System for widening hydrocracking raw material source and improving naphtha yield

Abstract

The invention discloses a system for widening hydrocracking raw material sources and improving naphtha yield, which belongs to the technical field of naphtha refining and comprises a feeding unit, a first-stage reaction unit, a hydrogen circulation system, a second-stage reaction unit and a first-stage fractionation unit. The feeding unit comprises a buffer tank I for storing light raw oil, a refining feeding heating furnace and a hydrogen source; the primary reaction unit comprises a fixed bed refining reactor, a hot high-pressure separator and a cold high-pressure separator. According to the invention, the light raw oil and the external raw oil are subjected to cracking reaction at the same time, then the obtained different products are conveyed into the thermal high-pressure separator at the same time for separation, and then a series of subsequent separation and hydrogen purification treatments are carried out. Other products can be used as external raw oil for further cracking while the target product is obtained, so that the target product is obtained again, the yield of the target product can be improved, and the production cost can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of naphtha refining, in particular to a system for broadening the source of hydrocracking raw materials and improving the naphtha yield. Background Art

[0002] Naphtha is a light hydrocarbon liquid widely used in oil refining, chemical industry and petrochemical industry. It is separated from crude oil through the distillation process of crude oil or hydrocracking reaction. Naphtha is a common raw material for catalytic reforming. Through the catalytic reforming process, naphtha can be converted into high-octane gasoline (reformed gasoline) rich in aromatics, and liquefied petroleum gas and hydrogen are produced as by-products.

[0003] The current methods for preparing naphtha include fractionation and hydrocracking. The distillation method is specifically: the crude oil is divided into different fractions according to the boiling point differences of different components through the fractionation process of the crude oil distillation tower. Naphtha is generally separated from crude oil by distillation;

[0004] The hydrocracking method is as follows: Hydrocracking is the process of cracking heavy oil using hydrogen and a hydrocracking catalyst at high temperature and high pressure, and the products include naphtha, diesel, light hydrocarbon gas, etc.

[0005] Among them, conventional distillation is the basic production method of naphtha, which is suitable for separating the light part of crude oil, while hydrocracking can effectively remove impurities such as sulfur and nitrogen in the raw materials and produce high-quality naphtha.

[0006] However, both methods for preparing naphtha have yield problems. In order to increase the yield of naphtha, a series of processes are often used to return the tail oil obtained from the fractionation system to the raw material feed, thereby achieving the purpose of producing more heavy naphtha. However, this method only uses one raw material to repeatedly refine naphtha. When one raw material is used to refine naphtha, it becomes more difficult to refine naphtha, which will lead to a decrease in refining efficiency. Therefore, the present invention provides a system for broadening the source of hydrocracking raw materials and improving the yield of naphtha to solve the above-mentioned problems. Summary of the invention

[0007] The object of the present invention is to provide a system for broadening the source of hydrocracking raw materials and improving the yield of naphtha, so as to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] Feeding unit: comprising a buffer tank 1 for storing light crude oil, one end of the buffer tank 1 is connected to a refined feed heating furnace for heating the raw material, and a mixed hydrogen is connected to the refined feed heating furnace and the outlet of the buffer tank 1 through a pipeline;

[0010] The primary reaction unit comprises a fixed bed refining reactor, the discharge port of the fixed bed refining reactor is connected to a hot high pressure separator, and the discharge port of the hot high pressure separator is connected to a cold high pressure separator;

[0011] Hydrogen circulation system: comprising a circulating hydrogen compressor, wherein the top outlet of the cold high-pressure separator is connected to the circulating hydrogen compressor, and the outlet of the circulating hydrogen compressor is connected to a hydrogen source;

[0012] The secondary reaction unit includes a buffer tank 2 for storing external raw oil, one end of the buffer tank 2 is connected to a cracking feed heating furnace, and the other end is connected to a mixer, the discharge port of the cracking feed heating furnace is connected to a fixed bed cracking reactor, the discharge port of the fixed bed cracking reactor is also connected to a hot high-pressure separator, and the discharge port of the hot high-pressure separator is also connected to a hot low-pressure separator, and the discharge port of the hot low-pressure separator is connected to a cold low-pressure separator; the discharge port of the cold high-pressure separator is also connected to a cold low-pressure separator, and the top outlet of the cold low-pressure separator is a low-pressure gas;

[0013] The primary fractionation unit includes a stripping tower, one end of which is connected to a fractionation tower, and the other end is an outlet for sulfur-containing dry gas; one end of the fractionation tower is an outlet for naphtha, and the other end is connected to the feed port of the mixer through a conveying pipeline, so as to recycle the product after the first reaction to increase the output of naphtha;

[0014] The oil separated by the hot high-pressure separator will enter the hot low-pressure separator to reduce the gas content again, and the liquid separated by the cold high-pressure separator will be mixed with the oil and gas at the top outlet of the hot low-pressure separator and enter the cold low-pressure separator to obtain low-gas. Part of the product after the hot low-pressure separator will be sent to the cracking feed heating furnace for further reaction, thereby providing a raw material basis for external raw oil.

[0015] The oil treated by the cold low-pressure separator and another part of the hot low-pressure oil separated by the hot low-pressure separator will enter the stripping tower, and some sulfur-containing dry gas will be obtained after passing through the stripping tower, while other products will pass through the fractionation tower to finally obtain naphtha, crude white oil and tail oil, among which naphtha and part of the crude white oil will enter the naphtha tank and the crude white oil tank respectively, while part of the crude white oil and all the tail oil will enter the cracking feed heating furnace for re-reaction to obtain new naphtha, thereby increasing the yield of naphtha;

[0016] The product obtained by the external crude oil passing through the fixed bed cracking reactor will also enter the hot high-pressure separator and be mixed with the product obtained by the crude oil passing through the fixed bed refining reactor.

[0017] As a further solution of the present invention, one end of the fractionation tower is a naphtha tank, and the other end is connected to the feed port of the buffer tank 2 through a delivery pipeline. A crude white oil tank is also installed at one end of the fractionation tower, and a delivery pipeline is connected between the crude white oil tank and the fractionation tower, and the delivery pipeline between the crude white oil tank and the fractionation tower is connected to the feed port of the buffer tank 2. In this way, part of the crude white oil produced can be returned to the cracking feed heating furnace for further reaction, thereby increasing the output of naphtha;

[0018] The crude oil is mixed with mixed hydrogen before being pumped to the refining feed heating furnace, and then enters the fixed bed refining reactor through the refining feed heating furnace for reaction treatment.

[0019] As a further solution of the present invention, the external raw oil is mixed with mixed hydrogen and then enters the cracking feed heating furnace, and then enters the fixed bed cracking reactor after being heated. The hydrofined oil and hydrocracking oil obtained by the fixed bed refining reactor will enter the hot high-pressure separator, and then after the gas-liquid separation in the hot high-pressure separator, it needs to pass through the cold high-pressure separator, and finally the purified hydrogen is compressed by the circulating hydrogen compressor and then recycled. This method can reduce resource waste and save production costs.

[0020] When the raw oil mixed with mixed hydrogen enters the fixed bed refining reactor for reaction, a hydrogenation protective agent needs to be added into the fixed bed refining reactor.

[0021] As a further solution of the present invention, the hydroprocessing catalyst in the fixed bed refining reactor is arranged in multiple layers, and the reaction effect and reaction degree can be increased through the multi-layer design.

[0022] As a further solution of the present invention, the heating temperature is between 350°C and 450°C; heating can provide thermal energy to stimulate the reaction rate.

[0023] As a further embodiment of the present invention, the hydrorefining catalyst mainly includes molybdenum, cobalt, nickel, platinum, and rhenium, wherein the main carrier is bauxite, and the hydrorefining catalyst is one of molybdenum, cobalt, nickel, platinum, and rhenium metals;

[0024] The hydrocracking reaction catalyst mainly includes molybdenum, cobalt, nickel, platinum and rhenium, the main carrier of which is bauxite, and the hydrocracking reaction catalyst is a combination of two or more of molybdenum, cobalt, nickel, platinum and rhenium metals.

[0025] As a further embodiment of the present invention, the external raw oil includes crude white oil, tail oil, and thermal low-fraction oil, and the external raw oil is a combination of two or more of the crude white oil, tail oil, and thermal low-fraction oil.

[0026] As a further solution of the present invention, the mixer includes a mixing tube, and the mixing tube is connected to the feed port of the second buffer tank through a transport pipeline;

[0027] The end of the mixing pipe away from the second buffer tank is connected to a feed pipe through a flange, and the lower end of the feed pipe is connected to the conveying pipeline through a plurality of transition pipes, so as to facilitate the hot low-pressure oil separated by the hot low-pressure separator, the crude white oil and the tail oil in the fractionation tower to enter the interior of the second buffer tank after mixing;

[0028] A plurality of first mixing blades and second mixing blades are fixedly connected inside the mixing tube;

[0029] The inside of the feed pipe is also fixedly connected to a fusion pipe, and the lower end of the fusion pipe is fixedly connected to a plurality of feed pipes, which are respectively welded to the transition pipes, and the feed pipes and the transition pipes are interconnected, and a first one-way valve is installed outside the feed pipe.

[0030] As a further solution of the present invention, a second one-way valve is fixedly connected inside the transition pipe, a third one-way valve is slidably connected to one side of the second one-way valve located inside the transition pipe, and valve flaps with one-way rotation function are rotatably connected inside the second one-way valve and the third one-way valve;

[0031] The interior of the transition pipe is also fixedly connected with a pressure valve for limiting the liquid volume in the transition pipe, the upper end of the pressure valve is installed with a blocking cover, the lower end of the blocking cover is symmetrically fixedly connected with two sealing plugs, the upper end of the pressure valve is symmetrically opened with two flow windows, the two flow windows and the sealing plugs correspond to each other;

[0032] A sliding column is fixedly connected to the middle of the blocking cover, and the sliding column is slidably connected to the pressure valve. The lower end of the pressure valve is fixedly connected to an extrusion sleeve. The sliding column is located in the extrusion sleeve, and the sliding column is fixedly connected to the inner bottom end of the extrusion sleeve through an elastic rope.

[0033] As a further solution of the present invention, a gas tank for storing compressed gas is fixedly connected to the side wall of the transition pipe, the gas outlet end of the gas tank is connected to the transition pipe through a copper tube, and the copper tube is located between the second one-way valve and the third one-way valve, and the interior of the copper tube is connected to a solenoid valve, the gas inlet end of the gas tank is connected to the gas outlet of the supercharger through a connecting channel, and the supercharger is welded to the side wall of the transition pipe;

[0034] A power turbine is arranged inside the supercharger, and the power turbine is located inside the transition duct. A connecting shaft is fixedly connected to the middle of the power turbine, and a compression turbine is fixedly connected to one end of the connecting shaft away from the power turbine, and the compression turbine is located outside the transition duct.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. When the present invention is used, light crude oil and external crude oil are used for cracking reaction at the same time, and then the different products obtained are simultaneously transported to a hot high-pressure separator for separation, and then a series of subsequent separation treatments are carried out. While obtaining the target product, other products can also be used as external crude oil for further cracking to obtain the target product again. In this way, not only the yield of the target product can be improved, but also the production cost can be reduced.

[0037] 2. When the present invention is used, by placing multiple catalysts in layers, different components in the external raw oil can be fully reacted, thereby avoiding the problem that the same catalyst cannot adapt to multiple components. While significantly improving the yield of the target product, the effective components of the external raw oil are deeply cracked, avoiding the problem of waste of the external raw oil.

[0038] 3. When the present invention is used, the external raw oil and the light raw oil are processed simultaneously, thereby greatly improving the working efficiency of the entire system.

[0039] 4. When the present invention is used, the hydrocracking oil and the hydrorefining oil are allowed to enter the hot high oil separator together to mix the two, thereby increasing the density and viscosity of the mixed product. When the density and viscosity of the mixed product increase, the saturation of the target product components can be increased, and the impurity content can be reduced, thereby further increasing the output of the target product. At the same time, the fixed bed refining reactor and the fixed bed cracking reactor share a set of high and low pressure systems and a circulating hydrogen compressor, which not only saves design costs, but also increases the reaction rate and improves product quality.

[0040] 5. In the present invention, when there is only one liquid in the transition tube, the liquid will be broken up when passing through the mixing tube, and thus the liquid will be too viscous. When there are two or more liquids passing through the mixing tube, the multiple liquids will quickly enter the fusion tube and then impact and mix, and then pass through the mixing tube together to be fully mixed, thereby increasing the subsequent reaction rate, thereby increasing the yield of naphtha. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a flow chart of a system for broadening the source of hydrocracking feedstock and increasing the yield of naphtha.

[0042] Figure 2 The present invention is a structural diagram of a mixer in a system for broadening the source of hydrocracking feedstock and improving naphtha yield.

[0043] Figure 3 The figure is a diagram of a mixer split in a system for broadening the source of hydrocracking feedstock and increasing naphtha yield.

[0044] Figure 4The figure is a diagram of the internal structure of a mixer in a system for broadening the source of hydrocracking feedstock and increasing naphtha yield.

[0045] Figure 5 The present invention is a structural diagram of a pressure valve in a system for broadening the source of hydrocracking raw materials and improving the yield of naphtha.

[0046] In the figure: 1. Buffer tank 1; 2. Buffer tank 2; 3. Hydrogen source; 4. Low fraction gas; 5. Sulfur-containing dry gas; 6. Naphtha tank; 7. Crude white oil tank; 8. Fractionator; 9. Stripper; 10. Cold low-pressure separator; 11. Hot low-pressure separator; 12. Circulating hydrogen compressor; 13. Cold high-pressure separator; 14. Hot high-pressure separator; 15. Fixed bed refining reactor; 16. Fixed bed cracking reactor; 17. Cracking feed heating furnace; 18. Refining feed heating furnace; 19. Mixed hydrogen; 20. Tail oil; 21. Mixer;

[0047] 210. Mixing tube; 211. Butt-joint tube; 212. Feeding tube; 213. First mixing blade; 214. Second mixing blade; 215. Fusion tube; 216. Feeding tube; 217. First one-way valve; 218. Transition tube; 219. Gas tank; 220. Supercharger; 221. Connecting channel; 222. Solenoid valve; 223. Second one-way valve; 224. Third one-way valve; 225. Pressure valve; 226. Trigger sensor; 227. Sealing cover; 228. Sealing plug; 229. Sliding column; 230. Flow window; 231. Extrusion sleeve; 232. Elastic rope. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Please refer to Figure 1-5 , a system for broadening the source of hydrocracking raw materials and improving the yield of naphtha, the feed unit: comprising a buffer tank 1 for storing light raw oil, one end of the buffer tank 1 is connected to a refined feed heating furnace 18 for heating the raw material, and a mixed hydrogen 19 is connected to the refined feed heating furnace 18 and the outlet of the buffer tank 1 through a pipeline;

[0050] The primary reaction unit includes a fixed bed refining reactor 15, the discharge port of the fixed bed refining reactor 15 is connected to a hot high pressure separator 14, and the discharge port of the hot high pressure separator 14 is connected to a cold high pressure separator 13;

[0051] Hydrogen circulation system: including a circulating hydrogen compressor 12, wherein the discharge port of the cold high-pressure separator 13 is connected to the circulating hydrogen compressor 12, and the outlet of the circulating hydrogen compressor 12 is connected to the hydrogen source 3;

[0052] Secondary reaction unit: including a buffer tank 2 for storing external raw oil, one end of the buffer tank 2 is connected to a cracking feed heating furnace 17, and the other end is connected to a mixer 21, the discharge port of the cracking feed heating furnace 17 is connected to a fixed bed cracking reactor 16, the discharge port of the fixed bed cracking reactor 16 is also connected to a hot high-pressure separator 14, and the discharge port of the hot high-pressure separator 14 is also connected to a hot low-pressure separator 11, and the discharge port of the hot low-pressure separator 11 is connected to a cold low-pressure separator 10;

[0053] Among them, the discharge port of the cold high-pressure separator 13 is also connected to the cold low-pressure separator 10;

[0054] The primary fractionation unit includes a stripping tower 9, one end of which is connected to a fractionation tower 8, and the other end is an outlet for the sulfur-containing dry gas 5; one end of the fractionation tower 8 is a naphtha tank 6, and the other end is connected to the feed port of the mixer 21 through a conveying pipeline, so as to re-refine the product after the first reaction to increase the output of naphtha;

[0055] Among them, a crude white oil tank 7 is also installed at one end of the fractionation tower 8, and a delivery pipeline is connected between the crude white oil tank 7 and the fractionation tower 8, and the delivery pipeline between the crude white oil tank 7 and the fractionation tower 8 is connected to the feed port of the mixer 21. In this way, part of the crude white oil produced can be returned to the cracking feed heating furnace 17 for further reaction, thereby increasing the output of naphtha;

[0056] Among them, the discharge port of the hot low-pressure separator 11 is also connected to the mixer 21 through a conveying pipeline; in this way, the by-products produced by the hot low-pressure separator 11 or the mixed raw oil that has not been completely reacted can be returned to the cracking feed heating furnace 17 for further reaction, thereby increasing the output of naphtha.

[0057] Embodiment 1: A system for broadening the source of hydrocracking raw materials and improving the yield of naphtha according to the present invention, the main properties of the raw material oil are shown in Table 1; and the raw material oil is C5-450℃ distillate oil;

[0058] The crude oil is mixed with the mixed hydrogen 19 delivered by the mixed hydrogen 19 before being pumped to the refining feed heating furnace 18, and then enters the fixed bed refining reactor 15 through the refining feed heating furnace 18 for reaction treatment, and contacts with the hydrorefining catalyst inside the fixed bed refining reactor 15 to undergo hydrodesulfurization, hydrodenitrogenation, and aromatic saturation reactions;

[0059] When the raw oil mixed with the mixed hydrogen 19 enters the fixed bed refining reactor 15 for reaction, a hydrogenation protective agent needs to be added to the fixed bed refining reactor 15;

[0060] The hydrofining catalyst in the fixed bed refining reactor 15 is arranged in multiple layers, and the multi-layer design can increase the reaction effect and reaction degree;

[0061] The heating temperature is between 350°C and 450°C; the heating can provide thermal energy to stimulate the reaction rate;

[0062] Among them, the hydrorefining catalyst mainly includes molybdenum, cobalt, nickel, platinum, and rhenium, the main carrier of which is bauxite, and the hydrorefining catalyst is one of the metals of molybdenum, cobalt, nickel, platinum, and rhenium;

[0063] The proportion of hydrogenation is determined based on the nitrogen and sulfur content in the crude oil;

[0064] The specific calculation method is: every 1 mole of sulfide requires 1 mole of hydrogen to be converted into hydrogen sulfide and then mixed;

[0065] The amount of hydrogen required for the reaction: (e.g. RSH → RH + H2S) nH2 = nS × molar ratio (where nH2 is the number of moles of sulfur);

[0066] Each mole of nitride requires 3 moles of hydrogen to convert into ammonia:

[0067] The amount of hydrogen required for the reaction: (e.g. RNH2→RH+NH3)nH2=nN×3 (where nN is the number of moles of sulfur);

[0068] Each mole of aromatic hydrocarbon requires 3 moles of hydrogen to be converted into an alkane;

[0069] The amount of hydrogen required for the reaction: (e.g. C6H6+3H2→C6H 12 )nH2=naromatics×3 (where naromatics is the number of moles of aromatic hydrocarbons);

[0070] The hydrorefined oil and hydrocracking oil obtained after treatment in the fixed bed refining reactor 15 will enter the hot high-pressure separator 14, and then pass through the hot high-pressure separator 14 for gas-liquid separation, so that the oil and hydrogen are initially separated. After the hydrogen is initially separated, it needs to pass through the cold high-pressure separator 13. The hydrogen passing through the cold high-pressure separator 13 will be purified again. The purified hydrogen is compressed by the circulating hydrogen compressor 12 and then recycled. This method can reduce resource waste and save production costs.

[0071] The oil separated by the hot high-pressure separator 14 will enter the hot low-pressure separator 11 to reduce the gas content again, and the liquid separated by the cold high-pressure separator 13 will be mixed with the oil and gas at the top outlet of the hot low-pressure separator 11 and enter the cold low-pressure separator 10. After passing through the cold low-pressure separator 10, low-pressure gas 4 will be obtained, and part of the product after passing through the hot low-pressure separator 11 will be sent to the cracking feed heating furnace 17 for further reaction;

[0072] The oil treated by the cold low-pressure separator 10 and another part of the hot low-pressure oil separated by the hot low-pressure separator 11 will enter the stripping tower 9, and a part of the sulfur-containing dry gas 5 will be obtained after passing through the stripping tower 9, and other products will pass through the fractionation tower 8, and finally obtain naphtha, crude white oil and tail oil 20, wherein naphtha and part of the crude white oil will enter the naphtha tank 6 and the crude white oil tank 7 respectively, and part of the crude white oil and all the tail oil 20 will enter the cracking feed heating furnace 17 for further reaction to obtain new naphtha. In this way, the hot low-pressure oil and crude white oil can be used as raw materials for refining naphtha, thereby significantly increasing the output and efficiency of naphtha;

[0073] Embodiment 2: A system for broadening the source of hydrocracking raw materials and improving the yield of naphtha according to the present invention, wherein the external raw material oil includes crude white oil, tail oil 20, and hot low-fraction oil, and the external raw material oil is a combination of two or more of crude white oil, tail oil 20, and hot low-fraction oil; and the external raw material oil is stored in a buffer tank 2 through a mixer 21, and the physical properties of the external raw material oil refer to the physical property index of Table 1;

[0074] The external raw oil is mixed with hydrogen and then cracked into a feed heating furnace 17, and then enters a fixed bed cracking reactor 16 after heating. A multi-layer hydrocracking reaction catalyst is arranged inside the fixed bed cracking reactor 16, and the hydrocracking reaction catalyst mainly includes molybdenum, cobalt, nickel, platinum, and rhenium. Its main carrier is bauxite, and the hydrocracking reaction catalyst is a combination of two or more of molybdenum, cobalt, nickel, platinum, and rhenium metals. In this way, the external raw oil can be mixed with multiple hydrocracking reaction catalysts for reaction, and then one hydrocracking reaction catalyst cannot meet the reaction requirements of different fixed raw materials (crude white oil, tail oil 20, hot low-fraction oil), thereby increasing the reaction efficiency and reaction degree, thereby further increasing the output of naphtha;

[0075] The external raw oil after the fixed bed cracking reactor 16 will be subjected to the reaction to obtain hydrocracking oil, and then the hydrocracking oil and the hydrofining oil will enter the hot high-pressure separator 14 together, and then pass through the cold high-pressure separator 13, the circulating hydrogen compressor 12, the hot low-pressure separator 11, the cold low-pressure separator 10, the stripping tower 9 and the fractionation tower 8, and then the obtained naphtha will be stored and part of the crude white oil and all the tail oil 20 will flow back to the buffer tank 2 for further reaction. In this way, naphtha, crude white oil and tail oil 20 can be efficiently produced, and then the crude white oil and tail oil 20 can be used for circulation refining. This method can not only increase the output of naphtha, but also reduce the overall raw material cost;

[0076] When the external raw oil mixed with the mixed hydrogen 19 enters the fixed bed cracking reactor 16 for reaction, a hydrogenation protective agent needs to be added to the fixed bed cracking reactor 16;

[0077] Among them, the hydrocracking oil and the hydrorefining oil are allowed to enter the hot high-pressure separator 14 together to mix the two, thereby increasing the density and viscosity of the mixed product. When the density and viscosity of the mixed product increase, the saturation of the naphtha component can be increased, and the impurity content can be reduced, thereby further increasing the output of naphtha;

[0078] Among them, the proportion of the mixed hydrogen 19 can be adjusted through the circulating hydrogen compressor 12, and the flow rate of the mixed hydrogen 19 can be controlled through various valves, making the entire system more intelligent and allowing the entire system to be better controlled.

[0079] Embodiment 3: A system for broadening the source of hydrocracking raw materials and increasing the yield of naphtha according to the present invention,

[0080] Among them, the addition of a hydrogenation protective agent can effectively delay the deactivation of the catalyst and ensure the efficiency and stability of the hydrogenation reaction.

[0081] Among them, the control pressure range of the entire system is 12-16MPa.

[0082] Among them, the usage parameters of hydrotreating catalyst, hydrocracking catalyst and hydrogenation protective agent are shown in Table 2;

[0083] Among them, the physical and chemical property parameters of the hydrogenation protective agent are shown in Table 3.

[0084] Among them, the physical and chemical properties of hydrocracking catalyst and hydrorefining catalyst are shown in Table 4.

[0085] Example 4: Please refer to Figure 2-5 Based on the examples 1 and 2, the mixer 21 includes a mixing tube 210, which is connected to the feed port of the buffer tank 2 through a transport pipeline, so that the external raw oil entering the buffer tank 2 is already mixed;

[0086] Specifically, one end of the mixing tube 210 is fixedly connected to a butt-joint pipe 211, and the butt-joint pipe 211 is connected to the feed port of the buffer tank 2 through a flange;

[0087] The end of the mixing pipe 210 away from the buffer tank 2 is connected to the feed pipe 212 through a flange, and the lower end of the feed pipe 212 is connected to the conveying pipeline through a plurality of transition pipes 218, so that the hot low-pressure oil separated by the hot low-pressure separator 11 and the tail oil 20 in the fractionation tower 8 can be mixed and then enter the interior of the buffer tank 2;

[0088] A plurality of first mixing blades 213 and a second mixing blade 214 are fixedly connected inside the mixing tube 210. The plurality of first mixing blades 213 and the second mixing blades 214 are obtained by rotating a steel sheet 180 degrees, and the first mixing blades 213 and the second mixing blades 214 are welded alternately at 90 degrees. In this way, when the external raw oil passes through the mixing tube 210, it will pass through the first mixing blades 213 and the second mixing blades 214, thereby mixing various oils inside the external raw oil together, thereby facilitating subsequent reactions.

[0089] The inside of the feed pipe 212 is also fixedly connected with a fusion pipe 215, and the lower end of the fusion pipe 215 is fixedly connected with a plurality of feed pipes 216, and the plurality of feed pipes 216 are respectively welded with transition pipes 218, and the feed pipes 216 and the transition pipes 218 are interconnected, and a first one-way valve 217 is installed outside the feed pipe 216;

[0090] The transition pipe 218 is fixedly connected to a second one-way valve 223, and a third one-way valve 224 is slidably connected to one side of the second one-way valve 223 located inside the transition pipe 218. The second one-way valve 223 and the third one-way valve 224 are both rotatably connected to valve flaps with a one-way rotation function. Specifically, Figure 4 For reference, the disc can only be turned to the left;

[0091] The transition pipe 218 is also fixedly connected to a pressure valve 225 for limiting the liquid volume in the transition pipe 218. A blocking cover 227 is installed on the upper end of the pressure valve 225. Two sealing plugs 228 are symmetrically fixedly connected to the lower end of the blocking cover 227. Two flow windows 230 are symmetrically opened on the upper end of the pressure valve 225. The two flow windows 230 correspond to the sealing plugs 228. The flow windows 230 can be blocked by the sealing plugs 228.

[0092] A sliding column 229 is fixedly connected to the middle of the blocking cover 227. The sliding column 229 passes through the upper end of the pressure valve 225, and the sliding column 229 is slidably connected to the pressure valve 225. The lower end of the pressure valve 225 is fixedly connected to an extrusion sleeve 231. The sliding column 229 is located in the extrusion sleeve 231, and the sliding column 229 is fixedly connected to the inner bottom end of the extrusion sleeve 231 through an elastic rope 232. In order to facilitate the extrusion sleeve 231 to squeeze the sliding column 229, the lower end of the sliding column 229 is set to a cone, so as to facilitate the extrusion sleeve 231 to squeeze the sliding column 229. The lower end of the pressure valve 225 is also fixedly connected to a trigger sensor 226;

[0093] A gas tank 219 for storing compressed gas is also fixedly connected to the side wall of the transition pipe 218. The gas outlet of the gas tank 219 is connected to the transition pipe 218 through a copper tube, and the copper tube is located between the second one-way valve 223 and the third one-way valve 224. The inside of the copper tube is connected to a solenoid valve 222. The gas inlet of the gas tank 219 is connected to the gas outlet of the supercharger 220 through a connecting channel 221, and the supercharger 220 is welded to the side wall of the transition pipe 218.

[0094] Specifically, a power turbine is provided inside the supercharger 220 , and the power turbine is located inside the transition duct 218 . A connecting shaft is fixedly connected to the middle of the power turbine, and a compression turbine is fixedly connected to one end of the connecting shaft away from the power turbine, and the compression turbine is located outside the transition duct 218 .

[0095] The principle of this embodiment is:

[0096] When liquid enters the transition pipe 218, the liquid will drive the power turbine and then drive the compression turbine to rotate. When the compression turbine rotates, it will compress the air and send the compressed air into the gas tank 219 for storage. As the liquid in the transition pipe 218 flows, the liquid will pass through the second one-way valve 223 and the third one-way valve 224 in sequence. As the liquid accumulates at the left end of the third one-way valve 224, the liquid will gradually approach the pressure valve 225. As the liquid accumulates, the liquid will contact the trigger sensor 226, so that the trigger sensor 226 is activated. After the trigger sensor 226 is triggered, the solenoid valve 222 will open;

[0097] At this time, the compressed gas in the gas tank 219 will immediately enter between the second one-way valve 223 and the third one-way valve 224. Due to the rapid entry of the gas, the second one-way valve 223 will be pushed. When the second one-way valve 223 is pushed, the liquid will give a reaction force to the valve disc in the second one-way valve 223, thereby closing the second one-way valve 223. Due to the movement of the second one-way valve 223, the pressure in the transition pipe 218 will increase. After the pressure in the transition pipe 218 increases, it will squeeze the extrusion sleeve 231. When the extrusion sleeve 231 is squeezed, the sliding column 229 will be squeezed upward. When the sliding column 229 moves upward, it will cause the sealing plug 228 to separate from the circulation window 230, so that the liquid can quickly enter the mixing tube 210.

[0098] Then let the liquid quickly pass through a plurality of first mixing blades 213 and second mixing blades 214. In this way, when there is liquid in only one transition tube 218, the liquid will be broken up when passing through the mixing tube 210, and the liquid will be too viscous. When there are more than two liquids passing through the mixing tube 210, the multiple liquids will quickly enter the fusion tube 215 and then collide and mix, and then pass through the mixing tube 210 together to be fully mixed, thereby increasing the subsequent reaction rate, thereby increasing the yield of naphtha.

[0099] Table 1:

[0100] Main properties and composition of feed oil for fixed bed hydrogenation unit (C-450℃ distillate produced by fluidized bed)

[0101]

[0102]

[0103] Note: Other indicators of purchased crude oil refer to the above indicators. Among them, the N / μg·g-1 (nitrogen content) of purchased crude oil must be ≤15μg·g-1 to prevent cracking catalyst poisoning.

[0104] Table 2:

[0105]

[0106]

[0107] Table 3: Physicochemical properties of hydrogenation protective agent

[0108]

[0109]

[0110] Table 4:

[0111] Main physical and chemical properties of fixed bed hydrogenation catalysts (hydrocracking catalysts and hydrorefining catalysts)

[0112] Catalyst name FHMJ-2 FHMJ-3 Active metal components Mo-Ni W-Ni Physical properties Appearance and shape Shamrock Strips Shamrock Strips Pore ​​volume mL / g ≮0.32 ≥0.28 Specific surface area m2 / g ≮160 ≥170 Particle diameter mm 1.1-1.3 2.5-2.8 Particle length mm 2-8 3-8 Bulk density g / cm3 0.88-0.94 0.85-0.95 Crushing strength N / grain ≥18 ≥15

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A system for broadening the source of hydrocracking raw materials and improving naphtha yield, characterized in that: The feed unit comprises a buffer tank (1) for storing light crude oil, one end of the buffer tank (1) is connected to a refined feed heating furnace (18) for heating the raw material, and a mixed hydrogen (19) is connected to the refined feed heating furnace (18) and the outlet of the buffer tank (1) through a pipeline; The primary reaction unit comprises a fixed bed refining reactor (15), the discharge port of the fixed bed refining reactor (15) is connected to a hot high pressure separator (14), and the discharge port of the hot high pressure separator (14) is connected to a cold high pressure separator (13); A hydrogen circulation system: comprising a circulating hydrogen compressor (12), wherein the discharge port of the cold high-pressure separator (13) is connected to the circulating hydrogen compressor (12), and the outlet of the circulating hydrogen compressor (12) is connected to a hydrogen source (3); The secondary reaction unit comprises a buffer tank 2 (2) for storing external crude oil, one end of the buffer tank 2 (2) is connected to a cracking feed heating furnace (17), and the other end is connected to a mixer (21), the discharge port of the cracking feed heating furnace (17) is connected to a fixed bed cracking reactor (16), the discharge port of the fixed bed cracking reactor (16) is also connected to a high pressure separator (14), and the discharge port of the hot high pressure separator (14) is also connected to a hot low pressure separator (11), and the discharge port of the hot low pressure separator (11) is connected to a cold low pressure separator (10); the discharge port of the cold high pressure separator (13) is also connected to the cold low pressure separator (10), and the top outlet of the cold low pressure separator (10) is a low pressure gas (4); The primary fractionation unit comprises a stripping tower (9), one end of which is connected to a fractionation tower (8), and the other end is an outlet for the sulfur-containing dry gas (5); the top outlet of the fractionation tower (8) is a naphtha tank (6), and the other end is connected to a feed port of a mixer (21) through a conveying pipeline.

2. A system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: One end of the fractionation tower (8) is a naphtha tank (6), and the other end is connected to the feed port of the second buffer tank (2) through a delivery pipeline. A crude white oil tank (7) is also installed at one end of the fractionation tower (8), and a delivery pipeline is connected between the crude white oil tank (7) and the fractionation tower (8), and the delivery pipeline between the crude white oil tank (7) and the fractionation tower (8) is connected to the feed port of the second buffer tank (2). In this way, part of the crude white oil produced can be returned to the cracking feed heating furnace (17) for further reaction, thereby increasing the output of naphtha; The crude oil is mixed with hydrogen delivered by the hydrogen mixing device (19) before being pumped to the refining feed heating furnace (18), and then enters the fixed bed refining reactor (15) through the refining feed heating furnace (18) for reaction treatment to obtain the hydrorefined product oil.

3. A system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: The external raw oil is mixed with mixed hydrogen and then cracked into a feed heating furnace (17). After being heated, it enters a fixed bed cracking reactor (16) to obtain a hydrocracking product oil. The hydrorefined product oil and the hydrocracking product oil obtained after being treated in a fixed bed refining reactor (15) enter a hot high-pressure separator (14). After being separated from the gas and liquid in the hot high-pressure separator (14), they need to pass through a cold high-pressure separator (13). Finally, the purified hydrogen is treated by a circulating hydrogen compressor (12) and then recycled. This method can reduce resource waste and save production costs. The hot high-content oil separated by the hot high-pressure separator (14) will enter the hot low-pressure separator (11) to reduce the gas content again, and the liquid separated by the cold high-pressure separator (13) will be mixed with the oil and gas at the top outlet of the hot low-pressure separator (11) and enter the cold low-pressure separator (10), and then obtain the low-content gas (4), and part of the hot low-content oil separated by the hot low-pressure separator (11) will be sent to the cracking feed heating furnace (17) for further reaction after cooling, thereby providing a raw material basis for the external raw material oil; The oil separated by the cold low-pressure separator (10) and another part of the hot low-pressure oil separated by the hot low-pressure separator (11) will enter the stripping tower (9), and after passing through the stripping tower (9), a part of the sulfur-containing dry gas (5) will be obtained, and the other products will pass through the fractionation tower (8), and finally obtain naphtha, crude white oil and tail oil (20), wherein the naphtha and part of the crude white oil will enter the naphtha tank (6) and the crude white oil tank (7) respectively, and part of the crude white oil and all the tail oil (20) will enter the cracking feed heating furnace (17) to react again to obtain new naphtha, thereby increasing the yield of naphtha; The product obtained by the external crude oil passing through the fixed bed cracking reactor (16) will also enter the hot high-pressure separator (14) and be mixed with the product obtained by the crude oil passing through the fixed bed refining reactor (15); When the raw oil mixed with the mixed hydrogen enters the fixed bed refining reactor (15) for reaction, it is necessary to add a hydrogenation protective agent into the fixed bed refining reactor (15).

4. A system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: The hydrorefining catalyst in the fixed bed refining reactor (15) is arranged in multiple layers, and the reaction effect and reaction degree can be increased through the multi-layer design.

5. The system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: The heating temperature is between 350°C and 450°C; heating can provide thermal energy to stimulate the reaction rate.

6. A system for broadening the source of hydrocracking raw materials and increasing naphtha yield according to claim 1, characterized in that: The hydrorefining catalyst mainly includes molybdenum, cobalt, nickel, platinum, and rhenium, the main carrier of which is bauxite, and the hydrorefining catalyst is one of the metals of molybdenum, cobalt, nickel, platinum, and rhenium; The hydrocracking reaction catalyst mainly includes molybdenum, cobalt, nickel, platinum and rhenium, the main carrier of which is bauxite, and the hydrocracking reaction catalyst is a combination of two or more of molybdenum, cobalt, nickel, platinum and rhenium metals.

7. The system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: The external raw oil includes crude white oil, tail oil (20), and hot low-fraction oil, and the external raw oil is a combination of two or more of the crude white oil, tail oil 20, and hot low-fraction oil.

8. The system for broadening the source of hydrocracking raw materials and improving naphtha yield according to claim 1, characterized in that: The mixer (21) comprises a mixing tube (210), and the mixing tube (210) is connected to the feed port of the second buffer tank (2) through a transport pipeline; The end of the mixing pipe (210) away from the second buffer tank (2) is connected to a feed pipe (212) via a flange, and the lower end of the feed pipe (212) is connected to the conveying pipeline via a plurality of transition pipes (218), thereby facilitating the hot low-pressure oil separated by the hot low-pressure separator (11) and the tail oil (20) in the fractionation tower (8) to enter the interior of the second buffer tank (2) after mixing; A plurality of first mixing blades (213) and second mixing blades (214) are fixedly connected inside the mixing tube (210); The inside of the feed pipe (212) is also fixedly connected to a fusion pipe (215), and the lower end of the fusion pipe (215) is fixedly connected to a plurality of feed pipes (216), and the plurality of feed pipes (216) are respectively welded to transition pipes (218), and the feed pipes (216) and the transition pipes (218) are interconnected, and a first one-way valve (217) is installed outside the feed pipe (216).

9. A system for broadening the source of hydrocracking raw materials and increasing naphtha yield according to claim 8, characterized in that: A second one-way valve (223) is fixedly connected inside the transition pipe (218); a third one-way valve (224) is slidably connected to one side of the second one-way valve (223) located inside the transition pipe (218); valve flaps with one-way rotation function are rotatably connected inside the second one-way valve (223) and the third one-way valve (224); The transition pipe (218) is also fixedly connected to the inside thereof with a pressure valve (225) for limiting the liquid volume in the transition pipe (218); a sealing cover (227) is installed at the upper end of the pressure valve (225); two sealing plugs (228) are symmetrically fixedly connected to the lower end of the sealing cover (227); two flow windows (230) are symmetrically opened at the upper end of the pressure valve (225); the two flow windows (230) correspond to the sealing plugs (228); A sliding column (229) is fixedly connected to the middle of the blocking cover (227), and the sliding column (229) is slidably connected to the pressure valve (225). The lower end of the pressure valve (225) is fixedly connected to an extrusion sleeve (231). The sliding column (229) is located inside the extrusion sleeve (231), and the sliding column (229) is fixedly connected to the inner bottom end of the extrusion sleeve (231) via an elastic rope (232).

10. A system for broadening the source of hydrocracking raw materials and increasing naphtha yield according to claim 9, characterized in that: A gas tank (219) for storing compressed gas is also fixedly connected to the side wall of the transition pipe (218); the gas outlet end of the gas tank (219) is connected to the transition pipe (218) through a copper tube, and the copper tube is located between the second one-way valve (223) and the third one-way valve (224), and the interior of the copper tube is connected to a solenoid valve (222); the gas inlet end of the gas tank (219) is connected to the gas outlet of the supercharger (220) through a connecting channel (221), and the supercharger (220) is welded to the side wall of the transition pipe (218); A power turbine is arranged inside the supercharger (220), and the power turbine is located inside the transition duct (218). A connecting shaft is fixedly connected to the middle of the power turbine, and a compression turbine is fixedly connected to one end of the connecting shaft away from the power turbine, and the compression turbine is located outside the transition duct (218).

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