Pipeline type hydrogenation process method for injecting liquid catalyst

Abstract

The invention provides a pipeline type hydrogenation process method for injecting a liquid catalyst, and relates to the technical fields of oil refining, petrochemical industry and coal chemical industry. According to the present invention, the high metal impurity raw oil is subjected to hydrogenation pretreatment by using the pipeline type reactor, and the liquid catalyst is used in the hydrogenation pretreatment process, such that the process method can easily maintain the raw material concentration, reduce the material backmixing, and improve the catalytic reaction efficiency, the product yield and the product quality; and the continuous operation time and the working efficiency of hydrogenation pretreatment are greatly prolonged.

Description

Technical Field

[0001] The invention relates to the technical fields of oil refining, petrochemical industry and coal chemical industry, and in particular to a pipeline hydrogenation process method for injecting a liquid catalyst. Background Art

[0002] For the hydrogenation or hydro-upgrading of low-quality oils such as vegetable oils, animal fats, coal tar, waste mineral oils or petroleum residues with high metal impurities, the suspended bed heterogeneous catalytic reaction process is currently mostly used. Heterogeneous catalysis refers to the reactants and catalysts being in different phases. In the catalytic hydrogenation reaction of oil products, the reactants are liquid and gaseous, and the catalyst is solid. The catalyst conventionally used in suspended bed hydrogenation is in the form of fine solids, which are dispersed and added to the flowing reactants.

[0003] However, there are the following problems and shortcomings when using solid catalysts for suspended bed hydrogenation: on the one hand, solid catalysts are generally used once and in relatively large quantities. When used to treat high metal impurities, they are easily aggregated into larger particles and cause blockage. The reaction pressure drop of the device increases rapidly. When the upper limit is reached, it will be forced to stop working, and the continuous operation time is short; the activity of the catalyst decreases significantly during use, and it will cause permanent poisoning, and the catalyst needs to be replaced frequently, thus affecting the economic benefits. On the other hand, the suspended bed reactor is large in size. This is because in the process of suspended bed multiphase catalytic reaction, the material needs to stay in the reactor for a sufficient time from the perspective of reaction kinetics, so the reactor is required to have a corresponding volume; from the perspective of fluid dynamics, the material in the reactor cannot have an excessively fast flow rate, so that the catalyst particles suspended in the material can be deposited under the action of gravity to ensure that the material at the reactor outlet cannot carry out the catalyst, so the reactor must have a corresponding diameter; in addition, the activity of the solid catalyst used is low, and a large amount of use is required, which determines that the reactor must also have a corresponding volume. Based on the above reasons, it is determined that the suspended bed reactor has a large volume and a correspondingly large equipment manufacturing cost.

[0004] Therefore, the defects of the existing technology of producing fuel using the suspended bed heterogeneous catalytic reaction process need to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to provide a pipeline hydrogenation process with liquid catalyst injection to address the deficiencies of the prior art, thereby at least solving some of the problems existing in the prior art.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A pipeline hydrogenation process method with liquid catalyst injection includes using a pipeline reactor to perform hydrogenation pretreatment on crude oil with high metal impurities; liquid catalyst is used in the hydrogenation pretreatment process.

[0008] Furthermore, the pipeline reactor comprises a single row of spiral tubes or a parallel straight tube bundle, and a shell container is arranged outside the spiral tube or the straight tube bundle.

[0009] Further, the hydrogenation pretreatment step is:

[0010] The crude oil is pressurized by a pressure pump and mixed with hydrogen, heated in a heating furnace, and then the liquid catalyst is injected into the crude oil. After being evenly mixed with the crude oil, it is sent to a pipeline reactor for hydrogenation pretreatment to obtain a hydrogenation pretreatment product.

[0011] In the pipeline reactor of the present invention, during the hydrogenation pretreatment process, the raw oil enters the internal structure of the pipeline reactor, completes most of the chemical reactions from top to bottom in the form of plug flow with higher concentrations of reactants and catalysts, and then enters the reactor shell and returns from bottom to top to continue to complete the remaining reactions, and completes the gravity separation of materials and catalysts during the ascending process. The pipeline reactor of the present invention is equivalent to adding the internal structure of the pipeline reactor into the empty cylinder of the existing suspended bed reactor. By adding the internal structure, on the one hand, the material entering the reactor is constrained in a smaller space, avoiding mixing with the existing material in the reactor, reducing material backmixing, and increasing the concentration of reactants, creating good conditions for reducing the hydrogen-to-oil ratio of the feed, increasing the reactor air velocity, and shortening the reaction time; on the other hand, the low-activity solid catalyst is replaced by a high-activity liquid catalyst, so that the amount of catalyst used is reduced, the concentration of the separated material is reduced, and the space required for separation is correspondingly reduced. Thereby compensating for the problems of the existing suspended bed reactor catalytic hydrogenation process.

[0012] Furthermore, the hydrogenation pretreatment conditions are: reaction temperature 200-400°C, hydrogen pressure 1-6MPa, preferably hydrogen pressure 2-5MPa; volume space velocity 0.1-3.0h -1 , the volume ratio of hydrogen to oil is 100-600.

[0013] Furthermore, the concentration of the liquid catalyst injected into the feedstock oil is 100 to 1000 ppm.

[0014] Furthermore, the liquid catalyst is an oil-soluble liquid catalyst, and the oil-soluble liquid catalyst is prepared by the following method:

[0015] (1) Dissolve the metal salt in N,N-dimethylformamide, heat to 100-170°C, add acetylacetone, react for 1-4 hours, then cool to room temperature, and finally divide evenly into solution A and solution B;

[0016] (2) adding solvent a and water to solution A and mixing evenly, then adding triphenylphosphine and sodium carbonate, stirring and reacting for 0.5 to 3 hours to obtain solution C;

[0017] (3) Solution B and solution C are mixed, stirred and reacted at room temperature for 0.5 to 4 hours, and then the obtained solution is rotary evaporated, centrifuged, and washed to obtain an oil-soluble liquid catalyst.

[0018] Preferably, in step (1), the metal salt is any one of molybdenum salt, nickel salt, cobalt salt or iron salt, or a mixture of several of them.

[0019] Preferably, in step (1), the mass ratio of the metal salt, N,N-dimethylformamide and acetylacetone is 1:(5-20):(0.5-10).

[0020] Preferably, in step (2), the solvent a is a mixture of one or more of toluene, dichloromethane or diethyl ether.

[0021] Preferably, in step (2), the mass ratio of the metal salt to triphenylphosphine, solvent a, sodium carbonate and water is: 1:(0.1-0.5):(1-10):(0.1-1):(5-10).

[0022] Preferably, in step (3), the total mass content of metals in the obtained oil-soluble liquid catalyst is 5 to 30%.

[0023] More preferably, in step (3), the mass content ratio of iron, cobalt, nickel and molybdenum in the obtained oil-soluble liquid catalyst is (5-15):(15-30):(45-60):(10-20); preferably, the mass content ratio of iron, cobalt, nickel and molybdenum in the oil-soluble liquid catalyst is 10:20:50:20.

[0024] The present invention uses an oil-soluble liquid catalyst to perform hydrogenation pretreatment on low-quality oil with high metal impurities. The oil-soluble liquid catalyst can be evenly dispersed in the raw oil, and the added amount is small. The impurity metal elements in the raw oil can be efficiently removed, and the product yield and product quality are greatly improved. In addition, the low-activity solid catalyst is replaced by a high-activity oil-soluble liquid catalyst, so that the added amount of the catalyst is reduced from about 5% to less than 1000ppm or even 100ppm. The reduction in the amount of catalyst reduces the difficulty of separating the corresponding catalyst components in the product after the reaction, and correspondingly reduces the space required for separation.

[0025] Furthermore, the raw oil is selected from any one of vegetable oil, animal oil, coal tar, waste mineral oil, and petroleum residue oil.

[0026] Furthermore, the pipeline reactor is connected in series with a fixed bed reactor to perform hydrofining treatment on the product obtained from the hydrogenation pretreatment.

[0027] Furthermore, an ash discharge port is arranged at the bottom of the fixed bed reactor.

[0028] Furthermore, the product obtained from the hydrogenation pretreatment enters a fixed bed reactor for hydrogenation refining treatment; the conditions of the hydrogenation refining are: temperature of 300-350°C; pressure of 2-5 MPa; hydrogen-to-oil volume ratio of 50-300; volume space velocity of 0.1-2.5 h -1 .

[0029] Preferably, the fixed bed reactor is loaded with a solid catalyst, wherein the solid catalyst has molybdenum and nickel as active components and alumina as a carrier; the loading amount of the active components in the solid catalyst is 1 to 30%; the catalyst needs to be pre-sulfurized before use, and the pre-sulfurization treatment is a conventional method in the art.

[0030] Furthermore, the pipeline hydrogenation process for injecting liquid catalyst also includes the following steps:

[0031] (1) The product obtained by the hydrofining treatment in the fixed bed reactor enters the hot high-pressure separator to separate the hot high-fraction gas and the hot high-fraction oil;

[0032] (2) The hot high-fraction oil is then depressurized in a hot low-pressure separator, the tailings are removed, and the oil enters a distillation tower for distillation to obtain a naphtha fraction and a diesel fraction.

[0033] Preferably, in step (1), the temperature of the hot high-pressure separator is 300-350° C., and the pressure is 2-5 MPa.

[0034] Preferably, in step (2), the temperature of the hot low-pressure separator is 250-300° C., and the pressure is 0.6-1 MPa.

[0035] Preferably, in step (2), the top pressure of the fractionation tower is 10-30 KPa, the feed temperature is 260-380°C, and the top temperature is 150-220°C.

[0036] Furthermore, the pipeline hydrogenation process for injecting liquid catalyst further comprises the following steps:

[0037] (1) The heavy sediment produced at the bottom of the pipeline reactor and the fixed bed reactor is separated into hydrogen and oil by an ash discharge hot high-pressure separator;

[0038] (2) The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator and enters the cold high-pressure separator for further separation. The separated hydrogen is recycled;

[0039] (3) The oil is combined with the heavy sediment produced at the bottom of the hot low-pressure separator and enters the ash settling tank to separate the upper oil and ash-containing oil;

[0040] (4) The upper oil fraction and the unreacted oil fraction discharged from the bottom of the distillation tower are combined and mixed into the raw oil as circulating oil for recovery and use, and the ash-containing oil fraction is discharged.

[0041] Preferably, in step (2), the temperature of the cold high-pressure separator is 40-70° C., and the pressure is 1-6 MPa.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The pipeline hydrogenation process method with injection of liquid catalyst provided by the present invention uses liquid catalyst to treat low-quality oil with high metal impurities in the hydrogenation pretreatment step, which reduces material remixing, is beneficial to maintaining the concentration of raw materials, reducing material remixing, improving product yield and product quality, and greatly extending the continuous operation time and work efficiency of hydrogenation pretreatment.

[0044] 2. The pipeline hydrogenation process method with liquid catalyst injection provided by the present invention uses a pipeline reactor in the hydrogenation pretreatment process to replace the traditional suspended bed reactor. The internal structure of the tubular reactor can constrain the material entering the reactor to a smaller space, avoiding its mixing with the existing material in the reactor, reducing material backmixing, and improving the efficiency of the catalytic reaction, thereby effectively overcoming the constraint that the suspended bed reactor is difficult to reduce in volume. The use of the pipeline reactor can also utilize the chemical reaction heat in the product to heat the reactants themselves, thereby realizing the rational use of waste heat, which is beneficial to reducing energy consumption and reducing the heat load of the heating furnace.

[0045] 3. The pipeline hydrogenation process method for injecting liquid catalyst provided by the present invention replaces the low-activity solid catalyst with a high-activity liquid catalyst, so that the added amount of catalyst is reduced from about 5% to less than 1000ppm. The reduction in the amount of catalyst reduces the concentration of the separated product, and correspondingly reduces the space required for separation; the oil-soluble liquid catalyst is used to perform hydrogenation pretreatment on the inferior oil with high metal impurities. The oil-soluble liquid catalyst can be evenly dispersed in the raw oil, and the added amount is small, which can effectively remove the impure metal elements in the raw oil, improve the catalytic hydrogenation efficiency, and thus improve the quality of the final product; in addition, the use of the pipeline reactor and the liquid catalyst avoids the problems of obvious decrease in catalytic efficiency and rapid increase in reaction pressure drop during the use of the current solid catalyst, greatly reduces the bed pressure drop increase rate, and effectively extends the overall operation cycle and work efficiency of the device.

[0046] 4. The oil-soluble liquid catalyst of the present invention has good affinity with the raw material, has good dispersibility in the raw material, has a high contact rate with the reactants, and effectively reduces the hydrogen pressure and concentration.

[0047] 5. The pipeline hydrogenation process with liquid catalyst injection provided by the present invention provides a new process for the hydrogenation and demetallization of inferior oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The present invention is a flow chart of a pipeline hydrogenation process for injecting a liquid catalyst.

[0049] In the figure, 1-raw material storage tank, 2-boosting pump, 3-reaction heating furnace, 4-catalyst storage tank, 5-catalyst filling pump, 6-pipeline reactor, 7-fixed bed reactor, 8-hot high-pressure separator, 9-hot low-pressure separator, 10-cold high-pressure separator, 11-fractionation heating furnace, 12-fractionation tower, 13-circulating hydrogen compressor, 14-fresh hydrogen compressor, 15-ash discharge hot high-pressure separator, 16-ash settling tank. DETAILED DESCRIPTION

[0050] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0051] Figure 1 Flow chart of the pipeline hydrogenation process of the present invention with injection of liquid catalyst, such as Figure 1 As shown, the process of the pipeline hydrogenation process of the present invention with injection of liquid catalyst is as follows:

[0052] S1, the raw oil in the raw material storage tank 1 is pressurized by the pressure pump 2 and mixed with hydrogen, and then heated by the reaction heating furnace 3. The liquid catalyst in the catalyst storage tank 4 is injected into the raw oil by the catalyst filling pump 5, and then mixed with the raw oil and sent to the pipeline reactor 6 for hydrogenation pretreatment;

[0053] The crude oil enters the internal structure of the pipeline reactor, completes most of the chemical reactions from top to bottom in the form of plug flow with higher concentrations of reactants and catalysts, then enters the reactor shell and returns from bottom to top to continue the remaining reactions, and completes the gravity sedimentation separation of materials and catalysts during the rising process.

[0054] S2. The product obtained by hydrogenation pretreatment in the pipeline reactor 6 enters the fixed bed reactor 7 for hydrogenation refining treatment.

[0055] S3. The product after the hydrofining treatment in the fixed bed reactor 7 enters the hot high-pressure separator 8 to separate the hot high-fraction gas and the hot high-fraction oil.

[0056] S4, the hot high-fraction oil is then depressurized by a hot low-pressure separator 9, the homogeneous hydrogenation tailings are removed, and the oil enters a fractionating tower 12 for fractionation after passing through a fractionation heating furnace 11 to obtain a naphtha fraction and a diesel fraction.

[0057] The waste generated at the bottom of S5, the pipeline reactor 6 and the fixed bed reactor 7 is separated into hydrogen and oil by the ash discharge hot high-pressure separator 15.

[0058] The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator 8 and enters the cold high-pressure separator 10 for further separation. The further separated hydrogen is combined with the hydrogen injected by the fresh hydrogen compressor 14 and then injected into the system for recycling through the circulating hydrogen compressor 13. The components discharged from the bottom enter the fractionation tower 12 for fractionation.

[0059] The oil is combined with the waste generated at the bottom of the hot low-pressure separator 9 and enters the ash settling tank 16 to separate the upper oil and the ash-containing oil;

[0060] The upper oil fraction is discharged, and the ash-containing oil fraction and the unreacted oil fraction discharged from the bottom of the fractionation tower 12 are combined and mixed into the raw oil as circulating oil for recycling.

[0061] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention are obtained through conventional commercial channels.

[0062] Example 1

[0063] A pipeline hydrogenation process for injecting a liquid catalyst comprises the following steps:

[0064] S1. The crude oil (coconut oil) is pressurized by a pressure pump and mixed with hydrogen, and then heated by a heating furnace. The liquid catalyst is injected into the crude oil at a concentration of 100ppm, mixed with the crude oil and then sent to a pipeline reactor for hydrogenation pretreatment; the hydrogenation pretreatment conditions are: reaction temperature 400°C, hydrogen pressure 6MPa, volume space velocity 3.0h -1 , the hydrogen to oil volume ratio is 600.

[0065] S2. The product of the pipeline reactor pre-treatment is discharged from the top and enters the fixed bed reactor for hydrofining treatment; the hydrofining treatment conditions are: temperature 350°C, pressure 5MPa, hydrogen-oil volume ratio 300, volume space velocity 2.5h -1 The fixed bed reactor is filled with a solid catalyst, which is alumina loaded with 3% molybdenum.

[0066] S3. The product after the hydrofining treatment in the fixed bed reactor enters the hot high-pressure separator to separate the hot high-fraction gas and the hot high-fraction oil; the conditions of the hot high-pressure separator are: temperature 350°C, pressure 5MPa.

[0067] S4, the separated hot high-fraction oil is depressurized in a hot low-pressure separator, the homogeneous hydrogenation tailings are removed, and the oil enters a fractionation tower for fractionation to obtain a naphtha fraction and a diesel fraction;

[0068] Hot low-pressure separator conditions: temperature 300°C, pressure 1MPa;

[0069] The distillation conditions are: tower top pressure 30 KPa, feed temperature 380°C, tower top temperature 220°C.

[0070] S5, the heavy sediment produced at the bottom of the pipeline reactor and the fixed bed reactor is separated into hydrogen and oil by an ash discharge hot high-pressure separator;

[0071] The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator and enters the cold high-pressure separator for further separation. The separated hydrogen is recycled; the conditions of the cold high-pressure separator are: temperature 70°C, pressure 6MPa;

[0072] The oil is combined with the heavy sediment produced at the bottom of the hot low-pressure separator and enters the ash settling tank to separate the upper oil and ash-containing oil;

[0073] The upper oil fraction and the unreacted oil fraction discharged from the bottom of the distillation tower are combined and mixed into the raw oil as circulating oil for recovery and use, and the ash-containing oil fraction is discharged.

[0074] In this embodiment, the liquid catalyst is prepared by the following method:

[0075] (1) Add 1 part by weight of nitrates of molybdenum, nickel, cobalt and iron to 5 parts by weight of N,N-dimethylformamide, stir to fully dissolve, start cooling and reflux, raise the temperature to 100° C., add 0.5 parts by weight of acetylacetone to complete the reaction, react for 4 hours, cool to room temperature, and finally divide evenly into solution A and solution B;

[0076] (2) adding 1 part by weight of toluene and 5 parts by weight of water to solution A, and stirring evenly, then adding 0.1 parts by weight of triphenylphosphine and 0.1 parts by weight of sodium carbonate, stirring and reacting for 0.5 hours, to obtain solution C;

[0077] (3) Solution B and solution C were mixed, stirred and reacted at room temperature for 0.5 h, and then the obtained solution was rotary evaporated, centrifuged, and washed to obtain a liquid oil-soluble catalyst.

[0078] Example 2

[0079] Another pipeline hydrogenation process with injection of liquid catalyst comprises the following steps:

[0080] S1. The feedstock oil (coal tar) is pressurized by a pressure pump and then mixed with hydrogen. The feedstock oil is heated in a heating furnace, and a liquid catalyst (same as in Example 1) is injected into the feedstock oil at a concentration of 100 ppm. The liquid catalyst is mixed with the feedstock oil and then sent to a pipeline reactor for hydrogenation pretreatment. The hydrogenation pretreatment conditions are: reaction temperature 200°C, hydrogen pressure 1 MPa, volume space velocity 0.1 h -1 , the volume ratio of hydrogen to oil is 100.

[0081] S2. The product of the pipeline reactor pre-treatment is discharged from the top and enters the fixed bed reactor for hydrofining treatment; the hydrofining treatment conditions are: temperature 300 ° C, pressure 2 MPa, hydrogen-to-oil volume ratio 50, volume space velocity 0.1 h -1 The fixed bed reactor is filled with a solid catalyst, which is alumina loaded with 3.4% molybdenum.

[0082] S3. The product after the hydrofining treatment in the fixed bed reactor enters the hot high-pressure separator to separate the hot high-fraction gas and the hot high-fraction oil; the conditions of the hot high-pressure separator are: temperature 300°C, pressure 2MPa.

[0083] S4, the separated hot high-fraction oil is depressurized in a hot low-pressure separator, the homogeneous hydrogenation tailings are removed, and the oil enters a fractionation tower for fractionation to obtain a naphtha fraction and a diesel fraction;

[0084] Hot low-pressure separator conditions: temperature 250°C, pressure 0.6MPa;

[0085] The distillation conditions are: tower top pressure 10 KPa, feed temperature 260°C, tower top temperature 150°C.

[0086] S5, the heavy sediment produced at the bottom of the pipeline reactor and the fixed bed reactor is separated into hydrogen and oil by an ash discharge hot high-pressure separator;

[0087] The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator and enters the cold high-pressure separator for further separation. The separated hydrogen is recycled; the conditions of the cold high-pressure separator are: temperature 10°C, pressure 1MPa;

[0088] The oil is combined with the heavy sediment produced at the bottom of the hot low-pressure separator and enters the ash settling tank to separate the upper oil and ash-containing oil;

[0089] The upper oil fraction and the unreacted oil fraction discharged from the bottom of the distillation tower are combined and mixed into the raw oil as circulating oil for recovery and use, and the ash-containing oil fraction is discharged.

[0090] Example 3

[0091] Another pipeline hydrogenation process with injection of liquid catalyst comprises the following steps:

[0092] S1. The feedstock oil (petroleum residue oil) is pressurized by a pressure pump and mixed with hydrogen, and then heated in a heating furnace. The liquid catalyst (same as in Example 1) is injected into the feedstock oil at a concentration of 100 ppm, mixed with the feedstock oil and then sent to a pipeline reactor for hydrogenation pretreatment. The hydrogenation pretreatment conditions are: reaction temperature 400°C, hydrogen pressure 6MPa, volume space velocity 3.0h -1 , the hydrogen to oil volume ratio is 600.

[0093] S2. The product of the pipeline reactor pre-treatment is discharged from the top and enters the fixed bed reactor for hydrofining treatment; the hydrofining treatment conditions are: temperature 350°C, pressure 5MPa, hydrogen-oil volume ratio 300, volume space velocity 2.5h -1 The fixed bed reactor is filled with a solid catalyst, which is alumina loaded with 3.4% molybdenum.

[0094] S3. The product after the hydrofining treatment in the fixed bed reactor enters the hot high-pressure separator to separate the hot high-fraction gas and the hot high-fraction oil; the conditions of the hot high-pressure separator are: temperature 350°C, pressure 5MPa.

[0095] S4, the separated hot high-fraction oil is depressurized in a hot low-pressure separator, the homogeneous hydrogenation tailings are removed, and the oil enters a fractionation tower for fractionation to obtain a naphtha fraction and a diesel fraction;

[0096] Hot low-pressure separator conditions: temperature 300°C, pressure 1 MPa.

[0097] The distillation conditions are: tower top pressure 30 KPa, feed temperature 380°C, tower top temperature 220°C.

[0098] S5, the heavy sediment produced at the bottom of the pipeline reactor and the fixed bed reactor is separated into hydrogen and oil by an ash discharge hot high-pressure separator;

[0099] The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator and enters the cold high-pressure separator for further separation. The separated hydrogen is recycled; the conditions of the cold high-pressure separator are: temperature 70°C, pressure 6MPa;

[0100] The oil is combined with the heavy sediment produced at the bottom of the hot low-pressure separator and enters the ash settling tank to separate the upper oil and ash-containing oil;

[0101] The upper oil fraction and the unreacted oil fraction discharged from the bottom of the distillation tower are combined and mixed into the raw oil as circulating oil for recovery and use, and the ash-containing oil fraction is discharged.

[0102] The properties of the feedstock oil in the above Examples 1-3 are shown in Table 1 below:

[0103] Table 1. Raw oil properties

[0104] project Coconut Oil Coal tar Petroleum residue <![CDATA[Density (20 °C) (g / cm 3 )]]> 0.93 1.13 1.02 <![CDATA[Kinematic viscosity (50 °C) (mm 2 / s)]]> 58.31 320.6 3000.8 S content (weight %) 0.42 0.55 4.28 N content (weight %) 0.59 0.93 0.69 O content (weight %) 15.14 — — C content (weight %) 71.52 84.73 85.79 H content (weight %) 12.33 8.10 10.34 H / C atomic ratio 2.06 1.14 1.45 Acid value (mg KOH / g) 0.9 0.6 0.4

[0105] Examples 1-11

[0106] The difference from Example 1 is that the liquid catalyst is different, as shown in Table 2 below.

[0107] Table 2. Concentration of metals in catalysts

[0108]

[0109] Comparative Example 1

[0110] The difference from Example 1 is that in this comparative example, the hydrogenation pretreatment is carried out in a suspended bed hydrocracking reactor.

[0111] Comparative Example 2

[0112] The difference from Example 1 is that the catalyst used in the hydrogenation pretreatment process of this comparative example is a solid catalyst, which uses alumina as a carrier and is loaded with 2% Fe, 4% Co, 10% Ni and 4% Mo.

[0113] Comparative Example 3

[0114] The difference from Example 1 is that in this comparative example, the hydrogenation pretreatment is carried out in a suspended bed hydrocracking reactor, and the catalyst is a solid catalyst, which uses alumina as a carrier and is loaded with 2% Fe, 4% Co, 10% Ni and 4% Mo.

[0115] Comparative Example 4

[0116] The difference from Example 3 is that the hydrogenation pretreatment process of this comparative example is carried out in a fixed bed reactor, and the catalyst used in the process is a solid catalyst; wherein the solid catalyst is supported by alumina and loaded with 2% Fe, 4% Co, 10% Ni and 4% Mo.

[0117] Test Example 1

[0118] The hydrogenation pretreatment products obtained in the above examples and comparative examples were tested, and the results are shown in Table 3 below.

[0119] Table 3. Properties of Hydrogenation Pretreatment Products

[0120]

[0121]

[0122] The results show that the hydrogenation pretreatment product obtained by the pipeline hydrogenation process method of injecting liquid catalyst provided by the present invention has low sulfur content and low metal content, indicating that the hydrogenation pretreatment process provided by the present invention can effectively remove sulfur and metals in low-quality oil with high metal impurities, and can produce qualified naphtha and diesel using low-quality oil with high metal impurities, thus realizing continuous and industrialized production. Compared with Example 1 and Examples 4-11, this shows that the selection of the liquid catalyst of the specific component of the present invention is helpful to improve the efficiency of hydrogenation pretreatment and realize the maximum removal of sulfur, metals, etc. in low-quality oil.

[0123] Test Example 2

[0124] The product properties and yields of naphtha and diesel are shown in Tables 4 and 5 below.

[0125] Table 4. Naphtha properties and yields

[0126]

[0127]

[0128] Table 5. Diesel properties and yield

[0129]

[0130] As shown in the table, the naphtha and diesel obtained by the process provided by the present invention have low sulfur content and metal content, good product quality and high yield. The sulfur content and metal content of the hydrogenation pretreatment products obtained in Examples 4-11 and Comparative Examples are significantly higher than those in Example 1, and the yield is lower than that in Example 1, which shows that the combination of the liquid catalyst of the present invention and the pipeline reactor is conducive to improving the quality and yield of the product.

[0131] Test Example 3

[0132] According to the hydrogenation process provided in Example 3 and Comparative Example 4, after running for 100 hours, the reactor pressure drop and oil yield changes were analyzed to evaluate the device operation cycle. The results are shown in Table 6 below.

[0133] Table 6

[0134]

[0135] As shown in the table, in Example 3, the pipeline catalytic hydrogenation method with liquid injection was used, and the reaction efficiency and the total oil yield did not change significantly after running for 100 hours. In Comparative Example 4, a solid catalyst was used for hydrogenation pretreatment in a fixed bed reactor, and the reactor pressure drop was high. Although the initial oil yield was comparable to that in Example 3, the total oil yield dropped to 62% after running for 100 hours, which was a large difference from Example 3, and the reaction efficiency dropped significantly, indicating that the overall operation cycle of the device in Comparative Example 4 was short.

[0136] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A pipeline hydrogenation process with injection of liquid catalyst, characterized in that: The method comprises the following steps: using a pipeline reactor to perform hydrogenation pretreatment on crude oil with high metal impurities; and using a liquid catalyst during the hydrogenation pretreatment process.

2. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1, characterized in that: The pipeline reactor comprises a single row of spiral tubes or a parallel straight tube bundle, and a shell container is arranged outside the spiral tube or the straight tube bundle.

3. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1, characterized in that: The hydrogenation pretreatment steps are: The crude oil is pressurized by a pressure pump and mixed with hydrogen, and then heated by a heating furnace. The liquid catalyst is injected into the crude oil, mixed evenly with the crude oil, and then sent to a pipeline reactor for hydrogenation pretreatment to obtain a hydrogenation pretreatment product.

4. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1, characterized in that: The liquid catalyst is an oil-soluble liquid catalyst, and the liquid catalyst is prepared by the following method: (1) Dissolve the metal salt in N,N-dimethylformamide, heat to 100-170°C, add acetylacetone, react for 1-4 hours, then cool to room temperature, and finally divide evenly into solution A and solution B; (2) adding solvent a and water to solution A and mixing evenly, then adding triphenylphosphine and sodium carbonate, stirring and reacting for 0.5 to 3 hours to obtain solution C; (3) Solution B and solution C are mixed, stirred and reacted at room temperature for 0.5 to 4 hours, and then the obtained solution is rotary evaporated, centrifuged, and washed to obtain a liquid oil-soluble catalyst.

5. The pipeline hydrogenation process with injection of liquid catalyst according to claim 4, characterized in that: The metal salt is one or a mixture of molybdenum salt, nickel salt, cobalt salt and iron salt.

6. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1, characterized in that: The concentration of the liquid catalyst injected into the feedstock oil is 100 to 1000 ppm.

7. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1, characterized in that: The raw material oil is selected from any one of vegetable oil, animal oil, coal tar, waste mineral oil and petroleum residue oil.

8. The pipeline hydrogenation process with injection of liquid catalyst according to claim 1 or 3, characterized in that: The pipeline reactor is connected in series with a fixed bed reactor to perform hydrofining treatment on the hydrogenation pretreatment product.

9. The pipeline hydrogenation process with injection of liquid catalyst according to claim 8, characterized in that: The pipeline hydrogenation process for injecting liquid catalyst also includes the following steps: (1) The product obtained by the hydrofining treatment in the fixed bed reactor enters the hot high-pressure separator to separate the hot high-fraction gas and the hot high-fraction oil; (2) The hot high-fraction oil is then depressurized in a hot low-pressure separator, the tailings are removed, and the oil enters a distillation tower for distillation to obtain a naphtha fraction and a diesel fraction.

10. The pipeline hydrogenation process with injection of liquid catalyst according to claim 9, characterized in that: The pipeline hydrogenation process for injecting liquid catalyst also includes the following steps: (1) The heavy sediment produced at the bottom of the pipeline reactor and the fixed bed reactor is separated into hydrogen and oil by an ash discharge hot high-pressure separator; (2) The hydrogen is combined with the hydrogen discharged from the top of the hot high-pressure separator and enters the cold high-pressure separator for further separation. The separated hydrogen is recycled; (3) The oil is combined with the heavy sediment produced at the bottom of the hot low-pressure separator and enters the ash settling tank to separate the upper oil and ash-containing oil; (4) The upper oil fraction and the unreacted oil fraction discharged from the bottom of the distillation tower are combined and mixed into the raw oil as circulating oil for recovery and use, and the ash-containing oil fraction is discharged.

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