Hydrogenation treatment system for waste mineral oil

Abstract

A waste mineral oil hydrogenation treatment system comprises a filtering unit, a hot hydrogen flash evaporation unit and a hydrogenation reaction unit which are sequentially arranged in the flowing direction of raw oil, and the filtering unit is used for filtering out particle impurities larger than 25 micrometers in the raw oil; the hot hydrogen flash evaporation unit is used for heating raw oil to a preset temperature by using hot hydrogen, then carrying out reaction coupling removal on metal and colloid asphaltene, and then carrying out flash evaporation separation; the hydrogenation reaction unit is used for removing metal, organic chlorine and sulfur and nitrogen impurities in the raw oil; the clean oil product treated by the units sequentially serves as a pretreatment product to be subjected to deep hydrotreatment to obtain higher-quality base oil, or the clean oil product is directly used as a base oil blending component and a fuel oil product. According to the invention, pretreatment and hydrogenation processes are organically coupled, and waste mineral oil pretreatment and hydrofining are simultaneously carried out in the presence of hydrogen, so that the problem that coking is easily caused when a traditional heating furnace is heated is avoided, the catalyst activity in the hydrogenation process can be maintained, and the operation cycle of the device is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste mineral oil recovery and treatment, and particularly relates to a waste mineral oil hydrotreating system. Background Art

[0002] Traditional waste mineral oil recovery technologies mainly include acid-base washing, solvent refining + clay refining. The problems existing in these technologies are large solvent loss, low base oil yield, high sulfur content in the base oil product, poor blendability of the product, large energy consumption and environmental pollution, etc.

[0003] Hydrofining technology has only been industrialized in recent years. It is similar to traditional oil hydrofining technology. It means that in the presence of hydrogen pressure and a catalyst, harmful impurities such as sulfur, oxygen, and nitrogen in the oil are converted into corresponding hydrogen sulfide, water, and ammonia and removed, and olefins and diolefins are hydrogenated to saturation, and part of the aromatics is hydrogenated to saturation to improve the quality of the oil. The base oil after hydrofining can meet the standard of class II base oil, and the product value has been greatly improved.

[0004] However, at present, the problems of waste mineral oil hydrofining technology mainly focus on the easy coking of waste mineral oil during the heating process, resulting in pipeline and equipment blockage, too fast deactivation rate of the hydrofining catalyst, short operation cycle of the device, etc.; various impurities in waste mineral oil have a great impact on the catalyst life, and the catalyst in some hydrofining devices becomes deactivated within a few days and cannot be continuously produced. Therefore, in the pretreatment stage before hydrogenation, it is necessary to effectively remove the impurities that affect the catalyst through certain physical or chemical means to ensure the normal progress of the subsequent hydrogenation process.

[0005] The traditional hydrofining pretreatment technologies mainly include the following:

[0006] 1) Filtration - centrifugation - flash evaporation - vacuum technology: The general process is that first, the raw oil is centrifuged or mechanically filtered and heated to dehydrate and deslag; the raw oil after deslagging is heated in a heating furnace, and after reaching a certain temperature, it is pre-flash evaporated to remove water and light components, and then vacuum distilled. The pretreated raw material drawn from the side line of the vacuum tower is then subjected to subsequent hydrofining. The principle of this pretreatment process is mainly to remove heavy components through mechanical methods and fractional distillation principles, but impurities such as gum, metal, chlorine, and sulfur in the raw material are not removed, which affects the subsequent hydrotreating process.

[0007] 2) Acid and alkali washing - clay refining: The general process is to use the strong oxidizing property of concentrated sulfuric acid to forcibly oxidize the impurities in waste mineral oil to form flocculants for precipitation and separation, then neutralize with alkali and add clay for decolorization and filtration, and finally obtain the refined product. Due to high pollution, high product loss, great harm to the health of operators, and poor blendability of the produced product, this process has been phased out and is usually used in small-scale plants. At present, some waste oil recycling enterprises still use this technology without an alternative process;

[0008] 3) Solvent refining: This technology belongs to the traditional type I lubricating oil refining process and can also be used in non-mineral oil refining. In the process of non-mineral oil solvent refining, the selected solvent has a high solubility for impurities and non-ideal components in the oil, while having a low solubility for the ideal components in the oil. The non-ideal components are removed through liquid-liquid extraction. Common solvents for refining waste mineral oil include furfural, phenol, N-methylpyrrolidone, etc. The waste mineral oil after solvent refining is then adsorbed and decolorized with activated clay to obtain the refined product. This process route can only produce low-grade type I base oil products at present, and the production process requires chemical solvents, resulting in high production costs and environmental protection problems such as difficult treatment of waste solvents and waste clay.

[0009] Therefore, traditional pretreatment processes such as fine filtration, atmospheric and vacuum distillation, flash evaporation, and clay refining, which are physical methods, currently cannot effectively remove harmful metals, chlorine, nitrogen, asphaltenes, additives, and other harmful impurities. At the same time, the product yields of these conventional methods are low, and some high-value base oil components flow into low-value by-products such as heavy fuel oil. Secondly, traditional chemical methods such as acid and alkali washing, solvent refining, and clay refining mostly use chemical agents such as acid-base solutions and organic solvents, and a large amount of harmful chemical waste liquid is generated during the production process, which needs to be recycled or discharged up to standard. At the same time, these chemical methods can only remove some harmful components such as asphaltenes in the feedstock oil, and other metal elements, organic chlorine, sulfur and nitrogen and other impurities still cannot be removed. Summary of the Utility Model

[0010] Aiming at the problems of easy coking during the heating process of waste mineral oil in the hydrogenation process of waste mineral oil, too fast deactivation rate of the catalyst during the hydrogenation process, short operation cycle of the device, and unqualified product quality, the present utility model provides a waste mineral oil hydrotreating system, which organically couples the pretreatment and hydrogenation processes, and simultaneously performs waste mineral oil pretreatment and hydrorefining under hydrogenation conditions. This not only avoids the problem of easy coking in traditional furnace heating, but also can maintain the activity of the catalyst during the hydrogenation process, extend the operation cycle of the device, and the high-quality pretreatment product produced can be used as the raw material for deep hydrotreating to produce high-quality base oil, or can be directly used as a blending component for low-quality base oil or fuel oil products.

[0011] To achieve the above object, the technical solution adopted by the present utility model is as follows:

[0012] A waste mineral oil hydrotreating system includes a filtering unit, a hot hydrogen flash evaporation unit, and a hydrotreating reaction unit sequentially arranged along the flow direction of the feedstock oil.

[0013] The filtering unit is used to filter out particulate impurities larger than 25 μm in the feedstock oil.

[0014] The hot hydrogen flash evaporation unit is used to heat the feedstock oil to a preset temperature with hot hydrogen and then carry out the reaction coupling and removal of metals and asphaltenes, and then carry out flash separation.

[0015] The hydrotreating reaction unit is used to remove metals, organic chlorine, and sulfur and nitrogen impurities in the feedstock oil.

[0016] The clean oil product after being treated by the above units in sequence is subjected to deep hydrotreating to obtain a higher-quality base oil, or directly used as a base oil blending component and a fuel oil product.

[0017] In some technical solutions, the hot hydrogen flash evaporation unit includes a suspension bed reactor and a hot hydrogen flash evaporation tank connected in sequence. A hot hydrogen supply pipeline and a feedstock oil conveying pipeline are arranged in parallel upstream of the suspension bed reactor. A catalyst addition pipeline is connected to the feedstock oil conveying pipeline. The suspension bed reactor realizes the effective dispersion and mixing of the dispersed catalyst, hydrogen, and feedstock oil through the setting of different inlet flow channels, thereby realizing the reaction coupling and removal of metals and asphaltenes; the hot hydrogen flash evaporation tank is used to separate the asphaltene and heavy asphalt components carried in the feedstock oil.

[0018] In some technical solutions, a hot oil circulation pipeline is led out from the middle of the hot hydrogen flash evaporation tank. A hot oil circulation pump is arranged on the hot oil circulation pipeline, and the outlet end of the hot oil circulation pump is connected to the hot hydrogen supply pipeline.

[0019] In some technical solutions, the hot hydrogen flash evaporation unit further includes a first heat exchanger and a vacuum tower arranged downstream of the hot hydrogen flash evaporation tank. The first heat exchanger is connected to the gas phase outlet of the hot hydrogen flash evaporation tank and is used to cool the flashed light component substances into a liquid; the vacuum tower is connected to the liquid phase outlet of the hot hydrogen flash evaporation tank. The top of the vacuum tower is connected back to the feedstock oil conveying pipeline, and the bottom is connected to a heavy oil output pipeline.

[0020] In some technical solutions, the hot hydrogen flash evaporation tank is provided with a swirl internal part; and / or,

[0021] The hot hydrogen flash evaporation unit further includes a second heat exchanger connected in series to the pipeline between the hot hydrogen flash evaporation tank and the vacuum tower and a third heat exchanger connected in series to the pipeline of the connection back to the vacuum tower; and / or,

[0022] The hot hydrogen supply pipeline is provided with a hydrogen compressor, a fourth heat exchanger and a heating furnace in sequence along the hydrogen flow direction; and / or,

[0023] The hot hydrogen supply pipeline and the crude oil delivery pipeline are connected to the inlet of the suspended bed reactor through a mixed feed pipeline, and a pipeline mixer for fully mixing hydrogen and crude oil is arranged on the mixed feed pipeline.

[0024] In some technical solutions, the waste mineral oil hydroprocessing system further includes a high-pressure separation unit.

[0025] The high-pressure separation unit is used for oil and gas separation in the hydrogenation reaction effluent.

[0026] In some technical solutions, the hydrogenation reaction unit includes a hydrogenation reactor.

[0027] The high-pressure separation unit includes a cold high-pressure separator and a stripping tower.

[0028] The cold high-pressure separator is connected to the outlet of the hydrogenation reactor, and a fifth heat exchanger is arranged on the connecting pipeline and an alkali injection port is arranged on the inlet and outlet pipelines of the fifth heat exchanger. The gas phase outlet of the cold high-pressure separator is connected to the hot hydrogen supply pipeline, and the oil phase outlet is connected to the stripping tower. The top of the stripping tower is connected to an acid gas outlet pipe, and the bottom is connected to a product oil output pipeline.

[0029] In some technical schemes, the high-pressure separation unit also includes a hot high-pressure separator connected in series to the pipeline between the hydrogenation reactor and the cold high-pressure separator, the hot high-pressure separator is connected to a hydrogen inlet pipe, and the hydrogen inlet pipe is connected to the hot hydrogen supply pipeline, which is used for hydrogen stripping inside the hot high-pressure separator to remove residual chlorine in the hot high-separation oil, the gas phase outlet of the hot high-pressure separator is connected to the cold high-pressure separator, and the oil phase outlet is connected to the stripping tower.

[0030] In some technical solutions, the high-pressure separation unit further includes an acidic water stripping tower.

[0031] The cold high-pressure separator and the acidic water outlet pipe connected to the stripping tower are both connected to the acidic water stripping tower. The top of the acidic water stripping tower is connected to the acidic water outlet pipe, and the bottom is connected to the purified water outlet pipe.

[0032] In some technical solutions, the purified water outlet pipe of the acidic water stripping tower is connected back to the water washing section of the cold high-pressure separator;

[0033] And / or, the middle part of the acidic water stripping tower is connected with an ammonia water circulation pipeline, and the ammonia water circulation pipeline is connected with the alkali injection port.

[0034] The utility model adopting the above technical solutions has at least the following beneficial effects:

[0035] 1. For the waste mineral oil hydrotreating system proposed in this application, the heat source provided by recycle hydrogen and a small amount of middle distillate recycle oil is used to mix and heat up the raw materials under the condition of hydrogen, avoiding the problem of easy coking in traditional heating furnace heating and extending the operation cycle of the device;

[0036] 2. For the waste mineral oil hydrotreating system proposed in this application, a part of the high-temperature raw material oil of the middle distillate is drawn from the hot hydrogen flash tank, mixed with recycle hydrogen and used as the fuel of the heating furnace, and then merged with the low-temperature raw material oil, recovering part of the heat, solving the problem of the need for a large amount of recycle hydrogen in the traditional hydrogenation process, reducing energy consumption, and reducing the investment and floor area of the recycle hydrogen system;

[0037] 3. For the waste mineral oil hydrotreating system proposed in this application, the hydrotreating process is adopted, and heavy components such as harmful resins and asphaltenes are removed through a suspension bed reactor and a hot hydrogen flash tank; at the same time, reactions such as demetallization, dechlorination, desulfurization and denitrification are carried out in the subsequent hydrogenation reactor, providing high-quality raw materials for subsequent deep hydrotreating and ensuring the long-term operation of the hydrogenation process catalyst;

[0038] 4. For the waste mineral oil hydrotreating system proposed in this application, various impurities in the raw material oil are effectively removed through the hydrothermal flash and hydrogenation reaction processes. At the same time, no chemical agents such as acid-base solutions and solvents are used, and the production process is environmentally friendly without generating a large amount of organic waste liquid;

[0039] 5. For the waste mineral oil hydrotreating system proposed in this application, ammonia water washing is adopted, which can not only remove the ammonium salts generated by the reaction, but also neutralize acidic impurities such as hydrogen sulfide and hydrogen chloride in the reaction effluent into salts and finally dissolve them in acidic water; and the washing ammonia water used comes from the nitrogen element in the raw material oil and does not require external supply, solving the setting of the recycle hydrogen desulfurization system and the supporting solvent regeneration device in the traditional hydrogenation system, and reducing the device investment and operation cost;

[0040] 6. For the waste mineral oil hydrotreating system proposed in this application, a final water washing section is set in the cold high-pressure separator to dissolve the ammonia entrained in the recycle hydrogen in water, solving the problems of too high ammonia content in the recycle hydrogen, resulting in reduced catalyst activity and easy crystallization in the system;

[0041] 7. For the waste mineral oil hydrotreating system proposed in this application, by setting hydrogen stripping in the hot high-pressure separator, the residual chlorine, H2S, etc. in the hot high-pressure separator oil are further removed, reducing the load and energy consumption of the subsequent stripping tower for removal;

[0042] 8. The waste mineral oil hydrotreating system proposed in this application organically couples the pretreatment and hydrogenation processes, and performs partial hydrofining while carrying out the pretreatment under hydrogenation conditions, reducing the production cost, plant floor area and investment; adopting the process technology of the present utility model can not only produce high-quality pretreatment products that can be used as raw materials for deep hydrotreating to produce high-quality base oils, but also directly as blending components of low-quality base oils or fuel oil products. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings and their markings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0044] Figure 1 It is a schematic structural diagram of the waste mineral oil hydrotreating system described in the embodiments of the present utility model.

[0045] The meanings of the reference symbols in the drawings are as follows:

[0046] 10 - Filter;

[0047] 21 - Hydrogen compressor, 22 - Heating furnace, 23 - Hot hydrogen flash tank, 24 - Hot oil circulation pump, 25 - Vacuum tower, 26 - Slurry bed reactor;

[0048] 30 - Hydrotreating reactor;

[0049] 41 - Hot high-pressure separator, 42 - Cold high-pressure separator, 43 - Stripping tower, 44 - Acid water stripping tower. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will describe the specific embodiments of the present utility model with reference to the drawings. Obviously, the drawings described below are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings and other embodiments can be obtained.

[0051] To make the drawings concise, only the parts related to the utility model are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, for the sake of simplicity and understanding of the drawings, in some drawings, components with the same structure or function are only schematically shown or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation.

[0052] It should also be further understood that the term "and / or" used in the specification and appended claims of this application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0053] In this context, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0054] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0055] In one embodiment, the present utility model provides a waste mineral oil hydrotreating system. Please refer to Figure 1 , the treatment system includes a filtration unit, a hot hydrogen flash evaporation unit, and a hydrogenation reaction unit arranged in sequence along the flow direction of the feedstock oil. Among them, the filtration unit is used to filter out particulate impurities larger than 25 μm in the feedstock oil; the hot hydrogen flash evaporation unit is used to heat the feedstock oil to a preset temperature by hot hydrogen and then carry out the reaction coupling and removal of metals and asphaltenes, and then carry out flash evaporation and separate the asphaltenes and heavy asphalt components carried in the feedstock oil; the hydrogenation reaction unit is used to remove metals, organic chlorine, and sulfur and nitrogen impurities in the feedstock oil; the clean oil product after being processed by the above units in sequence is subjected to deep hydrogenation treatment to obtain a higher-quality base oil, or directly used as a base oil blending component and a fuel oil product.

[0056] This application uses the heat source provided by recycle hydrogen to mix and heat the feedstock oil under hydrogenation conditions, avoiding the problem of easy coking in traditional furnace heating and extending the operation cycle of the device; and uses the hydrogenation process for flash evaporation and removal of heavy components, removing harmful heavy components such as asphaltenes, and at the same time performing partial hydrorefining in the subsequent process to further remove impurities such as metals, organic chlorine, and sulfur and nitrogen, providing high-quality raw materials for the subsequent deep hydrogenation treatment as a pretreatment product.

[0057] In the above embodiments, the filtration unit may adopt mechanical filtration or centrifugal filtration, and may adopt membrane filtration and manually set the filtration accuracy according to the state of the crude oil and the requirements of the output oil. The device structure used includes but is not limited to centrifugal equipment, filter screens, membrane components and distillation devices; the filtration size can be adaptively adjusted according to the composition of the crude oil, and is not limited to the 25μm restriction requirement mentioned above in this application. Appropriate adjustments can be considered to be included in the scope of patent protection of this application; during the filtration process, larger particulate matter in the crude oil can be removed to reduce the operating load of subsequent impurity removal equipment and maintain the stability of the system's long-term operation.

[0058] In the above embodiment, the hot hydrogen flash unit includes a suspended bed reactor 26 and a hot hydrogen flash tank 23 connected in sequence, a hot hydrogen supply pipeline and a crude oil delivery pipeline are arranged in parallel upstream of the suspended bed reactor 26, and a catalyst addition pipeline is connected to the crude oil delivery pipeline. The suspended bed reactor 26 is provided with different inlet flow channel distributions to achieve effective dispersion and mixing of the dispersed catalyst, hydrogen and crude oil, thereby realizing the reaction coupling and removal of metal and colloid asphaltene, and the hot hydrogen flash tank 23 is used to separate the colloid and asphalt heavy components carried in the crude oil; specifically, A hydrogen compressor 21, a fourth heat exchanger and a heating furnace 22 are arranged in sequence on the hot hydrogen supply pipeline along the hydrogen flow direction; the hot hydrogen flash tank 23 is provided with a swirl internal component to prevent solid impurities from entering the subsequent hydrogenation reaction with the circulating hydrogen, so that most of the high recovery value fractions in the separated waste mineral oil can be subjected to subsequent hydrogenation dechlorination, demetallization, desulfurization, nitrogen removal and other impurities; preferably, the hot hydrogen supply pipeline and the raw oil delivery pipeline are connected to the inlet of the suspended bed reactor 26 through a mixed feed pipeline, and a pipeline mixer for fully mixing hydrogen and raw oil is arranged on the mixed feed pipeline.

[0059] In a preferred embodiment, a hot oil circulation pipeline is led out from the middle of the hot hydrogen flash tank 23, a hot oil circulation pump 24 is arranged on the hot oil circulation pipeline, and the outlet end of the hot oil circulation pump 24 is connected to the hot hydrogen supply pipeline.

[0060] In this embodiment, a portion of the intermediate distillate high-temperature crude oil is extracted from the hot hydrogen flash tank 23 and mixed with circulating hydrogen as fuel for the heating furnace 22, and then combined with the low-temperature crude oil to recover part of the heat, thereby solving the problem of requiring a large amount of circulating hydrogen in the traditional hydrogenation process, reducing energy consumption, and reducing the investment and footprint of the circulating hydrogen system.

[0061] In a specific embodiment, the hot hydrogen flash unit further includes a first heat exchanger and a vacuum tower 25 disposed downstream of the hot hydrogen flash tank 23. The first heat exchanger is communicated with the gas phase outlet of the hot hydrogen flash tank 23 and is used to cool the flashed light component substances into liquids. The vacuum tower 25 is communicated with the liquid phase outlet of the hot hydrogen flash tank 23. The top of the vacuum tower 25 is connected back to the raw oil pipeline, and the bottom is communicated with a heavy oil output pipeline. Preferably, the hot hydrogen flash unit further includes a second heat exchanger connected in series to the pipeline between the hot hydrogen flash tank 23 and the vacuum tower 25 and a third heat exchanger connected in series to the pipeline connecting back to the vacuum tower 25.

[0062] In the above embodiment, the hydrogenation reaction unit includes a hydrogenation reactor 30 filled with different catalyst gradings, which can realize the functions of hydrogenation refining such as hydrogenation de-metallization, de-chlorination, and desulfurization and denitrification of the raw oil, reducing the depth and difficulty of subsequent hydrogenation treatment.

[0063] In some specific embodiments, a high-pressure separation unit is further provided downstream of the above hydrogenation reaction unit for separating the oil and gas in the hydrogenation reaction effluent. Generally, the high-pressure separation unit needs to be equipped with a cold high-pressure separator 42 and a stripping column 43. The cold high-pressure separator 42 is connected to the outlet of the hydrogenation reactor 30, and a fifth heat exchanger is arranged on the connecting pipeline and an alkali injection port is arranged on the inlet and outlet pipelines of the fifth heat exchanger. The gas phase outlet of the cold high-pressure separator 42 is communicated with the hot hydrogen supply pipeline, and the oil phase outlet is connected to the stripping column 43. The top of the stripping column 43 is communicated with an acidic gas outlet pipe, and the bottom is communicated with a product oil output pipeline.

[0064] In an alternative embodiment, the high-pressure separation unit further includes a hot high-pressure separator 41 connected in series to the pipeline between the hydrogenation reactor 30 and the cold high-pressure separator 42. The hot high-pressure separator 41 is communicated with a hydrogen inlet pipe, and the hydrogen inlet pipe is communicated with the hot hydrogen supply pipeline for hydrogen stripping inside the hot high-pressure separator to remove the residual chlorine in the hot high-pressure separator oil. The gas phase outlet of the hot high-pressure separator 41 is connected to the cold high-pressure separator 42, and the oil phase outlet is communicated to the stripping column 43.

[0065] In this embodiment, through the series connection of the hot and cold high-pressure separators and the combined use of the stripping column 43, the acidic gas in the hydrogenation reaction effluent can be effectively removed to obtain high-quality output oil products.

[0066] In a preferred embodiment, the high-pressure separation unit further includes an acidic water stripping column 44. The acidic water outlet pipes connected to the cold high-pressure separator 42 and the stripping column 43 are both connected to the acidic water stripping column 44. The top of the acidic water stripping column 44 is communicated with an acidic gas outlet pipe, and the bottom is communicated with a purified water outlet pipe.

[0067] Preferably, the purified water outlet pipe is connected back to the water washing section of the cold high-pressure separator 42, and the purified water is reused as washing water in the cold high-pressure gas to absorb ammonia carried in the circulating hydrogen.

[0068] In this embodiment, in order to prevent ammonia from escaping, the cold high-pressure separator 42 is provided with a water washing section to dissolve the ammonia in the circulating hydrogen in water, thereby solving the problem of excessive ammonia content in the circulating hydrogen, resulting in reduced catalyst activity and easy crystallization in the system.

[0069] Preferably, the middle part of the acidic water stripping tower 44 is connected with an ammonia water circulation pipeline, and the ammonia water circulation pipeline is connected with the alkali injection port.

[0070] In this embodiment, ammonia water is used as the washing medium, which can not only remove the ammonia salt generated by the reaction, but also neutralize the acidic impurities such as hydrogen sulfide and hydrogen chloride in the reaction effluent into salts and finally dissolve them in the acidic water; and the washing ammonia water used is derived from the nitrogen element in the raw oil, and does not require external supply, which solves the setting of the circulating hydrogen desulfurization system and the supporting solvent regeneration device of the traditional hydrogenation system, and reduces the investment and operation costs of the device; and the use of ammonia water for washing solves the high cost of alkali solution used in the traditional reaction gas dechlorination and desulfurization, and solves the problem that the waste liquid generated by the use of alkali solution is difficult to recycle and treat, which pollutes the environment, simplifies the process and reduces costs.

[0071] In the present application, when the product target is lower quality base oil or fuel oil, the utility model can achieve this in one step without subsequent deep hydrogenation treatment.

[0072] In the present application, waste mineral oil pretreatment technology and hydrogenation technology are organically coupled, and mineral oil pretreatment and hydrogenation refining are simultaneously performed under hydrogen conditions, which simplifies the process compared with the traditional single pretreatment process.

[0073] In another embodiment, the present application further proposes a method for hydrogenating waste mineral oil, comprising the following steps:

[0074] Centrifuge or mechanically filter the crude oil to remove particle impurities larger than 25 μm;

[0075] The heated circulating hydrogen is fully mixed with the pressurized crude oil and the metal and colloid asphaltene are reacted and coupled to be removed, and then the colloid and asphalt heavy components carried in the crude oil are flashed and separated;

[0076] The gas phase components in the flash product are cooled to liquid phase and then subjected to hydrogenation reaction to remove metal, organic chlorine and sulfur and nitrogen impurities carried in the crude oil;

[0077] The effluent after the hydrogenation reaction is subjected to oil and gas separation to obtain a pretreated oil product or a base oil blending component or a fuel oil.

[0078] In some specific embodiments, the specific steps for separating oil and gas from the effluent after the hydrogenation reaction are as follows: The effluent after the hydrogenation reaction is heat-exchanged and then subjected to high-temperature separation, and hydrogen stripping is carried out inside to remove the residual chlorine in the high-temperature oil fraction. The separated high-temperature gas is heat-exchanged and cooled and then subjected to low-temperature separation. The low-temperature gas is recycled as recycle hydrogen. The low-temperature oil fraction is mixed with the high-temperature oil fraction and then stripped, and the separated acidic water is stripped again. The obtained acidic gas is sent to the downstream device for treatment, and the purified water is used to remove amines in the recycle hydrogen. The ammonia gas is mixed with the purified water and used as recycle ammonia water to neutralize acidic impurities in the effluent of the hydrogenation reaction and dissolve them in the acidic water, and the pretreated product is output.

[0079] In this embodiment, the heat source provided by the recycle hydrogen and a small amount of middle distillate recycle oil is used to mix and heat up the raw material under the condition of hydrogen, avoiding the problem of easy coking in traditional furnace heating and extending the operation cycle of the device.

[0080] In this embodiment, the hydrogenation process is adopted, and heavy components such as harmful resins and asphaltenes are removed through a suspension bed reactor and a hot hydrogen flash tank. At the same time, in the subsequent hydrogenation reaction, reactions such as demetallization, dechlorination, and desulfurization and denitrification are carried out, providing high-quality raw materials for subsequent deep hydrogenation treatment and ensuring the long-term operation of the catalyst in the hydrogenation process.

[0081] In another embodiment, on the basis of the above-mentioned waste mineral oil hydrogen treatment system solution, its treatment method is further provided and specifically described as follows:

[0082] The feedstock oil is filtered by filter 10 to remove particulate impurities larger than 25 μm in the feedstock, and then mixed with a dispersive catalyst and pressurized by a feedstock pump. The recycle hydrogen is mixed with the high-temperature feedstock oil withdrawn from the hot hydrogen flash drum 23, and then heated by the recycle hydrogen heating furnace. The heated hydrogen and feedstock oil enter the suspension bed reactor 26 through different flow channels. The reaction effluent at the top of the suspension bed enters the hot hydrogen flash drum 23 for pretreatment to remove slag and perform gas-liquid separation. The oil phase rich in gum, asphalt heavy components and other impurities coming out from the bottom of the hot hydrogen flash drum 23 enters the vacuum tower 25. The gas phase at the top of the hot hydrogen flash drum exchanges heat through a heat exchanger and then enters the reactor for demetallization, dechlorination, desulfurization and denitrification reactions. The reaction effluent after hydrogenation exchanges heat through a heat exchanger and then enters the hot high-pressure separator 41 for oil-gas separation. The hot high-pressure separator 41 is provided with hydrogen stripping to remove the residual chlorine in the hot high-pressure separator oil. The hot high-pressure separator oil at the bottom of the hot high-pressure separator 41 enters the stripping column 43. The hot high-pressure separator gas at the top is cooled after heat exchange and enters the cold high-pressure separator 42. The gas phase of the cold high-pressure separator 42 is pressurized by a recycle hydrogen compressor and then enters the recycle hydrogen heating furnace for heating after heat exchange as recycle hydrogen. The cold high-pressure separator oil at the bottom of the cold high-pressure separator 42 exchanges heat and then is mixed with the hot high-pressure separator oil and enters the stripping column 43. In order to remove acidic impurities such as hydrogen chloride in the reaction effluent and prevent crystallization salts from precipitating and blocking the pipeline at low-temperature positions, ammonia water is injected in front of the cold high-pressure separator 42 and the previous pipelines to neutralize acidic substances such as HCL and dissolve crystallization salts. In order to prevent the ammonia in the recycle hydrogen from affecting the activity of the reaction catalyst and crystallizing in the system pipelines and equipment, a water washing section is provided in the cold high-pressure separator 42 to remove the ammonia in the recycle hydrogen.

[0083] The light components at the top of the vacuum tower are sent to the feedstock oil line for recovery after heat exchange and cooling; the heavy oil product at the bottom of the vacuum tower is taken out of the unit after heat exchange and cooling as a heavy product.

[0084] The hot high-pressure separator oil and the cold high-pressure separator oil are combined and enter the stripping column 43. The gas at the top of the tower is acidic gas and is sent to downstream units for treatment; the bottom oil of the stripping column is cooled after recovering heat through a heat exchanger and is used as a pretreatment product.

[0085] The acidic water generated at the top of the stripping column and the acidic water generated by the cold high-pressure separator 42 are mixed and then sent to the acidic water stripping column 44 for separation. The acidic gas at the top goes to downstream units for treatment. Ammonia gas is drawn out from the middle of the acidic water stripping column and used as recycled ammonia water after being mixed and purified, and the purified water at the bottom of the column is used as the water injection for the water washing section of the cold high-pressure separator 42 for reuse.

[0086] When the plant scale is small, in order to reduce investment, this technical solution can only adopt the cold high-pressure separation process, that is, cancel the hot high-pressure separation tank, directly cool all the reaction effluents to the cold high-pressure separator 42, and the position of ammonia injection remains unchanged.

[0087] Among them, the parameter control of each process is as follows:

[0088] The temperature of the suspension bed reactor is 340°C, which can be adjusted between 300 - 400°C according to the raw material properties and product requirements; the addition amount of the suspension bed catalyst is 0.1 - 2%, which can be adjusted according to different raw material properties and product requirements;

[0089] The temperature of the hydroflash drum is 350°C, and it is recommended to be adjusted between 300 - 400°C according to the raw material properties;

[0090] The reactor temperature is 300°C, and the recommended operating temperature is 260 - 360°C, which can be adjusted according to the initial and final stages of operation and the catalyst grading scheme;

[0091] The temperature of the cold high-pressure separator 42 is 50°C, and the recommended operating temperature is 40 - 60°C;

[0092] The operating pressure of the recycle hydrogen system is 6.0 MPaG, and it is recommended to be between 5.0 - 10.0 MPa, which can be adjusted according to the raw material properties and the catalyst reaction requirements;

[0093] The circulation rate of the hot oil circulation pump 24 is 20% of the feed, and the actual circulation rate can be directly selected between 0 - 50% according to the plant scale, reactor temperature requirements and the configuration of the recycle hydrogen compressor;

[0094] According to the properties of typical waste mineral oils, the heavy oil yield of the present utility model is about 7 - 8%, and the recommended yield is 5 - 15% according to the product requirements;

[0095] According to the properties of typical waste mineral oils, the yield of the pretreatment product is about 87%, and the actual yield is recommended to be between 80 - 90% according to the raw material properties and the requirements of different final products;

[0096] The concentration of the circulating ammonia water is 20%, and it can be selected in the range of 10 - 30% according to the raw material characteristics and the net washing and neutralization effect.

[0097] The above-described embodiments only represent several implementation manners of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the appended claims.

Claims

1. A waste mineral oil hydrotreating system, characterized in that, It includes a filtering unit, a hot hydrogen flash unit and a hydrogenation reaction unit which are arranged in sequence along the flow direction of the crude oil. The filtering unit is used to filter out particulate impurities larger than 25 μm in the raw oil; The hot hydrogen flash unit is used to heat the crude oil to a preset temperature using hot hydrogen, then perform reaction coupling removal of metal and colloid asphaltene, and then perform flash separation; The hydrogenation reaction unit is used to remove metal, organic chlorine and sulfur and nitrogen impurities in the crude oil; The clean oil products processed by the above units are used as pre-treated products for deep hydrogenation treatment to obtain higher quality base oil, or directly used as base oil blending components and fuel oil products.

2. The waste mineral oil hydrotreatment system according to claim 1, characterized in that: The hot hydrogen flash unit includes a suspended bed reactor and a hot hydrogen flash tank connected in sequence. A hot hydrogen supply pipeline and a crude oil delivery pipeline are arranged in parallel upstream of the suspended bed reactor. A catalyst addition pipeline is connected to the crude oil delivery pipeline. The suspended bed reactor is provided with different inlet flow channel distributions to achieve effective dispersion and mixing of dispersed catalyst, hydrogen and crude oil, thereby realizing the reaction coupling and separation of metal and colloid asphaltene; the hot hydrogen flash tank is used to separate the colloid and asphalt heavy components carried in the crude oil.

3. The waste mineral oil hydrotreatment system according to claim 2, characterized in that: A hot oil circulation pipeline is led out from the middle of the hot hydrogen flash tank, a hot oil circulation pump is arranged on the hot oil circulation pipeline, and the outlet end of the hot oil circulation pump is connected to the hot hydrogen supply pipeline.

4. The waste mineral oil hydrotreatment system according to claim 2 or 3, characterized in that: The hot hydrogen flash unit also includes a first heat exchanger and a pressure reducing tower arranged downstream of the hot hydrogen flash tank, wherein the first heat exchanger is connected to the gas phase outlet of the hot hydrogen flash tank and is used to cool the light component material flashed out into liquid; the pressure reducing tower is connected to the liquid phase outlet of the hot hydrogen flash tank, the top of the pressure reducing tower is back-connected to the raw oil conveying pipeline, and the bottom is connected to the heavy oil output pipeline.

5. The waste mineral oil hydrotreatment system according to claim 4, characterized in that: The hot hydrogen flash tank is provided with swirl internals; and / or, The hot hydrogen flash unit further includes a second heat exchanger connected in series to the pipeline between the hot hydrogen flash tank and the vacuum tower and a third heat exchanger connected in series to the return pipeline of the vacuum tower; and / or, The hot hydrogen supply pipeline is provided with a hydrogen compressor, a fourth heat exchanger and a heating furnace in sequence along the hydrogen flow direction; and / or, The hot hydrogen supply pipeline and the crude oil delivery pipeline are connected to the inlet of the suspended bed reactor through a mixed feed pipeline, and a pipeline mixer for fully mixing hydrogen and crude oil is arranged on the mixed feed pipeline.

6. The waste mineral oil hydrotreatment system according to claim 2, characterized in that: The waste mineral oil hydroprocessing system also includes a high-pressure separation unit, The high-pressure separation unit is used for oil and gas separation in the hydrogenation reaction effluent.

7. The waste mineral oil hydrotreatment system according to claim 6, characterized in that: The hydrogenation reaction unit comprises a hydrogenation reactor, The high-pressure separation unit includes a cold high-pressure separator and a stripping column. The cold high-pressure separator is connected to the outlet of the hydrogenation reactor, and a fifth heat exchanger is arranged on the connecting pipeline, and an alkali injection port is arranged on the inlet and outlet pipelines of the fifth heat exchanger. The gas-phase outlet of the cold high-pressure separator is communicated with the hot hydrogen supply pipeline, and the oil-phase outlet is connected to the stripping column. The top of the stripping column is communicated with an acidic gas outlet pipe, and the bottom is communicated with a product oil output pipeline.

8. The waste mineral oil hydrotreating system according to claim 7, wherein The high-pressure separation unit further includes a hot high-pressure separator connected in series to the pipeline between the hydrogenation reactor and the cold high-pressure separator. The hot high-pressure separator is communicated with a hydrogen inlet pipe, and the hydrogen inlet pipe is communicated with the hot hydrogen supply pipeline for hydrogen stripping inside the hot high-pressure separator to remove the residual chlorine in the hot high-pressure oil. The gas-phase outlet of the hot high-pressure separator is connected to the cold high-pressure separator, and the oil-phase outlet is communicated to the stripping column.

9. The waste mineral oil hydrotreating system according to claim 7 or 8, wherein The high-pressure separation unit further includes an acidic water stripping column. The acidic water outlet pipes connected to the cold high-pressure separator and the stripping column are both connected to the acidic water stripping column. The top of the acidic water stripping column is communicated with an acidic water outlet pipe, and the bottom is communicated with a purified water outlet pipe.

10. The waste mineral oil hydrotreating system according to claim 9, wherein The purified water outlet pipe of the acidic water stripping column is connected back to the water washing section of the cold high-pressure separator; and / or, the middle of the acidic water stripping column is communicated with an ammonia water circulation pipeline, and the ammonia water circulation pipeline is communicated with the alkali injection port.

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