A short-process pretreatment device and process for waste bio-oil

Abstract

The invention discloses a short-process pretreatment device and process for waste bio-oil, comprising a heat exchanger, an emulsifier, an integrated dehydration and impurity removal device, a metal deep remover and an acid-water deep adsorption separator which are sequentially connected according to the flow direction of the waste bio-oil. In the device and process of the invention, after the waste bio-oil is heated and emulsified, it is deeply impurity-removed and dehydrated by the integrated dehydration and impurity removal device, then enters the metal deep remover, is acid-washed and deeply dechlorinated and demetallized, and finally the water and acid in the waste bio-oil are deeply removed by the acid-water deep adsorption separator; the purpose of desuspending, dehydrating, and deeply treating the metal and chloride salt content of the waste bio-oil is achieved, and rapid pretreatment of the waste bio-oil can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of waste bio-oil separation, and in particular relates to a short-process pretreatment device and process for waste bio-oil. Background Art

[0002] Waste bio-oil (including but not limited to waste animal and vegetable oils and waste cooking oil) is a recyclable resource. After chemical and physical transformation, it can be turned into treasure, generating considerable economic and social benefits. After pretreatment, hydrogenation and fractionation, it is finally made into bio-jet fuel. Using waste bio-oil as raw material to produce bio-jet fuel is not only cheap and easy to obtain, but also very effective in the comprehensive treatment of waste bio-oil, and the economic benefits are also very considerable.

[0003] The main components of waste bio-oil are waste cooking oil and animal fat, etc. It has a high viscosity at room temperature and good fluidity after being heated to 80-90°C. However, waste bio-oil itself often contains gray-white greasy floating objects and animal and plant food residues of different shapes, and waste bio-oil may come from urban sewers, restaurant swill, waste grease from food processing companies, etc. These sources make the waste oil mixed with a large amount of sewage, garbage, detergents and other pollutants. In particular, since waste bio-oil may contain a large amount of detergent, water exists in the waste bio-oil in the form of being coated by surfactants, and it is extremely difficult to separate it using traditional methods such as gravity sedimentation. Therefore, the types of solid suspended matter in waste oil are complex, the particle size distribution is uneven, the concentration is high, and most of them are long strips, granular spheres, and particles that are difficult to distinguish with the naked eye. It is difficult to use separation membranes or bag filters to separate the impurities therein.

[0004] Due to the addition of chemical additives in the food processing industry and various condiments in the catering industry, waste bio-oil often contains a large amount of water-soluble heavy metals and chloride salts, which leads to problems such as catalyst poisoning and deactivation in the subsequent processing of bio-jet fuel, and ultimately results in short operating cycles, substandard product quality, high energy consumption, and even the inability to obtain products, which greatly restricts the comprehensive utilization of waste oil. However, the existing technology usually directly injects a certain amount of hot water into the oil storage tank and applies mechanical stirring to enhance the mixing of the oil and water phases. The mixed oil and water phases are directly separated by centrifugal separation, which has high noise and power consumption, and is difficult to maintain. At the same time, the oil-water separation effect is poor, and the waste bio-oil will carry water, and additional drying (vacuum dryer) treatment is required, which is cumbersome to operate and has high energy consumption.

[0005] In view of the above technical difficulties, some solutions have been found in existing technologies:

[0006] CN113088401A discloses a waste oil pretreatment system, a waste oil storage tank, a heating and stirring tank, an oil-water mixer, an ultrasonic demulsification tank, an oil-water separation device and a desulfurization tower, wherein the outlet of the waste oil storage tank is connected to the inlet of the heating and stirring tank through a pipeline; a hot water inlet is provided at the top of the oil-water mixer, the hot water inlet is connected to a hot water pipe, and the outlet of the heating and stirring tank is connected to the inlet of the oil-water mixer through a pipeline; the outlet of the oil-water mixer is connected to the inlet of the ultrasonic demulsification tank through a pipeline; an oil discharge port is provided at the top of the oil-water separation device, and the outlet of the ultrasonic demulsification tank is connected to the inlet of the oil-water separation device through a pipeline. The invention has a simple structure, stable operation and convenient maintenance; however, the pretreatment system has the following defects: (1) the industrial application of ultrasonic demulsification requires high investment and requires frequent maintenance, resulting in high maintenance costs; (2) the process treatment effect is not good, and the pretreatment requirements may not be met by only one-way cyclone mixing + ultrasonic demulsification + coalescence oil-water separation, and additional series processing units will further increase the investment cost and energy consumption. Summary of the invention

[0007] The purpose of the present invention is to address the problem that the current waste bio-oil pretreatment process is too long and the treatment effect is poor, and to propose a waste bio-oil short-process pretreatment device and process.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] The first aspect of the present invention is to provide a short-process pretreatment device for waste bio-oil, comprising a heat exchanger, an emulsifier, an integrated dehydration and impurity removal device, a metal deep remover and an acid water deep adsorption separator connected in sequence according to the flow direction of the waste bio-oil, wherein:

[0010] The integrated dehydration and impurity removal equipment is used for deep filtration and dehydration, and comprises a vertical tank body, an inner cylinder located inside the vertical tank body, and an annular outer cylinder formed between the vertical tank body and the inner cylinder; the inner cylinder and the annular outer cylinder are filled with different coalescing media in sequence to achieve rapid classification of floating and suspended impurities;

[0011] The metal deep remover is used for deep dechlorination and metal removal by pickling, and comprises a horizontal tank body, an acid injection and mixing enhanced washing module, an acid droplet internal circulation deep extraction module and a fiber coagulation acid-water separation module sequentially arranged inside the horizontal tank body;

[0012] The acid injection and mixing enhanced washing module is used to inject fine acid droplets into the waste bio-oil and enhance the turbulent mixing between the acid droplets and the oil phase;

[0013] The acid droplet internal circulation deep extraction module is a Venturi structure with a built-in hydrophilic and oleophobic fiber module; the fiber coagulation acid-water separation module is composed of a hydrophilic and oleophobic fiber module;

[0014] The acid-water deep adsorption separator is used for deeply removing water and acid from waste bio-oil, and comprises a tank body and an acid-water deep adsorption module arranged inside the tank body.

[0015] The present invention is further configured such that the emulsifier is an ultrasonic emulsifier or a jet emulsifier.

[0016] The present invention is further configured such that the vertical tank body is provided with a top cavity and a bottom cavity on the upper and lower sides of the inner cylinder and the annular outer cylinder, respectively; the top of the vertical tank body is also provided with a waste bio-oil inlet and an oil phase outlet connected to the top cavity; the bottom of the vertical tank body is also provided with a water collection bag connected to the bottom cavity;

[0017] The top of the inner cylinder is connected to the waste bio-oil inlet through a pipeline, and a first axial rectification module, a ceramic particle layer module and a first water distribution cap are sequentially arranged inside the inner cylinder from top to bottom;

[0018] The top of the annular outer cylinder is connected to the oil phase outlet, and a second axial rectifying module, a hydrophilic and hydrophobic fiber ball module, and a second water distribution cap are sequentially arranged inside the annular outer cylinder from bottom to top;

[0019] The present invention is further configured such that the ceramic particle layer module is formed by stacking hydrophilic agglomeration materials, wherein the hydrophilic agglomeration materials include ceramic particles and one or more hydrophilic fillers such as glass microbeads, PP and PTFE;

[0020] The volume proportion of the ceramic particles in the ceramic particle layer module is 85-95%;

[0021] The particle size of the ceramic particles is 0.5-1 mm;

[0022] The ratio of the thickness of the ceramic particle layer module to the total height of the inner tube is 0.4-0.5;

[0023] The hydrophilic and hydrophobic fiber ball module is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls;

[0024] The interior of the hollow hydrophilic and hydrophobic fiber ball is a hollow spherical structure, and the exterior is a light fiber mass composed of a plurality of hydrophilic fibers and hydrophobic fibers;

[0025] The diameter of the hollow hydrophilic and hydrophobic fiber ball is 30-40 μm; the diameter ratio of the hollow spherical structure to the hollow hydrophilic and hydrophobic fiber ball is 0.1-0.2; the gap between the fibers in the light fiber group is 50-100 μm;

[0026] Preferably, the ratio of the thickness of the hydrophilic and hydrophobic fiber ball module to the total height of the annular outer cylinder is 0.3-0.4, and the module is located at the bottom of the annular outer cylinder;

[0027] The lightweight fiber mass is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3-8:2;

[0028] The material of the hydrophobic fiber is selected from one or both of polypropylene and polytetrafluoroethylene;

[0029] The hydrophilic fiber is a super-hydrophilic fiber obtained by hydrophilizing polypropylene fiber or polytetrafluoroethylene fiber, or cotton fiber;

[0030] The hydrophilization treatment adopts chemical grafting method, surface coating method or plasma treatment.

[0031] The present invention is further configured that a feed pipe, an oil discharge port and a water bag are provided on the horizontal tank body of the metal deep remover;

[0032] The acid injection and mixing enhanced washing module comprises a micro-acid droplet generator and a liquid distributor connected to the feed pipe in sequence, and a plurality of washing core tubes connected to the tail end of the liquid distributor; the micro-acid droplet generator is used to generate micro-acid droplets, and the washing core tube is used to enhance the turbulent mixing between the acid droplets and the waste bio-oil;

[0033] The particle size of the fine acid droplets generated by the micro-acid droplet generator is 30-200 μm, and the number of the micro-acid droplet generators is 4-6;

[0034] The acid droplet internal circulation deep extraction module comprises a fluid speed-up section with a gradually decreasing cross-sectional area, an internal circulation extraction section with a constant cross-sectional diameter, and a buffer section with a gradually increasing cross-sectional area, which are connected in sequence. The internal circulation extraction section is composed of a hydrophilic and oleophobic fiber module.

[0035] The fiber coagulation acid-water separation module is composed of a hydrophilic and oleophobic fiber module.

[0036] The present invention is further configured that the washing core tube includes a spinning section and a voltage transformation section, wherein:

[0037] The front end of the rotating section is connected to the rear end of the liquid distributor; the rotating section includes a cylinder, a support rod located at the axis of the cylinder, and a spiral blade arranged around the support rod, and the spiral blade includes a right-handed blade and a left-handed blade connected from bottom to top;

[0038] The helical angle α of the helical blade is 35-45°.

[0039] The present invention is further configured such that the transformer section includes a swirl buffer zone, a transformer oscillation zone and a transformer buffer zone which are connected in sequence, the transformer oscillation zone is a Venturi structure whose cross-sectional area changes continuously from gradually contracting, equal diameter to gradually expanding, and the swirl buffer zone of the transformer section is connected to the tail end of the swirl section;

[0040] The length ratio of the rotation section to the transformer section is 3:2-1:1, and the area ratio of the maximum cross section to the minimum cross section of the transformer section is 3:1-2:1.

[0041] The present invention is further configured such that the hydrophilic and oleophobic fiber modules in the internal circulation extraction section and the fiber coagulation and acid-water separation module are both acid-resistant and corrosion-resistant fiber modules, and the fiber modules are built with multiple groups of parallel-arranged hydrophilic and oleophobic fibers;

[0042] The hydrophilic and oleophobic fiber modules are woven in an X-shaped manner, with a porosity of 0.7-0.8 and a fiber diameter of 100-200 μm;

[0043] The hydrophilic and oleophobic fiber module is made of polyethyleneimine and fluorine-containing materials;

[0044] The cross-sectional area ratio of the hydrophilic and oleophobic fiber modules of the acid droplet internal circulation deep extraction module and the fiber coagulation acid-water separation module is 0.7-0.8;

[0045] The cross-sectional area of ​​the internal circulation extraction section in the acid drop internal circulation deep extraction module is 0.7-0.8 times the cross-sectional area of ​​the horizontal tank body;

[0046] The ratio of the overall length of the fiber coagulation acid-water separation module to the overall length of the acid droplet internal circulation deep extraction module is 1:1-2:3.

[0047] The present invention is further configured that the tank body of the acid water deep adsorption separator is also provided with an oil inlet, an oil outlet, a backwash gas inlet, a backwash gas outlet, and a liquid distributor and a hot steam purge module respectively arranged on the upper and lower sides of the acid water deep adsorption module; the backwash gas inlet is connected to the hot steam purge module;

[0048] The acid water deep adsorption module is formed by stacking deeply dehydrated and deacidified adsorption particles, and is used to separate acid and water;

[0049] The adsorption particles are activated carbon, molecular sieve or metal organic framework compound, preferably 5A type molecular sieve.

[0050] The second aspect of the present invention is to provide a short-process pretreatment process for waste bio-oil based on the above-mentioned equipment, comprising the following steps:

[0051] (I) Heat exchange:

[0052] Heating waste bio-oil to reduce the viscosity of the oil and improve its fluidity;

[0053] (II) Emulsification:

[0054] The heated waste bio-oil enters the emulsifier, so that the oil phase and the water phase in the waste bio-oil are fully mixed to form an emulsion;

[0055] (III) Deep filtration and dehydration:

[0056] The emulsified waste bio-oil enters the integrated dehydration and impurity removal equipment for deep filtration and dehydration. The coalescing medium is sequentially filled into the inner cylinder and the annular outer cylinder in a W-shaped series, which step-by-step strengthens the coalescence and separation of fine water droplets and step-by-step strengthens the capture and interception of suspended impurities in the waste bio-oil.

[0057] (IV) Acid washing for deep dechlorination and demetallization:

[0058] In the metal deep remover, fine acid droplets are injected into the waste bio-oil treated in the above step (III) through the acid injection and mixing enhanced washing module, and the turbulent mixing between the acid droplets and the oil phase is enhanced; the acidic environment is used to destroy the binding effect between the metal ions, chloride ions and oil molecules in the waste bio-oil; the fine acid droplets are then captured by the hydrophilic and oleophobic fiber module in the Venturi-type acid droplet internal circulation deep extraction module, and the metal ions and chloride ions are enriched by the internal circulation self-rotation function of the fine acid droplets in the shear flow field, and then the fine acid droplets enriched with metal ions and chloride ions are separated from the oil phase through the fiber coagulation acid-water separation module;

[0059] (V) Deep adsorption separation of acid water:

[0060] The water and acid in the waste bio-oil treated in the above step (IV) are deeply adsorbed and removed by the acid-water deep adsorption module in the acid-water deep adsorption separator.

[0061] The present invention is further configured that, in the step (I), the heating temperature is controlled in real time according to the viscosity of the waste bio-oil, the viscosity of the waste bio-oil is controlled to be less than 20 mPa·s, and the heating temperature is controlled to be 80-90°C;

[0062] Before the emulsification in step (II), adaptive water injection is performed according to the water content in the waste bio-oil:

[0063] If the water content of the original waste bio-oil is less than 1wt%, the amount of water injected is 3% of the volume of the waste bio-oil;

[0064] If the water content of the original waste bio-oil is higher than 3wt%, emulsification can be performed directly without water injection;

[0065] In the step (IV), the ratio of acid injection in the waste bio-oil is determined according to the metal content in the imported waste bio-oil, specifically as follows:

[0066] (a) If the total metal content of the imported waste bio-oil is within 100 ppm, the amount of acid injection shall be within 5% of the total volume of the waste bio-oil;

[0067] (b) If the total metal content of the imported waste bio-oil is between 100-500 ppm, the acid injection volume shall be 6-8% of the total volume of the waste bio-oil;

[0068] (c) If the total metal content of the imported waste bio-oil is between 500-1000 ppm, the acid injection volume shall be 8-10% of the total volume of the waste bio-oil;

[0069] In the step (IV), the fine acid droplets are organic acids, including oxalic acid or citric acid; the concentration of the organic acid is 0.5-1wt%.

[0070] The beneficial effects of the present invention are as follows:

[0071] The equipment and process of the present invention achieve the purpose of removing suspended solids, dehydrating, and deeply treating the metal and chloride salt content of waste bio-oil, and can realize rapid pretreatment of waste bio-oil. Compared with the existing treatment methods at home and abroad of repeatedly adding acid, alkali, and water for stirring and separation, and adopting a dehydration pretreatment and a hydrogenation demetallization process, the consumption of detergents (acid, alkali, and water) is small, the amount of waste liquid generated is small, and the method has the advantages of stable operation, high elution efficiency, and wide adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic diagram of the process of the short-process pretreatment equipment for waste bio-oil of the present invention.

[0073] Figure 2 It is a schematic diagram of the overall structure of the integrated equipment for dehydration and impurity removal of waste bio-oil according to the present invention.

[0074] Figure 3 It is a schematic structural diagram of the metal deep remover of the present invention.

[0075] Figure 4 It is a schematic structural diagram of the acid water deep adsorption separator of the present invention.

[0076] Figure 5 It is a specific structural schematic diagram of the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention.

[0077] Figure 6 It is the schematic diagram of the dehydration and impurity removal of the ceramic particle layer module.

[0078] Figure 7 It is a schematic diagram of the structure of the hollow hydrophilic-hydrophobic fiber ball of the hydrophilic-hydrophobic fiber ball module.

[0079] Figure 8 yes Figure 2 Cross-sectional view along the AA direction.

[0080] Fig. 9It is a schematic diagram of the dehydration and impurity removal route of the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention.

[0081] Fig.10 This is the schematic diagram of the dehydration and impurity removal of the hydrophilic and hydrophobic fiber ball module.

[0082] Fig.11 It is a schematic diagram of the backwash route of the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention.

[0083] Fig.12 It is a connection diagram of the micro-acid droplet generator, the liquid distributor and the washing core tube.

[0084] Fig.13 It is a structural schematic diagram of the washing core tube.

[0085] Fig.14 It is a schematic diagram of the structure of a spiral blade.

[0086] Fig.15 It is a structural diagram of a transformer type structure.

[0087] Fig.16 It is a schematic diagram of the flow process of metal salt and organic acid after the flow rate is increased when the acid droplets adhere to the fiber.

[0088] Fig.17 This is the schematic diagram of the internal circulation of acid drops.

[0089] In the figure:

[0090] 1-heat exchanger; 2-emulsifier; 3-dehydration and impurity removal integrated equipment; 4-metal deep remover; 5-acid water deep adsorption separator;

[0091] 31-vertical tank body; 311-top cavity; 312-bottom cavity; 313-waste bio-oil inlet; 314-oil phase outlet; 315-water collection bag;

[0092] 32-inner cylinder; 321-first axial rectifying module; 322-ceramic particle layer module; 323-first water distribution cap;

[0093] 33-annular outer cylinder; 331-second axial rectifying module; 332-hydrophilic and hydrophobic fiber ball module; 333-second water distribution cap; 334-hollow hydrophilic and hydrophobic fiber ball; 335-hollow ball structure; 336-light fiber group; 337-partition;

[0094] 34-automatic cleaning system; 341-backwash water inlet; 342-nitrogen purge inlet; 343-inner cylinder backwash water outlet; 344-annular outer cylinder backwash water outlet; 345-exhaust port; 346-nitrogen purge device; 347-differential pressure gauge.

[0095] 41-horizontal tank; 411-feed pipe; 412-oil outlet; 413-water bag;

[0096] 42-acid injection and mixing enhanced washing module; 421-micro-acid droplet generator; 422-liquid distributor; 4221-main pipe; 4222-distribution pipe; 423-washing core pipe; 4231-spinning section; 4232-voltage conversion section; 4233-cylinder; 4234-support rod; 4235-spiral blade; 4236-spinning buffer zone; 4237-voltage conversion oscillation zone; 4238-voltage conversion buffer zone;

[0097] 43-acid drop internal circulation deep extraction module; 431-fluid speed-up section; 432-internal circulation extraction section; 433-buffer section;

[0098] 44-fiber coagulation acid water separation module;

[0099] 45-rectifier plate;

[0100] 51-tank body; 511-oil inlet; 512-oil outlet; 513-backwash gas inlet; 514-backwash gas outlet; 52-acid water deep adsorption module; 53-liquid distributor; 54-hot steam purge module;

[0101] Figure 2-5 and Fig. 9 The arrow direction in the figure indicates the flow direction of the waste bio-oil. Fig.11 The arrow direction indicates the flow direction of nitrogen and backwash water. DETAILED DESCRIPTION

[0102] The technical solution of the present invention is clearly and completely described below by specific embodiments in conjunction with the accompanying drawings. It should be understood that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of the present invention.

[0103] The determination of water content, suspended matter content, total metal content and chlorine content in the waste bio-oil in the following examples refers to the following standards:

[0104] Determination of water content: GB / T 11133-2015 Determination of water content in petroleum products, lubricants and additives Karl Fischer coulometric titration method.

[0105] Determination of suspended matter content: GB / T 15688-2008 Determination of insoluble impurities content in animal and vegetable fats and oils.

[0106] Determination of total metal content: GB / T 17476-2023 Determination of multiple elements in lubricating oils and base oils Inductively coupled plasma optical emission spectrometry.

[0107] Determination of chlorine content: GB / T 40111-2021 Determination of fluorine, chlorine and sulfur content in petroleum products Combustion-ion chromatography method.

[0108] Example 1

[0109] like Figure 1 The waste bio-oil short-process pretreatment equipment shown comprises a heat exchanger 1, an emulsifier 2, a dehydration and impurity removal integrated equipment 3, a metal deep remover 4 and an acid water deep adsorption separator 5 which are sequentially connected according to the flow direction of the waste bio-oil, wherein:

[0110] The heat exchanger 1 is used to heat the waste bio-oil to reduce the viscosity of the oil and improve the fluidity of the oil.

[0111] The emulsifier 2 is used to fully mix the oil phase and the water phase in the waste bio-oil to form an emulsion, destroy the coating structure of the surfactant, and utilize the water in the waste bio-oil to emulsify and elute the metal;

[0112] Combination Figure 2 As shown, the integrated dehydration and impurity removal equipment 3 is used for deep impurity removal and dehydration, and includes a vertical tank body 31, an inner cylinder 32 located inside the vertical tank body 31, and an annular outer cylinder 33 formed between the vertical tank body 31 and the inner cylinder 32; the inner cylinder 32 and the annular outer cylinder 33 are filled with different agglomeration media in sequence to achieve rapid classification of floating and suspended impurities; some metals in the waste bio-oil exist in the form of hydrated metal salts, which also play an effect of preliminarily reducing the metal content in the waste bio-oil after dehydration;

[0113] Combination Figure 3 As shown, the metal deep remover 4 is used for deep dechlorination and metal removal by pickling based on internal circulation of acid droplets, and comprises a horizontal tank body 41, an acid injection and mixing enhanced washing module 42, an acid droplet internal circulation deep extraction module 43 and a fiber coagulation acid-water separation module 44 sequentially arranged inside the horizontal tank body 41;

[0114] The acid injection and mixing enhanced washing module 42 is used to inject fine acid droplets into the waste bio-oil and enhance the turbulent mixing between the acid droplets and the oil phase;

[0115] The acid droplet internal circulation deep extraction module 43 is a venturi structure with a built-in hydrophilic and oleophobic fiber module; the fiber coagulation acid-water separation module 44 is composed of a hydrophilic and oleophobic fiber module;

[0116] Combination Figure 4As shown, the acid-water deep adsorption separator 5 is used to deeply remove water and acid from waste bio-oil, and comprises a tank body 51 and an acid-water deep adsorption module 52 arranged inside the tank body 51 .

[0117] In the present invention, the emulsifier 2 is an ultrasonic emulsifier or a jet emulsifier. In the emulsifier 2, the oil phase in the waste bio-oil is fully in contact with the water phase, so that part of the metals and chloride salts in the oil are transferred to the water phase; at the same time, under the action of ultrasonic energy or shear cavitation, the coating structure caused by residual detergents and other surfactants in the oil phase is destroyed.

[0118] The ultrasonic emulsifier has a power of 3000-6000 kW, a frequency of 20-25 kHz, and a processing capacity of 0.3-0.6 m³ / h.

[0119] like Figure 2 and Figure 5 As shown, the vertical tank body 31 is provided with a top cavity 311 and a bottom cavity 312 on the upper and lower sides of the inner cylinder 32 and the annular outer cylinder 33, respectively. The top of the vertical tank body 31 is also provided with a waste bio-oil inlet 313 and an oil phase outlet 314 communicating with the top cavity 311, and the bottom is also provided with a water collection bag 315 communicating with the bottom cavity 312;

[0120] The top of the inner cylinder 32 is connected to the waste bio-oil inlet 313 through a pipeline, and a first axial rectifying module 321, a ceramic particle layer module 322 and a first water distribution cap 323 are sequentially arranged inside the inner cylinder 32 from top to bottom; the ceramic particle layer module 322 is used to intercept larger particles and long strips of suspended matter in the waste bio-oil to achieve rapid aggregation and dehydration;

[0121] The top of the annular outer cylinder 33 is connected to the oil phase outlet 314, and a second axial rectifying module 331, a hydrophilic and hydrophobic fiber ball module 332 and a second water distribution cap 333 are sequentially arranged inside the annular outer cylinder 33 from bottom to top; the hydrophilic and hydrophobic fiber ball module 332 is used to capture and separate fine and fibrous suspended matter in the waste bio-oil to achieve deep aggregation and dehydration.

[0122] In the present invention, the ceramic particle layer module 322 is formed by stacking hydrophilic agglomerating materials, and the hydrophilic agglomerating materials include ceramic particles and one or more hydrophilic fillers such as glass microspheres, PP and PTFE.

[0123] The volume proportion of the ceramic particles in the ceramic particle layer module 322 is 85-95%. The ceramic particles have the advantages of high efficiency filtration, strong chemical stability, strong anti-fouling ability and long life, and can cope with the complex and changeable characteristics of impurity morphology and composition in the waste bio-oil during the filtration process.

[0124] The particle size of the ceramic particles is 0.5-1 mm. Within this particle size range, the ceramic particle layer module 322 will not produce a large pressure drop while maintaining excellent performance in dehydration and impurity removal, which is conducive to backwashing.

[0125] Preferably, the ratio of the thickness of the ceramic particle layer module 322 to the total height of the inner tube 32 is 0.4-0.5.

[0126] After the waste bio-oil enters the inner cylinder 32 from the waste bio-oil inlet 313, it first passes through the first axial rectifying module 321 to adjust the cross-sectional flow rate entering the ceramic particle layer module 322 to ensure the impurity removal effect; Figure 6 As shown, most of the suspended matter carried in the waste bio-oil floats on the upper part of the ceramic particle layer module 322, and the granular and long strip-shaped suspended matter with slightly larger particle size is intercepted by the ceramic particle layer module 322 during the flow, thereby achieving separation; the water droplets in the waste bio-oil adhere to the hydrophilic agglomeration material, and agglomerate and grow into large water droplets, as the waste bio-oil evenly enters the bottom cavity 312 of the vertical tank body 31 through the first water distribution cap 323, and finally settles to the water collection bag 315 for separation. The first water distribution cap 323 plays a certain buffering role.

[0127] The cross-sectional flow rate of the waste bio-oil entering the ceramic particle layer module 322 of the inner cylinder 32 is controlled at 0.003-0.005 m / s.

[0128] In the present invention, combined with Figure 7 As shown, the hydrophilic and hydrophobic fiber ball module 332 is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls 334, which are used to adhere to the tiny water droplets in the waste bio-oil, aggregate and grow them, capture and intercept the tiny suspended matter, and finally achieve deep dehydration and impurity removal of the waste bio-oil.

[0129] In the present invention, the interior of the hollow hydrophilic and hydrophobic fiber ball 334 is a hollow ball structure 335, and the exterior thereof is a light fiber group 336 composed of a plurality of hydrophilic fibers and hydrophobic fibers;

[0130] Preferably, the diameter of the hollow hydrophilic and hydrophobic fiber ball 334 is 30-40 mm; the diameter ratio of the hollow spherical structure 335 to the hollow hydrophilic and hydrophobic fiber ball 334 is 0.1-0.2; and the gap between the fibers in the light fiber group 336 is 50-100 μm.

[0131] Preferably, the ratio of the thickness of the hydrophilic and hydrophobic fiber ball module 332 to the total height of the annular outer cylinder 33 is 0.3-0.4, and the module is located at the bottom of the annular outer cylinder 33;

[0132] The lightweight fiber group 336 is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3-8:2;

[0133] The material of the hydrophobic fiber is selected from one or both of polypropylene and polytetrafluoroethylene;

[0134] The hydrophilic fiber is a super-hydrophilic fiber obtained by hydrophilizing polypropylene fiber or polytetrafluoroethylene fiber, or cotton fiber;

[0135] The hydrophilization treatment may be carried out by conventional chemical grafting, surface coating or plasma treatment, for example, coating a layer of hydrophilic material such as polyvinyl alcohol (PVA), polyacrylic acid (PAA) etc. on the surface of hydrophobic fibers such as polypropylene fibers.

[0136] In the present invention, Figure 8 As shown, a plurality of partitions 337 are evenly arranged in the annular outer cylinder 33 to prevent the hollow hydrophilic and hydrophobic fiber balls 334 from making irregular movements around and to compress the hollow hydrophilic and hydrophobic fiber balls 334 to ensure the impurity removal effect. The number of the partitions 337 is preferably 2-4.

[0137] The second water distribution cap 333 is used to evenly discharge the waste bio-oil after deep dehydration and impurity removal, and at the same time plays a role in fixing and blocking the hollow hydrophilic and hydrophobic fiber balls 334 with a relatively small density.

[0138] like Fig. 9 As shown, after the full tank operation, after preliminary dehydration and impurity removal by the inner cylinder 32, the waste bio-oil carrying fine water droplets and fine suspended matter enters the annular outer cylinder 33 from the bottom cavity 312, and after the flow rate is adjusted by the second axial rectifying module 331, the hollow hydrophilic and hydrophobic fiber balls 334 in the hydrophilic and hydrophobic fiber ball module 332 are driven to move upward. When passing through the second water distribution cap 333, the hollow hydrophilic and hydrophobic fiber balls 334 are blocked by it and stay on the top of the annular outer cylinder 33, so that the hollow hydrophilic and hydrophobic fiber balls 334 are further fully contacted with the waste bio-oil, thereby achieving the purpose of rapid dehydration and suspension removal.

[0139] The cross-sectional flow rate of the waste bio-oil entering the hydrophilic and hydrophobic fiber ball module 332 of the annular outer cylinder 33 is controlled at 0.001-0.003 m / s.

[0140] like Fig.10As shown, in the hydrophilic and hydrophobic fiber ball module 332, the suspended impurities and water droplets in the waste bio-oil are fully in contact with the hollow hydrophilic and hydrophobic fiber ball 334. Due to the special structural characteristics of the light fiber component in the hollow hydrophilic and hydrophobic fiber ball 334, the fine water droplets in the waste bio-oil are captured and adhered by the fiber, and the fine water droplets flowing later are aggregated and grown into larger particles of water droplets, and finally separated from the hollow hydrophilic and hydrophobic fiber ball 334 and settled in the bottom cavity 312, so as to achieve the removal of fine water droplets. There are certain gaps between the fibers on the hollow hydrophilic and hydrophobic fiber ball 334, and fine suspended matter can easily enter therein, thereby achieving the deep capture and removal of suspended matter. The waste bio-oil after deep dehydration and impurity removal enters the top cavity 311 of the vertical tank body 31, and then is discharged from the oil phase outlet 314.

[0141] In the inner cylinder 32, most of the suspended matter carried by the waste bio-oil floats on the upper part of the ceramic particle layer module 322. After the equipment has been running for a long time, a large amount of suspended impurities gather on the top of the ceramic particle layer module 322, forming a thicker filter cake layer, which prevents the oil phase from passing smoothly, and the pressure difference gradually increases, eventually causing the equipment to stop. At the same time, the hollow hydrophilic and hydrophobic fiber balls 334 in the annular outer cylinder 33 have a strong interception effect on suspended matter due to their material structure characteristics, but when a large amount of suspended impurities gather on the surface and inside of the hollow hydrophilic and hydrophobic fiber balls 334, their performance will be seriously affected. Therefore, it is necessary to timely perform high-quality backwashing on the inner cylinder 32 and the annular outer cylinder 33 of the equipment.

[0142] Therefore, if Figure 2 and Fig.11 As shown, in the present invention, the equipment is also provided with an automatic cleaning system 34 controlled by a PLC, and the automatic cleaning system 34 includes a backwash water inlet 341 and a nitrogen purge inlet 342 arranged at the bottom of the vertical tank body 31, an inner cylinder backwash water outlet 343, an annular outer cylinder backwash water outlet 344, and an exhaust port 345 arranged at the top of the vertical tank body 31, a nitrogen purge device 346 arranged in the bottom cavity 312 of the vertical tank body 31, a differential pressure gauge 347 for measuring the inlet and outlet pressure difference of the ceramic particle layer module 322, a concentration detection device (not shown in the figure) for measuring the concentration of suspended matter in the imported waste bio-oil, and a PLC control system;

[0143] The nitrogen purge inlet 342 is connected to the nitrogen purge device 346 , and the inner cylinder backwash water outlet 343 and the annular outer cylinder backwash water outlet 344 are respectively connected to the top of the inner cylinder 32 and the top cavity 311 of the vertical tank body 31 .

[0144] Since the agglomerated material in the inner tube 32 is mainly ceramic particles, large suspended particles from the waste bio-oil are easily concentrated in the upper part of the ceramic particle layer module 322, and the backwashing frequency is higher; compared with the ceramic particle layer module 322, the suspended impurities on the surface of the hollow hydrophilic and hydrophobic fiber balls 334 will only affect its dehydration and impurity removal performance after a long period of operation, and the backwashing frequency is lower.

[0145] Therefore, the backwash frequency of the equipment is controlled by pressure difference, that is, the backwash frequency is controlled according to the inlet and outlet pressure difference of the ceramic particle layer module 322. The backwash start pressure difference is 0.8-1MPa. When the measured pressure difference is greater than the start pressure difference, the backwash is started. The backwash time is determined according to the concentration of suspended matter in the imported waste bio-oil, as follows:

[0146] (a) When the suspended solids concentration of the imported waste bio-oil is less than 0.1wt%, the backwash time is 40-60s;

[0147] (b) When the suspended solids concentration of the imported waste bio-oil is 0.1-0.5wt%, the backwash time is 60-80s;

[0148] (c) When the suspended solids concentration of the imported waste bio-oil is higher than 0.5 wt%, the backwash time is 80–150 s.

[0149] The backwash water inlet 341, the nitrogen purge inlet 342, the inner tube backwash water outlet 343, the annular outer tube backwash water outlet 344 and the exhaust port 345 are respectively provided with valves (not shown in the figure). The PLC control system is respectively connected to the differential pressure gauge 347, the concentration detection device and the valve. The PLC control system controls the opening of the valve according to the pressure difference measured by the differential pressure gauge 347 to perform backwashing, determines the backwashing time according to the suspended matter concentration measured by the concentration detection device, controls the closing of the valve, and thus realizes fully automatic backwashing.

[0150] When the equipment is backwashed, backwash water and nitrogen enter the vertical tank body 31 at the same time, blow off the suspended impurities on the top of the ceramic particle layer module 322 and the large amount of suspended matter carried on the hollow hydrophilic and hydrophobic fiber balls 334, carry and separate them, and then discharge the backwash water and nitrogen outside the vertical tank body 31 through the inner tube backwash water outlet 343, the annular outer tube backwash water outlet 344 and the exhaust port 345.

[0151] In the present invention, in actual application, two to three waste bio-oil dehydration and impurity removal integrated devices are usually used to operate in parallel and intermittently backwash. When one of them is performing dehydration and impurity removal treatment on the waste bio-oil, another one or more devices are performing backwashing.

[0152] The water collecting bag 315 is also provided with a liquid level meter (not shown in the figure), and the operating status of the equipment can be judged by the height of the water phase in the liquid level meter.

[0153] In the present invention, the ratio of the diameter of the inner cylinder 32 to the outer diameter of the annular outer cylinder 33 is determined by the water content and the suspended matter concentration of the imported waste bio-oil, and the water content and the suspended matter concentration are both measured in mass fractions, specifically as follows:

[0154] (a) When the water content of the imported waste bio-oil is less than 1wt% and the suspended matter concentration is less than 1wt%, the ratio of the diameter of the inner cylinder 32 to the outer diameter of the annular outer cylinder 33 is 0.5-0.6;

[0155] (b) when the water content of the imported waste bio-oil is 1-3 wt % and the suspended matter concentration is 1-5 wt %, the ratio of the diameter of the inner cylinder 32 to the outer diameter of the annular outer cylinder 33 is 0.6-0.7;

[0156] (c) When the water content of the imported waste bio-oil is 3-5 wt% and the suspended matter concentration is greater than 5 wt%, the ratio of the diameter of the inner cylinder 32 to the outer diameter of the annular outer cylinder 33 is 0.7-0.8.

[0157] In the present invention, Figure 3 As shown, the horizontal tank body 41 in the metal deep remover 4 is provided with a feed pipe 411, an oil discharge port 412 and a water bag 413;

[0158] Waste bio-oil enters the tank through the feed pipe 411, and after deep dechlorination and demetallization, it is discharged from the horizontal tank body 41 through the oil discharge port 412 and enters the downstream treatment.

[0159] Combination Fig.12 As shown, the acid injection and mixing enhanced washing module 42 includes a micro-acid droplet generator 421 and a liquid distributor 422 connected to the feed pipe 411 in sequence, and a plurality of washing core tubes 423 connected to the tail end of the liquid distributor 422;

[0160] The micro-acid droplet generator 421 is used to generate micro-acid droplets and evenly emulsify the acid droplets into the waste bio-oil to form acid-containing waste bio-oil. The liquid distributor 422 is used to evenly distribute the acid-containing waste bio-oil to each washing core tube 423. The washing core tube 423 is used to strengthen the turbulent mixing between the acid droplets and the waste bio-oil.

[0161] The particle size of the fine acid droplets generated by the micro-acid droplet generator 421 is 30-200 μm, and the number of the micro-acid droplet generators 421 is 4-6.

[0162] Back to Figure 3The acid droplet inner circulation deep extraction module 43 comprises a fluid speed-up section 431 with a gradually decreasing cross-sectional area, an inner circulation extraction section 432 with a constant cross-sectional diameter, and a buffer section 433 with a gradually increasing cross-sectional area, which are connected in sequence. The inner circulation extraction section 432 is composed of a hydrophilic and oleophobic fiber module, which facilitates the acid droplet to adhere to and stabilize on the hydrophilic and oleophobic fiber module;

[0163] The fluid speed-up section 431 is used to provide sufficient shear kinetic energy for the waste bio-oil; the buffer section 433 is used to reduce the flow rate, which is beneficial to the subsequent acid-water separation in the fiber coagulation acid-water separation module 44.

[0164] The fiber coagulation acid-water separation module 44 is composed of a hydrophilic and oleophobic fiber module, which is used to aggregate the fine acid droplets after washing and extracting chlorine and heavy metals into large acid droplets, which finally fall off the fibers and gather in the water bag 413 at the bottom of the horizontal tank body 41 for separation.

[0165] In this embodiment, Fig.12 As shown, the liquid distributor 422 includes a main pipe 4221 whose head end is connected to the feed pipe 411, and a plurality of distribution pipes 4222 connected to the tail end of the main pipe 4221, and the number of the distribution pipes 4222 is 4-6.

[0166] In this embodiment, Fig.13 As shown, the washing core tube 423 includes a rotation section 4231 and a voltage transformation section 4232, wherein:

[0167] Combination Fig.14 As shown, the front end of the rotating section 4231 is connected to the distribution pipe 4222 of the liquid distributor 422; the rotating section 4231 includes a cylinder 4233, a support rod 4234 located at the axis of the cylinder 4233, and a spiral blade 4235 arranged around the support rod 4234, the spiral blade 4235 includes a right-handed blade and a left-handed blade connected from front to back, which are used for rotating to enhance the mixing of acid droplets and oil phase, and the spiral angle α of the spiral blade 4235 is 35-45°.

[0168] The transformer section 4232 is used for breaking and shaking the acid droplets and the oil phase, strengthening the two-phase turbulent emulsification, and combining Fig.15 As shown, it includes a swirl buffer zone 4236, a voltage-changing oscillation zone 4237 and a voltage-changing buffer zone 4238 which are connected in sequence. The voltage-changing oscillation zone 4237 is a Venturi-type structure whose cross-sectional area changes continuously from gradually contracting, equal diameter to gradually expanding. The swirl buffer zone 4236 of the voltage-changing section 4232 is connected to the tail end of the swirl section 4231.

[0169] After the acid-containing waste bio-oil after vortex mixing from the vortex section 4231 enters the pressure transformation section 4232, it is first buffered in the vortex buffer zone 4236, and then pressure is generated in the pressure transformation oscillation zone 4237 due to the reduction of the cross-sectional area, thereby producing oscillation emulsification, and finally it is buffered in the pressure transformation buffer zone 4238 before entering the next module.

[0170] Preferably, the length ratio of the rotation section 4231 to the voltage transformation section 4232 is 3:2-1:1, and the area ratio of the maximum cross section to the minimum cross section of the voltage transformation section 4232 is 3:1-2:1.

[0171] Furthermore, the hydrophilic and oleophobic fiber module is an acid-resistant and corrosion-resistant fiber module, and the fiber module has multiple groups of parallel-arranged hydrophilic and oleophobic fibers built therein;

[0172] Preferably, the hydrophilic and oleophobic fiber modules are woven in an X-shaped manner, with a porosity of 0.7-0.8 and a fiber diameter of 100-200 μm.

[0173] Preferably, the hydrophilic and oleophobic fiber module is made by mixing polyethyleneimine and fluorine-containing material.

[0174] Preferably, the cross-sectional area ratio of the hydrophilic and oleophobic fiber modules of the acid droplet internal circulation deep extraction module 43 and the fiber coagulation and acid-water separation module 44 is 0.7-0.8.

[0175] Further, the cross-sectional area of ​​the internal circulation extraction section 432 in the acid drop internal circulation deep extraction module 43 is 0.7-0.8 times the cross-sectional area of ​​the horizontal tank body 41;

[0176] The ratio of the overall length of the fiber coagulation acid-water separation module 44 to the overall length of the acid droplet internal circulation deep extraction module 43 is 1:1-2:3.

[0177] like Fig.16 and Fig.17 As shown, the acid-containing waste bio-oil treated by the acid injection and mixed enhanced washing module 42 enters the acid droplet inner circulation deep extraction module 43, and enters the inner circulation extraction section 432 after the fluid speed-up section 431 initially increases the flow rate. The acid droplets in the acid-containing waste bio-oil are adsorbed by the hydrophilic and oleophobic fibers of the inner circulation extraction section 432. Under the action of the strong shear force of the external fluid (oil phase), a horseshoe-shaped symmetrical cross-flow zone is formed on both sides of the acid droplet, and an inner circulation flow occurs. The surface of the acid droplet captures chlorine and heavy metals until saturation. At the same time, the inner circulation accelerates the surface renewal of the acid droplet, thereby strengthening the convective mass transfer extraction of metal ions and chloride ions on the basis of diffusion mass transfer, and realizing the deep elution of heavy metals and chloride salts.

[0178] As time goes by, the acid droplets are intercepted by the hydrophilic oleophobic fibers, continuously aggregate and grow, and at the same time continuously capture new chlorine and heavy metals. Finally, under the action of gravity and external fluid impact, the acid droplets enriched with chlorine and heavy metals fall off the hydrophilic oleophobic fibers. Then, along with the waste bio-oil, they enter the fiber coagulation acid-water separation module 44, where the fine acid droplets are captured by the hydrophilic oleophobic fibers, gradually aggregate and grow into large acid droplets, and finally separate from the water bag 413 at the bottom of the device, and the purified waste bio-oil is sent to the downstream from the oil discharge port 412.

[0179] In the present invention, the device further comprises a flow stabilizing module (not marked in the figure), which comprises a rectifier plate 45 (see FIG. Figure 3 ), which is used to control the flow rate of the acid-containing waste bio-oil so that it can enter the acid droplet inner circulation deep extraction module 43 and the fiber coagulation acid-water separation module 44 more evenly to improve the separation effect.

[0180] The cross-sectional flow rate of the waste bio-oil when entering the acid droplet inner circulation deep extraction module 43 is controlled at 0.01-0.015 m / s; the cross-sectional flow rate of the waste bio-oil when entering the fiber coagulation acid-water separation module 44 is controlled at 0.003-0.005 m / s.

[0181] In the present invention, Figure 4 As shown, the tank body 51 of the acid water deep adsorption separator 5 is also provided with an oil inlet 511, an oil outlet 512, a backwash gas inlet 513, a backwash gas outlet 514, and a liquid distributor 53 and a hot steam purge module 54 respectively arranged on the upper and lower sides of the acid water deep adsorption module 52; the backwash gas inlet 513 is connected to the hot steam purge module 54.

[0182] The acid water deep adsorption module 52 is formed by stacking deeply dehydrated and deacidified adsorption particles, and is used to separate acid and water; the adsorption particles are selected from activated carbon, molecular sieves, metal organic framework compounds, and are preferably 5A type molecular sieves.

[0183] When the adsorption particles are saturated or the adsorption efficiency decreases, the hot steam is blown from bottom to top through the hot steam blowing module 54 at the bottom of the tank body 51 to activate and regenerate the adsorption particles.

[0184] The short-process pretreatment process of waste bio-oil based on the above equipment includes the following steps:

[0185] (I) Heat exchange:

[0186] Heating waste bio-oil to reduce the viscosity of the oil and improve its fluidity;

[0187] (II) Emulsification:

[0188] The heated waste bio-oil enters the emulsifier, so that the oil phase and the water phase in the waste bio-oil are fully mixed to form an emulsion, and the water in the waste bio-oil is used to emulsify and elute the metal, while destroying the coating structure of the surfactant;

[0189] (III) Deep dehydration and impurity removal:

[0190] The emulsified waste bio-oil enters the integrated dehydration and impurity removal device 3 for deep filtration and dehydration. The coalescing medium is sequentially filled into the inner cylinder 32 and the annular outer cylinder 33 in a W-shaped series, and the coalescence and separation of fine water droplets is stepped to strengthen the capture and interception of suspended impurities in the waste bio-oil.

[0191] (IV) Acid washing for deep dechlorination and demetallization:

[0192] In the metal deep remover 4, fine acid droplets are injected into the waste bio-oil treated in the above step (III) through the acid injection mixing and enhanced washing module 42, and the turbulent mixing between the acid droplets and the oil phase is enhanced; the acidic environment is used to destroy the binding effect between the metal ions, chloride ions and oil molecules in the waste bio-oil; the fine acid droplets are then captured by the hydrophilic and oleophobic fiber module in the acid droplet inner circulation deep extraction module 43, and the metal ions and chloride ions are enriched by the inner circulation self-rotation function of the fine acid droplets in the shear flow field, and then the fine acid droplets enriched with metal ions and chloride ions are separated from the oil phase through the fiber coagulation acid-water separation module 44;

[0193] (V) Deep adsorption separation of acid water:

[0194] The water and acid in the waste bio-oil treated in the above step (IV) are deeply adsorbed and removed by the acid-water deep adsorption module 52 in the acid-water deep adsorption separator 5 .

[0195] In the present invention, in the step (I), the heating temperature is controlled in real time according to the viscosity of the waste bio-oil, the viscosity of the waste bio-oil is controlled to be less than 20 mPa·s, and the heating temperature is controlled to be 80-90°C;

[0196] In the present invention, before the emulsification in step (II), adaptive water injection can be performed according to the water content in the oil:

[0197] If the water content of the original waste bio-oil is less than 1wt%, the amount of water injected is 3% of the volume of the waste bio-oil;

[0198] If the water content of the original waste bio-oil is higher than 3wt%, no water injection is required and emulsification can be performed directly.

[0199] In the present invention, in the step (IV), the ratio of acid injection in the waste bio-oil is determined according to the metal content in the imported waste bio-oil, specifically as follows:

[0200] (a) If the total metal content of the imported waste bio-oil is within 100 ppm, the amount of acid injection shall be within 5% of the total volume of the waste bio-oil;

[0201] (b) If the total metal content of the imported waste bio-oil is between 100-500 ppm, the acid injection volume shall be 6-8% of the total volume of the waste bio-oil;

[0202] (c) If the total metal content of the imported waste bio-oil is between 500-1000 ppm, the amount of acid injection shall be 8-10% of the total volume of the waste bio-oil.

[0203] Considering the demetallization efficiency and economic cost, in the step (IV), the fine acid droplets are organic acids, preferably oxalic acid or citric acid, and the concentration of the organic acid is 0.5-1 wt %.

[0204] Waste bio-oil (suspended matter concentration> 0.5wt%, total metal content> 100ppm, chloride content> 100ppm, water content> 0.5wt%) in the above pretreatment process:

[0205] After deep dehydration and impurity removal in step (III), the concentration of suspended matter in the waste bio-oil is reduced to less than 0.02wt%;

[0206] After the acid washing deep dechlorination and demetallization in step (IV), the total metal content in the waste bio-oil is reduced to 10-40 ppm, and the chloride salt content is reduced to 20-50 ppm;

[0207] After step (V) of deep acid-water adsorption separation, the water content in the waste bio-oil is finally removed to below 200 ppm, and the acid concentration is removed to below 0.05 wt%.

[0208] Application Examples

[0209] An environmental protection company used the waste bio-oil short-process pretreatment equipment of Example 1 to treat waste bio-oil. At the same time, an existing set of pretreatment process equipment (including a three-phase centrifuge, an oil-water mechanical stirring mixing tank, an ultrasonic demulsification tank, a gravity sedimentation oil-water separation tank, and a vacuum filter-type integrated filter connected in sequence) was used as Comparative Example 1. The reaction environment conditions, waste bio-oil properties and treatment effects of the two are shown in Table 1 below.

[0210] In this embodiment, the emulsifier 2 used is an ultrasonic emulsifier, which has a power of 5000 kW, a frequency of 20 kHz, and a processing capacity of 0.5 m³ / h.

[0211] The ceramic particle layer module 322 includes ceramic particles and glass beads, wherein the volume of the ceramic particles accounts for 90% and the volume of the glass beads accounts for 10%. The particle size of the ceramic particles is 0.6 mm.

[0212] The ceramic particles are typical silicate materials, which are made of clay as the main raw material and fired at high temperature.

[0213] The ratio of the thickness of the ceramic particle layer module 322 to the total height of the inner tube 32 is 0.4.

[0214] The diameter of the hollow hydrophilic and hydrophobic fiber ball 334 is 35 mm, and the diameter ratio of the hollow spherical structure 335 to the hollow hydrophilic and hydrophobic fiber ball 334 is 0.1; the gap between the fibers in the light fiber group 336 is 60 μm;

[0215] The lightweight fiber group 336 is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3;

[0216] The material of the hydrophobic fiber is polypropylene;

[0217] The hydrophilic fiber is a super hydrophilic fiber obtained by coating a layer of hydrophilic material polyvinyl alcohol (PVA) on the surface of polypropylene fiber.

[0218] The ratio of the thickness of the hydrophilic and hydrophobic fiber ball module 332 to the total height of the annular outer cylinder 33 is 0.3;

[0219] The ratio of the diameter of the inner cylinder 32 to the outer diameter of the annular outer cylinder 33 is 0.7.

[0220] The fine acid droplets are citric acid with a concentration of 0.8 wt %, and the solvent is water; the injection amount of the acid is 10 wt % of the total volume of the waste bio-oil.

[0221] The material of the adsorption particles in the acid water deep adsorption module 52 is 5A type molecular sieve.

[0222] Table 1

[0223]

[0224] From the results in Table 1, it can be seen that the demetallization efficiency of the waste bio-oil pretreatment using the equipment of the present invention is increased by 45%, the dechlorination efficiency is increased by 60%, and the impurity removal efficiency is increased by 10% compared with the existing equipment.

[0225] The principles and implementation methods of the present invention are described above through specific examples. The above embodiments are only used to help understand the method and core ideas of the present invention, so that ordinary technicians in the field can implement or use the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A short-process pretreatment device for waste bio-oil, characterized in that: The invention comprises a heat exchanger (1), an emulsifier (2), an integrated dehydration and impurity removal device (3), a metal deep remover (4) and an acid water deep adsorption separator (5) which are connected in sequence according to the flow direction of the waste bio-oil, wherein: The integrated dehydration and impurity removal device (3) is used for deep filtration and dehydration, and comprises a vertical tank body (31), an inner cylinder (32) located inside the vertical tank body (31), and an annular outer cylinder (33) formed between the vertical tank body (31) and the inner cylinder (32); the inner cylinder (32) and the annular outer cylinder (33) are filled with different agglomeration media in sequence, so as to achieve rapid classification of floating and suspended impurities; A ceramic particle layer module (322) is arranged in the inner cylinder (32), and the ceramic particle layer module (322) is formed by stacking hydrophilic agglomeration materials, wherein the hydrophilic agglomeration materials include ceramic particles, and one or more of glass microbeads, PP and PTFE; A hydrophilic and hydrophobic fiber ball module (332) is arranged in the annular outer cylinder (33), and the hydrophilic and hydrophobic fiber ball module (332) is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls (334); The interior of the hollow hydrophilic and hydrophobic fiber ball (334) is a hollow spherical structure (335), and the exterior thereof is a light fiber group (336) composed of a plurality of hydrophilic fibers and hydrophobic fibers; The metal deep remover (4) is used for deep dechlorination and metal removal by pickling, and comprises a horizontal tank body (41), an acid injection and mixing enhanced washing module (42), an acid droplet internal circulation deep extraction module (43), and a fiber coagulation acid-water separation module (44) which are sequentially arranged inside the horizontal tank body (41); The acid injection, mixing and enhanced washing module (42) is used to inject fine acid droplets into the waste bio-oil and enhance the turbulent mixing between the acid droplets and the oil phase; the fine acid droplets are organic acids, including citric acid or oxalic acid; The acid droplet internal circulation deep extraction module (43) is a Venturi-type structure with a built-in hydrophilic and oleophobic fiber module; the fiber coagulation acid-water separation module (44) is composed of a hydrophilic and oleophobic fiber module; The acid water deep adsorption separator (5) is used for deeply removing water and acid from waste bio-oil, and comprises a tank body (51) and an acid water deep adsorption module (52) arranged inside the tank body (51).

2. The waste bio-oil short-process pretreatment equipment according to claim 1, characterized in that: The emulsifier (2) is an ultrasonic emulsifier or a jet emulsifier; The vertical tank body (31) is provided with a top cavity (311) and a bottom cavity (312) on the upper and lower sides of the inner cylinder (32) and the annular outer cylinder (33), respectively; the top of the vertical tank body (31) is also provided with a waste bio-oil inlet (313) and an oil phase outlet (314) connected to the top cavity (311); the bottom of the vertical tank body (31) is also provided with a water collection bag (315) connected to the bottom cavity (312); The top of the inner cylinder (32) is connected to the waste bio-oil inlet (313) via a pipeline, and a first axial rectification module (321), a ceramic particle layer module (322) and a first water distribution cap (323) are arranged in sequence from top to bottom inside the inner cylinder (32); The top of the annular outer cylinder (33) is in communication with the oil phase outlet (314), and a second axial rectification module (331), a hydrophilic and hydrophobic fiber ball module (332), and a second water distribution cap (333) are arranged in sequence from bottom to top inside the annular outer cylinder (33).

3. The waste bio-oil short-process pretreatment equipment according to claim 1, characterized in that: The volume proportion of the ceramic particles in the ceramic particle layer module (322) is 85-95%; The particle size of the ceramic particles is 0.5-1 mm; The ratio of the thickness of the ceramic particle layer module (322) to the total height of the inner cylinder (32) is 0.4-0.5; The diameter of the hollow hydrophilic and hydrophobic fiber ball (334) is 30-40 mm; the diameter ratio of the hollow spherical structure (335) to the hollow hydrophilic and hydrophobic fiber ball (334) is 0.1-0.2; the gap between the fibers in the light fiber group (336) is 50-100 μm; The ratio of the thickness of the hydrophilic and hydrophobic fiber ball module (332) to the total height of the annular outer cylinder (33) is 0.3-0.4, and the module is located at the bottom of the annular outer cylinder (33); The lightweight fiber group (336) is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3-8:2; The material of the hydrophobic fiber is selected from one or both of polypropylene and polytetrafluoroethylene; The hydrophilic fiber is a super-hydrophilic fiber obtained by hydrophilizing polypropylene fiber or polytetrafluoroethylene fiber, or cotton fiber; The hydrophilization treatment adopts chemical grafting method, surface coating method or plasma treatment.

4. The waste bio-oil short-process pretreatment equipment according to claim 1, characterized in that: The horizontal tank body (41) of the metal deep remover (4) is provided with a feed pipe (411), an oil discharge port (412) and a water bag (413); The acid injection and mixing enhanced washing module (42) comprises a micro-acid droplet generator (421) and a liquid distributor (422) connected to the feed pipe (411) in sequence, and a plurality of washing core tubes (423) connected to the tail end of the liquid distributor (422); the micro-acid droplet generator (421) is used to generate micro-acid droplets, and the washing core tubes (423) are used to enhance turbulent mixing between the acid droplets and the waste bio-oil; The particle size of the fine acid droplets generated by the micro-acid droplet generator (421) is 30-200 μm, and the number of the micro-acid droplet generators (421) is 4-6; The acid droplet internal circulation deep extraction module (43) comprises a fluid speed-up section (431) with a gradually decreasing cross-sectional area, an internal circulation extraction section (432) with a constant cross-sectional diameter, and a buffer section (433) with a gradually increasing cross-sectional area, which are connected in sequence; the internal circulation extraction section (432) is composed of a hydrophilic and oleophobic fiber module; The fiber coagulation acid-water separation module (44) is composed of a hydrophilic and oleophobic fiber module.

5. The waste bio-oil short-process pretreatment equipment according to claim 4, characterized in that: The washing core tube (423) comprises a spinning section (4231) and a voltage transformation section (4232), wherein: The front end of the rotating section (4231) is connected to the rear end of the liquid distributor (422); the rotating section (4231) comprises a cylinder (4233), a support rod (4234) located at the axis of the cylinder (4233), and a spiral blade (4235) arranged around the support rod (4234), the spiral blade (4235) comprising a right-handed blade and a left-handed blade connected from front to back; The helical angle α of the spiral blade (4235) is 35-45°.

6. The waste bio-oil short-process pretreatment equipment according to claim 5, characterized in that: The voltage transformation section (4232) comprises a swirl buffer zone (4236), a voltage transformation oscillation zone (4237) and a voltage transformation buffer zone (4238) which are connected in sequence; the voltage transformation oscillation zone (4237) is a Venturi-type structure whose cross-sectional area changes continuously from gradually contracting, constant diameter to gradually expanding; the swirl buffer zone (4236) of the voltage transformation section (4232) is connected to the tail end of the swirl section (4231); The ratio of the length of the rotation section (4231) to the voltage transformation section (4232) is 3:2-1:1, and the ratio of the area of ​​the maximum cross section to the minimum cross section of the voltage transformation section (4232) is 3:1-2:

1.

7. The waste bio-oil short-process pretreatment equipment according to claim 4, characterized in that: The hydrophilic and oleophobic fiber modules in the internal circulation extraction section (432) and the fiber coagulation and acid-water separation module (44) are both acid-resistant and corrosion-resistant fiber modules, and the fiber modules are internally provided with a plurality of groups of parallel-arranged hydrophilic and oleophobic fibers; The hydrophilic and oleophobic fiber modules are woven in an X-shaped manner, with a porosity of 0.7-0.8 and a fiber diameter of 100-200 μm; The hydrophilic and oleophobic fiber module is made of polyethyleneimine and fluorine-containing materials; The cross-sectional area ratio of the hydrophilic and oleophobic fiber modules of the acid droplet internal circulation deep extraction module (43) and the fiber coagulation acid-water separation module (44) is 0.7-0.8; The cross-sectional area of ​​the internal circulation extraction section (432) in the acid drop internal circulation deep extraction module (43) is 0.7-0.8 times the cross-sectional area of ​​the horizontal tank body (41); The ratio of the overall length of the fiber coagulation acid-water separation module (44) to the overall length of the acid droplet internal circulation deep extraction module (43) is 1:1-2:

3.

8. The waste bio-oil short-process pretreatment equipment according to claim 1, characterized in that: The tank body (51) of the acid water deep adsorption separator (5) is also provided with an oil inlet (511), an oil outlet (512), a backwash gas inlet (513), a backwash gas outlet (514), and a liquid distributor (53) and a hot steam purge module (54) respectively arranged on the upper and lower sides of the acid water deep adsorption module (52); the backwash gas inlet (513) is in communication with the hot steam purge module (54); The acid water deep adsorption module (52) is formed by stacking deeply dehydrated and deacidified adsorption particles, and is used to separate acid and water; the adsorption particles are activated carbon, molecular sieves or metal organic framework compounds.

9. A short-process pretreatment process for waste bio-oil, characterized in that: The waste bio-oil short-process pretreatment equipment according to any one of claims 1 to 8 comprises the following steps: (I) Heat exchange: Heating waste bio-oil to reduce the viscosity of the oil and improve its fluidity; (II) Emulsification: The heated waste bio-oil enters the emulsifier, so that the oil phase and the water phase in the waste bio-oil are fully mixed to form an emulsion; (III) Deep filtration and dehydration: The emulsified waste bio-oil enters the integrated dehydration and impurity removal device (3) for deep filtration and dehydration, and utilizes the coalescence medium that is sequentially filled into the inner cylinder (32) and the annular outer cylinder (33) in a W-shaped series connection to step-enhance the coalescence and separation of fine water droplets, and step-enhance the capture and interception of suspended impurities in the waste bio-oil; (IV) Acid washing for deep dechlorination and demetallization: In the metal deep remover (4), fine acid droplets are injected into the waste bio-oil treated in the above step (III) through the acid injection mixing and enhanced washing module (42), and the turbulent mixing between the acid droplets and the oil phase is enhanced; the acidic environment is used to destroy the binding effect between the metal ions, chloride ions and oil molecules in the waste bio-oil; the fine acid droplets are then captured by the hydrophilic and oleophobic fiber module in the Venturi-type acid droplet internal circulation deep extraction module (43), and the metal ions and chloride ions are enriched by the internal circulation self-rotation function of the fine acid droplets in the shear flow field, and then the fine acid droplets enriched with metal ions and chloride ions are separated from the oil phase through the fiber coagulation acid-water separation module (44); (V) Deep adsorption separation of acid water: The water and acid in the waste bio-oil treated in step (IV) are deeply adsorbed and removed by the acid-water deep adsorption module (52) in the acid-water deep adsorption separator (5).

10. The short-process pretreatment process for waste bio-oil according to claim 9, characterized in that: In the step (I), the heating temperature is controlled in real time according to the viscosity of the waste bio-oil, the viscosity of the waste bio-oil is controlled to be less than 20 mPa·s, and the heating temperature is controlled to be 80-90°C; Before the emulsification in step (II), adaptive water injection is performed according to the water content in the waste bio-oil: If the water content of the original waste bio-oil is less than 1wt%, the amount of water injected is 3% of the volume of the waste bio-oil; If the water content of the original waste bio-oil is higher than 3wt%, emulsification can be performed directly without water injection; In the step (IV), the ratio of acid injection in the waste bio-oil is determined according to the metal content in the imported waste bio-oil, specifically as follows: (a) If the total metal content of the imported waste bio-oil is within 100 ppm, the acid injection volume shall be within 5% of the total volume of the oil phase; (b) If the total metal content of the imported waste bio-oil is between 100-500 ppm, the acid injection amount is 6-8% of the total volume of the oil phase; (c) If the total metal content of the imported waste bio-oil is between 500-1000 ppm, the acid injection volume is 8-10% of the total volume of the oil phase; In the step (IV), the fine acid droplets are organic acids, and the concentration of the organic acid is 0.5-1 wt %.

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