Integrated equipment and method for dehydrating and removing impurities from waste bio-oil

Abstract

The present invention discloses an integrated device and method for dehydrating and removing impurities from waste bio-oil. The device comprises a vertical tank body, an inner cylinder located inside the vertical tank body, and an annular outer cylinder formed between the inner cylinder and the vertical tank body; the inner cylinder and the annular outer cylinder are sequentially filled with different coalescing media in a W-shaped series connection, so as to capture and intercept suspended matter of different sizes and types, and to aggregate, grow and separate water droplets of different sizes, so as to achieve rapid, deep and efficient dehydration and impurity removal in waste bio-oil. The device has a compact structure, greatly shortens the treatment process of waste bio-oil, has high separation efficiency and low investment cost. At the same time, a PLC-controlled automatic cleaning system is adopted to improve the backwashing efficiency of the equipment, extend the operation cycle of the equipment, and achieve the goal of solving many problems caused by the current dehydration and impurity removal of waste bio-oil by using only one device.

Description

Technical Field

[0001] The invention belongs to the technical field of waste bio-oil impurity removal, and in particular relates to integrated equipment and method for dehydrating and removing impurities from waste bio-oil. Background Art

[0002] Waste bio-oil (including but not limited to waste animal and vegetable oils and waste cooking oils) is a recyclable resource. After chemical and physical transformation or physical refining, it can be turned into treasure and generate considerable economic and social benefits. Through pretreatment, hydrogenation, hydrogenation conversion 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 beneficial to 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 contains a large amount of water and solid suspended impurities, which lead to problems such as catalyst hydrolysis, poisoning, and coking in the subsequent processing of bio-jet fuel. At the same time, the continuous accumulation of suspended matter in the equipment increases the pressure difference between the inside and outside of the equipment, causing blockage, resulting in short operating cycle, unqualified product quality, high energy consumption, and even the serious consequence of being unable to obtain products, which greatly restricts the comprehensive utilization of waste bio-oil. Therefore, before using waste bio-oil to prepare bio-jet fuel, it is necessary to conduct deep dehydration and impurity removal pretreatment on the waste bio-oil, so as to further improve the recovery rate of oil and fat and avoid affecting the subsequent process.

[0004] Waste bio-oil itself often contains gray-white greasy floating objects and animal and plant food residues of different shapes. In addition, waste bio-oil may come from urban sewers, restaurant swill, waste grease from food processing companies, etc. These sources make the waste kitchen grease mixed with a large amount of sewage, garbage, detergents and other pollutants. Therefore, the types of its solid suspended matter 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. In particular, since waste bio-oil may contain a large amount of detergent, water mostly exists in the waste bio-oil in the form of emulsions, and it is extremely difficult to separate it using traditional methods such as gravity sedimentation. Therefore, the rapid and efficient dehydration and impurity removal of waste bio-oil is still a problem that restricts the rapid development of oil hydrogenation technology.

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

[0006] CN209836129U discloses a waste oil impurity removal device. The device is divided into a separation zone and an oil storage zone by a partition. A detachable filter screen is provided in the separation zone and at the feed port to remove large particles of residue in the oil. After the filtered waste oil is left to stand for a certain period of time in the separation zone, some sand and other materials will settle to the cone bucket at the bottom for removal. In addition, there are two circulation pipes arranged in parallel in the upper and lower parts of the device. The two ends of the circulation pipes are respectively connected to the separation zone and the oil storage zone, so that multiple cycles of filtering and impurity removal can be achieved. The invention has a simple structure, is easy to disassemble and assemble, and has a high impurity removal efficiency for large particles of residue. However, the precision of the filter screen is aimed at the extremely fine suspended particles in the waste bio-oil, and the impurity removal efficiency is low. In addition, the static sedimentation impurity removal results in a small unit area processing capacity of the device, which is not easy to realize industrialization. Summary of the invention

[0007] The present invention aims to solve the problems in the prior art that the entire treatment process of waste bio-oil is too long, the impurity removal system has low impurity removal accuracy, the dehydration system does not dehydrate thoroughly, and the equipment backwashing is difficult, and proposes an integrated device and method for dehydrating and impurity removal of waste bio-oil.

[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 an integrated device for dehydrating and removing impurities from waste bio-oil, comprising a vertical tank body, an inner cylinder located inside the vertical tank body, and an annular outer cylinder formed between the inner cylinder and the vertical tank body, wherein:

[0010] 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;

[0011] 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;

[0012] The top of the annular outer cylinder is communicated with 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.

[0013] The present invention is further configured such that the ceramic particle layer module is formed by stacking hydrophilic agglomerate materials, wherein the hydrophilic agglomerate materials include ceramic particles and one or more of glass microspheres, PP and PTFE;

[0014] The volume proportion of the ceramic particles in the ceramic particle layer module is 85-95%;

[0015] The particle size of the ceramic particles is 0.5-1 mm;

[0016] The ratio of the thickness of the ceramic particle layer module to the total height of the inner tube is 0.4-0.5.

[0017] The present invention is further configured that the hydrophilic and hydrophobic fiber ball module is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls; the interior of the hollow hydrophilic and hydrophobic fiber balls is a hollow ball structure, and the exterior thereof is a light fiber mass composed of a plurality of hydrophilic fibers and hydrophobic fibers;

[0018] The diameter of the hollow hydrophilic and hydrophobic fiber ball is 30-40 mm;

[0019] The diameter ratio of the hollow spherical structure to the hollow hydrophilic and hydrophobic fiber ball is 0.1-0.2;

[0020] The gap between the fibers in the light fiber group is 50-100 μm;

[0021] 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;

[0022] The lightweight fiber mass is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3-8:2;

[0023] The material of the hydrophobic fiber is selected from one or both of polypropylene and polytetrafluoroethylene;

[0024] The hydrophilic fiber is a super-hydrophilic fiber obtained by hydrophilizing polypropylene fiber or polytetrafluoroethylene fiber, or cotton fiber;

[0025] The hydrophilization treatment adopts chemical grafting method, surface coating method or plasma treatment.

[0026] The present invention is further configured that a plurality of partitions are evenly arranged in the annular outer cylinder to prevent the hollow hydrophilic and hydrophobic fiber balls from moving irregularly around, and to play the role of pressing the hollow hydrophilic and hydrophobic fiber balls to ensure the impurity removal effect;

[0027] The number of the partitions is preferably 2-4.

[0028] The present invention is further configured that the device is also provided with a PLC-controlled automatic cleaning system, the automatic cleaning system comprising a backwash water inlet and a nitrogen purge inlet arranged at the bottom of the vertical tank body, an inner cylinder backwash water outlet, an annular outer cylinder backwash water outlet, and an exhaust port arranged at the top of the vertical tank body, a nitrogen purge device arranged in the bottom cavity of the vertical tank body, a differential pressure gauge for measuring the inlet and outlet pressure difference of the ceramic particle layer module, a concentration detection device for measuring the concentration of suspended matter in the imported waste bio-oil, and a PLC control system;

[0029] The nitrogen purge inlet is communicated with the nitrogen purge device, and the inner cylinder backwash water outlet and the annular outer cylinder backwash water outlet are communicated with the top of the inner cylinder and the top cavity of the vertical tank body respectively.

[0030] Valves are respectively provided at the backwash water inlet, nitrogen purge inlet, inner tube backwash water outlet, annular outer tube backwash water outlet and exhaust port. The PLC control system is respectively connected to the differential pressure gauge, 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 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.

[0031] The present invention is further configured such that the ratio of the diameter of the inner cylinder to the outer diameter of the annular outer cylinder is determined by the water content and the suspended matter concentration of the imported waste bio-oil, the water content and the suspended matter concentration being both measured in mass fractions, specifically as follows:

[0032] (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 to the outer diameter of the annular outer cylinder is 0.5-0.6;

[0033] (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 to the outer diameter of the annular outer cylinder is 0.6-0.7;

[0034] (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 to the outer diameter of the annular outer cylinder is 0.7-0.8;

[0035] When the water content and suspended matter concentration of the imported waste bio-oil correspond to different ratios, the suspended matter concentration shall prevail.

[0036] The second aspect of the present invention is to provide a method for dehydrating and removing impurities from waste bio-oil based on the above-mentioned integrated equipment for dehydrating and removing impurities from waste bio-oil, comprising the following steps:

[0037] (I) Preliminary dehydration and impurity removal: waste bio-oil enters the inner cylinder from the waste bio-oil inlet on the top of the vertical tank, and most of the suspended matter it carries floats on the upper part of the ceramic particle layer module. The suspended matter in the form of particles and strips with slightly larger particle sizes is intercepted by the ceramic particle layer module during the flow, thereby achieving separation; the water droplets in the waste bio-oil adhere and aggregate in the ceramic particle layer module, grow into large water droplets, and flow to the bottom cavity of the vertical tank along with the waste bio-oil, and finally settle to the water collection bag for separation and discharge to downstream treatment;

[0038] (II) Deep dehydration and impurity removal: The bio-oil carrying fine water droplets and fine suspended matter enters the annular outer cylinder from the bottom cavity. The hydrophilic and hydrophobic fiber ball module in the annular outer cylinder further intercepts the fine suspended matter entrained in the waste bio-oil, aggregates, intercepts and separates the entrained fine water droplets, and the grown water droplets settle to the bottom cavity for separation. The treated oil phase is discharged from the top cavity of the vertical tank body, thereby achieving deep dehydration and impurity removal of the oil.

[0039] The present invention is further configured such that the water content in the inlet waste bio-oil is usually 1-5wt% and the suspended matter concentration is 0.5-2wt%;

[0040] The inlet flow rate of the waste bio-oil is 8-10m³ / h, and the operating temperature is controlled at 80-110°C;

[0041] The cross-sectional flow rate of the waste bio-oil entering the ceramic particle layer module of the inner cylinder is controlled at 0.003-0.005 m / s, and the cross-sectional flow rate of the waste bio-oil entering the hydrophilic and hydrophobic fiber ball module of the annular outer cylinder is controlled at 0.001-0.003 m / s.

[0042] The present invention is further configured as follows: in the present invention, the method further includes step (III) backwashing: backwash water and nitrogen enter the inner cylinder and the annular outer cylinder from the bottom cavity of the vertical tank body, flow in the same direction from bottom to top, and then are discharged from the top of the vertical tank body.

[0043] The backwash is controlled by differential pressure, that is, the backwash frequency is controlled according to the inlet and outlet pressure difference of the ceramic particle layer module. The backwash starting pressure difference is 0.8-1MPa. When the measured pressure difference is greater than the starting pressure difference, the backwash is started.

[0044] The present invention is further configured such that the backwashing time is determined according to the concentration of suspended matter in the imported waste bio-oil, specifically as follows:

[0045] (a) When the suspended solids concentration of the imported waste bio-oil is less than 0.1wt%, the backwash time is 40-60s;

[0046] (b) When the suspended solids concentration of the imported waste bio-oil is 0.1-0.5wt%, the backwash time is 60-80s;

[0047] (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.

[0048] The beneficial effects of the present invention are as follows:

[0049] 1. The present invention proposes an integrated device for dehydration and impurity removal of waste bio-oil. The device sequentially fills the coalescing fillers of different materials into the inner cylinder and the annular outer cylinder of the device in a W-shaped series connection, captures and intercepts suspended matter of different sizes and types, and aggregates, grows and separates water droplets of different sizes, thereby realizing rapid, deep and efficient dehydration and impurity removal in waste bio-oil, greatly shortening the treatment process of waste bio-oil, with high separation efficiency and low investment cost. At the same time, the automatic cleaning system controlled by PLC is adopted to improve the backwashing efficiency of the equipment, extend the operation cycle of the equipment, and realize that many problems caused by the current dehydration and impurity removal of waste bio-oil can be solved by using only one device.

[0050] 2. Based on agglomeration and dehydration materials of different materials and types, the present invention proposes a method for step-by-step enhanced aggregation and separation of fine water droplets and step-by-step enhanced capture and interception of suspended impurities in waste bio-oil. First, a ceramic particle layer module is used to achieve aggregation, growth, and separation of larger water droplets, as well as capture and interception of larger particle-size suspended matter, greatly reducing the water content and suspended matter concentration in the oil; then, a hydrophilic and hydrophobic fiber ball module is used to achieve aggregation, growth, and separation of fine water droplets, as well as capture and interception of fine suspended matter, further reducing the water content and suspended matter concentration in the oil, and ultimately obtaining high-purity bio-oil.

[0051] 3. The main modules in the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention are in the form of internal components and can be directly modified in the crude oil water separator or filter without re-processing a new separator. The construction is simple, cost and land saving, and the economic benefits are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 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.

[0053] Figure 2 It is a specific structural schematic diagram of the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention.

[0054] Figure 3 It is the schematic diagram of the dehydration and impurity removal of the ceramic particle layer module.

[0055] Figure 4 It is a schematic diagram of the structure of the hollow hydrophilic-hydrophobic fiber ball of the hydrophilic-hydrophobic fiber ball module.

[0056] Figure 5 yes Figure 1 Cross-sectional view along the AA direction.

[0057] Figure 6 It 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.

[0058] Figure 7 This is the schematic diagram of the dehydration and impurity removal of the hydrophilic and hydrophobic fiber ball module.

[0059] Figure 8 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.

[0060] In the figure:

[0061] 1-vertical tank body; 11-top cavity; 12-bottom cavity; 13-waste bio-oil inlet; 14-oil phase outlet; 15-water collection bag;

[0062] 2-inner cylinder; 21-first axial rectifying module; 22-ceramic particle layer module; 23-first water distribution cap;

[0063] 3-annular outer cylinder; 31-second axial rectifying module; 32-hydrophilic and hydrophobic fiber ball module; 33-second water distribution cap; 34-hollow hydrophilic and hydrophobic fiber ball; 35-hollow ball structure; 36-light fiber group; 37-partition;

[0064] 4-automatic cleaning system; 41-backwash water inlet; 42-nitrogen purge inlet; 43-inner cylinder backwash water outlet; 44-annular outer cylinder backwash water outlet; 45-exhaust port; 46-nitrogen purge device; 47-differential pressure gauge. DETAILED DESCRIPTION

[0065] The technical scheme of the present invention is clearly and completely described below in conjunction with the accompanying drawings through specific embodiments. It should be understood that the following 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, other embodiments obtained by ordinary technicians in this field all belong to the scope of protection of this application.

[0066] The determination of water content and suspended matter content in waste bio-oil in the following examples refers to the following standards:

[0067] Determination of water content: GB / T 11133-2015 Determination of water content in petroleum products, lubricants and additives Karl Fischer coulometric titration method;

[0068] Determination of suspended matter content: GB / T 15688-2008 Determination of insoluble impurities content in animal and vegetable fats and oils.

[0069] Waste bio-oil recovered from food wastewater and other sources contains many solid impurities and water, among which the impurity particles have a wide distribution of particle sizes, various shapes, and high concentrations; the water phase is mainly composed of fine water droplets of different sizes, which are usually uniformly emulsified in the bio-oil, resulting in difficulty in oil-water separation and incomplete separation, which seriously affects the normal operation of the subsequent oil hydrogenation process. Therefore, it is necessary to deeply dehydrate and remove impurities from the waste bio-oil.

[0070] Example 1

[0071] like Figure 1 As shown, the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention comprises a vertical tank body 1, an inner cylinder 2 located inside the vertical tank body 1, and an annular outer cylinder 3 formed between the inner cylinder 2 and the vertical tank body 1, wherein:

[0072] Combination Figure 2 As shown, the vertical tank body 1 is provided with a top cavity 11 and a bottom cavity 12 on the upper and lower sides of the inner cylinder 2 and the annular outer cylinder 3, respectively. The top of the vertical tank body 1 is also provided with a waste bio-oil inlet 13 and an oil phase outlet 14 connected to the top cavity 11, and the bottom is also provided with a water collection bag 15 connected to the bottom cavity 12;

[0073] The top of the inner cylinder 2 is connected to the waste bio-oil inlet 13 through a pipeline, and a first axial rectifying module 21, a ceramic particle layer module 22 and a first water distribution cap 23 are sequentially arranged inside the inner cylinder 2 from top to bottom; the ceramic particle layer module 22 is used to intercept larger particles and long strips of suspended matter in the waste bio-oil to achieve rapid aggregation and dehydration;

[0074] The top of the annular outer cylinder 3 is connected to the oil phase outlet 14, and a second axial rectifying module 31, a hydrophilic and hydrophobic fiber ball module 32 and a second water distribution cap 33 are sequentially arranged inside the annular outer cylinder 3 from bottom to top; the hydrophilic and hydrophobic fiber ball module 32 is used to capture and separate fine and fibrous suspended matter in the waste bio-oil to achieve deep aggregation and dehydration.

[0075] In the present invention, the ceramic particle layer module 22 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.

[0076] The volume proportion of the ceramic particles in the ceramic particle layer module 22 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.

[0077] The particle size of the ceramic particles is 0.5-1 mm. Within this particle size range, the ceramic particle layer module 22 will not produce a large pressure drop while maintaining excellent performance in dehydration and impurity removal, which is conducive to backwashing.

[0078] Preferably, the ratio of the thickness of the ceramic particle layer module 22 to the total height of the inner tube 2 is 0.4-0.5.

[0079] After the waste bio-oil enters the inner cylinder 2 from the waste bio-oil inlet 13, it first passes through the first axial rectifying module 21 to adjust the cross-sectional flow rate entering the ceramic particle layer module 22 to ensure the impurity removal effect; Figure 3 As shown, most of the suspended matter carried in the waste bio-oil floats on the upper part of the ceramic particle layer module 22, and the granular and long strip-shaped suspended matter with slightly larger particle size is intercepted by the ceramic particle layer module 22 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 12 of the vertical tank body 1 through the first water distribution cap 23, and finally settles to the water collection bag 15 for separation, the first water distribution cap 23 plays a certain buffering role.

[0080] In the present invention, combined with Figure 4 As shown, the hydrophilic and hydrophobic fiber ball module 32 is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls 34, 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.

[0081] In the present invention, the interior of the hollow hydrophilic and hydrophobic fiber ball 34 is a hollow spherical structure 35, and the exterior thereof is a light fiber group 36 composed of a plurality of hydrophilic fibers and hydrophobic fibers.

[0082] Preferably, the diameter of the hollow hydrophilic and hydrophobic fiber ball 34 is 30-40 mm; the diameter ratio of the hollow spherical structure 35 to the hollow hydrophilic and hydrophobic fiber ball 34 is 0.1-0.2; and the gap between the fibers in the light fiber group 36 is 50-100 μm.

[0083] Preferably, the ratio of the thickness of the hydrophilic and hydrophobic fiber ball module 32 to the total height of the annular outer cylinder 3 is 0.3-0.4, and the module is located at the bottom of the annular outer cylinder 3;

[0084] The lightweight fiber group 36 is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3-8:2;

[0085] The material of the hydrophobic fiber is selected from one or both of polypropylene and polytetrafluoroethylene;

[0086] The hydrophilic fiber is a super-hydrophilic fiber obtained by hydrophilizing polypropylene fiber or polytetrafluoroethylene fiber, or cotton fiber;

[0087] 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.

[0088] In the present invention, Figure 5 As shown, a plurality of partitions 37 are evenly arranged in the annular outer cylinder 3 to prevent the hollow hydrophilic and hydrophobic fiber balls 34 from making irregular movements around, and to compress the hollow hydrophilic and hydrophobic fiber balls 34 to ensure the impurity removal effect. The number of the partitions 37 is preferably 2-4.

[0089] The second water distribution cap 33 is used to uniformly 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 34 with a relatively small density.

[0090] like Figure 6 As shown, after the full tank operation, after the initial dehydration and impurity removal by the inner cylinder 2, the waste bio-oil carrying fine water droplets and fine suspended matter enters the annular outer cylinder 3 from the bottom cavity 12, and after the flow rate is adjusted by the second axial rectifying module 31, the hollow hydrophilic and hydrophobic fiber balls 34 in the hydrophilic and hydrophobic fiber ball module 32 are driven to move upward. When passing through the second water distribution cap 33, the hollow hydrophilic and hydrophobic fiber balls 34 are blocked by it and stay on the top of the annular outer cylinder 3, so that the hollow hydrophilic and hydrophobic fiber balls 34 are further fully contacted with the waste bio-oil, thereby achieving the purpose of rapid dehydration and suspension removal.

[0091] like Figure 7 As shown, in the hydrophilic and hydrophobic fiber ball module 32, the suspended impurities and water droplets in the waste bio-oil are fully in contact with the hollow hydrophilic and hydrophobic fiber balls 34. Due to the special structural characteristics of the light fiber components in the hollow hydrophilic and hydrophobic fiber balls 34, the fine water droplets in the waste bio-oil are captured and adhered by the fibers, 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 balls 34 and settled in the bottom cavity 12, thereby achieving the removal of fine water droplets. There are certain gaps between the fibers on the hollow hydrophilic and hydrophobic fiber balls 34, and fine suspended matter can easily enter them, thereby achieving deep capture and removal of suspended matter. The waste bio-oil after deep dehydration and impurity removal enters the top cavity 11 of the vertical tank body 1, and then is discharged from the oil phase outlet 14.

[0092] In the inner cylinder 2, most of the suspended matter carried by the waste bio-oil floats on the upper part of the ceramic particle layer module 22. 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 22, forming a thicker filter cake layer, which makes it impossible for the oil phase to pass smoothly, and the pressure difference gradually increases, eventually causing the equipment to stop. At the same time, the hollow hydrophilic and hydrophobic fiber balls 34 in the annular outer cylinder 3 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 34, their performance will be seriously affected. Therefore, it is necessary to timely perform high-quality backwashing on the inner cylinder 2 and the annular outer cylinder 3 of the equipment.

[0093] Therefore, if Figure 1 and Figure 8 As shown, in the present invention, the equipment is also provided with an automatic cleaning system 4 controlled by a PLC, and the automatic cleaning system 4 includes a backwash water inlet 41 and a nitrogen purge inlet 42 arranged at the bottom of the vertical tank body 1, an inner cylinder backwash water outlet 43, an annular outer cylinder backwash water outlet 44, and an exhaust port 45 arranged at the top of the vertical tank body 1, a nitrogen purge device 46 arranged in the bottom cavity 12 of the vertical tank body 1, a differential pressure gauge 47 for measuring the inlet and outlet pressure difference of the ceramic particle layer module 22, 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;

[0094] The nitrogen purge inlet 42 is connected to a nitrogen purge device 46 , and the inner tube backwash water outlet 43 and the annular outer tube backwash water outlet 44 are connected to the top of the inner tube 2 and the top cavity 11 of the vertical tank body 1 , respectively.

[0095] Since the agglomeration material in the inner cylinder 2 is mainly ceramic particles, large suspended particles from the waste bio-oil tend to concentrate on the upper part of the ceramic particle layer module 22, and the backwashing frequency is high;

[0096] Compared with the ceramic particle layer module 22, the suspended impurities on the surface of the hollow hydrophilic and hydrophobic fiber balls 34 will only affect its dehydration and impurity removal performance after a long period of operation, and the backwashing frequency is lower. Therefore, the backwashing frequency of the equipment is controlled by pressure difference, that is, the backwashing frequency is controlled according to the inlet and outlet pressure difference of the ceramic particle layer module 22. The backwashing starting pressure difference is 0.8-1MPa. When the measured pressure difference is greater than the starting pressure difference, the backwashing is started; the backwashing time is determined according to the suspended matter concentration in the imported waste bio-oil.

[0097] The backwash water inlet 41, the nitrogen purge inlet 42, the inner tube backwash water outlet 43, the annular outer tube backwash water outlet 44 and the exhaust port 45 are respectively provided with valves (not shown in the figure). The PLC control system is respectively connected to the differential pressure gauge 47, 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 47 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.

[0098] When the equipment is backwashed, backwash water and nitrogen enter the vertical tank body 1 at the same time, blow off the suspended impurities on the top of the ceramic particle layer module 22 and the large amount of suspended matter carried on the hollow hydrophilic and hydrophobic fiber balls 34, carry and separate them, and then discharge the backwash water and nitrogen outside the vertical tank body 1 through the inner tube backwash water outlet 43, the annular outer tube backwash water outlet 44 and the exhaust port 45.

[0099] 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.

[0100] The water collecting bag 15 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.

[0101] In the present invention, the ratio of the diameter of the inner cylinder 2 to the outer diameter of the annular outer cylinder 3 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:

[0102] (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 2 to the outer diameter of the annular outer cylinder 3 is 0.5-0.6;

[0103] (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 2 to the outer diameter of the annular outer cylinder 3 is 0.6-0.7;

[0104] (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 2 to the outer diameter of the annular outer cylinder 3 is 0.7-0.8;

[0105] When the water content and suspended matter concentration of the imported waste bio-oil correspond to different ratios, the suspended matter concentration shall prevail.

[0106] The method for dehydrating and removing impurities from waste bio-oil based on the above-mentioned integrated equipment for dehydrating and removing impurities from waste bio-oil comprises the following steps:

[0107] (I) Preliminary dehydration and impurity removal: waste bio-oil enters the inner cylinder 2 from the waste bio-oil inlet 13 at the top of the vertical tank body 1, and most of the suspended matter it carries floats on the upper part of the ceramic particle layer module 22. The suspended matter in the form of particles and strips with slightly larger particle sizes is intercepted by the ceramic particle layer module 22 during the flow process, thereby achieving separation; the water droplets in the waste bio-oil adhere and aggregate in the ceramic particle layer module 22, grow into large water droplets, and flow to the bottom cavity 12 of the vertical tank body 1 along with the waste bio-oil, and finally settle to the water collection bag 15 for separation and discharge to downstream treatment;

[0108] (II) Deep dehydration and impurity removal: The bio-oil carrying fine water droplets and fine suspended matter enters the annular outer cylinder 3 from the bottom cavity 12. The hydrophilic and hydrophobic fiber ball module 32 in the annular outer cylinder 3 further intercepts the fine suspended matter entrained in the waste bio-oil, aggregates, intercepts and separates the entrained fine water droplets, and the grown water droplets settle to the bottom cavity 12 for separation. The treated oil phase is discharged from the top cavity 11 of the vertical tank body 1, thereby achieving deep dehydration and impurity removal of the oil.

[0109] Preferably, the inlet flow rate of the waste bio-oil is 8-10m³ / h, the operating temperature is controlled at 80-110°C, the cross-sectional flow rate of the waste bio-oil entering the ceramic particle layer module 22 of the inner tube 2 is controlled at 0.003-0.005m / s, and the cross-sectional flow rate of the waste bio-oil entering the hydrophilic and hydrophobic fiber ball module 32 of the annular outer tube 3 is controlled at 0.001-0.003m / s.

[0110] Usually, the water content in the inlet waste bio-oil is 1-5wt%. The suspended matter concentration is 0.5-2wt%. By using the integrated dehydration and impurity removal device of the present invention, the dehydration rate can reach 99%, and the outlet suspended matter concentration is less than 0.1wt%. Among them, after the ceramic particle layer module 22 performs preliminary dehydration and impurity removal treatment, the water content and suspended matter concentration in the waste bio-oil are reduced by about 80%. After the hydrophilic and hydrophobic fiber ball module 32 performs deep dehydration and impurity removal treatment, the water content and suspended matter concentration in the waste bio-oil are reduced by 98%.

[0111] In the present invention, the method further comprises step (III) backwashing: backwash water and nitrogen enter the inner cylinder 2 and the annular outer cylinder 3 from the bottom cavity 12 of the vertical tank body 1, flow in the same direction from bottom to top, and then are discharged from the top of the vertical tank body 1. `

[0112] The backwash is controlled by differential pressure, that is, the backwash frequency is controlled according to the inlet and outlet pressure difference of the ceramic particle layer module 22. The backwash starting pressure difference is 0.8-1MPa. When the measured pressure difference is greater than the starting pressure difference, the backwash is started.

[0113] The backwash time is determined according to the concentration of suspended matter in the imported waste bio-oil, as follows:

[0114] (a) When the suspended solids concentration of the imported waste bio-oil is less than 0.1wt%, the backwash time is 40-60s;

[0115] (b) When the suspended solids concentration of the imported waste bio-oil is 0.1-0.5wt%, the backwash time is 60-80s;

[0116] (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.

[0117] Application Examples

[0118] An environmental protection company used the integrated equipment for dehydration and impurity removal of waste bio-oil of the above-mentioned embodiment 1 to dehydrate and remove impurities from waste bio-oil. At the same time, the wire mesh filter and filter filter commonly used in industry were used to replace the integrated equipment for dehydration and impurity removal of waste bio-oil of the present application as comparative examples 1 and 2, respectively, to conduct comparative tests. The reaction environment conditions of the tests and the product properties before and after treatment are shown in Table 1.

[0119] In this embodiment, the ceramic particle layer module 22 includes ceramic particles and glass beads, 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;

[0120] The ceramic particles are typical silicate materials, which are made of clay as the main raw material and fired at high temperature.

[0121] The ratio of the thickness of the ceramic particle layer module 22 to the total height of the inner tube 2 is 0.4.

[0122] The diameter of the hollow hydrophilic and hydrophobic fiber ball 34 is 35 mm, and the diameter ratio of the hollow spherical structure 35 to the hollow hydrophilic and hydrophobic fiber ball 34 is 0.1; the gap between the fibers in the light fiber group 36 is 60 μm;

[0123] The lightweight fiber group 36 is mainly composed of hydrophilic fibers, and the ratio of hydrophilic fibers to hydrophobic fibers is 7:3;

[0124] The material of the hydrophobic fiber is polypropylene;

[0125] 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.

[0126] The ratio of the thickness of the hydrophilic and hydrophobic fiber ball module 32 to the total height of the annular outer cylinder 3 is 0.3;

[0127] The ratio of the diameter of the inner cylinder 2 to the outer diameter of the annular outer cylinder 3 is 0.6.

[0128] The inlet flow rate of the waste bio-oil is 9m³ / h, the operating temperature is controlled at 100°C, the cross-sectional flow rate of the waste bio-oil entering the ceramic particle layer module 22 of the inner tube 2 is controlled at 0.004m / s, and the cross-sectional flow rate of the waste bio-oil entering the hydrophilic and hydrophobic fiber ball module 32 of the annular outer tube 3 is controlled at 0.002m / s.

[0129] The wire mesh filter and the strainer filter are both conventional devices in the art. The wire mesh filter comprises a housing, a waste bio-oil inlet and a waste bio-oil outlet arranged on the housing, and a metal wire mesh vertically arranged inside the housing along the logistics direction; the metal wire mesh is made of 316L stainless steel with a pore size of 50 μm;

[0130] The filter screen comprises a shell, a waste bio-oil inlet and a waste bio-oil outlet arranged on the shell, and a filter screen arranged vertically along the logistics direction inside the shell; the filter screen is made of Hastelloy and has a pore size of 30 μm.

[0131] Table 1

[0132]

[0133] From the data in Table 1, it can be seen that compared with the existing conventional impurity removal equipment, the integrated equipment for dehydration and impurity removal of waste bio-oil of the present invention has a dehydration efficiency increased by up to 38.3%, a suspended matter removal efficiency increased by up to 58%, and the suspended matter content in the exported oil is as low as 0.08%.

[0134] 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. An integrated device for dehydrating and removing impurities from waste bio-oil, characterized in that: It comprises a vertical tank body (1), an inner cylinder (2) located inside the vertical tank body (1), and an annular outer cylinder (3) formed between the inner cylinder (2) and the vertical tank body (1), wherein: The vertical tank body (1) is provided with a top cavity (11) and a bottom cavity (12) on the upper and lower sides of the inner cylinder (2) and the annular outer cylinder (3), respectively; the top of the vertical tank body (1) is also provided with a waste bio-oil inlet (13) and an oil phase outlet (14) connected to the top cavity (11); the bottom of the vertical tank body (1) is also provided with a water collection bag (15) connected to the bottom cavity (12); The top of the inner cylinder (2) is connected to the waste bio-oil inlet (13) through a pipeline, and a first axial rectification module (21), a ceramic particle layer module (22) and a first water distribution cap (23) are sequentially arranged inside the inner cylinder from top to bottom; The top of the annular outer cylinder (3) is connected to the oil phase outlet (14), and a second axial rectifying module (31), a hydrophilic and hydrophobic fiber ball module (32) and a second water distribution cap (33) are sequentially arranged inside the annular outer cylinder from bottom to top; The ceramic particle layer module (22) is formed by stacking hydrophilic agglomerate materials, wherein the hydrophilic agglomerate materials include ceramic particles and one or more of glass microspheres, PP and PTFE; The hydrophilic and hydrophobic fiber ball module (32) is filled with dandelion-like hollow hydrophilic and hydrophobic fiber balls (34); the interior of the hollow hydrophilic and hydrophobic fiber balls (34) is a hollow ball structure (35), and the exterior is a light fiber group (36) composed of a plurality of hydrophilic fibers and hydrophobic fibers.

2. The integrated equipment for dehydration and impurity removal of waste bio-oil according to claim 1, characterized in that: The volume proportion of the ceramic particles in the ceramic particle layer module (22) is 85-95%, and the particle size of the ceramic particles is 0.5-1 mm; The ratio of the thickness of the ceramic particle layer module (22) to the total height of the inner tube (2) is 0.4-0.

5.

3. The integrated equipment for dehydration and impurity removal of waste bio-oil according to claim 1, characterized in that: The diameter of the hollow hydrophilic and hydrophobic fiber ball (34) is 30-40 mm; the diameter ratio of the hollow spherical structure (35) to the hollow hydrophilic and hydrophobic fiber ball (34) is 0.1-0.2; and the gap between the fibers in the light fiber cluster (36) is 50-100 μm.

4. The integrated equipment for dehydration and impurity removal of waste bio-oil according to claim 1, characterized in that: The ratio of the thickness of the hydrophilic and hydrophobic fiber ball module (32) to the total height of the annular outer cylinder (3) is 0.3-0.4, and the module is located at the bottom of the annular outer cylinder (3); The lightweight fiber mass (36) 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.

5. The integrated equipment for dehydration and impurity removal of waste bio-oil according to claim 1, characterized in that: The device is also provided with a PLC-controlled automatic cleaning system (4), the automatic cleaning system (4) comprising a backwash water inlet (41) and a nitrogen purge inlet (42) arranged at the bottom of the vertical tank body (1), an inner cylinder backwash water outlet (43), an annular outer cylinder backwash water outlet (44), and an exhaust port (45) arranged at the top of the vertical tank body (1), a nitrogen purge device (46) arranged in the bottom cavity (12) of the vertical tank body (1), a differential pressure gauge (47) for measuring the inlet and outlet pressure difference of the ceramic particle layer module (22), a concentration detection device for measuring the concentration of suspended matter in the imported waste bio-oil, and a PLC control system; The nitrogen purge inlet (42) is in communication with a nitrogen purge device (46), and the inner cylinder backwash water outlet (43) and the annular outer cylinder backwash water outlet (44) are in communication with the top of the inner cylinder (2) and the top cavity (11) of the vertical tank body (1), respectively; Valves are respectively provided at the backwash water inlet (41), the nitrogen purge inlet (42), the inner tube backwash water outlet (43), the annular outer tube backwash water outlet (44) and the exhaust port (45). The PLC control system is respectively connected to the differential pressure gauge (47), the concentration detection device and the valve. The PLC control system controls the opening of the valve according to the differential pressure measured by the differential pressure gauge (47) 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.

6. The integrated equipment for dehydration and impurity removal of waste bio-oil according to claim 1, characterized in that: The ratio of the diameter of the inner cylinder (2) to the outer diameter of the annular outer cylinder (3) is determined by the water content and suspended matter concentration of the imported waste bio-oil, wherein the water content and suspended matter concentration are both measured in mass fractions, and are specifically as follows: (a) when the water content of the imported waste bio-oil is less than 1 wt% and the suspended matter concentration is less than 1 wt%, the ratio of the diameter of the inner cylinder (2) to the outer diameter of the annular outer cylinder (3) is 0.5-0.6; (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 (2) to the outer diameter of the annular outer cylinder (3) is 0.6-0.7; (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 (2) to the outer diameter of the annular outer cylinder (3) is 0.7-0.8; When the water content and suspended matter concentration of the imported waste bio-oil correspond to different ratios, the suspended matter concentration shall prevail.

7. A method for dehydrating and removing impurities from waste bio-oil, characterized in that: The integrated equipment for dehydration and impurity removal of waste bio-oil according to any one of claims 1 to 6 comprises the following steps: (I) Preliminary dehydration and impurity removal: waste bio-oil enters the inner cylinder (2) from the waste bio-oil inlet (13) at the top of the vertical tank (1), and most of the suspended matter carried by the waste bio-oil floats on the upper part of the ceramic particle layer module (22). Particles and long strips of suspended matter with slightly larger particle sizes are intercepted by the ceramic particle layer module (22) during the flow process, thereby achieving separation; water droplets in the waste bio-oil adhere and aggregate in the ceramic particle layer module (22), grow into large water droplets, flow to the bottom cavity (12) of the vertical tank (1) along with the waste bio-oil, and finally settle to the water collection bag (15) for separation; (II) Deep dehydration and impurity removal: waste bio-oil carrying fine water droplets and fine suspended matter enters the annular outer cylinder (3) from the bottom cavity (12), and the hydrophilic and hydrophobic fiber ball module (32) in the annular outer cylinder (3) further intercepts the entrained fine suspended matter in the waste bio-oil, aggregates, intercepts and separates the entrained fine water droplets, and the grown water droplets settle to the bottom cavity (12) for separation, and the treated oil phase is discharged from the top cavity (11) at the top of the vertical tank body (1), thereby achieving deep dehydration and impurity removal of the waste bio-oil.

8. The method for dehydrating and removing impurities from waste bio-oil according to claim 7, characterized in that: The water content in the inlet waste bio-oil is 1-5wt% and the suspended matter concentration is 0.5-2wt%; The inlet flow rate of the waste bio-oil is 8-10m 3 / h, the operating temperature is controlled at 80-110℃; The cross-sectional flow rate of the waste bio-oil entering the ceramic particle layer module (22) of the inner cylinder (2) is controlled at 0.003-0.005 m / s, and the cross-sectional flow rate of the waste bio-oil entering the hydrophilic and hydrophobic fiber ball module (32) of the annular outer cylinder (3) is controlled at 0.001-0.003 m / s.

9. The method for dehydrating and removing impurities from waste bio-oil according to claim 7, characterized in that: The method further comprises a step (III) of backwashing: backwash water and nitrogen enter the inner cylinder (2) and the annular outer cylinder (3) from the bottom cavity (12) of the vertical tank body (1), flow in the same direction from bottom to top, and then are discharged from the top of the vertical tank body (1); The backwash is controlled by differential pressure, that is, the backwash frequency is controlled according to the inlet and outlet pressure difference of the ceramic particle layer module (22). 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.

10. The method for dehydrating and removing impurities from waste bio-oil according to claim 9, characterized in that: The backwash time is determined according to the concentration of suspended matter in the imported waste bio-oil, as follows: (a) When the suspended solids concentration of the imported waste bio-oil is less than 0.1 wt%, the backwash time is 40-60 s; (b) When the suspended matter concentration of the imported waste bio-oil is 0.1-0.5 wt %, the backwash time is 60-80 s; (c) When the suspended solids concentration of the imported waste bio-oil is higher than 0.5wt%, the backwash time is 80-150s.

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