Preparation method of desulfurization adsorbent carrier, prepared desulfurization adsorbent carrier and application of prepared desulfurization adsorbent carrier

Abstract

The invention relates to the technical field of chemical engineering, and discloses a preparation method of a desulfurization adsorbent carrier, the prepared desulfurization adsorbent carrier and application of the desulfurization adsorbent carrier, the method comprises the following steps: (1) mixing a zinc source, a silicon source, an aluminum source and a molecular sieve with a nitric acid solution to obtain slurry; (2) the slurry is conveyed into spraying equipment through a diaphragm type high-pressure pump to be subjected to spraying forming and curing; and (3) roasting the cured product in the step (2) in a direct-fired hot blast stove step by step to obtain the desulfurization adsorbent carrier. According to the preparation method, the nitric acid solution is added for mixing, the slurry is conveyed into the spraying equipment through the diaphragm type high-pressure pump for spraying, forming and curing, and step-by-step roasting is performed in the direct-fired hot blast stove, so that the prepared desulfurization adsorbent carrier is high in yield, the production energy consumption is reduced, and the equipment field noise is low and leakage is avoided.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and specifically relates to a preparation method of a desulfurization adsorbent carrier, the obtained desulfurization adsorbent carrier and its application. Background Art

[0002] The adsorbent is composed of zinc oxide, nickel oxide and silica-alumina material. Zinc oxide is used to absorb gaseous H2S, nickel oxide plays a role in promoting combustion after reduction, and the silicon component serves as a structural unit and binder. The preparation of its carrier goes through processes such as raw material pulping, spray drying and carrier calcination. CN102343252B discloses a hydrocarbon oil adsorbent and its preparation method and application. The carrier slurry is spray-dried by a spray dryer of the Niro Bowen Nozzle TowerTM model, the spray drying pressure is 8.5 to 9.5 MPa, the inlet temperature is below 500 °C, and the outlet temperature is about 150 °C. The microspheres obtained by spray drying are first dried at 180 °C for 1 hour, and then calcined at 635 °C for 1 hour to obtain the adsorbent carrier. This kind of adsorbent carrier preparation method has the characteristics of high energy consumption, low yield and uneven product particle size distribution. Summary of the Invention

[0003] The purpose of the present invention is to overcome the problems of high energy consumption and low yield in the preparation of desulfurization adsorbent carriers existing in the prior art, and to provide a preparation method of a desulfurization adsorbent carrier, the obtained desulfurization adsorbent carrier and its application. This preparation method mixes with a nitric acid solution, transports the slurry to a spray device through a diaphragm high-pressure pump for spray forming and curing, and performs step-by-step calcination in a direct-fired hot blast stove. The obtained desulfurization adsorbent carrier has a high yield, reduces production energy consumption, and has low noise and no leakage at the equipment site.

[0004] To achieve the above purpose, the first aspect of the present invention provides a preparation method of a desulfurization adsorbent carrier, wherein the method includes the following steps:

[0005] (1) Mix a zinc source, a silicon source, an aluminum source and a molecular sieve with a nitric acid solution to obtain a slurry;

[0006] (2) Transport the slurry to a spray device through a diaphragm high-pressure pump for spray forming and curing;

[0007] (3) Perform step-by-step calcination on the cured product in step (2) in a direct-fired hot blast stove to obtain a desulfurization adsorbent carrier.

[0008] Preferably, in step (1), the addition amounts of each component are in weight, and the weight ratio of the zinc source: the silicon source: the aluminum source: the molecular sieve: the nitric acid solution is 15 - 35:15 - 35:15 - 35:70 - 110:10 - 30, preferably 20 - 30:20 - 30:20 - 30:80 - 100:15 - 20.

[0009] Preferably, based on the total mass of the zinc source, silicon source, aluminum source and molecular sieve being 1 t, the dropping rate of the nitric acid solution is 1-6 L / min, preferably 1.25-2.5 L / min.

[0010] The second aspect of the present invention provides a desulfurization adsorbent carrier prepared by the preparation method described in the first aspect.

[0011] The third aspect of the present invention provides an application of the desulfurization adsorbent carrier described in the second aspect in the field of fuel oil desulfurization.

[0012] By the above technical solutions, the following beneficial effects are obtained:

[0013] (1) The present invention uses a diaphragm high-pressure pump to replace the original stuffing box high-pressure pump, eliminating problems such as high-pressure pump stuffing box failure maintenance, uses a direct-fired hot blast stove to replace the existing vertical roasting furnace, reducing gas consumption, and optimizing the carrier particle size distribution and improving the product yield.

[0014] (2) In the present invention, preferably, a dropping pump is used to add nitric acid to achieve trace addition of nitric acid within a certain time; a bucket elevator is used to replace the existing scraper conveyor, thereby reducing the equipment failure rate, increasing the yield, and optimizing the on-site operation environment. Description of the Drawings

[0015] Figure 1 is a process flow diagram of the preparation method of the desulfurization adsorbent carrier.

[0016] Description of the Reference Numerals

[0017] 1 - dropping pump 2 - batching kettle 3 - diaphragm high-pressure pump

[0018] 4 - hot blast stove 5 - spraying equipment 6 - bucket elevator

[0019] 7 - direct-fired hot blast stove Detailed Embodiments

[0020] The endpoints and any values disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0021] The first aspect of the present invention provides a preparation method of a desulfurization adsorbent carrier, wherein the method comprises the following steps:

[0022] (1) Mix a zinc source, a silicon source, an aluminum source and a molecular sieve with a nitric acid solution to obtain a slurry;

[0023] (2) Deliver the slurry to a spray device through a diaphragm high-pressure pump for spray forming and curing;

[0024] (3) Calcinate the cured product obtained in step (2) step by step in a direct-fired hot blast stove to obtain a desulfurization adsorbent carrier.

[0025] In the present invention, a diaphragm high-pressure pump is used to replace the original packing high-pressure pump. During the use of the original plunger packing high-pressure pump, the packing seal wears out quickly, the service life is short, and the pump head assembly is easily worn. The cost of replacing the packing and repairing the equipment is relatively high. There is also a problem that the packing needs to be replaced frequently, resulting in material loss and affecting the yield. The treatment of the lost materials also increases the environmental protection pressure. The preparation process is affected by the performance of the packing and the equipment body, and the spray pressure fluctuates greatly, affecting the process quality. By using a diaphragm high-pressure pump, the material is in the pump head chamber when entering and leaving the pump body. The connecting rod drives the plunger, and through the movement of the diaphragm, the medium is inhaled and discharged. The medium only contacts the diaphragm and does not contact the external and internal transmission machinery of the pump body, and is transported in a sealed environment, fundamentally eliminating leakage.

[0026] In the present invention, in step (2), by controlling the head and flow rate of the diaphragm high-pressure pump, the pump outlet pipeline is optimized to stabilize the pipeline pressure and reduce the influence of pressure fluctuation on the process quality. A pressure gauge warning is added at the pump head to timely detect the diaphragm breakage situation and achieve long-term stable operation of the high-pressure pump.

[0027] In the present invention, preferably, at least one of PTFE diaphragm, PVDF diaphragm and ETFE diaphragm is used for the part of the diaphragm high-pressure pump in contact with the material, and a stainless steel one-way valve is used for the inlet and outlet, and the valve ball is made of ceramic material and / or Si3N4 (silicon nitride).

[0028] According to the present invention, the type of the zinc source is not particularly limited, and those skilled in the art can select a conventional zinc source. Preferably, the zinc source is selected from at least one of zinc oxide, zinc sulfate, zinc chloride, zinc carbonate, zinc sulfide, zinc hydroxide, zinc acetate and zinc nitrate.

[0029] According to the present invention, the type of the silicon source is not particularly limited, and those skilled in the art can select a conventional silicon source. Preferably, the silicon source is selected from at least one of diatomite, silicon oxide, silica gel, siliceous rock, silicic acid, sodium silicate, ammonium silicate, tetraethyl orthosilicate and tetramethyl orthosilicate.

[0030] According to the present invention, the type of the aluminum source is not particularly limited, and those skilled in the art can select a conventional aluminum source. Preferably, the aluminum source is selected from at least one of aluminum oxide, hydrated aluminum oxide and aluminum salts.

[0031] According to the present invention, the type of the molecular sieve is not particularly limited, and those skilled in the art can select conventional molecular sieves. Preferably, the molecular sieve is a Y-type molecular sieve and / or a SAPO-11 molecular sieve. The source of the molecular sieve is not particularly limited, and it can be commercially purchased or prepared by existing methods. The molar ratio of SiO2 / Al2O3, specific surface area and pore volume of the molecular sieve are not particularly limited, as long as a desulfurization adsorbent carrier can be prepared.

[0032] According to the present invention, preferably, in step (1), the addition amounts of the components are by weight, and the weight ratio of the zinc source: the silicon source: the aluminum source: the molecular sieve: the nitric acid solution is 15-35:15-35:15-35:70-110:10-30, preferably 20-30:20-30:20-30:80-100:15-20. By adding the above components according to the above weight ratio, the prepared desulfurization adsorbent carrier and further prepared desulfurization adsorbent have a better desulfurization effect.

[0033] According to the present invention, preferably, the mass concentration of the nitric acid solution is 2-20 wt%, such as 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, or the range between any two of them, preferably 4-12 wt%.

[0034] According to the present invention, preferably, in step (1), a metering pump is used to add the nitric acid solution and mix it with the zinc source, the silicon source, the aluminum source and the molecular sieve. In the present invention, compared with the conventional manual control of feeding, there is a hidden danger of nitric acid leakage during the metering process, resulting in personal injury and equipment corrosion. By using a metering pump to control the feeding rate of the nitric acid solution, the feeding system automatically completes the nitric acid receiving process of the entire batching kettle, without manual intervention, reducing labor intensity, saving energy, enabling trace addition of nitric acid within a certain time, with small feeding error and high precision in the metering process, optimizing the particle size distribution of the prepared desulfurization adsorbent carrier and ensuring stable product quality.

[0035] According to the present invention, preferably, based on the total mass of the zinc source, the silicon source, the aluminum source and the molecular sieve being 1 t, the dropping rate of the nitric acid solution is 1-6 L / min, such as 1 L / min, 1.25 L / min, 1.5 L / min, 2 L / min, 2.5 L / min, 3 L / min, 3.5 L / min, 4.5 L / min, 5 L / min, 5.5 L / min, 6 L / min, or the range between any two of them, preferably 1.25-2.5 L / min. In the present invention, 1 t means 1 ton.

[0036] In the present invention, controlling the dropping rate of the nitric acid solution to meet the above range can achieve the uniform and slow addition of nitric acid in the industrial-scale preparation of the desulfurization adsorbent, reduce local heat accumulation caused by the one-time addition of nitric acid, prevent the slurry from denaturing to produce zinc aluminate, and reduce the desulfurization activity of the desulfurization adsorbent.

[0037] In the present invention, there are no specific limitations on the equipment for mixing in step (1). Those skilled in the art can select a suitable mixing device to mix the zinc source, silicon source, aluminum source, molecular sieve, and nitric acid solution evenly to obtain a slurry. Preferably, the above mixing is carried out in a batching kettle.

[0038] According to a preferred embodiment of the present invention, in step (1), the zinc source, silicon source, aluminum source, and molecular sieve are placed in a batching kettle, and the nitric acid solution is added to the batching kettle through a metering pump, and the above raw materials are fully mixed in the batching kettle to form a uniform slurry.

[0039] According to the present invention, preferably, the conditions for spray forming in step (2) include: the forming temperature is 180 - 250 °C, preferably 200 - 230 °C. In the present invention, by controlling the pressure of the pressure-type spray equipment, the particle size of the carrier can be accurately controlled.

[0040] In the present invention, by connecting a hot blast stove to the spray equipment, the heat source required to control the spray forming temperature is provided.

[0041] In the present invention, by controlling the spray forming conditions and the pressure of the diaphragm high-pressure pump, it is ensured that the average particle size of the desulfurization catalyst carrier is 1 - 200 μm, such as 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 150 μm, 170 μm, 200 μm, or the range between any two of them, preferably 90 - 150 μm. In the present invention, the average particle size of the desulfurization catalyst carrier is measured by a laser particle size analyzer.

[0042] According to the present invention, preferably, in step (3), the conditions for stepwise calcination include: calcining at 300 - 450 °C for 1 - 4 h and at 450 - 650 °C for 2 - 6 h in an air atmosphere; preferably, calcining at 350 - 400 °C for 2 - 3 h and at 500 - 600 °C for 3 - 5 h.

[0043] According to the present invention, preferably, the heating rate for the stepwise calcination is independently 10 - 30 °C / min, such as 10 °C / min, 12 °C / min, 15 °C / min, 17 °C / min, 20 °C / min, 22 °C / min, 25 °C / min, 27 °C / min, 30 °C / min, or the range between any two of them, preferably 15 - 25 °C / min.

[0044] In the present invention, by adopting the step-by-step roasting method, it is beneficial to the dispersion of the active components on the surface of the carrier. The roasting temperature of the first step is 200-400 °C. During this process, the active metal precursor decomposes and the chemically bound water is removed, which is beneficial to the increase of the pore volume and specific surface area of the product. The roasting temperature of the second step is 400-600 °C, which is beneficial to the interaction and uniform dispersion of the active components on the surface of the carrier.

[0045] According to the present invention, preferably, the step-by-step roasting in step (3) is carried out in a direct-fired hot blast stove. In the present invention, a direct-fired hot blast stove is used to replace the existing conventional vertical roasting furnace. The original spray vertical hot blast stove has problems such as high energy consumption, unstable temperature control, low automation level, and low operation safety level. The direct-fired hot blast stove adopts an automatic ignition device, which can reduce the consumption of combustion energy during the step-by-step roasting process, improve the yield of the desulfurization adsorbent carrier, and has a high safety factor at the same time.

[0046] According to the present invention, preferably, the solidified product of step (2) is sent to the direct-fired hot blast stove for step-by-step roasting by a combination of a bucket elevator and a screw conveyor for cooling. In the present invention, a bucket elevator is used to replace the conventional scraper conveyor. The conventional conveyor equipment is huge, has a large conveying capacity, and has many leakage points during the conveying process. Using a bucket elevator can reduce the equipment failure rate, improve the yield of the desulfurization adsorbent carrier, optimize the on-site operation environment, and reduce energy consumption.

[0047] In the present invention, preferably, the hopper of the bucket elevator is made of polyamide and / or glass fiber, and the conveying chain is made of rubber, which improves the wear resistance of the equipment and is strengthened.

[0048] The second aspect of the present invention provides a desulfurization adsorbent carrier prepared by the preparation method described in the first aspect.

[0049] In the present invention, the desulfurization adsorbent carrier prepared by the preparation method described in the first aspect has a concentrated particle size distribution and a high product yield.

[0050] According to the present invention, preferably, the average particle diameter of the desulfurization adsorbent carrier particles is 1-200 μm, preferably 90-150 μm.

[0051] The third aspect of the present invention provides an application of the desulfurization adsorbent carrier described in the second aspect in the field of fuel oil desulfurization.

[0052] In the present invention, when the desulfurization adsorbent carrier is used to prepare a desulfurization adsorbent, and the desulfurization adsorbent is used for fuel oil desulfurization, it has the advantage of high desulfurization depth. Those skilled in the art can select a conventional method for preparing a desulfurization adsorbent as long as a desulfurization adsorbent can be prepared.

[0053] According to a particularly preferred embodiment of the present invention, in accordance with Figure 1 the shown technological process, the desulfurization adsorbent carrier is prepared. Zinc source, silicon source, aluminum source, and molecular sieve are placed in the batching kettle 2, and then nitric acid solution is added to the batching kettle 2 through the metering pump 1. The above raw materials are fully mixed in the batching kettle 2 into a uniform slurry; the prepared uniform slurry is transported to the pressure spray equipment 5 through the diaphragm high-pressure pump 3, and the heat source is provided by the hot blast stove 4, and the spray forming method is used for solidification; the solidified product is transported to the direct-fired hot blast stove 7 through the bucket elevator 6, and is subjected to step-by-step roasting treatment in an air atmosphere to obtain the desulfurization adsorbent carrier.

[0054] The present invention will be described in detail below through examples and comparative examples. In the following examples and comparative examples, unless otherwise specified, the reagents used in the present invention are all commercially available;

[0055] The SiO2 / Al2O3 molar ratio of the SAPO-11 molecular sieve is 0.75;

[0056] In the examples of the present invention, 1 part by weight is 10 kg.

[0057] Example 1

[0058] In accordance with Figure 1 the shown technological process, the desulfurization adsorbent carrier is prepared.

[0059] (1) According to parts by weight, 20 parts of zinc oxide, 30 parts of diatomite, 25 parts of alumina, and 100 parts of SAPO-11 molecular sieve are placed in the batching kettle 2, and then 20 parts of nitric acid solution with a mass fraction of 8 wt% is added to the batching kettle 2 through the metering pump 1, and the dropping rate is 3 L / min. The above raw materials are fully mixed in the batching kettle 2 into a uniform slurry;

[0060] (2) The prepared uniform slurry is transported to the pressure spray equipment 5 through the diaphragm high-pressure pump 3, and the heat source is provided by the hot blast stove 4, and the spray forming method is used for solidification, and the spray forming temperature is 200 °C;

[0061] (3) The solidified product is transported to the direct-fired hot blast stove 7 through the bucket elevator 6, and is subjected to roasting treatment in an air atmosphere to obtain the desulfurization adsorbent carrier; among them, the step-by-step roasting conditions are: roasting at 350 °C for 2 h, roasting at 600 °C for 3 h, and the heating rate is 20 °C / min for each.

[0062] Example 2

[0063] (1) By weight, 30 parts of zinc sulfate, 25 parts of colloidal silica, 20 parts of hydrated alumina, and 90 parts of SAPO-11 molecular sieve are placed in the batching kettle 2, and then 20 parts of a nitric acid solution with a mass fraction of 8 wt% are added to the batching kettle 2 through the titration pump 1 at a dropping rate of 3 L / min. The above raw materials are fully mixed in the batching kettle 2 to form a uniform slurry;

[0064] (2) The prepared uniform slurry is transported to the pressure spray equipment 5 through the diaphragm high-pressure pump 3, and the hot blast stove 4 provides heat source. The spray forming method is used for curing, and the spray forming temperature is 200 °C;

[0065] (3) The cured product is transported to the direct-fired hot blast stove 7 by the bucket elevator 6 and calcined in an air atmosphere to obtain the desulfurization adsorbent carrier; among them, the step-by-step calcination conditions are: calcination at 350 °C for 2 h, calcination at 600 °C for 3 h, and the heating rate is 20 °C / min.

[0066] Example 3

[0067] (1) The desulfurization adsorbent carrier is prepared according to the method of Example 1. The difference is that the calcination conditions in step (3) are: calcination at 600 °C for 5 h, and the heating rate is 20 °C / min. Other conditions are the same as those in Example 3.

[0068] Example 4

[0069] The desulfurization adsorbent carrier is prepared according to the method of Example 1. The difference is that in step (1), 15 parts of a nitric acid solution with a mass fraction of 8 wt% are directly added to the batching kettle 2 and mixed with the zinc source, aluminum source, and silicon source. Other conditions are the same as those in Example 2.

[0070] Comparative Example 1

[0071] The desulfurization adsorbent carrier is prepared according to the method of Example 1. The difference is that in step (2), the diaphragm high-pressure pump is not used, and the packed high-pressure pump is used to transport the slurry. Other conditions are the same as those in Example 3.

[0072] Comparative Example 2

[0073] The desulfurization adsorbent carrier is prepared according to the method of Example 1. The difference is that in step (3), the vertical calcination furnace is used to replace the direct-fired hot blast stove. Other conditions are the same as those in Example 3.

[0074] The test results of the particle size of the prepared desulfurization adsorbent carrier, the product yield, and the energy consumption during the preparation process are shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] Product yield = (mass of the prepared desulfurization adsorbent carrier / total mass of the input raw materials) × 100%;

[0079] The energy consumption is calculated according to the unified calculation method of the energy consumption of industrial enterprise products. t standard coal / t product represents the mass of standard coal consumed for producing a unit mass of product, and t represents ton.

[0080] It can be seen from the results in Table 1 that the desulfurization adsorbent carrier prepared by the preparation method provided in the embodiment of the present invention has the advantages of high product yield and low energy consumption. In Comparative Example 1, a diaphragm high-pressure pump is not used, and the product yield drops significantly; in Comparative Example 2, a vertical roasting furnace is used to replace the direct-fired hot blast stove, and the energy consumption increases significantly.

[0081] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A preparation method of a desulfurization adsorbent carrier, characterized in that, The method comprises the following steps: (1) mixing a zinc source, a silicon source, an aluminum source, and a molecular sieve with a nitric acid solution to obtain a slurry; (2) transporting the slurry to the spray equipment through a diaphragm high-pressure pump for spray molding and curing; (3) The solidified product of step (2) is calcined in a direct-fired hot air furnace to obtain a desulfurization adsorbent carrier.

2. The preparation method according to claim 1, wherein, The solidified product of step (2) is sent to a direct-fired hot air furnace for step-by-step roasting by using a bucket elevator combined with spiral conveying and cooling.

3. The preparation method according to claim 1 or 2, wherein The zinc source is selected from at least one of zinc oxide, zinc sulfate, zinc chloride, zinc carbonate, zinc sulfide, zinc hydroxide, zinc acetate and zinc nitrate; Preferably, the silicon source is selected from at least one of diatomaceous earth, silicon oxide, silica gel, siliceous rock, silicic acid, sodium silicate, ammonium silicate, ethyl orthosilicate and methyl orthosilicate; Preferably, the aluminum source is selected from at least one of aluminum oxide, hydrated aluminum oxide and aluminum salt; Preferably, the molecular sieve is a Y-type molecular sieve and / or a SAPO-11 molecular sieve.

4. The preparation method according to any one of claims 1 to 3, wherein, In step (1), the added amount of each component is calculated by weight, and the weight ratio of zinc source: silicon source: aluminum source: molecular sieve: nitric acid solution is 15-35:15-35:15-35:70-110:10-30, preferably 20-30:20-30:20-30:80-100:15-20.

5. The preparation method according to any one of claims 1-4, wherein, The mass concentration of the nitric acid solution is 2-20wt%, preferably 4-12wt%; Preferably, in step (1), a titration pump is used to add nitric acid solution and mix it with the zinc source, silicon source, aluminum source and molecular sieve; Preferably, based on the total mass of the zinc source, silicon source, aluminum source and molecular sieve being 1 t, the dripping rate of the nitric acid solution is 1-6 L / min, preferably 1.25-2.5 L / min.

6. The preparation method according to any one of claims 1-5, wherein The spray molding conditions in step (2) include: a molding temperature of 180-250°C, preferably 200-230°C.

7. The preparation method according to any one of claims 1-6, wherein, In step (3), the conditions for the stepwise calcination include: calcination at 300-450°C for 1-4h and calcination at 450-650°C for 2-6h in an air atmosphere; preferably calcination at 350-400°C for 2-3h and calcination at 500-600°C for 3-5h.

8. The preparation method according to any one of claims 1-7, wherein, The heating rates of the stepwise calcinations are each independently 10-30°C / min, preferably 15-25°C / min.

9. A desulfurization adsorbent carrier prepared according to the preparation method according to any one of claims 1 to 8; Preferably, the average particle size of the desulfurization adsorbent carrier particles is 1-200 μm, preferably 90-150 μm.

10. Use of the desulfurization adsorbent carrier according to claim 9 in the field of fuel oil desulfurization.

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