Preparation method of bird nest type silicon capturing agent
By preparing bird's nest-type silicon capture agent, the catalyst deactivation problem caused by silicon deposition in coking naphtha and coking dry gas is solved, and the efficient silicon capture effect and catalyst life are achieved. It is suitable for hydrorefining technology.
Patent Information
- Application Number
- CN202510631579.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-08-19
AI Technical Summary
In the existing hydrorefining technology, silicon deposition in oils such as coking naphtha and coking dry gas leads to a decrease in catalyst activity and blockage of micropores, resulting in a short catalyst operation cycle. Devices without adding silicon trapping agents need to use low-active metals and large specific surface area catalysts, which cannot effectively extend the service life.
Using the preparation method of bird's nest-type silicon capture agent, by mixing high-specific surface silica powder, pseudo-thin aluminite, alumina powder, field cyanine powder and cellulose, adding nitric acid and citric acid aqueous solution, loading metals Mo, Ni, and P after molding, drying and calcining, forming a silicon capture agent carrier with high pore volume and specific surface area for adsorption and fixing of silicon.
It improves the silicon capture effect of the catalyst, extends the service life of the catalyst, reduces the risk of inactivation caused by carbon deposits and coking, and is suitable for the hydrogenation and purification of coking naphtha and coking dry gas.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of bird's nest type silicon scavengers, in particular to a method for preparing a bird's nest type silicon scavenger. Background Art
[0002] Hydrotreating technology can remove or partially remove impurities such as sulfur, olefins, and aromatics from raw materials. The products after hydrotreating can be used as chemical raw materials and gasoline fuel, etc.
[0003] Coker naphtha, coker dry gas, and other oil products contain high levels of silicon. This silicon deposits on the hydrogenation catalyst, easily leading to a decrease in active surface area, clogging of micropores, and permanent catalyst deactivation. Therefore, mature hydrorefining processes for coker naphtha and coker dry gas typically incorporate an appropriate amount of silicon scavenger at the top of the reactor to protect the primary hydrorefining catalyst.
[0004] At present, most hydrotreating refining units do not add silicon scavengers for special treatment, but instead choose some hydrogenation catalysts with low active metal content and large specific surface area. Due to factors such as silicon deposition in oil products, the operating cycle is continuously short and needs to be further improved. Summary of the Invention
[0005] In order to address the deficiencies of the prior art, the present invention provides a method for preparing a bird's nest type silicon scavenger, which has a good silicon scavenging effect while extending the service life of the catalyst, and can better serve the hydrorefining technology.
[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:
[0007] A method for preparing a bird's nest type silicon trap comprises the following steps:
[0008] Step a, preparation of catalyst carrier:
[0009] After uniformly mixing high-specific-surface-area silica powder, pseudo-boehmite, alumina powder, sesbania powder, and cellulose in a kneader, adding a mixed aqueous solution of nitric acid and citric acid, kneading the powder into a slurry, and then kneading the slurry, shaping, drying, and calcining to obtain a bird's nest-shaped silicon scavenger carrier; wherein the high-specific-surface-area silica powder and pseudo-boehmite comprise 30-50 parts of high-specific-surface-area silica powder, 30-50 parts of pseudo-boehmite, 10-30 parts of alumina powder, 1-15% of the total weight of the sesbania powder, and 1-15% of the total weight of the cellulose;
[0010] Step b, dissolving the metal compound in deionized water or distilled water to prepare a metal aqueous solution;
[0011] Step c: loading active elements Mo, Ni, and P on the catalyst carrier of step a by an impregnation method, and obtaining a bird's nest type silicon trapping agent through drying and calcination.
[0012] Furthermore, in the above step a, a mixed aqueous solution of nitric acid and citric acid is added during the preparation of the catalyst carrier, wherein the amount of water added is 70-90% of the total weight of the powder, the amount of nitric acid added is 0.5-4% of the total weight of the powder, and the amount of citric acid added is 0.5-7% of the total weight of the powder.
[0013] Furthermore, in the above step a, the binder is sesbania powder and cellulose.
[0014] Furthermore, in the above step a, the powder is mixed evenly in the kneader for about 25 to 35 minutes, the mud material is required to have a moisture content of about 45% to 55% and a mud material temperature of 30 to 35°C when discharged, and the mud material is in a loose block shape when discharged from the pot.
[0015] Furthermore, in the above step a, the kneaded clay material is required to be kneaded 4.8 to 5.2 minutes after being taken out of the pot.
[0016] Furthermore, in the above step a, the vacuum degree during the mud kneading process is required to be 0.04 to 0.11 MPa, and the pressure used for mud kneading is 8 to 22 MPa.
[0017] Furthermore, in the above step a, the pressure used during the molding process is 8 to 22 MPa, and the mold specification used during the molding is Φ10.5 / 450 mesh.
[0018] Furthermore, in the above step a, the ambient temperature of the shade drying process is 18-42° C., the ambient humidity is 48-52%, and the shade drying time is 11-13 hours.
[0019] Furthermore, in the above step a, the drying temperature of the drying process is 67-83°C.
[0020] Furthermore, in the above step a, the product can be roasted only after the moisture content of the product during the drying process is ≤8-22%.
[0021] Furthermore, in the above step a, the calcination temperature of the carrier during the calcination process is 600±10° C., and the carrier is pure white after calcination.
[0022] Furthermore, in the preparation method of the above-mentioned bird's nest type silicon scavenger, the sources of the active elements Ni, Mo, and P are NiO, MoO3, and H3PO4, respectively.
[0023] Furthermore, in the above step b, the metal aqueous solution contains: 70 to 90 parts by mass of water, 6 to 8 parts by mass of NiO, 8 to 12 parts by mass of MoO3, and 2 to 4 parts by mass of H3PO4.
[0024] Furthermore, in the above step c, the impregnated product is dried using a mesh belt drying belt at a drying temperature of 35 to 65°C.
[0025] Furthermore, in the above step c, the product can be roasted only after the moisture content of the product during the drying process is ≤8-22%.
[0026] Furthermore, in the above step c, the roasting temperature of the impregnated product is 430-470° C., and the roasted product is beige.
[0027] The properties of the bird's nest type silicon scavenger prepared by the above-mentioned method are as follows: specific surface area of about 290 to 300 m2 / g, pore volume of about 0.6 to 0.7 ml / g, water absorption rate of about 80 to 90%, bulk density of about 470 to 480 kg / m3, and strength of about 35 to 36 N / grain.
[0028] Due to the adoption of the above technical solution, the present invention has the following advantages:
[0029] The preparation method of the bird's nest type silicon scavenger of the present invention uses deionized water or distilled water during the preparation and impregnation of the catalyst carrier, which can reduce the negative impact of calcium and magnesium ions in tap water on the catalyst metal and enable the metal liquid to be better dispersed on the catalyst carrier.
[0030] The preparation method of the bird's nest type silicon trap of the present invention, the addition of silicon oxide can increase the acidity of the catalyst surface as an active center to enhance reactions such as ring opening and cleavage of silicon-containing compounds, and then adsorb and fix on the surface of the catalyst to achieve silicon trapping.
[0031] In the preparation method of the bird's nest type silicon scavenger of the present invention, hydrogenation active components such as Mo and Ni added during the preparation process can be used to inhibit the deactivation of the silicon scavenger caused by carbon deposition and coking.
[0032] The preparation method of the bird's nest type silicon scavenger of the present invention has simple process, convenient operation, low cost, easy operation and is suitable for industrial production.
[0033] The method for preparing a bird's nest type silicon scavenger of the present invention has the characteristics of high water absorption, large pore volume and specific surface area, high metal dispersion, and multiple edge active center sites.
[0034] The method for preparing a bird's nest type silicon scavenger of the present invention can improve the silicon scavenging effect of the prepared bird's nest type silicon scavenger while prolonging the service life of the catalyst, thereby better serving the hydrorefining technology. DETAILED DESCRIPTION
[0035] Example 1
[0036] Take 300g of high specific surface area silica powder, 300g of pseudo-boehmite, 100g of alumina powder, 1-15% of the total weight of sesbania powder, and 1-15% of the total weight of cellulose, add them into a mixer and mix for 10-30 minutes, add about 600-675g of water, 7.5-22.5g of nitric acid, and 7.5-37.5g of citric acid, and knead for about 30 minutes until the moisture content of the mud reaches 49-52% before discharging. After discharging, the mud is kneaded and formed, and then dried in the shade and baked. After drying, the mud has a moisture content of ≤15% and can be roasted at a temperature of 600±10°C. After roasting, a pure white carrier is obtained. NiO, MoO3 and H3PO4 are prepared into a metal aqueous solution in a certain proportion, wherein the ratio of water: NiO: MoO3: H3PO4 in the metal aqueous solution is 80:7.0:10:3. After the preparation is completed, the carrier and the metal aqueous solution are added into an impregnation cylinder in a ratio of about 1:1 for impregnation. The impregnated product is dried at 35-65°C. After drying until the moisture content of the product is ≤8-22%, a second calcination can be carried out. The second calcination temperature is 430-470°C. After calcination, a beige bird's nest-shaped silicon capture agent is obtained.
[0037] Example 2
[0038] Take 400g of high specific surface area silica powder, 400g of pseudo-boehmite, 200g of alumina powder, 1-15% of the total weight of sesbania powder and 1-15% of the total weight of cellulose, add them into a mixer and mix for 10-30 minutes, add about 800-900g of water, 10-30g of nitric acid and 10-50g of citric acid, knead for about 30 minutes until the moisture content of the mud reaches 49-52% and the mud can be discharged. After the mud is discharged, it is kneaded and formed, and then dried in the shade and baked. After drying, the mud can be roasted when the moisture content is ≤15%. The roasting temperature is 600±10°C, and a pure white carrier is obtained after roasting. NiO, MoO3 and H3PO4 are prepared into a metal aqueous solution in a certain proportion, wherein the ratio of water: NiO: MoO3: H3PO4 in the metal aqueous solution is 80:7.0:10:3. After the preparation is completed, the carrier and the metal aqueous solution are added into an impregnation cylinder in a ratio of about 1:1 for impregnation. The impregnated product is dried at 35-65°C. After drying until the moisture content of the product is ≤8-22%, a second calcination can be carried out. The second calcination temperature is 430-470°C. After calcination, a beige bird's nest-shaped silicon capture agent is obtained.
[0039] Example 3
[0040] Take 500g of high specific surface area silica powder, 500g of pseudo-boehmite, 300g of alumina powder, 1-15% of the total weight of sesbania powder and 1-15% of the total weight of cellulose, add them into a mixer and mix for 10-30 minutes, add about 1000-1125g of water, 12.5-37.5g of nitric acid and 12.5-62.5g of citric acid, knead for about 30 minutes until the moisture content of the mud reaches 49-52% and the mud can be discharged. After the mud is discharged, it is kneaded and formed, and then dried in the shade and baked. After drying, the mud can be roasted when the moisture content is ≤15%. The roasting temperature is 600±10°C, and a pure white carrier is obtained after roasting. A metal aqueous solution is prepared by mixing NiO, MoO3, and H3PO4 in a certain ratio. The ratio of water: NiO: MoO3: H3PO4 in the metal aqueous solution is 80:7.0:10:3. After the preparation is completed, the carrier and the metal aqueous solution are added to the impregnation cylinder at a ratio of approximately 1:1 for impregnation. The impregnated product is dried at 35-65°C until the product moisture content is ≤8-22%. It can then be calcined for the second time at a temperature of 430-470°C. After calcination, a beige bird's nest-shaped silicon capture agent is obtained.
[0041] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for preparing a bird's nest type silicon trapping agent, characterized by: It includes the following steps: Step a, preparation of catalyst carrier: After uniformly mixing high specific surface area silica powder, pseudo-boehmite, alumina powder, sesbania powder and cellulose in a kneader, adding a mixed aqueous solution of nitric acid and citric acid, kneading the powder into a mud, and then kneading the mud, shaping, air-drying, drying and roasting to obtain a bird's nest type silicon capture agent carrier; The components include 30-50 parts of high surface area silica powder, 30-50 parts of pseudo-boehmite, 10-30 parts of alumina powder, 1-15% of the total weight of the sesbania powder, and 1-15% of the total weight of the cellulose. Step b, dissolving the metal compound in deionized water or distilled water to prepare a metal aqueous solution; Step c: loading active elements Mo, Ni, and P on the catalyst carrier of step a by an impregnation method, and obtaining a bird's nest type silicon trapping agent through drying and calcination.
2. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: In step a, a mixed aqueous solution of nitric acid and citric acid is added during the preparation of the catalyst carrier, wherein the amount of water added is 70-90% of the total weight of the powder, the amount of nitric acid added is 0.5-4% of the total weight of the powder, and the amount of citric acid added is 0.5-7% of the total weight of the powder.
3. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: In step a, the binder is sesbania powder and cellulose.
4. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: In step a, the powder is mixed uniformly in the kneader for about 25 to 35 minutes.
5. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: The first roasting temperature is 600±10℃, and the second roasting temperature after impregnation is 430-470℃.
6. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: The sources of its active elements Ni, Mo, and P are NiO, MoO3, and H3PO4, respectively.
7. The method for preparing the bird's nest type silicon scavenger according to claim 1, wherein: During immersion, the weight of water is 70 to 90 parts, the weight of NiO is 6 to 8 parts, the weight of MoO3 is 8 to 12 parts, and the weight of H3PO4 is 2 to 4 parts.
8. The preparation method according to claims 1 to 6, characterized in that: The properties of the bird's nest type silicon scavenger prepared are as follows: specific surface area of 280-310㎡ / g, pore volume of 0.5-0.8ml / g, water absorption rate of 75-95%, bulk density of 465-485kg / m 3 , the strength is 30~40N / grain.