System for producing biological fuel oil by hydrogenation of industrial mixed oil and fat

Abstract

The invention relates to the field of new energy, in particular to a system for producing biofuel oil by hydrogenation of industrial mixed grease, which comprises a hydrofining system and an isodewaxing system, the hydrofining system comprises a hydrofining reaction device, a hydrofining separation device, a hydrofining fractionation device and a hydrofining low-pressure gas dry gas desulfurization device; the isomerization pour point depressing system comprises an isomerization pour point depressing reaction device, an isomerization pour point depressing separation device and an isomerization pour point depressing fractionation device. According to the method, the abundant resource of the waste animal and vegetable oil can be fully utilized, large-scale production of clean and environment-friendly biological fuel oil is realized, the continuously increasing market demand is met, meanwhile, the economic benefit is remarkably improved, and the sustainable development of the biological fuel oil industry is promoted.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and particularly to a system for hydrogenating industrial mixed oils and fats to produce biofuels. Background Art

[0002] With the increasing global attention to energy sustainability and environmental protection, the market demand for clean and environmentally friendly biofuels has shown a significant growth trend. Using waste animal and vegetable oils and fats to produce biofuels can not only effectively meet this market demand, but also open up new economic growth points for enterprises, which has important strategic significance and economic value. In the process flow, some traditional processes have problems such as high energy consumption and complex processes, resulting in waste of resources and low production efficiency. In addition, there is still room for improvement in the product yield. How to further improve the yield of biofuels on the premise of ensuring product quality is a common challenge in the industry.

[0003] In view of this, the present invention provides a system for hydrogenating industrial mixed oils and fats to produce biofuels. Summary of the Invention

[0004] The purpose of the present invention is to provide a system for hydrogenating industrial mixed oils and fats to produce biofuels in view of the deficiencies of the prior art.

[0005] In order to solve the above technical problems, the following technical solutions are adopted:

[0006] A system for hydrogenating industrial mixed oils and fats to produce biofuels includes a hydrofining system and an isomerization and dewaxing system.

[0007] The hydrofining system includes a hydrofining reaction device, a hydrofining separation device, a hydrofining fractionation device, and a hydrofining low-pressure gas and dry gas desulfurization device;

[0008] The isomerization and dewaxing system includes an isomerization and dewaxing reaction device, an isomerization and dewaxing separation device, and an isomerization and dewaxing fractionation device;

[0009] The hydrofining reaction device: is used for filtering the feedstock oil and the recycle oil, then mixing with hydrogen-rich gas under the protection of inert gas, entering the hydrogenation protection reactor for pre-reaction, and then entering the hydrofining reactor for refining and deoxidation reaction after heating in sequence to obtain the initial product of the refining reaction;

[0010] The hydrofining separation device: is used for feeding the initial product of the refining reaction into a hot high-pressure separator for gas-liquid separation to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase;

[0011] The hot high-pressure gas in the gas phase undergoes oil, gas, and water three-phase separation through a hot high-pressure gas air cooler and a cold high-pressure separator. The recycled hydrogen in the gas phase is recycled, processed, and reused, and the cold high-pressure oil in the oil phase enters a cold low-pressure separator to obtain low-pressure oil.

[0012] The hot high-pressure fraction of the oil phase enters the cold low-pressure separator under liquid level control to obtain the low-pressure fraction oil.

[0013] The hydrofining fractionation unit: used to feed the low-pressure fraction oil into the hydrogen sulfide stripping column. After separation and reflux operations, the bottom oil of the stripping column enters the refined oil dehydration column to obtain the bottom oil of the dehydration column. A part of the bottom oil of the dehydration column is used as recycle oil, and another part of the bottom oil of the dehydration column is used as the feed for the hydrofining system.

[0014] The hydrofining low-pressure gas dry gas desulfurization unit: used to cool and separate the low-pressure gas from the cold low-pressure separator and the top gas from the hydrogen sulfide stripping column, and then enter the dry gas desulfurization column for desulfurization. The desulfurized dry gas is sent out of the system.

[0015] The isomerization and dewaxing reaction unit: used to feed the bottom oil of the dehydration column of the hydrofining system into the isomerization feed buffer tank after desulfurization reaction. After boosting pressure, mixing with hydrogen, heat exchange, and heating treatment, it enters the hydroisomerization reactor for isomerization reaction to obtain the isomerization reaction product.

[0016] The isomerization and dewaxing separation unit: The isomerization reaction product undergoes heat exchange, cooling, and separation operations to obtain gaseous recycle hydrogen and liquid-phase isomerization hot high-pressure fraction oil. A part of the recycle hydrogen is discharged, and another part of the recycle hydrogen is used for the isomerization reaction. The liquid-phase isomerization hot high-pressure fraction oil enters the isomerization cold low-pressure separator for oil, water, and gas three-phase separation to obtain the isomerization cold low-pressure fraction oil of the oil phase. The isomerization cold low-pressure fraction oil of the oil phase enters the isomerization and dewaxing fractionation unit.

[0017] The isomerization and dewaxing fractionation unit: used to feed the isomerization cold low-pressure fraction oil into the fractionation column. A part of the top product of the fractionation column is used as light biodiesel. The bottom material of the fractionation column enters the product fractionation column for product fractionation. A part of the top product of the product fractionation column is used as product bio-aviation kerosene. A part of the bottom oil of the product fractionation column returns to the product fractionation column through the bottom reboiler of the product fractionation column, and another part of the bottom oil of the product fractionation column returns to the isomerization feed buffer tank.

[0018] Furthermore, the hydrofining reaction unit includes an automatic backwashing filter, a raw material oil buffer tank, a hydrofining protection reactor, a reaction inlet inclined heating furnace, and a hydrofining reactor.

[0019] The automatic backwashing filter: used to receive the raw material oil and the recycle oil of the hydrofining fractionation unit, and remove particles larger than 25 μm in the raw material oil.

[0020] The raw material oil buffer tank: used to receive the raw material oil filtered by the automatic backwashing filter. The raw material oil buffer tank is protected by inert gas to ensure that the raw material oil does not contact air.

[0021] The hydrogenation protection reactor: It is used to receive the feedstock oil after pressure boosting and heat exchange, and receive the mixed hydrogen from the fresh hydrogen compressor and the recycle hydrogen compressor. After the feedstock oil and the mixed hydrogen are mixed, a pre-reaction is carried out to obtain a preliminary pre-reaction product.

[0022] The reaction inlet inclined heating furnace: It is used to heat the preliminary pre-reaction product to the reaction temperature and discharge the waste gas G1.

[0023] The hydrofining reactor includes a hydrofining reactor I and a hydrofining reactor II. The heated preliminary pre-reaction product sequentially enters the hydrofining reactor I and the hydrofining reactor II for the refining and deoxidation reaction to obtain a preliminary refining reaction product.

[0024] Further, the fresh hydrogen compressor is connected to a fresh hydrogen compressor inlet liquid separator, and a fresh hydrogen inlet is provided on the fresh hydrogen compressor inlet liquid separator.

[0025] The recycle hydrogen compressor is connected to a refined recycle hydrogen compressor inlet liquid separator, and the refined recycle hydrogen compressor inlet liquid separator is connected to a recycle hydrogen desulfurization tower.

[0026] Further, the hydrofining separation device includes a hot high-pressure separator, a hot high-pressure gas air cooler, a cold high-pressure separator, a hot low-pressure separator, a hot low-pressure gas air cooler, and a cold low-pressure separator.

[0027] The hot high-pressure separator: It is used to receive the preliminary refining reaction product after heat exchange by a heat exchanger, and then separate the gas and liquid of the preliminary refining reaction product to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase. The hot high-pressure gas in the gas phase enters the hot high-pressure gas air cooler, and the hot high-pressure oil in the oil phase enters the hot low-pressure separator.

[0028] The hot high-pressure gas air cooler: It is used to receive the hot high-pressure gas in the gas phase from the hot high-pressure separator, and cool the hot high-pressure gas and then introduce it into the cold high-pressure separator.

[0029] The cold high-pressure separator: It is used to separate the oil, gas, and water of the cooled hot high-pressure gas to obtain cold high-pressure oil in the oil phase, recycle hydrogen in the gas phase, and waste water in the water phase. The cold high-pressure oil in the oil phase enters the cold low-pressure separator to obtain low-pressure oil, the recycle hydrogen in the gas phase is recycled, processed, and reused, and the waste water in the water phase is discharged and treated as acidic waste water.

[0030] The hot low-pressure separator: It is used to receive the hot high-pressure oil in the oil phase from the hot high-pressure separator, and process the hot high-pressure oil to obtain hot low-pressure gas in the gas phase and low-pressure oil in the oil phase.

[0031] The hot low-pressure gas air cooler: It is used to receive the hot low-pressure gas of the gas phase from the hot low-pressure separator, and cool the hot low-pressure gas and then introduce it into the cold low-pressure separator;

[0032] The cold low-pressure separator: It is used to separate the cooled hot low-pressure gas into three phases of oil, gas and water, obtaining low-pressure oil in the oil phase and waste water in the water phase. The waste water in the water phase is discharged as acidic waste water for treatment;

[0033] Furthermore, the hydrofining fractionation unit includes a hydrogen sulfide stripping column and a refined oil dehydration column,

[0034] The hydrogen sulfide stripping column: It is used to receive the low-pressure oil, steam and corrosion inhibitor from the cold low-pressure separator and the hot low-pressure separator. The steam enters from the bottom of the hydrogen sulfide stripping column, and overhead gas and overhead oil are obtained from the top of the hydrogen sulfide stripping column. Stripped tower bottom oil is obtained from the bottom of the hydrogen sulfide stripping column. After the stripped tower bottom oil is heat-exchanged by the stripped tower bottom oil steam generator, it enters the refined oil dehydration column;

[0035] The refined oil dehydration column: It is used to receive the stripped tower bottom oil, and after a reaction, dehydrated tower bottom oil is obtained. A part of the dehydrated tower bottom oil is used as recycle oil, and another part of the dehydrated tower bottom oil is used as the feed for the hydrofining system;

[0036] Furthermore, the hydrofining low-pressure gas dry gas desulfurization unit includes a dry gas knockout drum and a dry gas desulfurization tower,

[0037] The dry gas knockout drum: It is used to receive the low-pressure gas from the cold low-pressure separator and the overhead gas from the hydrogen sulfide stripping column. After liquid separation in the dry gas knockout drum, it enters the lower part of the dry gas desulfurization tower to obtain knockout drum gas;

[0038] The dry gas desulfurization tower: It is used to receive the knockout drum gas from the dry gas knockout drum and the lean solution, and obtain dry gas after desulfurization.

[0039] Furthermore, the isomerization and dewaxing reaction unit includes an isomerization feed buffer tank, an isomerization reaction heating furnace, and a hydroisomerization reactor,

[0040] The isomerization feed buffer tank: It is used to receive the dehydrated tower bottom oil after the desulfurization reaction;

[0041] The isomerization reaction heating furnace: It is used to receive the dehydrated tower bottom oil that has been pressurized from the isomerization feed buffer tank. After the dehydrated tower bottom oil is mixed with the hydrogenated hydrogen, it is heated by the isomerization reaction feed heating furnace to the temperature required at the inlet of the hydroisomerization reactor;

[0042] The hydroisomerization reactor: It is used to mix the dehydrated tower bottom oil with the hydrogenated hydrogen and carry out an isomerization reaction to obtain an isomerization reaction product.

[0043] Furthermore, the isomerization dewaxing separation device includes an isomerization cold high-pressure separator and an isomerization cold low-pressure separator.

[0044] Isomerization cold high-pressure separator: It is used to receive the isomerization reaction product, and then separate the gas and liquid of the isomerization reaction product to obtain gaseous hydrogen and isomerization hot high-pressure oil in the oil phase. The gaseous hydrogen enters the hot high-pressure gas air cooler. A part of the gaseous hydrogen is sent to the PSA as the discharged hydrogen, and another part of the gaseous hydrogen enters the inlet buffer tank of the isomerization recycle hydrogen compressor and is separated into two paths after liquid separation. One path is sent to the hydroisomerization reactor as cold hydrogen, and the other path is pressurized by the isomerization recycle hydrogen compressor and mixed with the make-up hydrogen and then sent to the isomerization reaction heating furnace; The isomerization hot high-pressure oil in the oil phase enters the isomerization cold low-pressure separator.

[0045] The isomerization cold low-pressure separator: It is used to receive the isomerization hot high-pressure oil in the oil phase of the isomerization cold high-pressure separator, and perform three-phase separation of oil, water, and gas on the isomerization hot high-pressure oil to obtain isomerization cold high-pressure oil in the oil phase, non-condensable gas in the gas phase, and wastewater in the water phase.

[0046] Furthermore, the isomerization dewaxing fractionation device includes a fractionation tower and a product fractionation tower.

[0047] The fractionation tower: It is used to receive the isomerization cold low-pressure oil after heat exchange and temperature rise, and obtain the top product and bottom material of the fractionation tower through reaction. The top product is cooled by the fractionation tower top air cooler and the fractionation tower top water cooler in sequence, and then enters the fractionation tower top reflux tank. The non-condensable gas in the fractionation tower top reflux tank is sent to the inlet of the desorbed gas compressor. The oil-phase product in the fractionation tower top reflux tank is pressurized by the fractionation tower top reflux pump and divided into two parts: One part of the oil-phase product is used as the top reflux, and the other part of the oil-phase product is used as light biodiesel; The bottom material enters the product fractionation tower for product fractionation.

[0048] The product fractionation tower: It is used to receive the bottom material after pressure increase and heat exchange, and obtain the top product and bottom oil of the product fractionation tower through reaction. The top product is cooled by the low-pressure oil / product fractionation tower top gas heat exchanger, the product fractionation tower top gas / deaerated water heat exchanger, the product fractionation tower top air cooler, and the product fractionation tower top water cooler in sequence, and then enters the product fractionation tower top reflux tank. The oil-phase product in the product fractionation tower top reflux tank is pressurized by the fractionation tower top reflux pump. One part of the oil-phase product is used as the top reflux, and the other part of the oil-phase product is used as product bio-aviation kerosene.

[0049] A part of the bottom oil is pressurized by the product fractionation tower bottom reboiler pump and enters the product fractionation tower bottom reboiler for heating and then returns to the product fractionation tower. Another part of the bottom oil is pressurized by the heavy biofuel pump, exchanges heat with the topped oil through the topped oil / heavy biofuel heat exchanger, and then exchanges heat and cools down through the heavy biofuel steam generator, and then returns to the isomerization feed buffer tank.

[0050] Due to the above technical solution, the following beneficial effects are achieved:

[0051] By providing a system for hydrogenating industrial mixed oils and fats to produce biofuels, the core chemical reaction of the present invention is a series of reactions such as hydrogenation and hydrogenation of industrial mixed oils and fats with hydrogen under the action of a specific catalyst. Specifically, the unsaturated components in the industrial mixed oils and fats react with hydrogen to gradually transform into saturated aliphatic hydrocarbons, and this process ultimately produces second-generation biofuels. This reaction process follows specific chemical principles, and by precisely controlling the reaction conditions, it can ensure that the reaction proceeds efficiently in the direction of generating the target product. The present invention can make full use of the rich resource of waste animal and vegetable oils and fats, realize the large-scale production of clean and environmentally friendly biofuels, meet the growing market demand, significantly improve economic benefits, and promote the sustainable development of the biofuel industry. Specifically, it has the following advantages:

[0052] Advantages of the refining process: One of the characteristics of the industrial mixed oils and fats hydrogenation refining process is that it mainly conducts hydrogenation saturation and deoxygenation reactions, and no cracking or pyrolysis reactions occur during the whole process. This characteristic enables the device to maintain a high biofuel yield, and the expected total liquid yield of the hydrogenation refining part (relative to the fresh feedstock oil and fat for refining) can reach 82.0% - 82.5%.

[0053] Advantages of the pour point reduction process: The main function of the hydroisomerization pour point reduction process is to reduce the pour point of the refined biofuel. Although there are certain cracking and pyrolysis reactions during this process, through reasonable process design, it is ensured that the total liquid yield of the hydroisomerization pour point reduction is not less than 94%. The expected total liquid yield of the isomerization pour point reduction part (relative to the high pour point biodiesel of the fresh feedstock for isomerization) is 94.94% - 97.51%.

[0054] Temperature control and catalyst loading: The refining reactor and the hydroisomerization pour point reduction reactor of the industrial mixed oils and fats hydrogenation process are both filled with catalysts in a certain proportion. This precise loading ratio design enables the reaction heat to be distributed at the optimal position, which is beneficial to improving the reaction efficiency and product quality. At the same time, cold hydrogen is injected between the reactor beds, and in this way, the reaction temperature can be accurately controlled to ensure that the reaction proceeds within an appropriate temperature range, avoiding adverse effects on the reaction caused by too high or too low temperature.

[0055] Pre-protection design: In order to extend the service life of the refined deoxygenation catalyst, the industrial mixed oils and fats hydrogenation process is specifically provided with a pre-protection reactor. The main function of this reactor is to saturate the highly unsaturated fatty acids (mainly linoleic acid and linolenic acid) in the raw materials, effectively prevent the hydrogenation deoxygenation catalyst from coking, solve the problem of the performance decline of the catalyst due to coking from the source, reduce the replacement frequency of the catalyst, and save production costs.

[0056] Raw material pretreatment: After the raw material oil in the raw material tank farm enters the unit, it will first undergo backwashing filtration treatment. This pretreatment step can effectively remove solid impurities in the raw materials and remove some metal ions, enabling the raw materials to meet the strict requirements for entering the hydrogenation reactor, ensuring the smooth progress of subsequent reactions, and reducing reaction abnormalities and equipment failures caused by raw material impurity problems.

[0057] Process optimization design: The hydrofining section adopts a hot high-pressure separator process, which can effectively reduce energy consumption and improve energy utilization efficiency. The fractionation in the isomerization and dewaxing section adopts a double fractionation tower process, which maximizes the draw ratio on the premise of ensuring the distillation range of the bio-aviation fuel product, further improving the product yield and quality.

[0058] Internal structure of the reactor: Three catalyst beds are arranged inside the reactor, and cold hydrogen boxes are equipped between the beds. This structural design is conducive to better controlling the reaction temperature, making the reaction proceed more smoothly and efficiently, and also providing more flexibility for temperature regulation during the reaction process.

[0059] Heat exchanger and hydrogen mixing process: The wound tube type and double shell type high-pressure heat exchangers are adopted, significantly improving the heat transfer efficiency, accelerating the reaction process, and reducing energy consumption. At the same time, the pre-furnace hydrogen mixing process is adopted, simplifying the process flow, further improving the heat transfer efficiency, enabling the hydrogen and raw material oil to be more fully mixed, and improving the uniformity and effect of the reaction. Brief description of the drawings

[0060] The present invention will be further described below in conjunction with the drawings:

[0061] Figure 1 It is a process block diagram of the industrial mixed oil hydrogenation production biofuel system according to an embodiment of the present invention. Detailed implementation manners

[0062] To make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below through the drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concept of the present invention.

[0063] Refer to Figure 1 , the industrial mixed oil hydrogenation production biofuel system includes a hydrofining system and an isomerization and dewaxing system. Process principle: The industrial mixed oil is mixed with hydrogen and undergoes hydrogenation and other reactions under the action of a catalyst to produce saturated aliphatic hydrocarbons, that is, second-generation biofuels are obtained. The main reaction chemical equations are as follows:

[0064]

[0065] The hydrofining system includes a hydrofining reaction unit, a hydrofining separation unit, a hydrofining fractionation unit, and a hydrofining low-pressure gas and dry gas desulfurization unit.

[0066] The isomerization and dewaxing system includes an isomerization and dewaxing reaction unit, an isomerization and dewaxing separation unit, and an isomerization and dewaxing fractionation unit.

[0067] The hydrofining reaction unit: After filtering the feedstock oil and recycle oil, they are mixed with hydrogenated hydrogen under the protection of inert gas and enter the hydrofining protection reactor for pre-reaction. Then, after heating, they enter the hydrofining reactor in sequence for refining and deoxidation reaction to obtain the initial product of the refining reaction.

[0068] The hydrofining separation unit: It is used to send the initial product of the refining reaction into a hot high-pressure separator for gas-liquid separation to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase.

[0069] The hot high-pressure gas in the gas phase undergoes oil, gas, and water three-phase separation through a hot high-pressure gas air cooler and a cold high-pressure separator. The recycled hydrogen in the gas phase is recycled, processed, and reused. The cold high-pressure oil in the oil phase enters the cold low-pressure separator to obtain low-pressure oil.

[0070] The hot high-pressure oil in the oil phase enters the cold low-pressure separator under liquid level control to obtain the low-pressure oil.

[0071] The hydrofining fractionation unit: It is used to send the low-pressure oil into a hydrogen sulfide stripping column. After separation and reflux operations, the bottom oil of the stripping column enters a refined oil dehydration column to obtain the bottom oil of the dehydration column. A part of the bottom oil of the dehydration column is used as recycle oil, and another part of the bottom oil of the dehydration column is used as the feed for the hydrofining system.

[0072] The hydrofining low-pressure gas and dry gas desulfurization unit: It is used to send the low-pressure gas from the cold low-pressure separator and the overhead gas from the hydrogen sulfide stripping column into a dry gas desulfurization tower for desulfurization after cooling and liquid separation. The desulfurized dry gas is sent out of the system.

[0073] Furthermore, the hydrofining reaction unit includes an automatic backwashing filter, a feedstock oil buffer tank, a hydrofining protection reactor, a reaction inlet inclined heating furnace, and a hydrofining reactor.

[0074] The automatic backwashing filter: It is used to receive the feedstock oil and the recycle oil of the hydrofining fractionation unit and remove particles larger than 25 μm in the feedstock oil.

[0075] The feedstock oil buffer tank: It is used to receive the feedstock oil filtered by the automatic backwashing filter. The feedstock oil buffer tank is protected by inert gas to ensure that the feedstock oil does not contact air.

[0076] Specifically, the feedstock oil is the processed industrial mixed oil and grease, and the supply method is pipeline transportation. The feedstock oil from outside the device is mixed with the recycle oil from the fractionation section. After heat exchange with the bottom oil of the stripping column through the bottom oil of the dehydration column / feedstock oil heat exchanger I, the particles larger than 25 μm in the feedstock are removed through the feedstock oil filter, and then it enters the feedstock oil buffer tank (V-101). The feedstock oil buffer tank is protected by inert gas to prevent the feedstock oil from contacting air.

[0077] The hydrogenation protection reactor: is used to receive the feedstock oil after pressure boosting and heat exchange treatment, and receive the mixed hydrogen from the new hydrogen compressor and the recycle hydrogen compressor. After the feedstock oil and the mixed hydrogen are mixed, a pre-reaction is carried out to obtain a preliminary pre-reaction product.

[0078] The reaction inlet inclined heating furnace: is used to heat the preliminary pre-reaction product to the reaction temperature and discharge the waste gas G1.

[0079] Specifically, the feedstock oil from the feedstock oil buffer tank is boosted by the hydrogenation feed pump, then heat-exchanged with the bottom oil of the dehydration column through the bottom oil of the dehydration column / feedstock oil heat exchanger II, mixed with the mixed hydrogen, and after heat exchange through the reaction product / mixed hydrogen oil heat exchanger, it enters the refining protection reactor for pre-reaction to obtain a preliminary pre-reaction product.

[0080] The hydrorefining reactor includes a hydrorefining reactor I and a hydrorefining reactor II. The heated preliminary pre-reaction product sequentially enters the hydrorefining reactor I and the hydrorefining reactor II for refining and deoxidation reactions to obtain a preliminary refining reaction product.

[0081] Specifically, after the preliminary pre-reaction product is heated to the reaction temperature by the refining reaction feed heating furnace, it sequentially enters the hydrorefining reactor I and the hydrorefining reactor II for refining and deoxidation reactions. Quench hydrogen injection is provided between the beds of each reactor and between the reactors.

[0082] Among them, the initial operation and final conditions in the above hydrogenation protection reactor and hydrorefining reactor are as follows:

[0083] Table 1 - Refining section operation conditions (initial stage)

[0084]

[0085] Table 2 - Refining section operation conditions (final stage)

[0086]

[0087] Specifically, the refining catalyst is as follows:

[0088] In the HVO series of hydrogenation protectants, HVO-B and HVO-C adopt a four-impeller structure design, which makes the stacking voids between the protectant particles uniform, effectively preventing the interlocking of the convex and concave parts between the protectant particles, and the deposition of impurities between the particles is uniform, further enhancing the dirt-holding capacity of the protectant; the hydrodynamic performance of the protectant is further improved, and it has been operating in the hydrogenation reactor of the industrialized biofuel device, achieving the expected application effect.

[0089] The HVO-512 series of hydrodeoxygenation catalysts uses Mo-Ni components as the hydrogenation active components, and has evolved from the first-generation clover and the second-generation four-leaf clover at the beginning of the industrial production of biofuel devices to the current tooth-ball structure.

[0090] The tooth-ball catalyst completely eliminates the possible channeling and bridging phenomena of the strip catalyst, the catalyst bed is more uniform, and no hot spots will occur.

[0091] The tooth-ball catalyst has a large external surface area and high hydrogenation activity. Industrial production practice shows that the reaction temperature is low, and the inlet temperature of the catalyst bed is 5-10°C lower than that of the first-generation clover and the second-generation four-leaf clover catalysts.

[0092] The tooth-ball catalyst has small mass transfer resistance and axial pressure difference in the reactor, a large void fraction in the bed, and strong anti-coking and dirt-holding capabilities. The tooth-ball catalyst has an axial pressure difference 50% lower than that of the strip catalyst.

[0093] The tooth-ball catalyst has strong hydrothermal stability resistance, large anti-abrasion strength, small wear, and long service life. The refined catalyst is loaded with sulfided catalyst.

[0094] Furthermore, the fresh hydrogen compressor is connected with a fresh hydrogen compressor inlet liquid separator, and a fresh hydrogen inlet is provided on the fresh hydrogen compressor inlet liquid separator.

[0095] The recycle hydrogen compressor is connected with a refined recycle hydrogen compressor inlet liquid separator, and the refined recycle hydrogen compressor inlet liquid separator is connected with a recycle hydrogen desulfurization tower.

[0096] Furthermore, the hydrofining separation device includes a hot high-pressure separator, a hot high-pressure gas air cooler, a cold high-pressure separator, a hot low-pressure separator, a hot low-pressure gas air cooler, and a cold low-pressure separator.

[0097] The hot high-pressure separator: is used to receive the initial product of the refined reaction after heat exchange treatment by the heat exchanger, and then separate the gas and liquid of the initial product of the refined reaction to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase. The hot high-pressure gas in the gas phase enters the hot high-pressure gas air cooler, and the hot high-pressure oil in the oil phase enters the hot low-pressure separator.

[0098] The hot high-pressure separator gas air cooler: It is used to receive the hot high-pressure separator gas in the gas phase of the hot high-pressure separator, and cool the hot high-pressure separator gas and then introduce it into the cold high-pressure separator.

[0099] The cold high-pressure separator: It is used to separate the cooled hot high-pressure separator gas into three phases of oil, gas, and water, obtaining cold high-pressure separator oil in the oil phase, recycled hydrogen in the gas phase, and wastewater in the water phase. The cold high-pressure separator oil in the oil phase enters the cold low-pressure separator to obtain low-pressure separator oil. The recycled hydrogen in the gas phase is recycled, processed, and reused, and the wastewater in the water phase is discharged as acidic wastewater for treatment.

[0100] Specifically, the initial product of the refining reaction from the hydrofining reactor II exchanges heat through the reaction product / mixed hydrogen oil heat exchanger and then enters the hot high-pressure separator for gas-liquid separation. The hot high-pressure separator gas exchanges heat with the mixed hydrogen through the hot high-pressure separator / mixed hydrogen heat exchanger, and then is cooled by the hot high-pressure separator gas air cooler. The cooled hot high-pressure separator gas is separated into three phases of oil, gas, and water in the cold high-pressure separator, obtaining cold high-pressure separator oil in the oil phase, recycled hydrogen in the gas phase, and wastewater in the water phase. The recycled hydrogen coming out from the top is separated through the inlet liquid separation tank of the recycled hydrogen desulfurization tower and then sent to the recycled hydrogen desulfurization tower for desulfurization. After desulfurization, it is separated through the inlet liquid separation tank of the refined recycled hydrogen compressor. Part of it is sent as off-gas hydrogen to the PSA to recover hydrogen, and the desorbed gas is boosted by the desorbed gas compressor and then sent out of the unit; the other part enters the refined recycled hydrogen compressor as recycled hydrogen for boosting. The boosted recycled hydrogen is divided into two paths: one path is used as quench hydrogen to control the inlet temperature of the reactor bed layer in the reactor, and the other path is mixed with the fresh hydrogen and the feedstock oil and then used as the reaction feed.

[0101] The hot low-pressure separator: It is used to receive the hot high-pressure separator oil in the oil phase of the hot high-pressure separator, and process the hot high-pressure separator oil to obtain hot low-pressure separator gas in the gas phase and low-pressure separator oil in the oil phase.

[0102] The hot low-pressure separator gas air cooler: It is used to receive the hot low-pressure separator gas in the gas phase of the hot low-pressure separator, and cool the hot low-pressure separator gas and then introduce it into the cold low-pressure separator.

[0103] The cold low-pressure separator: It is used to separate the cooled hot low-pressure separator gas into two phases of oil and water, obtaining low-pressure separator oil in the oil phase and wastewater in the water phase. The wastewater in the water phase is discharged as acidic wastewater for treatment.

[0104] Specifically, the hot high-pressure separator oil enters the hot low-pressure separator under liquid level control, and the cold high-pressure separator oil enters the cold low-pressure separator under liquid level control. The hot low-pressure separator gas enters the hot low-pressure separator gas air cooler for cooling and then mixes with the cold high-pressure separator oil and enters the cold low-pressure separator. The cold low-pressure separator oil exchanges heat through the bottom oil of the dehydration tower / cold low-pressure separator oil heat exchanger and then enters the hydrogen sulfide stripping tower. The hot low-pressure separator oil enters the hydrogen sulfide stripping tower under liquid level control. The cold low-pressure separator gas and the top gas of the hydrogen sulfide stripping tower are sent to the dry gas desulfurization tower for desulfurization and then sent out of the unit.

[0105] Further, the hydrofining fractionation unit includes a hydrogen sulfide stripping column and a refined oil dehydration column.

[0106] The hydrogen sulfide stripping column: is used to receive the low - point oil, steam and corrosion inhibitor from the cold low - pressure separator and the hot low - pressure separator. The steam enters from the bottom of the hydrogen sulfide stripping column. The overhead gas and overhead oil are obtained from the top of the hydrogen sulfide stripping column, and the stripped bottom oil is obtained from the bottom of the hydrogen sulfide stripping column. After the stripped bottom oil is heat - exchanged by the stripped bottom oil steam generator, it enters the refined oil dehydration column.

[0107] The refined oil dehydration column: is used to receive the stripped bottom oil. After a reaction, the dehydrated bottom oil is obtained. A part of the dehydrated bottom oil is used as recycle oil, and another part of the dehydrated bottom oil is used as the feed for the hydrofining system.

[0108] Specifically, the low - point oil from the reaction section enters the hydrogen sulfide stripping column. The stripping column has 20 layers of valve trays, and the stripping steam enters from the bottom of the column. The overhead gas is cooled by the overhead air cooler of the hydrogen sulfide stripping column and the overhead water cooler of the hydrogen sulfide stripping column and then enters the overhead reflux drum of the hydrogen sulfide stripping column for three - phase separation of oil, water and gas. The overhead oil phase is boosted by the overhead reflux pump of the hydrogen sulfide stripping column and used as the reflux of the hydrogen sulfide stripping column under the cascade control of flow and liquid level. The non - condensable gas at the top is sent to the dry gas desulfurization tower for desulfurization.

[0109] The stripped bottom oil is heat - exchanged by the stripped bottom oil steam generator and then enters the refined oil dehydration column (T - 202). The overhead gas enters the vacuum unit for cooling and boosting. The non - condensable gas is sent to the vent main pipe. The oil - containing water enters the overhead reflux drum of the dehydration column for three - phase separation of oil, water and gas. The oil phase is boosted by the overhead reflux pump of the dehydration column and mixed with the recycled dehydrated oil under the cascade control of flow and liquid level as the reflux of the refined dehydration column.

[0110] The dehydrated bottom oil is boosted by the bottom oil pump of the dehydration column and then heat - exchanged successively by the heat exchanger II between the dehydrated bottom oil and the feedstock oil, the heat exchanger between the dehydrated bottom oil and the cold low - point oil, and the heat exchanger I between the dehydrated bottom oil and the feedstock oil. A part of it is cooled by the recycle oil air cooler (A - 103) and then divided into two paths: one path is used as recycle oil. After passing through the coke - removing powder facility, it is mixed with the feedstock oil, and the other path is cooled by the recycled dehydrated oil cooler and then enters the refined oil dehydration column as recycled dehydrated oil; another part is used as the feed for the isomerization and dewaxing section.

[0111] Further, the hydrofining low - point gas dry gas desulfurization unit includes a dry gas knockout drum and a dry gas desulfurization tower.

[0112] The dry gas knockout drum: is used to receive the low - point gas from the cold low - pressure separator and the overhead gas of the hydrogen sulfide stripping column. After liquid separation in the dry gas knockout drum, it enters the lower part of the dry gas desulfurization tower to obtain the knockout drum gas.

[0113] The dry gas desulfurization tower: It is used to receive the separated gas from the dry gas liquid separator and the lean solution, and obtain dry gas after desulfurization.

[0114] Specifically, the low-pressure gas from the refined refrigeration low-pressure separator and the top gas of the hydrogen sulfide stripping tower are first cooled by the dry gas cooler, then enter the dry gas liquid separator for liquid separation, and then enter the lower part of the dry gas desulfurization tower. The desulfurized dry gas is sent outside the device. The lean solvent comes from the buffer tank and enters the upper part of the dry gas desulfurization tower after being boosted by the low-pressure lean solvent pump.

[0115] The isomerization and dewaxing reaction device: It is used to send the bottom oil of the dehydration tower in the hydrofining system into the isomerization feed buffer tank after desulfurization reaction, and after boosting, hydrogen mixing, heat exchange, and heating treatment, it enters the hydroisomerization reactor for isomerization reaction to obtain the isomerization reaction product.

[0116] The isomerization and dewaxing separation device: The isomerization reaction product undergoes heat exchange, cooling, and separation operations to obtain the circulating hydrogen in the gas phase and the isomerization hot high-pressure oil in the liquid phase. Part of the circulating hydrogen is discharged, and the other part of the circulating hydrogen is used for the isomerization reaction. The isomerization hot high-pressure oil in the liquid phase enters the isomerization cold low-pressure separator for oil, water, and gas three-phase separation to obtain the isomerization cold low-pressure oil in the oil phase. The isomerization cold low-pressure oil in the oil phase enters the isomerization and dewaxing fractionation device.

[0117] The isomerization and dewaxing fractionation device: It is used to send the isomerization cold low-pressure oil into the fractionation tower. Part of the overhead product of the fractionation tower is used as light biodiesel, and the bottom material of the fractionation tower enters the product fractionation tower for product fractionation. Part of the overhead product of the product fractionation tower is used as product bio-aviation kerosene, part of the bottom oil of the product fractionation tower returns to the product fractionation tower through the reboiler at the bottom of the product fractionation tower, and the other part of the bottom oil of the product fractionation tower returns to the isomerization feed buffer tank.

[0118] Furthermore, the isomerization and dewaxing reaction device includes an isomerization feed buffer tank, an isomerization reaction heating furnace, and a hydroisomerization reactor.

[0119] The isomerization feed buffer tank: It is used to receive the bottom oil of the dehydration tower after desulfurization reaction.

[0120] The isomerization reaction heating furnace: It is used to receive the bottom oil of the dehydration tower that has been boosted from the isomerization feed buffer tank. After the bottom oil of the dehydration tower is mixed with hydrogen, it is heated by the isomerization reaction feed heating furnace to the temperature required at the inlet of the hydroisomerization reactor.

[0121] The hydroisomerization reactor: It is used to carry out isomerization reaction after mixing the bottom oil of the dehydration tower with hydrogen to obtain the isomerization reaction product.

[0122] Specifically, the bottom oil of the dehydration tower in the hydrofining section enters the isomerization feed buffer tank after being desulfurized in the desulfurization reactor. After being boosted by the hydroisomerization feed pump, it is mixed with the hydrogenated hydrogen. The hydrogenated feedstock exchanges heat with the reaction products in the isomerization reaction product / hydrogenated oil heat exchanger, and then enters the hydroisomerization reactor after being heated to the required temperature at the reactor inlet by the isomerization reaction feed heater. The main reaction in the hydroisomerization reactor is the isomerization reaction. In order to effectively control the temperature rise during the reaction process, quench hydrogen injection is provided between the beds and reactors of the reactor.

[0123] The reaction products of the hydroisomerization reactor first exchange heat with the feedstock in the isomerization reaction product / hydrogenated oil heat exchanger, then exchange heat with the isomerized cold low-pressure oil in the isomerization reaction product / low-pressure oil heat exchanger, and finally enter the reaction product air cooler and the reaction product cooler for cooling and then enter the isomerized cold high-pressure separator.

[0124] Specifically, the initial operating conditions and final operating conditions of the isomerization reaction are as follows:

[0125] Table 3 Isomerization section operating conditions (initial stage)

[0126]

[0127] Table 4 Isomerization section operating conditions (final stage)

[0128]

[0129]

[0130] The isomerization catalyst is the BDI-01 hydroisomerization catalyst, which is a catalyst developed specifically for hydroisomerization dewaxing of high-quality hydrocarbon biodiesel / bio-aviation fuel. The feedstock for processing is the mixed n-paraffins after hydrodeoxygenation of various animal and vegetable oils and waste cooking oil. This catalyst has excellent hydroisomerization performance and can be flexibly adjusted according to product requirements to moderately crack the feedstock to meet the production of low-freezing-point biodiesel and low-freezing-point biofuels with high yields.

[0131] Furthermore, the isomerization dewaxing separation device includes an isomerized cold high-pressure separator and an isomerized cold low-pressure separator.

[0132] Isomerized cold high-pressure separator: It is used to receive the isomerization reaction products, and then separate the gas and liquid of the isomerization reaction products to obtain gaseous hydrogen and isomerized hot high-pressure oil in the oil phase. The gaseous hydrogen enters the hot high-pressure gas air cooler. A part of the gaseous hydrogen is sent to the PSA as the off-gas hydrogen, and another part of the gaseous hydrogen enters the inlet buffer tank of the isomerization recycle hydrogen compressor and is separated into two paths after liquid separation. One path is sent to the hydroisomerization reactor as the cold hydrogen, and the other path is boosted by the isomerization recycle hydrogen compressor and mixed with the make-up hydrogen and then sent to the isomerization reaction heater. The isomerized hot high-pressure oil in the oil phase enters the isomerized cold low-pressure separator.

[0133] The isomerization cold low-pressure separator: It is used to receive the isomerization hot high-pressure oil from the oil phase of the isomerization hot high-pressure separator, and separate the isomerization hot high-pressure oil into three phases of oil, water, and gas to obtain isomerization cold high-pressure oil in the oil phase, non-condensable gas in the gas phase, and waste water in the water phase.

[0134] Specifically, a part of the gas phase of the isomerization hot high-pressure separator is sent to the PSA as the discharged hydrogen, and the other part enters the inlet buffer tank of the isomerization recycle hydrogen compressor and is separated into two paths after liquid separation. One path is sent to the hydroisomerization reactor as the quench hydrogen, and the other path is sent to the isomerization reaction section after being pressurized by the isomerization recycle hydrogen compressor and mixed with the make-up hydrogen; the liquid phase enters the isomerization cold low-pressure separator for three-phase separation of oil, water, and gas: the gas phase is sent to the fuel gas network, and the oil phase is sequentially heated through the isomerization reaction product / low-pressure oil heat exchanger, low-pressure oil / product fractionation tower top gas heat exchanger, and low-pressure oil / fractionation tower top circulation heat exchanger and then enters the fractionation tower of the fractionation section.

[0135] A certain amount of hydrogen is consumed during the isomerization dewaxing reaction process. In order to maintain the hydrogen partial pressure in the reaction system, hydrogen needs to be continuously supplemented into the reaction system. The fresh hydrogen comes from the outlet of the fresh hydrogen compressor and is supplemented into the outlet of the isomerization recycle hydrogen compressor.

[0136] Furthermore, the isomerization dewaxing fractionation device includes a fractionation tower and a product fractionation tower.

[0137] The fractionation tower: It is used to receive the isomerization cold low-pressure oil after heat exchange and temperature rise, and obtain the top product and bottom material of the fractionation tower through reaction. The top product is sequentially cooled by the fractionation tower top air cooler and the fractionation tower top water cooler and then enters the fractionation tower top reflux drum. The non-condensable gas in the fractionation tower top reflux drum is sent to the inlet of the desorbed gas compressor, and the oil phase product in the fractionation tower top reflux drum is pressurized by the fractionation tower top reflux pump and divided into two parts: one part of the oil phase product is used as the top reflux, and the other part of the oil phase product is used as light biodiesel. The bottom material enters the product fractionation tower for product fractionation.

[0138] The product fractionation tower: It is used to receive the bottom material after pressure increase and heat exchange, and obtain the top product and bottom oil of the product fractionation tower through reaction. The top product is sequentially cooled by the low-pressure oil / product fractionation tower top gas heat exchanger, the product fractionation tower top gas / deaerated water heat exchanger, the product fractionation tower top air cooler, and the product fractionation tower top water cooler and then enters the product fractionation tower top reflux drum. The oil phase product in the product fractionation tower top reflux drum is pressurized by the fractionation tower top reflux pump, and one part of the oil phase product is used as the top reflux, and the other part of the oil phase product is used as product bio-aviation kerosene.

[0139] A part of the bottom oil of the tower is pressurized by the bottom reboiler pump of the product fractionation tower and then enters the bottom reboiler of the product fractionation tower for heating and returns to the product fractionation tower. Another part of the bottom oil of the tower is pressurized by the heavy biofuel pump, exchanges heat with the topped oil in the topped oil / heavy biofuel heat exchanger, and then exchanges heat and cools down in the heavy biofuel steam generator before returning to the isomerization feed buffer tank.

[0140] Specifically, the isomerized cold low - fraction oil after heat exchange enters the fractionation tower. The oil - gas at the top of the tower is cooled successively by the air cooler at the top of the fractionation tower and the water cooler at the top of the fractionation tower and then enters the reflux drum at the top of the fractionation tower. The non - condensable gas in the reflux drum is sent to the inlet of the desorbed gas compressor. The oil phase is pressurized by the reflux pump at the top of the fractionation tower, and a part is used as the top reflux, and the other part is sent out of the unit as light biofuel. The heat source of the bottom reboiler of the fractionation tower is the circulating oil at the bottom of the product fractionation tower. The bottom material is pressurized by the topped oil pump, exchanges heat in the topped oil / heavy biofuel heat exchanger, and then enters the product fractionation tower. The product fractionation tower is equipped with a bottom reboiler furnace of the product fractionation tower, a bottom reboiler pump of the product fractionation tower, and a heavy biofuel pump. The oil - gas at the top of the product fractionation tower is cooled by the low - fraction oil / product fractionation tower top gas heat exchanger, the product fractionation tower top gas / deaerated water heat exchanger, the air cooler at the top of the product fractionation tower, and the water cooler at the top of the product fractionation tower and then enters the reflux drum at the top of the product fractionation tower. The liquid oil phase in the reflux drum is pressurized by the reflux pump at the top of the product fractionation tower and is divided into two parts: one part is used as the top reflux; the other part is sent out of the unit as product bio - aviation kerosene. A part of the bottom oil of the tower is pressurized by the bottom reboiler pump of the product fractionation tower and then enters the bottom reboiler of the product fractionation tower for heating and returns to the bottom of the tower, and another part is pressurized by the heavy biofuel pump, exchanges heat with the topped oil in the topped oil / heavy biofuel heat exchanger, and then exchanges heat and cools down in the heavy biofuel steam generator before returning to the isomerization feed buffer tank.

[0141] Final destinations of the products: Bio - aviation kerosene → Tank farm; Biodiesel → Tank farm; Light bio - oil → Tank farm; Desulfurized low - fraction gas, non - condensable gas → Fuel gas pipeline network.

[0142] The process features are as follows:

[0143] 1) The hydrogenation technology of Nanjing Kangxincheng Biotechnology Co., Ltd. is adopted, using a variety of protective catalysts with high metal - holding capacity, hydro - deoxygenation catalysts with high hydro - genation performance and high hydrothermal stability, and isomerization catalysts with high selectivity.

[0144] 2) The industrial mixed oil hydrogenation refining process mainly conducts hydrogenation saturation and deoxygenation reactions, without cracking and pyrolysis reactions. Therefore, the device has a high bio - fuel yield, and the total liquid yield is greater than 80%.

[0145] 3) The hydro - isomerization dewaxing process mainly reduces the pour point of the refined bio - fuel, and there are certain cracking and pyrolysis reactions. The total liquid yield of hydro - isomerization dewaxing is not less than 94%.

[0146] 4) The refining reactor and the isomerization and dewaxing reactor in the industrial mixed oil hydrogenation process are respectively filled with catalysts in a certain proportion. Cold hydrogen is injected between the reactor beds to control the temperature. An appropriate catalyst filling proportion enables the reaction heat to be distributed at the optimal position.

[0147] 5) The industrial mixed oil hydrogenation process is provided with a pre-protection reactor to saturate the highly unsaturated fatty acids (mainly linoleic acid and linolenic acid) in the raw materials, which can prevent coking of the hydrodesulfurization catalyst and extend the service life of the refining desulfurization catalyst.

[0148] 6) The raw oil in the raw material tank area enters the device and is first subjected to backwashing filtration treatment to remove solid impurities and remove some metal ions to meet the requirements of the raw materials for entering the hydrogenation reactor.

[0149] 7) The hydrorefining part adopts a hot high-pressure separator process to reduce energy consumption.

[0150] 8) The fractionation in the isomerization and dewaxing part adopts a double fractionation tower process to maximize the draw ratio on the premise of ensuring the distillation range of the bio-aviation kerosene product.

[0151] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all covered by the protection scope of the present invention.

Claims

1. A system for hydrogenating industrial mixed oils to produce biofuels, characterized in that: It includes a hydrofining system and an isomerization and dewaxing system. The hydrofining system includes a hydrofining reaction unit, a hydrofining separation unit, a hydrofining fractionation unit, and a hydrofining low-pressure gas and dry gas desulfurization unit. The isomerization and dewaxing system includes an isomerization and dewaxing reaction unit, an isomerization and dewaxing separation unit, and an isomerization and dewaxing fractionation unit. The hydrofining reaction unit: It is used to filter the feedstock oil and recycle oil, then mix with hydrogenated hydrogen under the protection of inert gas, enter the hydroprotection reactor for pre-reaction, and then enter the hydrofining reactor for refining and deoxidation reaction after heating in sequence to obtain the initial product of the refining reaction. The hydrofining separation unit: It is used to send the initial product of the refining reaction into the hot high-pressure separator for gas-liquid separation to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase. The hot high-pressure gas in the gas phase undergoes oil, gas, and water three-phase separation through a hot high-pressure gas air cooler and a cold high-pressure separator. The recycled hydrogen in the gas phase is recycled, processed, and reused. The cold high-pressure oil in the oil phase enters the cold low-pressure separator to obtain low-pressure oil. The hot high-pressure oil in the oil phase enters the cold low-pressure separator under liquid level control to obtain the low-pressure oil. The hydrofining fractionation unit: It is used to send the low-pressure oil into the hydrogen sulfide stripping column. After separation and reflux operations, the bottom oil of the stripping column enters the refined oil dehydration column to obtain the bottom oil of the dehydration column. A part of the bottom oil of the dehydration column is used as recycle oil, and another part of the bottom oil of the dehydration column is used as the feed for the hydrofining system. The hydrofining low-pressure gas and dry gas desulfurization unit: It is used to send the low-pressure gas from the cold low-pressure separator and the top gas from the hydrogen sulfide stripping column into the dry gas desulfurization column for desulfurization after cooling and liquid separation. The desulfurized dry gas is sent out of the system. The isomerization and dewaxing reaction unit: It is used to send the bottom oil of the dehydration column of the hydrofining system into the isomerization feed buffer tank after desulfurization reaction. After boosting pressure, mixing with hydrogen, heat exchange, and heating treatment, it enters the hydroisomerization reactor for isomerization reaction to obtain the isomerization reaction product. The isomerization and dewaxing separation unit: The isomerization reaction product undergoes heat exchange, cooling, and separation operations to obtain recycled hydrogen in the gas phase and isomerized hot high-pressure oil in the liquid phase. A part of the recycled hydrogen is discharged, and another part of the recycled hydrogen is used for the isomerization reaction. The isomerized hot high-pressure oil in the liquid phase enters the isomerized cold low-pressure separator for oil, water, and gas three-phase separation to obtain the isomerized cold low-pressure oil in the oil phase. The isomerized cold low-pressure oil in the oil phase enters the isomerization and dewaxing fractionation unit. The isomerization and dewaxing fractionation unit: It is used to send the isomerized cold low-pressure oil into the fractionation column. A part of the top product of the fractionation column is used as light biodiesel. The bottom material of the fractionation column enters the product fractionation column for product fractionation. A part of the top product of the product fractionation column is used as product bio-aviation kerosene. A part of the bottom oil of the product fractionation column returns to the product fractionation column through the reboiler at the bottom of the product fractionation column, and another part of the bottom oil of the product fractionation column returns to the isomerization feed buffer tank.

2. The industrial mixed grease hydrogenation production biofuel system according to claim 1, wherein: The hydrofining reaction unit includes an automatic backwashing filter, a feedstock oil buffer tank, a hydroprotection reactor, a reaction inlet inclined heating furnace, and a hydrofining reactor. The automatic backwashing filter: is used to receive the feedstock oil and the recycle oil of the hydrofining fractionation unit, and remove particles larger than 25 μm in the feedstock oil; The feedstock oil buffer tank: is used to receive the feedstock oil filtered by the automatic backwashing filter. The feedstock oil buffer tank is protected by inert gas to ensure that the feedstock oil does not contact air; The hydrogenation protection reactor: is used to receive the feedstock oil after pressure boosting and heat exchange treatment, and receive the mixed hydrogen from the new hydrogen compressor and the recycle hydrogen compressor. After the feedstock oil and the mixed hydrogen are mixed, a pre-reaction is carried out to obtain a preliminary pre-reaction product; The reaction inlet inclined heating furnace: is used to heat the preliminary pre-reaction product to the reaction temperature and discharge the waste gas G1; The hydrofining reactor includes a hydrofining reactor I and a hydrofining reactor II. The heated preliminary pre-reaction product sequentially enters the hydrofining reactor I and the hydrofining reactor II for a refining deoxidation reaction to obtain a preliminary refining reaction product.

3. The industrial mixed grease hydrogenation production biofuel system according to claim 2, wherein: The new hydrogen compressor is connected with a new hydrogen compressor inlet liquid separation tank, and a new hydrogen inlet is provided on the new hydrogen compressor inlet liquid separation tank; The recycle hydrogen compressor is connected with a refined recycle hydrogen compressor inlet liquid separation tank, and the refined recycle hydrogen compressor inlet liquid separation tank is connected with a recycle hydrogen desulfurization tower.

4. The industrial mixed grease hydrogenation production biofuel system according to claim 2, characterized in that: The hydrofining separation unit includes a hot high-pressure separator, a hot high-pressure gas air cooler, a cold high-pressure separator, a hot low-pressure separator, a hot low-pressure gas air cooler and a cold low-pressure separator, The hot high-pressure separator: is used to receive the preliminary refining reaction product after heat exchange treatment by a heat exchanger, and then separate the gas and liquid of the preliminary refining reaction product to obtain hot high-pressure gas in the gas phase and hot high-pressure oil in the oil phase. The hot high-pressure gas in the gas phase enters the hot high-pressure gas air cooler, and the hot high-pressure oil in the oil phase enters the hot low-pressure separator; The hot high-pressure gas air cooler: is used to receive the hot high-pressure gas in the gas phase of the hot high-pressure separator, and cool the hot high-pressure gas and then introduce it into the cold high-pressure separator; The cold high-pressure separator: is used to separate the cooled hot high-pressure gas into three phases of oil, gas and water to obtain cold high-pressure oil in the oil phase, recycle hydrogen in the gas phase and waste water in the water phase. The cold high-pressure oil in the oil phase enters the cold low-pressure separator to obtain low-pressure oil. The recycle hydrogen in the gas phase is recycled, processed and reused, and the waste water in the water phase is discharged as acidic waste water for treatment; The hot low-pressure separator: is used to receive the hot high-pressure oil in the oil phase of the hot high-pressure separator, and process the hot high-pressure oil to obtain hot low-pressure gas in the gas phase and low-pressure oil in the oil phase; The hot low-pressure gas air cooler: is used to receive the hot low-pressure gas in the gas phase of the hot low-pressure separator, and cool the hot low-pressure gas and then introduce it into the cold low-pressure separator; The cold low-pressure separator: is used to separate the cooled hot low-pressure gas into three phases of oil, gas and water to obtain low-pressure oil in the oil phase and waste water in the water phase. The waste water in the water phase is discharged as acidic waste water for treatment.

5. The industrial mixed grease hydrogenation production biofuel system according to claim 4, characterized in that: The hydrofining fractionation unit includes a hydrogen sulfide stripping column and a refined oil dehydration column, The hydrogen sulfide stripping column: It is used to receive the low-pressure separated oil, steam and corrosion inhibitor from the cold low-pressure separator and the hot low-pressure separator. The steam enters from the bottom of the hydrogen sulfide stripping column, and overhead gas and overhead oil are obtained from the top of the hydrogen sulfide stripping column. Stripped bottom oil is obtained from the bottom of the hydrogen sulfide stripping column. After the stripped bottom oil is heated by the stripped bottom oil steam generator, it enters the refined oil dehydration column; The refined oil dehydration column: It is used to receive the stripped bottom oil, and after the reaction, the bottom oil of the dehydration column is obtained. A part of the bottom oil of the dehydration column is used as recycled oil, and another part of the bottom oil of the dehydration column is used as the feed for the hydrofining system.

6. The industrial mixed grease hydrogenation production biofuel system according to claim 5, wherein: The hydrofining low-pressure dry gas desulfurization device includes a dry gas knockout drum and a dry gas desulfurization tower, The dry gas knockout drum: It is used to receive the low-pressure dry gas from the cold low-pressure separator and the overhead gas from the hydrogen sulfide stripping column. After liquid separation in the dry gas knockout drum, it enters the lower part of the dry gas desulfurization tower to obtain knockout drum gas; The dry gas desulfurization tower: It is used to receive the knockout drum gas from the dry gas knockout drum and the lean solution, and dry gas is obtained after desulfurization.

7. The industrial mixed oil hydrogenation production biological fuel oil system according to claim 1, wherein: The isomerization and dewaxing reaction device includes an isomerization feed buffer tank, an isomerization reaction heating furnace and a hydroisomerization reactor, The isomerization feed buffer tank: It is used to receive the bottom oil of the dehydration column after the desulfurization reaction; The isomerization reaction heating furnace: It is used to receive the bottom oil of the dehydration column after pressure boosting from the isomerization feed buffer tank. After the bottom oil of the dehydration column is mixed with hydrogen-rich gas, it is heated to the temperature required at the inlet of the hydroisomerization reactor by the isomerization reaction feed heating furnace; The hydroisomerization reactor: It is used to carry out an isomerization reaction after mixing the bottom oil of the dehydration column with hydrogen-rich gas to obtain an isomerization reaction product.

8. The industrial mixed oil hydrogenation biofuel production system according to claim 7, characterized in that: The isomerization and dewaxing separation device includes an isomerization cold high-pressure separator and an isomerization cold low-pressure separator, The isomerization cold high-pressure separator: It is used to receive the isomerization reaction product, and then gas-liquid separate the isomerization reaction product to obtain hydrogen gas in the gas phase and isomerization hot high-pressure separated oil in the oil phase. The hydrogen gas in the gas phase enters the hot high-pressure gas air cooler. A part of the hydrogen gas in the gas phase is sent to PSA as the off-gas hydrogen, and another part of the hydrogen gas in the gas phase enters the inlet buffer tank of the isomerization recycle hydrogen compressor and is separated into two paths after liquid separation. One path is sent to the hydroisomerization reactor as cold hydrogen, and the other path is sent to the isomerization reaction heating furnace after being pressurized by the isomerization recycle hydrogen compressor and mixed with the make-up hydrogen; The isomerization hot high-pressure separated oil in the oil phase enters the isomerization cold low-pressure separator; The isomerization cold low-pressure separator: It is used to receive the isomerization hot high-pressure separated oil in the oil phase from the isomerization cold high-pressure separator, and carry out three-phase separation of oil, water and gas on the isomerization hot high-pressure separated oil to obtain isomerization cold high-pressure separated oil in the oil phase, non-condensable gas in the gas phase and waste water in the water phase.

9. The industrial mixed grease hydrogenation production biofuel system according to claim 8, wherein: The isomerization and dewaxing fractionation device includes a fractionation tower and a product fractionation tower, The fractionating column: It is used to receive the isomerized cold low-temperature fractionated oil after heat exchange and temperature rise, and obtain the overhead product and bottom material of the fractionating column through reaction. After the overhead product is cooled by the overhead air cooler of the fractionating column and the overhead water cooler of the fractionating column in sequence, it enters the overhead reflux drum of the fractionating column. The non-condensable gas in the overhead reflux drum of the fractionating column is sent to the inlet of the desorbed gas compressor. The oil-phase product in the overhead reflux drum of the fractionating column is pressurized by the overhead reflux pump of the fractionating column and then divided into two parts: one part of the oil-phase product is used as the overhead reflux, and the other part of the oil-phase product is used as light biodiesel; the bottom material enters the product fractionating column for product fractionation; The product fractionating column: It is used to receive the bottom material after pressure increase and heat exchange, and obtain the overhead product and bottom oil of the product fractionating column through reaction. The overhead product passes through the low-temperature fractionated oil / product fractionating column top gas heat exchanger, the product fractionating column top gas / deaerated water heat exchanger, the product fractionating column top air cooler and the product fractionating column top water cooler in sequence, and after cooling, it enters the overhead reflux drum of the product fractionating column. The oil-phase product in the overhead reflux drum of the product fractionating column is pressurized by the overhead reflux pump of the fractionating column. One part of the oil-phase product is used as the overhead reflux, and the other part of the oil-phase product is used as product bio-aviation kerosene; A part of the bottom oil is pressurized by the product fractionating column bottom reboiler pump and then enters the product fractionating column bottom reboiler for heating and then returns to the product fractionating column. Another part of the bottom oil is pressurized by the heavy biofuel pump, exchanges heat with the topped oil through the topped oil / heavy biofuel heat exchanger, and then exchanges heat and cools down through the heavy biofuel steam generator, and then returns to the isomerization feed buffer tank.

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