High-quality fuel oil and processing technology thereof

Abstract

The invention relates to high-quality fuel oil and a processing technology thereof, and belongs to the technical field of petrochemical engineering, and the processing technology is as follows: in the presence of hydrogen, a residual oil raw material enters a hydrogenation reaction zone to contact with a hydrodesulfurization catalyst for reaction and fractionation to obtain the high-quality fuel oil. The preparation method of the hydrodesulfurization catalyst comprises the following steps: A1, mixing aluminum oxide, halloysite nanotubes and asphalt to obtain a mixture 1; a2, crushing the mixture 1 to obtain mixed powder; a3, mixing the mixed powder, a pore-forming agent, high-alumina cement and deionized water, and then carrying out molding, drying and primary roasting to obtain a mixture 2; a4, carrying out acid treatment on the mixture 2, washing and drying to obtain a carrier; and A5, impregnating the carrier in an impregnation liquid containing active metal, drying, and carrying out secondary roasting to obtain the hydrodesulfurization catalyst. The hydrodesulfurization catalyst provided by the invention is added in the hydrodesulfurization process of a residual oil raw material, so that the desulfurization efficiency can be effectively improved, and high-quality fuel oil is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of petrochemical industry, and specifically relates to a high-quality fuel oil and its processing technology. Background Art

[0002] The Marine Environment Protection Committee of the International Maritime Organization decided at its 70th session that as of January 1, 2020, the regulation of the sulfur content of marine fuel oil not exceeding 0.50% m / m will be implemented globally. This means that low-sulfur fuel oil will gradually replace ordinary high-sulfur marine fuel oil as the mainstream fuel oil in the market. Hydrodesulfurization is an effective means to reduce the sulfur content of fuel oil, and the performance of hydrodesulfurization catalysts significantly affects the desulfurization rate.

[0003] Hydrodesulfurization catalysts are divided into supported catalysts and bulk catalysts according to the presence or absence of a carrier. Among them, supported catalysts have problems such as limited loading of active metals and strong interaction between the active component and the carrier. Therefore, it is of great significance to develop a hydrodesulfurization catalyst with a large specific surface area, many active sites, and moderate interaction between the active metal and the carrier. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-quality fuel oil and its processing technology. Alumina and halloysite nanotubes are mixed as the carrier. Halloysite nanotubes have a hollow pipe structure. Through the synergistic effect of alumina and halloysite nanotubes with different shapes, the specific surface area of the carrier is significantly increased, and the desulfurization performance of the catalyst is effectively improved. The present invention also adds asphalt during the preparation of the carrier and performs acid treatment on the carrier. Through the synergistic effect of asphalt and acid, the acidic active centers of the carrier are increased, thereby improving the desulfurization performance of the catalyst. Adding the hydrodesulfurization catalyst provided by the present invention during the hydrodesulfurization process of residue raw materials can effectively improve the desulfurization efficiency and obtain high-quality fuel oil.

[0005] The technical problem to be solved by the present invention: Supported catalysts have problems such as limited loading of active metals and strong interaction between the active component and the carrier.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A processing technology for high-quality fuel oil, comprising the following steps: In the presence of hydrogen, the residue raw material enters the hydrotreating reaction zone to contact with the hydrodesulfurization catalyst for reaction, and then fractionation is carried out to obtain high-quality fuel oil.

[0007] Further, the reactor used for the hydrotreating reaction can be at least one of a fixed-bed hydrotreating reactor, a fluidized-bed hydrotreating reactor, and a slurry-bed hydrotreating reactor.

[0008] Further, the reaction conditions in the hydrogenation reaction zone are as follows: the reaction pressure is 12 - 20 MPa, the reaction temperature is 360 - 430 °C, the liquid hourly space velocity is 0.1 - 0.7 h -1 , and the hydrogen - to - oil volume ratio is 300 - 900.

[0009] Further, before use, the hydrodesulfurization catalyst needs to be sulfided by contacting with a sulfiding solution and hydrogen.

[0010] Further, the specific steps of sulfiding are as follows: dissolve carbon disulfide in cyclohexane to obtain a sulfiding agent; in a hydrogen atmosphere, load the hydrodesulfurization catalyst into a tubular reactor, then introduce the sulfiding agent, maintain at 170 - 200 °C for 2 - 4 h first, and then raise the temperature to 260 - 320 °C and maintain for 3 - 6 h.

[0011] Further, the concentration of carbon disulfide in the sulfiding agent is 2 - 8 wt%.

[0012] Further, the dosage of the sulfiding agent is 0.5 - 6.0 g / h per gram of the hydrodesulfurization catalyst.

[0013] Further, during the sulfiding process, the hydrogen pressure is 1.0 - 20.0 MPa, preferably 2.0 - 16.0 MPa, and the hydrogen flow rate is 5 - 12 mL / min per gram of the catalyst.

[0014] Further, the preparation method of the hydrodesulfurization catalyst includes the following steps: A1. Mix alumina, halloysite nanotubes, and pitch to obtain mixture 1; Further, in step A1, the mass ratio of alumina, halloysite nanotubes, and pitch is (1.2 - 3):(1 - 1.5):(0.1 - 0.5).

[0015] Further, in step A1, the particle size of alumina is 30 - 60 μm.

[0016] Further, in step A1, the diameter of halloysite nanotubes is 30 - 70 nm, and the length is 5 - 20 μm.

[0017] A2. Crush mixture 1 to obtain a mixed powder; A3. Mix the mixed powder, a pore - forming agent, high - alumina cement, and deionized water, and then through forming, drying, and primary calcination to obtain mixture 2; Further, in step A3, the pore - forming agent is at least one of urea, oxalic acid, and starch; the mass of the pore - forming agent is 0.5 - 3% of the mass of the mixed powder.

[0018] Further, in step A3, the mass of high - alumina cement is 1 - 4% of the mass of the mixed powder.

[0019] Further, in step A3, the temperature of the first roasting is 500 - 750 °C, and the time is 3 - 7 h.

[0020] A4. Acid-treat the mixture 2 with an acid, then wash and dry it to obtain a support. Further, in step A4, the specific surface area of the support is 180 - 250 m 2 / g, and the pore volume is 0.6 - 1.2 mL / g.

[0021] Further, in step A4, the acid is at least one of sulfuric acid, nitric acid, and hydrochloric acid.

[0022] Further, in step A4, the concentration of the acid is 1 - 4 wt%.

[0023] Further, in step A4, the time of the acid treatment is 0.5 - 2.5 h.

[0024] A5. Immerse the support in an impregnating solution containing active metals, then dry and perform a second roasting to obtain a hydrodesulfurization catalyst.

[0025] Further, in step A5, the impregnating solution containing active metals includes cobalt salts, molybdenum salts, and a solvent.

[0026] Further, the cobalt salts include at least one of cobalt nitrate, cobalt sulfate, and basic cobalt carbonate, the molybdenum salts include at least one of ammonium tetramolybdate and ammonium heptamolybdate, and the solvent is deionized water.

[0027] Further, in the impregnating solution containing active metals, the concentration of the cobalt salts is 6 - 12 wt%, and the concentration of the molybdenum salts is 5 - 10 wt%.

[0028] Further, in step A5, the impregnation time is 2 - 6 h.

[0029] Further, in step A5, the temperature of the second roasting is 400 - 550 °C, and the time is 3 - 8 h.

[0030] In the above preparation process, first, pitch is used as a binder to bond alumina and halloysite nanotubes together, and then after drying and pulverization, a mixed powder is obtained. Then, high-alumina cement is used as a binder to mix and mold the mixed powder and a pore-forming agent, and then after a first calcination, a mixture 2 is obtained. The mixture 2 is treated by pickling, and after pickling, it is impregnated in an impregnating solution containing an active metal, and then after a second calcination, a hydrodesulfurization catalyst is obtained. In the technical solution of the present invention, on the one hand, pitch can be used as a binder to bond alumina and halloysite nanotubes together; on the other hand, pitch contains a small amount of heteroatoms, which can increase the acidic active centers of the carrier. Treating the mixture 2 by pickling can increase the specific surface area of the carrier and also increase the acidic active centers of the carrier. The present invention increases the acidic active centers of the carrier through the synergistic effect of pitch and acid, thereby improving the desulfurization performance of the catalyst. The present invention uses a mixture of alumina and halloysite nanotubes as a carrier. Halloysite nanotubes have a hollow pipe structure. Through the synergistic effect of alumina and halloysite nanotubes with different shapes, the specific surface area of the carrier is significantly increased, effectively improving the desulfurization performance of the catalyst.

[0031] The present invention also provides a high-quality fuel oil prepared by using the above processing technology.

[0032] Advantages of the present invention: (1) In the technical solution of the present invention, on the one hand, pitch can be used as a binder to bond alumina and halloysite nanotubes together; on the other hand, pitch contains a small amount of heteroatoms, which can increase the acidic active centers of the carrier. Treating the mixture 2 by pickling can increase the specific surface area of the carrier and also increase the acidic active centers of the carrier. The present invention increases the acidic active centers of the carrier through the synergistic effect of pitch and acid, thereby improving the desulfurization performance of the catalyst.

[0033] (2) In the technical solution of the present invention, a mixture of alumina and halloysite nanotubes is used as a carrier. Halloysite nanotubes have a hollow pipe structure. Through the synergistic effect of alumina and halloysite nanotubes with different shapes, the specific surface area of the carrier is significantly increased, effectively improving the desulfurization performance of the catalyst. Adding the hydrodesulfurization catalyst provided by the present invention during the hydrodesulfurization process of the residue oil raw material can effectively improve the desulfurization efficiency and obtain a high-quality fuel oil. Description of the drawings

[0034] Figure 1 It is the SEM diagram of the mixed powder and the hydrodesulfurization catalyst prepared in Preparation Example 1 of the present invention.

[0035] In the figure: A, the SEM diagram of the mixed powder; B, the SEM diagram of the hydrodesulfurization catalyst. Detailed implementation manners

[0036] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0037] Preparation Example 1 This preparation example provides a method for preparing a hydrodesulfurization catalyst, including the following steps: A1. Heat 1.2 kg of γ-alumina, 1 kg of halloysite nanotubes, and 0.1 kg of pitch to 150 °C respectively, and then mix the three to obtain mixture 1; among them, the average particle size of γ-alumina is 38 μm; the average diameter of halloysite nanotubes is 42 nm, and the average length is 6 μm; A2. Crush mixture 1 to obtain a mixed powder with an average particle size of 83 μm; A3. Mix 1 kg of the mixed powder, 5 g of urea, 10 g of high-alumina cement, and 140 g of deionized water, then form, dry, and calcine at 500 °C for 3 h for the first time to obtain mixture 2; A4. Treat mixture 2 with sulfuric acid with a concentration of 1 wt% for 1 h, then wash and dry to obtain a carrier; the specific surface area of the carrier is 182 m 2 / g, and the pore volume is 0.65 mL / g; A5. Immerse the carrier in an impregnating solution containing active metals for 2 h, then dry and calcine at 400 °C for 4 h for the second time to obtain a hydrodesulfurization catalyst; among them, in the impregnating solution containing active metals, the concentration of cobalt nitrate is 6 wt%, and the concentration of ammonium tetramolybdate is 10 wt%.

[0038] Preparation Example 2 This preparation example provides a method for preparing a hydrodesulfurization catalyst, including the following steps: A1. Heat 2.4 kg of γ-alumina, 1.3 kg of halloysite nanotubes, and 0.33 kg of pitch to 160 °C respectively, and then mix the three to obtain mixture 1; among them, the average particle size of γ-alumina is 53 μm; the average diameter of halloysite nanotubes is 52 nm, and the average length is 16 μm; A2. Crush mixture 1 to obtain a mixed powder with an average particle size of 91 μm; A3. Mix 1 kg of the mixed powder, 18 g of oxalic acid, 29 g of high-alumina cement, and 200 g of deionized water, then form, dry, and calcine at 600 °C for 5 h for the first time to obtain mixture 2; A4. Acid-treat the mixture 2 with sulfuric acid at a concentration of 2.2 wt% for 1.5 h, then wash and dry to obtain a support; the specific surface area of the support is 231 m 2 / g, and the pore volume is 0.92 mL / g; A5. Immerse the support in an impregnating solution containing active metals for 4 h, then dry and calcine it twice at 500 °C for 5 h to obtain a hydrodesulfurization catalyst; among them, in the impregnating solution containing active metals, the concentration of cobalt sulfate is 8 wt%, and the concentration of ammonium tetramolybdate is 7 wt%.

[0039] Preparation Example 3 This preparation example provides a method for preparing a hydrodesulfurization catalyst, including the following steps: A1. Heat 3 kg of γ-alumina, 1.5 kg of halloysite nanotubes, and 0.5 kg of pitch to 170 °C respectively, and then mix the three to obtain a mixture 1; among them, the average particle size of γ-alumina is 58 μm; the average diameter of halloysite nanotubes is 60 nm, and the average length is 15 μm; A2. Crush the mixture 1 to obtain a mixed powder with an average particle size of 92 μm; A3. Mix 1 kg of the mixed powder, 25 g of starch, 34 g of high-alumina cement, and 220 g of deionized water, then form, dry, and calcine it once at 750 °C for 3 h to obtain a mixture 2; A4. Acid-treat the mixture 2 with sulfuric acid at a concentration of 4 wt% for 1 h, then wash and dry to obtain a support; the specific surface area of the support is 241 m 2 / g, and the pore volume is 1.16 mL / g; A5. Immerse the support in an impregnating solution containing active metals for 6 h, then dry and calcine it twice at 550 °C for 8 h to obtain a hydrodesulfurization catalyst; among them, in the impregnating solution containing active metals, the concentration of basic cobalt carbonate is 12 wt%, and the concentration of ammonium heptamolybdate is 5 wt%.

[0040] Comparative Example 1 Compared with Preparation Example 2, in Comparative Example 1, pitch is replaced by carboxymethyl cellulose, and other steps and raw materials are the same as those in Preparation Example 2.

[0041] Comparative Example 2 Compared with Preparation Example 2, in Comparative Example 2, halloysite nanotubes are not included, and other steps and raw materials are the same as those in Preparation Example 2. Example 1

[0042] A processing technology for high-quality fuel oil, including the following steps: Carbon disulfide was dissolved in cyclohexane to obtain a sulfiding agent with a concentration of 2 wt%. In a hydrogen atmosphere, the hydrodesulfurization catalyst prepared in Preparation Example 2 was loaded into a tubular reactor, and then the sulfiding agent was introduced. The dosage of the sulfiding agent was 0.5 g / h per gram of the hydrodesulfurization catalyst. It was first maintained at 170 °C for 2 h, then heated to 280 °C and maintained for 6 h to obtain the sulfided hydrodesulfurization catalyst. Among them, the hydrogen pressure was 2.0 MPa, and the hydrogen flow rate was 5 mL / min per gram of the catalyst. In the presence of hydrogen, vacuum residue was contacted with the hydrodesulfurization catalyst in a fixed-bed hydrotreating reactor for reaction. The reaction pressure was 12 MPa, the reaction temperature was 360 °C, and the liquid hourly space velocity was 0.1 h -1 , and the hydrogen-oil volume ratio was 300. After fractionation, high-quality fuel oil was obtained. Example 2

[0043] A processing process for high-quality fuel oil includes the following steps: Carbon disulfide was dissolved in cyclohexane to obtain a sulfiding agent with a concentration of 5 wt%. In a hydrogen atmosphere, the hydrodesulfurization catalyst prepared in Preparation Example 2 was loaded into a tubular reactor, and then the sulfiding agent was introduced. The dosage of the sulfiding agent was 3.0 g / h per gram of the hydrodesulfurization catalyst. It was first maintained at 190 °C for 3 h, then heated to 300 °C and maintained for 4 h to obtain the sulfided hydrodesulfurization catalyst. Among them, the hydrogen pressure was 12.0 MPa, and the hydrogen flow rate was 9 mL / min per gram of the catalyst. In the presence of hydrogen, vacuum residue was contacted with the hydrodesulfurization catalyst in a fixed-bed hydrotreating reactor for reaction. The reaction pressure was 16 MPa, the reaction temperature was 400 °C, and the liquid hourly space velocity was 0.4 h -1 , and the hydrogen-oil volume ratio was 600. After fractionation, high-quality fuel oil was obtained. Example 3

[0044] A processing process for high-quality fuel oil includes the following steps: Carbon disulfide was dissolved in cyclohexane to obtain a sulfiding agent with a concentration of 8 wt%. In a hydrogen atmosphere, the hydrodesulfurization catalyst prepared in Preparation Example 2 was loaded into a tubular reactor, and then the sulfiding agent was introduced. The dosage of the sulfiding agent was 6.0 g / h per gram of the hydrodesulfurization catalyst. It was first maintained at 200 °C for 4 h, then heated to 320 °C and maintained for 6 h to obtain the sulfided hydrodesulfurization catalyst. Among them, the hydrogen pressure was 16.0 MPa, and the hydrogen flow rate was 12 mL / min per gram of the catalyst. In the presence of hydrogen, vacuum residue was contacted with the hydrodesulfurization catalyst in a fixed-bed hydrotreating reactor for reaction. The reaction pressure was 20 MPa, the reaction temperature was 430 °C, and the liquid hourly space velocity was 0.7 h -1 , and the hydrogen-oil volume ratio was 900. After fractionation, high-quality fuel oil was obtained.

[0045] Comparative Example 3 Compared with Example 1, in Comparative Example 3, the hydrodesulfurization catalyst was replaced with the substance prepared in Comparative Example 1, and the other steps and raw materials were the same as those in Example 1.

[0046] Comparative Example 4 Compared with Example 1, in Comparative Example 4, the hydrodesulfurization catalyst was replaced with the substance prepared in Comparative Example 2, and the other steps and raw materials were the same as those in Example 1.

[0047] Performance Detection The contents of various impurities in the oil after 2200 h of hydrodesulfurization in Examples 1 - 3 and Comparative Examples 3 - 4 were measured, and the removal rate of impurities was calculated. The results are shown in Table 1.

[0048]

[0049] It can be seen from the data in Table 1 that the hydrodesulfurization catalyst provided by the present invention has excellent activity and can effectively remove metals, sulfur, and nitrogen. By comparing the data of Example 1 and Comparative Example 3, it can be seen that replacing asphalt with carboxymethyl cellulose results in a decrease in the acidic active centers of the catalyst, thereby leading to a decrease in the removal rate. By comparing the data of Example 1 and Comparative Example 4, it can be seen that there is a synergistic effect between halloysite nanotubes and alumina. Due to the absence of halloysite nanotubes, the desulfurization performance of the catalyst decreases.

[0050] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0051] The above content is only an example and explanation of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A processing technology for high-quality fuel oil, characterized in that: It includes the following steps: In the presence of hydrogen, the residue oil feedstock enters the hydrotreating reaction zone to contact with the hydrodesulfurization catalyst for reaction, and then is fractionated to obtain high-quality fuel oil; The preparation method of the hydrodesulfurization catalyst includes the following steps: A1. Mix alumina, halloysite nanotubes and pitch to obtain mixture 1; A2. Crush mixture 1 to obtain a mixed powder; A3. Mix the mixed powder, pore-forming agent, high-alumina cement and deionized water, and then form, dry and calcine for the first time to obtain mixture 2; A4. Acid-treat mixture 2 with an acid, then wash and dry to obtain a support; A5. Immerse the support in an impregnating solution containing active metals, then dry and calcine for the second time to obtain the hydrodesulfurization catalyst.

2. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: The reaction conditions in the hydrogenation reaction zone are as follows: the reaction pressure is 12 - 20 MPa, the reaction temperature is 360 - 430 °C, the liquid hourly space velocity is 0.1 - 0.7 h -1 , and the hydrogen-oil volume ratio is 300 - 900.

3. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: Before use, the hydrodesulfurization catalyst needs to be contacted with a sulfiding solution and hydrogen for sulfiding.

4. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In step A1, the mass ratio of alumina, halloysite nanotubes and pitch is (1.2 - 3):(1 - 1.5):(0.1 - 0.5).

5. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In step A1, the particle size of alumina is 30 - 60 μm; the diameter of halloysite nanotubes is 30 - 70 nm, and the length is 5 - 20 μm.

6. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In step A3, the pore-forming agent is at least one of urea, oxalic acid, and starch; the mass of the pore-forming agent is 0.5 - 3% of the mass of the mixed powder; the mass of the high-alumina cement is 1 - 4% of the mass of the mixed powder.

7. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In step A3, the temperature of the first calcination is 500 - 750 °C, and the time is 3 - 7 h.

8. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In the step A4, the specific surface area of the carrier is 180 - 250 m 2 / g, and the pore volume is 0.6 - 1.2 mL / g.

9. The processing technology of a high-quality fuel oil according to claim 1, characterized in that: In step A5, the impregnating solution containing active metals includes cobalt salts, molybdenum salts and a solvent; the cobalt salts include at least one of cobalt nitrate, cobalt sulfate, and basic cobalt carbonate, the molybdenum salts include at least one of ammonium tetramolybdate and ammonium heptamolybdate, and the solvent is deionized water; the concentration of cobalt salts in the impregnating solution containing active metals is 6 - 12 wt%, and the concentration of molybdenum salts is 5 - 10 wt%.

10. A high-quality fuel oil prepared by the processing technology according to any one of claims 1 - 9.

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