Method for vulcanizing shift catalyst by adding sulfur into low-sulfur coal

Abstract

The invention relates to the technical field of catalyst sulfuration in a coal gasification process, and particularly discloses a method for sulfuration of a shift catalyst by adding sulfur into low-sulfur coal, and the method comprises the following steps: fully mixing byproduct sulfur with boiler slag by adopting an internal mixing process to prepare a slag-sulfur mixture; fully and uniformly mixing the slag-sulfur mixture with low-sulfur coal, and feeding the mixture into a coal mill for milling to obtain pulverized coal; the method comprises the following steps: in a coal gasifier, carrying out online vulcanization on a shift catalyst by using pulverized coal, setting slag sampling once every half an hour after adding a slag-sulfur mixture, and monitoring the H2S concentration, the ash water pH value and the sulfate radical concentration in the synthesis gas in real time. According to the method, the by-product sulfur and the boiler slag are subjected to banburying compounding to prepare the slag-sulfur mixture, the slag-sulfur mixture and the low-sulfur coal are uniformly mixed in proportion to prepare powder, and by controlling the outlet temperature of the coal mill, the circulating air volume and the pressurized conveying temperature, the stable combustion of the coal powder and the on-line vulcanization of the shift catalyst are realized.

Description

Technical Field

[0001] This invention relates to the field of catalyst sulfidation technology in coal gasification processes, and more specifically, to a method for adding sulfur to low-sulfur coal for catalyst sulfidation. Background Technology

[0002] Syngas produced by coal gasification mainly consists of CO and H2, with a typically high CO content, making it unsuitable for downstream processes. To increase the effective hydrogen yield of the syngas, a partial conversion of CO to H2 is usually required. Cobalt-molybdenum based catalysts are currently the main catalysts used in low-temperature shift reactions. These catalysts require sulfidation before use and after desulfurization to convert oxides such as CoO and MoO3 into sulfides, thus acquiring catalytic activity. Traditional catalyst sulfidation typically uses high-sulfur coal or adds sulfiding agents such as CS2, or pre-treats the catalyst. However, this approach has several drawbacks: 1. High-sulfur coal affects coal quality stability, alters gasifier operating conditions, and poses operational risks; 2. Using sulfiding agents such as CS2 is toxic and complex; 3. Pre-treating the catalyst is time-consuming or difficult to operate continuously online. Therefore, achieving online catalyst sulfidation while maintaining a stable supply of low-sulfur coal, ensuring high catalytic activity and safety and economy, is a pressing technical challenge.

[0003] Based on the above statements, the present invention proposes a method for adding sulfur to low-sulfur coal for conversion catalyst sulfidation. Summary of the Invention

[0004] To address the problems of unstable coal quality, large volatilization loss of sulfiding agents, high safety risks, and mismatched process parameters in existing technologies for sulfidation of low-sulfur coal catalysts, this invention provides a method for adding sulfur to low-sulfur coal for catalyst sulfidation. This invention achieves safe, efficient, and stable online sulfidation of the catalyst during continuous coal gasification production by adding a composite mixture of by-product sulfur and boiler slag prepared in a specific ratio to low-sulfur coal, and by synchronously controlling key process parameters. This method overcomes the technical defects of traditional sulfidation methods, ensures a significant improvement in catalyst activity and service life, and has excellent practical value and market application potential.

[0005] This invention provides a method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst, employing the following technical solution:

[0006] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0007] Step 1: The by-product sulfur and boiler slag are thoroughly mixed using a mortar mixing process to prepare a slag-sulfur mixture;

[0008] Step 2: After thoroughly mixing the slag-sulfur mixture with the low-sulfur coal, feed it into a coal mill for pulverization to obtain pulverized coal.

[0009] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour, and the concentration of H2S in the syngas, the pH value of the ash water and the sulfate concentration are monitored in real time.

[0010] Preferably, the mass ratio of by-product sulfur to boiler slag in step 1 is 1:1.5-3.

[0011] Preferably, the particle size of the slag-sulfur mixture in step 1 is 5-10 mm.

[0012] This invention ensures uniform distribution, improves sulfur dispersion, reduces volatilization, and guarantees the uniformity of sulfur content by controlling the mass ratio of by-product sulfur to boiler slag and refining the particle size of the slag-sulfur mixture. This, in turn, ensures good stability and reactivity.

[0013] Preferably, the raw materials for preparing the slag-sulfur mixture in step 1 further include a carrier additive, the mass of which is 5-8% of the total mass of by-product sulfur and boiler slag.

[0014] Preferably, the carrier additive is fly ash and solid sodium silicate in a mass ratio of 1-3:1.

[0015] Preferably, the fly ash is secondary fly ash; the modulus of the solid sodium silicate is 3.10-3.40.

[0016] Preferably, in step 2, the mass ratio of the slag-sulfur mixture to the low-sulfur coal is 1:70-90.

[0017] Preferably, in step 2, the outlet temperature of the coal mill is 90-95℃, the circulating air volume is 85000-90000Nm³ / h, the temperature of the pulverized coal silo is 98-102℃, and the temperature of the pressurized carbon dioxide conveying system is 100-108℃.

[0018] This invention ensures the release of effective sulfur components while maintaining coal quality stability, preserving coal powder flowability and gasification performance, thereby rapidly achieving catalyst sulfidation. Controlling the pulverizer outlet temperature helps maintain coal powder dryness, preventing sulfur melting or decomposition, and thus preventing catalyst activity reduction caused by sulfur volatilization. Controlling the pulverizer circulating air volume helps maintain a stable furnace atmosphere, ensuring sufficient sulfur reaction, effectively enhancing the sulfidation rate and maintaining catalyst activity.

[0019] Preferably, the real-time monitoring of H2S concentration, ash water pH value and sulfate concentration in step 3 specifically refers to: using a continuous online H2S gas and ash water electrochemical sensor, setting the sampling cycle to once every 2 hours, to monitor the H2S concentration, ash water pH value and sulfate concentration in the syngas in real time.

[0020] In summary, the present invention has the following beneficial effects:

[0021] This invention utilizes a process of preparing a slag-sulfur mixture by intensifying the mixing of by-product sulfur and boiler slag, then uniformly mixing this mixture with low-sulfur coal in a specific ratio for pulverization. By controlling the pulverizer outlet temperature, circulating air volume, and pressurized conveying temperature, stable combustion of pulverized coal and online sulfidation of the shift catalyst are achieved. This method achieves the following technical effects:

[0022] 1. This invention significantly improves the uniformity and stability of sulfur distribution, reduces sulfur volatilization loss, and achieves stable release of effective sulfur source by rationally combining by-product sulfur with boiler slag.

[0023] 2. This invention ensures the stability of the physical properties of pulverized coal and the atmosphere inside the gasifier by precisely controlling the outlet temperature of the coal mill, the circulating air volume, and the temperature of the pressurized carbon dioxide. This avoids sulfur melting and volatilization, and ensures the controllability and safety of the online sulfidation process of the catalyst.

[0024] 3. This invention achieves closed-loop control of the catalyst sulfidation process by continuously monitoring the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration online, and dynamically adjusting the process parameters based on this data, thereby improving sulfidation efficiency and catalyst activity.

[0025] 4. By adding carrier additives (fly ash and solid sodium silicate), this invention further enhances the mechanical strength and thermal stability of the composite, improves process stability, and extends catalyst lifespan.

[0026] 5. This invention avoids the use of high-sulfur coal and the addition of toxic sulfiding agents. The process is simple, safe and environmentally friendly, suitable for continuous gasification production of low-sulfur coal, and has significant economic benefits.

[0027] 6. This invention shortens the catalyst activation time by 10%-20%, extends the catalyst lifespan by 26%-37% compared to unsulfurized catalysts, significantly improves CO conversion rate by 15%-23%, solves the catalyst sulfidation problem under low-sulfur coal conditions, and has broad industrial application prospects. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments.

[0029] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0030] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0031] Example 1

[0032] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0033] Step 1: Mix the by-product sulfur and boiler slag at a mass ratio of 1:2 using a mortar mixing process to prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg.

[0034] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0035] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0036] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 18% compared with the unsulfurized version, and the catalyst lifespan was extended by 30% compared with the unsulfurized version.

[0037] Example 2

[0038] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0039] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:1.5 using a mortar mixing process to prepare a slag-sulfur mixture with a particle size of 7mm.

[0040] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:70, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 90℃, the circulating air volume is 85000 Nm³ / h, the coal pulverizer temperature is 98℃, and the high-pressure carbon dioxide temperature is 100℃ to produce pulverized coal.

[0041] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours. The concentration of H2S in the syngas, the pH value of the ash water and the sulfate concentration are monitored in real time to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0042] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 15% compared with the unsulfurized state, and the catalyst life was extended by 26% compared with the unsulfurized state.

[0043] Example 3

[0044] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0045] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2.5 using a mortar mixing process to prepare a slag-sulfur mixture with a particle size of 9mm.

[0046] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:90, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 95℃, the circulating air volume is 89000 Nm³ / h, the coal pulverizer temperature is 102℃, and the high-pressure carbon dioxide temperature of the pressurized conveyor is 108℃ to obtain pulverized coal.

[0047] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours. The concentration of H2S in the syngas, the pH value of the ash water and the sulfate concentration are monitored in real time to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0048] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 17% compared with the unsulfurized state, and the catalyst life was extended by 28% compared with the unsulfurized state.

[0049] Example 4

[0050] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0051] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2, add 6.5% of the total mass of by-product sulfur and boiler slag as a carrier additive, and use an internal mixing process to fully mix and prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg. The carrier additive includes secondary fly ash at a mass ratio of 2:1 and solid sodium silicate with a modulus of 3.10.

[0052] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0053] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0054] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 23% compared with the unsulfurized state, and the catalyst life was extended by 37% compared with the unsulfurized state.

[0055] Example 5

[0056] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0057] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2, add 5% of the total mass of by-product sulfur and boiler slag as a carrier additive, and use an internal mixing process to fully mix and prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg. The carrier additive includes secondary fly ash at a mass ratio of 1:1 and solid sodium silicate with a modulus of 3.10.

[0058] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0059] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0060] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 22% compared with the unsulfurized version, and the catalyst lifespan was extended by 35% compared with the unsulfurized version.

[0061] Example 6

[0062] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0063] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2, add 8% of the total mass of by-product sulfur and boiler slag as a carrier additive, and use an internal mixing process to fully mix and prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg. The carrier additive includes secondary fly ash at a mass ratio of 3:1 and solid sodium silicate with a modulus of 3.10.

[0064] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0065] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0066] In this embodiment, the H2S concentration in the syngas was stably controlled within the range of 110-120 ppm, the pH value of the ash water was maintained at 7.0-7.5, the sulfate concentration was maintained within the range of 90-115 mg / L, the CO conversion rate was increased by 20% compared with the unsulfurized state, and the catalyst life was extended by 34% compared with the unsulfurized state.

[0067] Comparative Example 1

[0068] Comparative Example 1 is the same as Example 1, except that the coal mill outlet temperature is not controlled. Details are as follows:

[0069] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0070] Step 1: Mix the by-product sulfur and boiler slag at a mass ratio of 1:2 using a mortar mixing process to prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg.

[0071] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 112℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0072] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0073] In this embodiment, the H2S concentration in the syngas fluctuated drastically, ranging from 20 to 200 ppm; the pH of the ash water fluctuated drastically from 6.5 to 8.0; the catalyst activity decreased by 17%, and the CO conversion rate increased by only 5% compared to the unsulfurized version.

[0074] Comparative Example 2

[0075] Comparative Example 2 is the same as Example 1, except that the mass ratio of the slag-sulfur mixture to low-sulfur coal is 1:40. Details are as follows:

[0076] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0077] Step 1: Mix the by-product sulfur and boiler slag at a mass ratio of 1:2 using a mortar mixing process to prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg.

[0078] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:40, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature of the pressurized conveyor is 104℃ to obtain pulverized coal.

[0079] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0080] In this embodiment, the H2S concentration in the syngas fluctuated between 80 and 160 ppm; the pH of the ash water fluctuated between 6.8 and 7.8; the sulfate concentration increased to 105-130 mg / L; the catalyst activity decreased by 13%; and the CO conversion rate increased by only 10% compared to the unsulfurized version.

[0081] Comparative Example 3

[0082] Comparative Example 3 is the same as Example 1, except that the slag-sulfur mixture is replaced with a single by-product sulfur. Details are as follows:

[0083] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0084] Step 1: The by-product sulfur is thoroughly mixed using an intensive mixing process to prepare sulfur granules with a particle size of 8mm, yielding a total of 1000kg.

[0085] Step 2: After thoroughly mixing sulfur particles with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to obtain pulverized coal.

[0086] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding sulfur particles, the slag quality is sampled every half hour to confirm that the sulfur particles are evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0087] In this embodiment, the H2S concentration in the syngas fluctuated between 15 and 180 ppm; the pH of the ash water fluctuated drastically between 6.2 and 7.7; the catalyst activity decreased by 12%, and the CO conversion rate did not show a significant improvement compared to the unsulfurized version.

[0088] Comparative Example 4

[0089] Comparative Example 4 is the same as Example 4, except that the carrier additive used is only secondary fly ash. Details are as follows:

[0090] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0091] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2, add 6.5% of secondary fly ash (based on the total mass of by-product sulfur and boiler slag), and use a mortar mixing process to fully mix and prepare a slag-sulfur mixture with a particle size of 8mm, yielding a total of 1000kg.

[0092] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0093] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0094] In this embodiment, the H2S concentration in the synthesis gas fluctuated between 90 and 120 ppm; the pH of the ash water fluctuated drastically between 6.6 and 7.8; the sulfate concentration fluctuated between 80 and 125 mg / L; and the catalyst lifespan was shortened by 7% compared to Example 4.

[0095] Comparative Example 5

[0096] Comparative Example 5 is the same as Example 4, except that the carrier additive used is only solid sodium silicate with a modulus of 3.10. Details are as follows:

[0097] A method for adding sulfur to low-sulfur coal for shift catalyst sulfidation includes the following steps:

[0098] Step 1: Mix by-product sulfur and boiler slag at a mass ratio of 1:2, add 6.5% of the total mass of by-product sulfur and boiler slag, and add solid sodium silicate with a modulus of 3.10. Use a intensive mixing process to fully mix and prepare a slag-sulfur mixture with a particle size of 8mm, and a total of 1000kg is obtained.

[0099] Step 2: After thoroughly mixing the slag-sulfur mixture with low-sulfur coal (sulfur content 0.21%) at a mass ratio of 1:80, the mixture is fed into a coal mill for pulverization. The outlet temperature of the coal mill is controlled at 93℃, the circulating air volume is 87000 Nm³ / h, the coal pulverizer temperature is 100℃, and the high-pressure carbon dioxide temperature is 104℃ to produce pulverized coal.

[0100] Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour to confirm that the slag-sulfur mixture is evenly distributed. Continuous online H2S gas and ash water electrochemical sensors are used, with a sampling cycle of once every 2 hours, to monitor the H2S concentration in the syngas, the pH value of the ash water, and the sulfate concentration in real time, to ensure that the sulfidation process operates in a safe and optimal state, and to achieve safe and efficient catalyst sulfidation.

[0101] In this embodiment, the H2S concentration in the synthesis gas fluctuated within a relatively low range, between 80 and 110 ppm; the pH of the ash water fluctuated between 6.5 and 7.5; the sulfate concentration increased to 110-135 mg / L; and the catalyst lifespan was shortened by 11% compared to Example 4.

[0102] In summary, the H2S concentration fluctuation range in the syngas of Examples 1-6 of this invention was controlled within 110-120 ppm, demonstrating the stable sulfur source release function of the slag-sulfur mixture and process parameters. Data fluctuations were all less than 10%, meeting the legal standards for sulfidation operation. The pH value of the ash water was maintained between 7.0 and 7.5, a slightly alkaline environment that is suitable for the catalyst sulfidation reaction and within a safe range, preventing premature catalyst deactivation due to excessive acidity. The sulfate concentration was maintained within the range of 90-115 mg / L, indicating stable sulfide circulation and no abnormal accumulation during coal gasification and sulfidation. CO conversion rate increased by 15-23%, catalyst lifespan was extended by 26-37%, and the slag-sulfur mixture showed significant protection and activity maintenance effects on the catalyst, conforming to the actual process of catalyst sulfidation under low-sulfur coal conditions and possessing good engineering replicability.

[0103] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst, characterized in that, Includes the following steps: Step 1: The by-product sulfur and boiler slag are thoroughly mixed using a mortar mixing process to prepare a slag-sulfur mixture; Step 2: After thoroughly mixing the slag-sulfur mixture with the low-sulfur coal, feed it into a coal mill for pulverization to obtain pulverized coal. Step 3: In the coal gasification furnace, online sulfidation of the shift catalyst is carried out using pulverized coal. After adding the slag-sulfur mixture, the slag quality is sampled every half hour, and the concentration of H2S in the syngas, the pH value of the ash water and the sulfate concentration are monitored in real time.

2. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst, as described in claim 1, is characterized in that... In step 1, the mass ratio of by-product sulfur to boiler slag is 1:1.5-3.

3. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst, as described in claim 1, is characterized in that... The particle size of the slag-sulfur mixture in step 1 is 5-10 mm.

4. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst, as described in claim 1, is characterized in that... The raw materials for preparing the slag-sulfur mixture in step 1 also include a carrier additive, the mass of which is 5-8% of the total mass of by-product sulfur and boiler slag.

5. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst according to claim 4, characterized in that, The carrier additive is fly ash and solid sodium silicate in a mass ratio of 1-3:

1.

6. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst according to claim 5, characterized in that, The fly ash is secondary fly ash; the modulus of the solid sodium silicate is 3.10-3.

40.

7. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst according to claim 1, characterized in that, In step 2, the mass ratio of the slag-sulfur mixture to the low-sulfur coal is 1:70-90.

8. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst according to claim 1, characterized in that, In step 2, the coal mill outlet temperature is 90-95℃, the circulating air volume is 85000-90000Nm³ / h, the pulverized coal silo temperature is 98-102℃, and the pressurized carbon dioxide conveying temperature is 100-108℃.

9. The method for adding sulfur to low-sulfur coal for sulfidation using a shift catalyst according to claim 1, characterized in that, The real-time monitoring of H2S concentration, ash water pH value and sulfate concentration in step 3 specifically refers to: using a continuous online H2S gas and ash water electrochemical sensor, setting the sampling cycle to once every 2 hours, to monitor the H2S concentration, ash water pH value and sulfate concentration in real time.