[0066] S2. Dehydration;

[0067] The dust-removed industrial synthesis gas (the temperature is about 60℃ at this time) is passed into a tube condenser, the synthesis gas passes through the tube, the cooling medium (industrial circulating water) passes through the shell, the cooling temperature is 15℃, and the gas stays in the tube. By condensation, saturated water vapor in the synthesis gas is removed, enters the gas-liquid separator, and the liquid water formed by condensation is separated;

[0068] S3. Humidity adjustment;

[0069] The dehydrated industrial synthesis gas is passed into a humidity adjustment tower, and deionized water is sprayed into the tower through a tower top atomizing nozzle to control the water content to 10%;

[0070] S4. Preheating;

[0071] The temperature of the humidity-adjusted industrial synthesis gas is adjusted to 300℃ by a preheater;

[0072] S5. Fixed bed adsorption;

[0073] The preheated industrial synthesis gas is passed into the fixed bed reactor filled with the sulfur removal agent, the outlet pressure is 2-3 MPa, the gas velocity is 1500 h -1 -3000 h -1 The sulfur removal agent has a bulk density of 0.8 g / cm 3 -1.2 g / cm 3 The total sulfur content of the gas at the outlet of the fixed bed is determined by a coulomb instrument to be ≤0.1 ppm, and if it is >0.1 ppm, the gas is returned to the fixed bed reactor for sulfur removal again;

[0074] S6. Post-treatment after regeneration;

[0075] The sulfur removal agent is purged with inert gas at 200℃ for 1 h to remove impurities such as physically adsorbed hydrocarbons and moisture; the temperature is raised to 500℃, and a mixed gas containing 5% O2 by volume is passed in to oxidize and decompose the adsorbed sulfides to generate SO2, and the process is maintained for 2 h; the reducing gas is switched to and reduction is carried out at 280℃ for 1 h to achieve regeneration of the sulfur removal agent; the SO2-containing tail gas generated during the regeneration process is passed into a lye absorption tower (NaOH solution concentration 5%) for neutralization and absorption, and the tail gas is then discharged.

[0076] Embodiment 2: The present embodiment provides a sulfur removal agent and a removal method for removing organic sulfur from industrial synthesis gas, and the preparation method of the sulfur removal agent comprises the following steps:

[0077] S1. Modification of ZSM-5 molecular sieve;

[0078] The ZSM-5 molecular sieve is placed in a muffle furnace and calcined at 600℃ for 6 h, and then ground to pass through an 80-120 mesh sieve after cooling to room temperature;

[0079] A 2 mol / L ammonium chloride solution is prepared, and the pH is adjusted to 4.0-5.5 by adding dilute hydrochloric acid dropwise;

[0080] The ZSM-5 molecular sieve is mixed with the ammonium chloride solution at a solid-liquid ratio of 1 g:10 mL, stirred at 80℃ and 300 r / min for 4 h, and the solid phase and liquid phase are separated by vacuum filtration, and the solid phase is washed with deionized water at 90℃ until there is no chloride ion in the washing liquid (no white precipitate is detected by using 0.1 mol / L silver nitrate solution), to obtain modified ZSM-5 molecular sieve;

[0081] S2. Preparation of carrier;

[0082] 85 parts by weight of modified ZSM-5 molecular sieve, 6 parts by weight of silicon carbide powder, and 20 parts by weight of pseudo-boehmite are weighed into a mixer and dry mixed at 500 r / min for 60 min, and then ground to pass through a 200 mesh sieve to obtain a carrier with a particle size of 200 mesh;

[0083] S3. Preparing the active dispersion liquid;

[0084] A mixed solution containing Ce(NO3)3, Cu(NO3)2 and Co(NO3)2 was prepared, with the total concentration of metal ions being 1.5 mol / L. A graphene oxide solution accounting for 2% of the mass of the mixed solution was added dropwise at a speed of 3 mL / min, and ultrasonic dispersion was performed for 40 min. Starch accounting for 8% of the mass of the mixed solution was added, and stirring was performed at 300 r / min for 22 min to obtain an active dispersion liquid.

[0085] The molar ratio of Ce, Cu and Co in the mixed solution was 3:5:4.

[0086] S4. Compounding;

[0087] The carrier and the active dispersion liquid were impregnated at a ratio of 1 g:2 mL for 4 h, and then dried at 120℃ until the weight was constant to obtain a precursor powder.

[0088] S5. Shaping;

[0089] The precursor powder was made into small balls with a particle size of 4-6 mm by using a disc-type ball machine, and the small balls were calcined at 550℃ for 4 h to obtain a sulfur removal agent.

[0090] The ZSM-5 molecular sieve was produced by Rui Zhi New Material (Shandong) Co., Ltd. 2-3 mm hydrogen type ZSM-5 molecular sieve;

[0091] The silicon carbide powder was produced by Henan Fengkai Refractory Material Co., Ltd. with the product number FK-0930;

[0092] The pseudo-boehmite was produced by Ningbo Jiemicro Nanometer New Material Technology Co., Ltd. with the model number JWN-AN-GN11;

[0093] The method for removing organic sulfur in industrial synthesis gas by using the sulfur removal agent specifically comprises:

[0094] S1. Dust removal;

[0095] Industrial synthesis gas (initial temperature ≥80℃) was passed into a CLT / A cyclone separator at an inlet flow rate of 18-20 m / s, and the coarse particle dust with a particle size of ≥10 μm was separated by centrifugal force.

[0096] S2. Dehydration;

[0097] The dust-removed industrial synthesis gas (at this time, the temperature was about 60℃) was passed into a tube condenser, the synthesis gas passed through the tube, and the cooling medium (industrial circulating water) passed through the shell. The cooling temperature was 25℃. The gas remained in the tube, and the saturated water vapor in the synthesis gas was removed by condensation. The gas entered a gas-liquid separator, and the liquid water formed by condensation was separated.

[0098] S3. Humidity adjustment;

[0099] The dehydrated industrial synthesis gas is passed into the humidity adjusting tower, and deionized water is sprayed into the tower through the atomizing nozzle at the top to control the water content at 20%;

[0100] S4. Preheating;

[0101] The humidity-adjusted industrial synthesis gas is passed through the preheater to adjust the temperature to 400℃;

[0102] S5. Fixed bed adsorption;

[0103] The preheated industrial synthesis gas is passed into the fixed bed reactor filled with the sulfur removal agent, the outlet pressure is 2-3 MPa, the gas velocity is 1500 h -1 -3000 h -1 , the bulk density of the sulfur removal agent is 0.8 g / cm 3 -1.2 g / cm 3 , the total sulfur content of the gas at the outlet of the fixed bed is determined by the coulomb instrument to be ≤0.1 ppm, and if it is >0.1 ppm, it is returned to the fixed bed reactor for sulfur removal again;

[0104] S6. Post-regeneration treatment;

[0105] The inert gas is passed into the sulfur removal agent, and the inert gas mixed gas containing 10% O2 is blown for 2 h at 250℃ to remove the physically adsorbed hydrocarbons, moisture and other impurities; the temperature is raised to 650℃, the inert gas mixed gas containing 10% O2 is passed in, the adsorbed sulfide is oxidized and decomposed to generate SO2, and the process is maintained for 3 h; the reducing gas is switched to reduce at 320℃ for 2 h to realize the regeneration of the sulfur removal agent; the SO2-containing tail gas generated during the regeneration process is passed into the lye absorption tower (NaOH solution concentration 5%) for neutralization and absorption, and the tail gas is discharged again.

[0106] Embodiment 3: The embodiment provides a sulfur removal agent for removing organic sulfur in industrial synthesis gas and a removal method, and the preparation method of the sulfur removal agent comprises the following steps:

[0107] S1. Modification of ZSM-5 molecular sieve;

[0108] The ZSM-5 molecular sieve is placed in a muffle furnace and calcined at 530℃ for 4 h, and then ground through an 80-120 mesh sieve after cooling to room temperature;

[0109] An ammonium chloride solution with a concentration of 0.8 mol / L is prepared, and the pH is adjusted to 4.0-5.5 by adding dilute hydrochloric acid dropwise;

[0110] The ZSM-5 molecular sieve was mixed with an ammonium chloride solution at a solid-liquid ratio of 1 g:6 mL, stirred at 73°C and 220 r / min for 3 h, the solid phase was separated from the liquid phase by vacuum filtration, and the solid phase was washed with deionized water at 86°C until there was no chloride ion in the washing liquid (no white precipitate was detected by using 0.1 mol / L silver nitrate solution), to obtain modified ZSM-5 molecular sieve;

[0111] S2. Preparation of a carrier;

[0112] 71 parts by weight of the modified ZSM-5 molecular sieve, 5 parts by weight of silicon carbide powder and 14 parts by weight of pseudo-boehmite were weighed into a mixer and dry-mixed at 420 r / min for 50 min, and then ground and sieved to obtain a carrier with a particle size of 200 mesh;

[0113] S3. Preparation of an active dispersion liquid;

[0114] A mixed solution containing Ce(NO3)3, Cu(NO3)2 and Co(NO3)2 was prepared, the total concentration of metal ions was 1.4 mol / L, 2 mL / min of graphene oxide solution accounting for 1.5% of the mass of the mixed solution was added dropwise, ultrasonic dispersion was performed for 25 min, 5% of starch accounting for the mass of the mixed solution was added, and stirring was performed at 220 r / min for 20 min to obtain an active dispersion liquid;

[0115] The molar ratio of Ce, Cu and Co in the mixed solution was 3:4:2;

[0116] S4. Compounding;

[0117] The carrier and the active dispersion liquid were impregnated at a solid-liquid ratio of 1 g:1.6 mL for 3 h, and then dried at 110°C to constant weight to obtain a precursor powder;

[0118] S5. Shaping;

[0119] The precursor powder was made into small balls with a particle size of 4-6 mm by using a disc-type ball machine, the small balls were calcined at 530°C for 4 h to obtain a sulfur removal agent.

[0120] The ZSM-5 molecular sieve was produced by Rui Zhi Anxin New Materials (Shandong) Co., Ltd. 2-3 mm hydrogen type ZSM-5 molecular sieve;

[0121] The silicon carbide powder was produced by Henan Fengkai Refractory Material Co., Ltd., and the product number was FK-0930;

[0122] The pseudo-boehmite was produced by Ningbo Jixi Nan New Material Technology Co., Ltd., and the model number was JWN-AN-GN11;

[0123] The method for removing organic sulfur in industrial synthesis gas by using the sulfur removal agent specifically comprises the following steps:

[0124] S1. Dust removal;

[0125] The industrial synthesis gas (initial temperature ≥ 80℃) is passed into the CLT / A cyclone separator at an inlet flow rate of 17-20 m / s, and the coarse particulate dust with a particle size ≥ 10 μm is separated by centrifugal force;

[0126] S2. Dehydration;

[0127] The dust-removed industrial synthesis gas (temperature about 60℃ at this time) is passed into the shell-and-tube condenser, the synthesis gas goes through the tube side, and the cooling medium (industrial circulating water) goes through the shell side, the cooling temperature is 20℃, and the gas stays in the tube, and the saturated water vapor in the synthesis gas is removed by condensation, and enters the gas-liquid separator, and the liquid water formed by condensation is separated off;

[0128] S3. Humidity adjustment;

[0129] The dehydrated industrial synthesis gas is passed into the humidity adjustment tower, and deionized water is sprayed into the tower through the atomizing nozzles at the top of the tower to control the water content to 14%;

[0130] S4. Preheating;

[0131] The humidity-adjusted industrial synthesis gas is adjusted to 330℃ in temperature by the preheater;

[0132] S5. Fixed bed adsorption;

[0133] The preheated industrial synthesis gas is passed into the fixed bed reactor filled with the sulfur removal agent, the outlet pressure is 2-3 MPa, the gas velocity is 1500 h -1 -3000 h -1 , the bulk density of the sulfur removal agent is 0.8 g / cm 3 -1.2 g / cm 3 , the total sulfur content of the gas at the outlet of the fixed bed is determined by the coulomb instrument to be ≤ 0.1 ppm, and if it is > 0.1 ppm, the gas is returned to the fixed bed reactor for sulfur removal again;

[0134] S6. Post-treatment after regeneration;

[0135] The inert gas is passed into the sulfur removal agent, and the inert gas mixed gas containing 6% O2 is blown for 2 h at 220℃ to remove the impurities such as physically adsorbed hydrocarbons and moisture; the temperature is raised to 570℃, the inert gas mixed gas containing 6% O2 is passed in, the adsorbed sulfide is oxidized and decomposed to generate SO2, and the process is maintained for 3 h; the reducing gas is switched in, and the sulfur removal agent is regenerated at 310℃ for 1 h; the SO2-containing tail gas generated in the regeneration process is passed into the alkali liquor absorption tower (NaOH solution concentration 5%) for neutralization and absorption, and the tail gas is discharged.

[0136] Embodiment 4: The embodiment provides a sulfur removal agent for removing organic sulfur in industrial synthesis gas and a removal method, and the preparation method of the sulfur removal agent comprises the following steps:

[0137] S1. Modification of ZSM-5 molecular sieve;

[0138] The ZSM-5 molecular sieve was placed in a muffle furnace and calcined at 580℃ for 5h, and then ground to pass through an 80-120 mesh sieve after cooling to room temperature;

[0139] A 1.5mol / L ammonium chloride solution was prepared, and the pH was adjusted to 4.0-5.5 by dropwise addition of dilute hydrochloric acid;

[0140] The ZSM-5 molecular sieve was mixed with the ammonium chloride solution at a solid-liquid ratio of 1g:8mL, and stirred at 78℃ and 260r / min for 2h. The solid phase and the liquid phase were separated by vacuum filtration, and the solid phase was washed with deionized water at 82℃ until there was no chloride ion in the washing liquid (no white precipitate was detected using 0.1mol / L silver nitrate solution), to obtain the modified ZSM-5 molecular sieve;

[0141] S2. Preparation of carrier;

[0142] 80 parts by weight of the modified ZSM-5 molecular sieve, 4 parts by weight of silicon carbide powder, and 16 parts by weight of pseudo-boehmite were placed in a mixer and dry-mixed at 460r / min for 40min, and then ground to pass through a 200 mesh sieve to obtain a carrier with a particle size of 200 mesh;

[0143] S3. Preparation of active dispersion liquid;

[0144] A mixed solution containing Ce(NO3)3, Cu(NO3)2, and Co(NO3)2 was prepared, wherein the total concentration of metal ions was 1.3mol / L. A graphene oxide solution accounting for 1% of the mass of the mixed solution was added dropwise at a speed of 3mL / min, ultrasonic dispersion was performed for 30min, 7% of starch accounting for the mass of the mixed solution was added, and stirring was performed at 250r / min for 18min to obtain an active dispersion liquid;

[0145] The molar ratio of Ce, Cu, and Co in the mixed solution was 2:3:3;

[0146] S4. Compounding;

[0147] The carrier and the active dispersion liquid were impregnated at a solid-liquid ratio of 1g:2mL for 4h, and then dried at 105℃ until the weight was constant to obtain a precursor powder;

[0148] S5. Shaping;

[0149] The precursor powder was made into small balls with a particle size of 4-6mm using a disc-type rolling ball machine, and the small balls were calcined at 535℃ for 4h to obtain a sulfur removal agent.

[0150] The ZSM-5 molecular sieve was produced by Rui Zhi Anxin New Materials (Shandong) Co., Ltd. 2-3mm hydrogen type ZSM-5 molecular sieve;

[0151] The silicon carbide micropowder is produced by Henan Fengkai Refractory Material Co., Ltd., and the item number is FK-0930;

[0152] The pseudo-boehmite is produced by Ningbo Juxin Nano New Material Technology Co., Ltd., and the model number is JWN-AN-GN11;

[0153] The method for removing organic sulfur in industrial synthesis gas by using the sulfur removal agent is specifically as follows:

[0154] S1. Dust removal;

[0155] The industrial synthesis gas (initial temperature ≥ 80℃) is passed into the CLT / A cyclone separator at an inlet flow rate of 13-15 m / s, and the coarse particle dust with a particle size ≥ 10 μm is separated by centrifugal force;

[0156] S2. Dehydration;

[0157] The dust-removed industrial synthesis gas (at this time, the temperature is about 60℃) is passed into the tube condenser, the synthesis gas goes through the tube, the cooling medium (industrial circulating water) goes through the shell, the cooling temperature is 23℃, and when the gas stays in the tube, the saturated water vapor in the synthesis gas is removed by condensation, enters the gas-liquid separator, and the liquid water formed by condensation is separated off;

[0158] S3. Humidity adjustment;

[0159] The dehydrated industrial synthesis gas is passed into the humidity adjustment tower, and deionized water is sprayed into the tower through the top atomizing nozzle, so that the water content is controlled at 16%;

[0160] S4. Preheating;

[0161] The humidity-adjusted industrial synthesis gas is adjusted to 370℃ in temperature by the preheater;

[0162] S5. Fixed bed adsorption;

[0163] The preheated industrial synthesis gas is passed into the fixed bed reactor filled with the sulfur removal agent, the outlet pressure is 2-3 MPa, the gas velocity is 1500 h -1 -3000 h -1 , the bulk density of the sulfur removal agent is 0.8 g / cm 3 -1.2 g / cm 3 , the total sulfur content of the fixed bed outlet gas is ≤ 0.1 ppm as determined by the coulomb instrument, and if it is > 0.1 ppm, the gas is returned to the fixed bed reactor for sulfur removal again;

[0164] S6. Post-regeneration treatment;

[0165] The desulfurizing agent is purged with inert gas at 230℃ for 2h to remove physically adsorbed hydrocarbons, moisture and other impurities; the temperature is raised to 620℃, and the inert gas mixed gas containing 8% O2 is introduced to oxidize and decompose the adsorbed sulfide to generate SO2, and the process is maintained for 3h; the reducing gas is switched to and the desulfurizing agent is regenerated at 300℃ for 2h; the SO2-containing tail gas generated during the regeneration process is introduced into the lye absorption tower (NaOH solution concentration 5%) for neutralization and absorption, and the tail gas is then discharged.

[0166] Comparative Example 1: The difference between this comparative example and Example 3 is that the ZSM-5 molecular sieve is not modified.

[0167] Comparative Example 2: The difference between this comparative example and Example 3 is that the silicon carbide powder is not added to the carrier.

[0168] Comparative Example 3: The difference between this comparative example and Example 3 is that the molar ratio of Ce, Cu and Co in the mixed solution is 5:1:7.

[0169] Comparative Example 4: The difference between this comparative example and Example 3 is that the industrial synthesis gas is not dehydrated and humidity adjusted.

[0170] Comparative Example 5: The difference between this comparative example and Example 3 is that the ZSM-5 molecular sieve is not modified, the silicon carbide powder is not added to the carrier, the molar ratio of Ce, Cu and Co in the mixed solution is 5:1:7, and the industrial synthesis gas is not dehydrated and humidity adjusted.

[0171] Experimental Example 1: Characterization of the desulfurizing agent;

[0172] It can be seen that the modified ZSM-5 molecular sieve, silicon carbide, γ-alumina (derived from the high-temperature calcination phase transition of pseudoboehmite) and CeO2, CuO and Co3O4 characteristic diffraction peaks appear in the desulfurizing agent: Figure 2 The diffraction peak positions of the modified ZSM-5 molecular sieve are 7.9°, 8.8°, 23.1°, 23.9° and 24.4°, and the corresponding crystal faces are (101), (020), (501), (303) and (133), respectively;

[0173] The diffraction peak position of the silicon carbide is 35.6°, and the corresponding crystal face is (111);

[0174] The diffraction peak positions of the γ-alumina are 37.5°, 45.8° and 66.7°, and the corresponding crystal faces are (311), (400) and (440), respectively;

[0175]

[0176] ​CeO2 appeared diffraction peak position is 28.6°, 33.1°, 47.5°, 56.3°, corresponding to the crystal face is (111), (200), (220), (311) respectively;

[0177] CuO appeared diffraction peak position is 35.5°, 38.7°, corresponding to the crystal face is (002), (111) respectively;

[0178] Co3O4 appeared diffraction peak position is 19.0°, 31.3°, 36.8°, 44.8°, corresponding to the crystal face is (111), (220), (311), (400) respectively;

[0179] Thus it is concluded that the crystal phase structure of each active component and carrier in the prepared sulfur removal agent meets the expected preparation effect, no impurity phase is generated and the crystallinity is good.

[0180] Experimental example 2: detection of organic sulfur removal rate and regeneration life of sulfur removal agent;

[0181] After inert gas cleaning, the stainless steel sampling cylinder (volume 1L) was used to collect the gas samples at the inlet (raw material gas) and outlet (purified gas) of the fixed bed reactor respectively, and the sampling pressure was 0.3MPa, and 3 parallel samples were collected for each sample to ensure data repeatability.

[0182] Detection instrument and parameter setting;

[0183] The gas chromatograph was equipped with a flame photometric detector (FPD), the sulfur element response wavelength was 394nm, and the detector temperature was 250℃;

[0184] The chromatographic column used a packed column (GDX-104 high polymer porous small ball column, column length 2m, inner diameter 3mm);

[0185] The column temperature was programmed, the initial temperature was 40℃ and maintained for 2min, then increased to 160℃ at 10℃ / min and maintained for 5min;

[0186] The carrier gas was high-purity nitrogen, and the column flow was 5mL / min;

[0187] The combustion gas was hydrogen, the flow was 40mL / min, and the air flow was 400mL / min.

[0188] Draw the standard curve: prepare a mixed standard gas containing COS, CS2, methyl mercaptan and thiophene with nitrogen as the base gas, the concentration gradient of each component is 10-1000ppm (calculated by sulfur), inject the standard gas, record the chromatographic peak height of each component, and draw the standard working curve with the logarithm of component concentration as the abscissa and the logarithm of peak height as the ordinate;

[0189] The industrial synthesis gas samples after desulfurization of each example and comparative example were injected into a chromatograph, each organic sulfur component was qualitatively identified according to the retention time of a standard curve, the concentration of a single component was quantitatively calculated by peak height, the total organic sulfur content was the sum of the contents of each component, and the removal rate was calculated according to the following formula:

[0190]

[0191] In the formula, C1 is the total organic sulfur content at the inlet of the fixed bed reactor (ppm), and C2 is the total organic sulfur content at the outlet of the fixed bed reactor (ppm).

[0192] After each sulfur removal agent was subjected to S6 regeneration treatment once (P1), three times (P3), five times (P5), seven times (P7), and ten times (P10), the organic sulfur removal rate (‰) was detected by the above method. 10

[0193] The results are shown in the following table:

[0194]

[0195] It should be noted that when the organic sulfur removal rate is <999.83‰, i.e., the total organic sulfur content at the outlet is >0.1 ppm, the sulfur removal agent is ineffective.

[0196] As shown in the above table, the sulfur removal agent prepared in the examples and subjected to a series of industrial synthesis gas pretreatment can still maintain high sulfur removal efficiency after 10 times of regeneration;

[0197] The absence of any key technical link (such as unmodified molecular sieve, carrier without silicon carbide powder, deviation of metal ion ratio from the set range, and raw gas without dehydration and humidity adjustment) will cause the sulfur removal effect or regeneration life to decrease to varying degrees;

[0198] The unmodified molecular sieve itself cannot provide a stable support, and the carrier without silicon carbide powder loses the guarantee of structural mechanical strength and uniform heat conduction, the deviated metal ions cannot effectively capture sulfides, and the fluctuation of water vapor will cause the contact efficiency of the sulfur removal agent with organic sulfur to be high and low, which cannot form a continuous removal reaction and cannot achieve effective removal of organic sulfur.

[0199] The above examples only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.​

Claims

1. A desulfurizing agent for removing organic sulfur from industrial synthesis gas, characterized in that, The method for preparing the desulfurizing agent includes the following steps: S1.ZSM-5 molecular sieve modification; ZSM-5 molecular sieves were calcined at 500-600℃, cooled, ground, and sieved. An ammonium chloride solution was prepared, and the pH was adjusted to 4.0-5.5 by adding dilute hydrochloric acid. The ZSM-5 molecular sieves and the ammonium chloride solution were mixed and stirred, the solid and liquid phases were separated, and the solid phase was washed to obtain the modified ZSM-5 molecular sieves. S2. Preparation of the carrier; Weigh 60-85 parts by weight of modified ZSM-5 molecular sieve, 4-6 parts by weight of silicon carbide micro powder, and 13-20 parts by weight of pseudoboehmite, dry mix, grind and sieve to obtain the carrier. S3. Prepare the active dispersion; Prepare a mixed solution containing Ce(NO3)3, Cu(NO3)2, and Co(NO3)2, add 0.5-2% (by mass) of graphene oxide solution to the mixed solution, disperse by ultrasonication, add 4-8% (by mass) of starch to the mixed solution, and stir to obtain an active dispersion. The molar ratio of Ce, Cu, and Co in the mixed solution is 1-3:2-5:1-4; S4. Compound formulation; The carrier and active dispersion were impregnated at a solid-liquid ratio of 1g:1.2-2mL and dried to constant weight to obtain precursor powder. S5. Molding; The precursor powder is made into small balls with a particle size of 4-6 mm, and the small balls are calcined at 520-550℃ for 2-4 hours to obtain the desulfurizing agent.

2. The desulfurizing agent for removing organic sulfur from industrial synthesis gas as described in claim 1, characterized in that, S1 specifically involves placing ZSM-5 molecular sieves in a muffle furnace, calcining them at 500-600℃ for 4-6 hours, cooling them to room temperature, and then grinding them through an 80-120 mesh sieve. Prepare a 0.5-2 mol / L ammonium chloride solution, and adjust the pH to 4.0-5.5 by adding dilute hydrochloric acid dropwise; ZSM-5 molecular sieve and ammonium chloride solution were mixed at a solid-liquid ratio of 1g:5-10mL and stirred at 60-80℃ and 200-300r / min for 2-4h. The solid and liquid phases were separated by vacuum filtration. The solid phase was washed with deionized water at 80-90℃ to obtain modified ZSM-5 molecular sieve.

3. The desulfurizing agent for removing organic sulfur from industrial synthesis gas as described in claim 1, characterized in that, S3 specifically involves preparing a mixed solution containing Ce(NO3)3, Cu(NO3)2, and Co(NO3)2, with a total metal ion concentration of 1.2-1.5 mol / L. Then, 0.5-2% (by mass) of graphene oxide solution is added dropwise at a rate of 2-3 mL / min. The mixture is ultrasonically dispersed for 20-40 min. Finally, 4-8% (by mass) of starch is added, and the mixture is stirred at 200-300 r / min for 15-22 min to obtain the active dispersion.

4. A method for removing organic sulfur from industrial synthesis gas using the desulfurizing agent according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Dust removal; Industrial syngas is introduced into a cyclone separator at an inlet flow rate of 12-20 m / s, and coarse dust particles with a diameter of ≥10 μm are separated by centrifugal force. S2. Dehydration; S3. Humidity adjustment; The dehydrated industrial syngas is fed into a humidity control tower, and deionized water is sprayed into the tower through atomizing nozzles at the top of the tower to control the water content at 10-20%. S4. Preheating; The temperature of the industrial syngas, after humidity regulation, is adjusted to 300-400℃ by the preheater; S5. Introduce adsorption into a fixed bed filled with the desulfurizing agent; S6. Post-regeneration treatment; Inert gas is introduced into the desulfurizing agent and purged at 200℃-250℃ for 1-2 hours. The temperature is then raised to 500℃-650℃, and an inert gas mixture containing 5-10% O2 volume fraction is introduced to oxidize and decompose the adsorbed sulfides, generating SO2. This process is maintained for 2-3 hours. The desulfurizing agent is then regenerated by switching to a reducing gas and reducing it at 280-320℃ for 1-2 hours.

5. The removal method as described in claim 4, characterized in that, S2 specifically involves: passing the dust-removed industrial syngas into a shell-and-tube condenser, with the syngas flowing through the tubes and the cooling medium flowing through the shell, at a cooling temperature of 15℃-25℃. When the gas remains in the tubes, the saturated water vapor in the syngas is removed through condensation, and then it enters a gas-liquid separator to separate the liquid water formed by condensation.

6. The removal method as described in claim 4, characterized in that, In step S5, preheated industrial syngas is introduced into a fixed-bed reactor filled with the desulfurizing agent, with an outlet pressure of 2-3 MPa and a gas velocity of 1500 h⁻¹. -1 -3000h -1 .

7. The removal method as described in claim 4, characterized in that, In S5, the bulk density of the desulfurizing agent is 0.8 g / cm³. 3 -1.2g / cm 3 .

8. The removal method as described in claim 4, characterized in that, In S6, the SO2-containing tail gas generated during the regeneration process is fed into an alkaline absorption tower for neutralization and absorption before being discharged.

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