A pretreatment device and a pretreatment method for kitchen organic slurry

Abstract

The application discloses a pretreatment device and method for kitchen organic slurry, and belongs to the technical field of organic garbage treatment. The pretreatment device comprises a homogenate reactor, a high-pressure pyrolysis reactor and a flash evaporation reactor which are sequentially connected. Different temperature treatments are arranged in the homogenate reactor, the high-pressure pyrolysis reactor and the flash evaporation reactor through the pretreatment device, so that the cell walls of organic matter in the kitchen organic slurry are broken, the biodegradability of the slurry is improved, and subsequent anaerobic fermentation treatment is facilitated.

Description

TECHNICAL FIELD

[0001] The application relates to a pretreatment device and a pretreatment method for kitchen organic slurry, and belongs to the technical field of organic garbage treatment. BACKGROUND

[0002] The kitchen organic slurry generally contains a large amount of decomposable organic matter, in order to improve resource utilization and reduce resource waste, anaerobic treatment is usually used to produce biogas as an organic waste resource utilization approach.

[0003] However, due to the high water content, low calorific value and easy corruption of the kitchen organic slurry, and the fact that the slurry is rich in glue and starch substances, the slurry contains a large amount of intercellular water, and the protection of cell walls and cell membranes makes it difficult to degrade the organic matter in the slurry, and the treatment effect is poor. Therefore, there are problems such as difficult debugging, long residence time, high energy consumption, high investment, low biogas production rate and poor economic benefit in the anaerobic treatment of kitchen organic slurry. SUMMARY

[0004] In order to solve the above problems, the application provides a pretreatment device and a pretreatment method for kitchen organic slurry. Through the pretreatment method, the cells of the organic matter in the kitchen organic slurry can be broken, the biodegradability of the slurry can be improved, and the subsequent anaerobic fermentation treatment is facilitated.

[0005] According to one aspect of the application, a pretreatment device for kitchen organic slurry is provided, comprising:

[0006] A homogenate reactor is provided with a homogenate feed inlet, a waste steam inlet and a homogenate discharge outlet. The kitchen organic slurry enters the homogenate reactor through the homogenate feed inlet. The homogenate reactor is provided with a first stirring paddle. The particle size of the kitchen organic slurry is less than or equal to 10 mm, the water content is 85-95%, and the oil content is less than or equal to 1%.

[0007] A high-pressure pyrolysis reactor is provided with a high-pressure pyrolysis feed inlet, a new steam inlet and a high-pressure pyrolysis discharge outlet. The high-pressure pyrolysis feed inlet is connected to the homogenate discharge outlet through a high-pressure pyrolysis feed pipeline. The new steam inlet is connected to a steam feed pipeline. The high-pressure pyrolysis reactor is also provided with a second stirring paddle.

[0008] A flash reactor is provided with a flash feed inlet, a flash discharge outlet and a waste steam outlet. The flash feed inlet is connected to the high-pressure pyrolysis discharge outlet through a high-pressure pyrolysis discharge pipeline. The flash discharge outlet is connected to a flash discharge pipeline. The waste steam outlet is connected to the waste steam inlet through a waste steam pipeline.

[0009] Optionally, the second stirring paddle comprises a stirring shaft and stirring blades, and a discharge slot is arranged on one side of the stirring blades, and the discharge slot is used for placing the pretreatment agent;

[0010] The discharge slot is square, and the discharge slot is hollow inside to form a containing cavity for containing the pretreatment agent. The top of the discharge slot is provided with a movable cover plate, and the movable cover plate is opened to place the pretreatment agent in the containing cavity. The bottom of the discharge slot is provided with a discharge port.

[0011] Optionally, the bottom of the discharge slot is inverted trapezoidal, and the discharge port is arranged at the lowermost part of the bottom.

[0012] Optionally, a preheating feeding pipe is further included, and the kitchen organic slurry enters the homogenizing reactor through the preheating feeding pipe and the homogenizing feeding port.

[0013] Optionally, the homogenizing reactor, the high-pressure pyrolysis reactor, and the flash reactor are all provided with a heat preservation structure.

[0014] Optionally, the homogenizing reactor, the high-pressure pyrolysis reactor, and the flash reactor are all provided with a temperature sensor, a pressure sensor, and a liquid level sensor.

[0015] According to another aspect of the present application, a pretreatment method for kitchen organic slurry is provided, which is performed by using the pretreatment device for kitchen organic slurry described in any one of the above, and comprises the following steps:

[0016] (1) The kitchen organic slurry with a particle size of ≤10 mm, a water content of 85-95%, and an oil content of ≤1% is transported into the homogenizing reactor through the homogenizing feeding port, and the waste steam flowing out of the flash reactor enters the homogenizing reactor through the waste steam inlet, so that the waste steam heats the kitchen organic slurry in the homogenizing reactor. The kitchen organic slurry is heated to 80-90°C by the first stirring paddle, and after being treated for 20-30 min, an intermediate material A is obtained;

[0017] (2) The intermediate material A enters the high-pressure pyrolysis reactor through the homogenizing discharge port, the high-pressure pyrolysis feeding pipe, and the high-pressure pyrolysis feeding port, and the new steam transported by the steam feeding pipe also enters the high-pressure pyrolysis reactor through the new steam inlet. Under the stirring of the second stirring paddle, the new steam and the intermediate material A are mixed, and are treated at 0.6-1.6 MPa and 140-160°C for at least 30 min to obtain an intermediate material B;

[0018] (3) The intermediate material B and the steam in the high-pressure cracking reactor are under the action of the pressure difference between the high-pressure cracking reactor and the flash reactor, and flow into the flash reactor through the high-pressure cracking outlet, the high-pressure cracking pipeline and the flash feeding inlet. The intermediate material B is cooled to 110-120 DEG C in the flash reactor, and is reduced to normal pressure. The pre-treatment material is obtained from the flash outlet. The waste steam in the flash reactor flows out from the waste steam outlet to the waste steam inlet of the homogenizing reactor.

[0019] The pre-treatment method can break the cell wall of the organic matter in the kitchen organic slurry through the high-pressure cracking reaction, improve the biodegradability of the slurry, reduce the anaerobic scum, shorten the anaerobic time and improve the biogas production rate, thereby reducing the anaerobic area and investment cost and obtaining higher benefits.

[0020] Optionally, the second stirring paddle comprises a stirring shaft and a stirring blade, and a discharge groove is arranged on one side of the stirring blade, and the discharge groove is used for placing the pre-treatment agent. In step (2), the new steam, the pre-treatment agent and the intermediate material A are mixed under the stirring of the second stirring paddle, and are treated at 0.6-1.6 MPa and 140-160 DEG C for at least 30 min to obtain the intermediate material B. In step (3), the material flowing out from the flash outlet is filtered to obtain the pre-treatment material.

[0021] Because the kitchen organic slurry contains sulfur-containing organic matter, sulfate and carbonate, the sulfur-containing organic matter is easy to produce H2S gas in the anaerobic treatment, which not only causes equipment damage, but also threatens the health and life of the operator when improperly operated. The sulfate and carbonate have an inhibitory effect on anaerobic treatment, which is not conducive to subsequent anaerobic treatment. At present, some desulfurizing agents are added in some anaerobic fermentation to remove sulfur elements, but the desulfurizing agents are not uniformly dispersed in the fermentation process, and the removal capacity of sulfur elements is limited, and the production of H2S gas cannot be avoided. The removal of sulfate and carbonate often uses the water washing method, but the water consumption is generally 1.5 times or more than the slurry, so a large amount of wastewater is generated, causing resource waste. The wastewater needs to be treated again before being recycled, increasing the post-treatment cost. Therefore, the discharge groove for placing the pre-treatment agent is arranged in the second stirring paddle of the high-pressure cracking reactor. The pre-treatment agent flows out of the discharge groove under the stirring of the second stirring paddle, which can improve the dispersion efficiency and pre-treatment efficiency of the pre-treatment agent, thereby improving the removal efficiency of the sulfur ions, calcium ions, sulfate ions and carbonate ions, reducing the pre-treatment time and saving the pre-treatment cost.

[0022] Optionally, the preparation method of the pre-treatment agent is as follows:

[0023] S1: 2-4 parts of chitosan are dissolved in 100-120 parts of acetic acid solution to swell, and alumina with a particle size greater than 10 mm is added as a carrier, then heated to 60℃, and then 100-200 parts of liquid paraffin and 1-5 parts of sorbitan monooleate are emulsified, then 10-20 parts of formaldehyde solution and 15-25 parts of 2,4-dihydroxybenzaldehyde solution are added, the pH value is adjusted to 7-10, and then reacted for 30 min, filtered, washed with water to neutral, extracted, and dried to obtain an intermediate;

[0024] S2: the intermediate is added to 100-120 parts of copper nitrate solution, and reacted at 30-40℃ and pH 3-5 for 2-5h, then filtered and dried to obtain the pretreatment agent.

[0025] The pretreatment agent used in the present application is obtained by crosslinking formaldehyde, 2,4-dihydroxybenzaldehyde and chitosan on the surface of alumina to obtain an intermediate, and then modifying the intermediate with copper nitrate. The 2,4-dihydroxybenzaldehyde in the pretreatment agent introduces phenolic hydroxyl groups, which can adsorb calcium ions, and the copper ions in the copper nitrate can react with sulfur ions to form copper sulfide and be adsorbed on the surface of the pretreatment agent. The intermediate contains a large amount of hydroxyl groups, amino groups, imino groups and carbon-nitrogen double bonds, which can adsorb sulfate ions and carbonate ions in the system. Therefore, the pretreatment agent can simultaneously adsorb calcium ions, sulfur ions, sulfate ions and carbonate ions, greatly reducing the content of the four ions in the kitchen organic slurry, and facilitating the smooth operation of subsequent anaerobic operation.

[0026] In addition, since the carrier used has a diameter greater than 10 mm, and the particle size of other particles in the intermediate B after the above high-pressure cracking treatment is ≤10 mm, the pretreatment agent can be intercepted by filtering the material flowing out of the flash discharge port, thereby removing calcium ions, sulfur ions, sulfate ions and carbonate ions in the kitchen organic slurry.

[0027] Optionally, the mass concentration of 2,4-dihydroxybenzaldehyde in the 2,4-dihydroxybenzaldehyde solution is 50%-70%, and the mass concentration of formaldehyde in the formaldehyde solution is 35%-40%.

[0028] Optionally, the concentration of copper ions in the copper nitrate solution is 500-600mg / L.

[0029] The beneficial effects that can be produced by the present application include but are not limited to:

[0030] 1. The pretreatment device and method for kitchen organic slurry of the present application, through high-pressure cracking reaction, the cell wall is broken, the biodegradability of the organic slurry is improved, the difficulty of subsequent anaerobic treatment is reduced, the anaerobic reaction residence time is reduced, and the slurry biogas production rate is improved.

[0031] 2. The pretreatment agent added in the pretreatment method for kitchen organic slurry of the present application can realize the synchronous removal of calcium ions, sulfur ions, sulfate ions and carbonate ions, improve the ion removal efficiency, reduce the treatment cost of kitchen organic slurry, and improve the anaerobic efficiency and anaerobic safety. BRIEF DESCRIPTION OF DRAWINGS

[0032] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their description serve to explain the present application. They do not constitute an improper limitation on the present application. In the drawings:

[0033] Fig. 1 A structural schematic diagram of the pretreatment device for kitchen organic slurry involved in the embodiment 1 of the present application;

[0034] Fig. 2 A side sectional schematic diagram of the discharge chute involved in the embodiment 1 of the present application;

[0035] List of components and reference numerals:

[0036] 1, homogenate reactor; 2, high-pressure pyrolysis reactor; 3, flash reactor; 4, high-pressure pyrolysis feed pump; 5, flash discharge pump; 6, preheating feed pipeline; 7, steam feed pipeline; 8, flash discharge pipeline; 9, high-pressure pyrolysis feed pipeline; 10, high-pressure pyrolysis discharge pipeline; 11, flash discharge pipeline; 12, discharge chute; 13, movable cover plate; 14, discharge port. DETAILED DESCRIPTION

[0037] In order to more clearly explain the overall concept of the present application, the following will be described in detail with reference to the drawings.

[0038] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0040] In addition, in the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0041] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0042] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection, or communication; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0044] The kitchen organic slurry involved in the following examples 1 and 2 refers to the organic slurry obtained by filtering and separating the kitchen waste collected from various restaurant kitchen waste and household kitchen waste, and the oil extraction is only carried out on the kitchen waste with high oil content. If the oil content meets the requirement of ≤1%, oil extraction is not required.

[0045] Example 1

[0046] refer to Figs. 1-2 This application discloses a pretreatment device for kitchen waste organic slurry, comprising: a homogenizing reactor 1, which is provided with a homogenizing inlet, a waste steam inlet, and a homogenizing outlet 14, through which the kitchen waste organic slurry enters the homogenizing reactor 1, and a first stirring paddle is provided inside the homogenizing reactor 1; a high-pressure pyrolysis reactor 2, which is provided with a high-pressure pyrolysis inlet, a new steam inlet, and a high-pressure pyrolysis outlet 14, wherein the high-pressure pyrolysis inlet is connected to the homogenizing outlet 14 through a high-pressure pyrolysis inlet pipe 9, the new steam inlet is connected to a steam inlet pipe 7, and a second stirring paddle is also provided inside the high-pressure pyrolysis reactor 2; and a flash evaporation reactor 3, which includes a flash evaporation inlet, a flash evaporation outlet 14, and a waste steam outlet, wherein the flash evaporation inlet is connected to the high-pressure pyrolysis outlet 14 through a high-pressure pyrolysis outlet pipe 10, the flash evaporation outlet 14 is connected to a flash evaporation outlet pipe 118, and the waste steam outlet is connected to the waste steam inlet through a waste steam pipe.

[0047] In this pretreatment device, a homogenizing reactor 1, a high-pressure pyrolysis reactor 2, and a flash reactor 3 are connected in sequence to achieve pretreatment of kitchen waste organic slurry. Specifically, kitchen waste organic slurry with a particle size ≤10mm, a moisture content of 85-95%, and an oil content ≤1% is fed into the homogenizing reactor 1, where it is stirred and mixed with waste steam from the flash reactor 3. After being heated to a specified temperature, it is sent to the high-pressure pyrolysis reactor 2 through the high-pressure pyrolysis feed pump 4 and the high-pressure pyrolysis feed pipe 9, where it is stirred and mixed with fresh steam, resulting in a high-pressure pyrolysis reaction that degrades the organic matter. The slurry after the reaction is sent to the flash reactor 3 for depressurization and cooling, and the generated waste steam is returned to the homogenizing reactor 1. After the slurry is cooled, it is sent to the next treatment unit through the flash discharge pump 5 and the flash discharge pipe 118.

[0048] Under the aforementioned pretreatment, the kitchen waste organic slurry undergoes high-pressure pyrolysis in the high-pressure pyrolysis reactor 2, which disrupts the cell walls within the slurry, thereby improving its biodegradability. This reduces the difficulty of subsequent anaerobic treatment, shortens the anaerobic treatment time, and increases the biogas production rate of the organic slurry. In other words, it reduces costs while increasing production capacity, resulting in significant economic benefits. Furthermore, the heating of the kitchen waste organic slurry in the homogenizing reactor 1 utilizes the waste steam flowing out of the flash reactor 3. This treatment improves steam utilization efficiency, further reducing production costs.

[0049] In one embodiment, the second stirring paddle includes a stirring shaft and stirring blades. A discharge trough 12 is provided on one side of the stirring blades. The discharge trough 12 is used to place the pretreatment agent. The discharge trough 12 is square and hollow inside to form a receiving cavity for accommodating the pretreatment agent. A movable cover plate 13 is provided on the top of the discharge trough 12. Opening the movable cover plate 13 is used to place the pretreatment agent into the receiving cavity. A discharge port 14 is provided at the bottom of the discharge trough 12.

[0050] The discharge tank 12 is designed to store pretreatment agents, and during the high-pressure pyrolysis reaction, the pretreatment agents are mixed into the kitchen waste organic slurry by the stirring of the second agitator, thereby achieving the adsorption treatment of harmful substances in the organic slurry and preventing harmful substances from affecting subsequent anaerobic operations.

[0051] In one implementation, the bottom of the discharge trough 12 is inverted trapezoidal, and the discharge port 14 is located at the bottommost point. This arrangement facilitates the outflow of the pretreatment agent, improves the pretreatment efficiency of kitchen waste organic slurry, and further reduces the content of harmful substances in the kitchen waste organic slurry.

[0052] Specifically, the discharge trough 12 can be fixedly connected or detachably connected to the stirring blade. When fixedly connected, to facilitate the addition of pretreatment agent into the discharge trough 12, a feeding pipe connected to the discharge trough 12 can be installed. This feeding pipe passes through the movable cover plate 13 and penetrates into the discharge trough 12 to feed the pretreatment agent. This connection and feeding method enable automatic feeding, and no baffle is needed at the discharge port. The addition of pretreatment agent can be automatically stopped when the high-pressure cracking reaction ends or the amount of pretreatment agent added reaches the set value. When detachably connected, pretreatment agent needs to be added... During the pretreatment process, the operator removes the discharge trough 12 and places the pretreatment agent into it by opening the movable cover plate 13. Then, the discharge trough 12 is installed on the stirring blade. It should be noted that this connection and the method of adding the pretreatment agent require an automatically opening and closing baffle to be installed at the discharge port 14 to prevent the pretreatment agent from flowing out. When adding material to the discharge trough 12, the baffle is set to the closed state. When the pretreatment agent needs to flow out, the baffle is set to the open state to allow the pretreatment agent to flow out. The automatically opening and closing baffle can be electrically driven, and the power source can be an external wire or an energy storage battery.

[0053] In one embodiment, a preheated feed pipe 6 is also included, through which the kitchen waste organic slurry enters the homogenizing reactor 1. The preheated feed pipe 6 facilitates the transport of the kitchen waste organic slurry into the homogenizing reactor 1, making it easier for operators to use and improving the ease of use of the device.

[0054] In one implementation, the homogenizing reactor 1, the high-pressure pyrolysis reactor 2, and the flash reactor 3 are all equipped with external insulation structures. The insulation structures improve the temperature stability of these three reactors, thus enhancing the stability of the treatment of kitchen waste organic slurry and enabling the device to operate efficiently and continuously.

[0055] Optionally, the homogenizing reactor 1, the high-pressure pyrolysis reactor 2, and the flash reactor 3 are all equipped with temperature sensors, pressure sensors, and liquid level sensors.

[0056] The above settings allow for controllable temperature, pressure, and liquid level in the homogenizing reactor 1, high-pressure pyrolysis reactor 2, and flash reactor 3, facilitating operation and improving the efficiency and convenience of pretreatment.

[0057] In one implementation, the high-pressure pyrolysis process of the pretreatment device of this application can be a sequential batch operation, and the high-pressure pyrolysis reactor 2 can be set up in series with one or more reactors depending on the processing capacity.

[0058] As one implementation method, the high-pressure pyrolysis process can be operated continuously, and the high-pressure pyrolysis reactor 2 needs to be set up with multiple reactors in parallel according to the processing capacity.

[0059] As a specific implementation method, the operation stages of the homogenizing reactor 1 are divided into feeding, preheating, stirring, and discharging. Depending on the material conditions, waste steam volume, and homogenization reaction time, the preheating stage of the homogenizing reactor 1 may or may not introduce new steam. The operation stages of the high-pressure pyrolysis reactor 2 are divided into feeding, heating, heat preservation and pressure holding, high-pressure pyrolysis, and pressure relief and discharging. Depending on the preheating status of the homogenizing reactor 1, the heating stage may or may not introduce waste steam. When there is a surplus of waste steam after the homogenizing reactor 1 has completed preheating, the high-pressure pyrolysis reactor 2 introduces waste steam first, followed by new steam, during the heating stage. The operation stages of the flash reactor 3 are divided into feeding, atmospheric pressure flash evaporation, waste steam discharge, and discharging. Depending on the amount of waste steam discharged, the process of introducing waste steam into the high-pressure pyrolysis reactor 2 may or may not be selected; this process is controlled by an automatic valve.

[0060] It should be noted that the device used in this embodiment for the pretreatment of kitchen waste organic slurry uses a PLC as the controller. Other details not described herein do not constitute a limitation on the present invention. Those skilled in the art can choose conventional operations from the prior art according to actual needs.

[0061] Example 2

[0062] This embodiment relates to a pretreatment method for kitchen waste organic slurry, which uses the pretreatment device for kitchen waste organic slurry of Embodiment 1. It uses kitchen waste organic slurry with a particle size of 10mm, a water content of 85%, and an oil content of 1% as the pretreatment raw material. Pretreatment materials 1#-5# are obtained through different treatments as follows:

[0063] Pre-treated material #1:

[0064] (1) The kitchen waste organic slurry is transported to the homogenizing reactor 1 through the homogenizing feed inlet. The waste steam flowing out of the flash reactor 3 enters the homogenizing reactor 1 through the waste steam inlet. The waste steam heats the kitchen waste organic slurry in the homogenizing reactor 1. The kitchen waste organic slurry is stirred and heated to 80°C by the first stirring paddle. After 30 minutes of treatment, intermediate material A is obtained.

[0065] (2) Intermediate material A enters the high-pressure pyrolysis reactor 2 through the homogenization outlet 14, the high-pressure pyrolysis feed pipe 9 and the high-pressure pyrolysis feed port. The new steam delivered by the steam feed pipe 7 also enters the high-pressure pyrolysis reactor 2 through the new steam inlet. Under the stirring of the second stirring paddle, the new steam and intermediate material A are mixed and treated at 0.6 MPa and 160℃ for 30 min to obtain intermediate material B.

[0066] (3) Under the pressure difference between intermediate material B and the high-pressure pyrolysis reactor 2, the steam flows into the flash reactor 3 by gravity through the high-pressure pyrolysis outlet 14, the high-pressure pyrolysis outlet pipe 10 and the flash inlet. The intermediate material B is cooled to 120°C and reduced to atmospheric pressure in the flash reactor 3 and then flows out from the flash outlet 14 to obtain pretreated material 1#. The waste steam in the flash reactor 3 flows out from the waste steam outlet to the waste steam inlet of the homogenizing reactor 1.

[0067] Pre-treated material #2:

[0068] Preparation of pretreatment agent:

[0069] S1: Dissolve 2 parts of chitosan in 100 parts of acetic acid solution to swell, and add alumina with a particle size of 12 mm as a carrier. After heating to 60℃, add 200 parts of liquid paraffin and 1 part of sorbitan monooleate for emulsification. Then add 20 parts of formaldehyde solution with a mass concentration of 35% and 15 parts of 2,4-dihydroxybenzaldehyde solution with a mass concentration of 50%. Adjust the pH to 7 and react for 30 min. Filter, wash with water until neutral, extract and dry to obtain the intermediate.

[0070] S2: The intermediate was added to 120 parts of copper nitrate solution with a copper ion concentration of 500 mg / L. The reaction was carried out at 40 °C and pH 3 for 2 h. After filtration and drying, the pretreatment agent was obtained.

[0071] Preparation of pretreated material #2:

[0072] (1) The kitchen waste organic slurry is transported to the homogenizing reactor 1 through the homogenizing feed inlet. The waste steam flowing out of the flash reactor 3 enters the homogenizing reactor 1 through the waste steam inlet. The waste steam heats the kitchen waste organic slurry in the homogenizing reactor 1. The kitchen waste organic slurry is stirred and heated to 90°C by the first stirring paddle. After 20 minutes of treatment, intermediate material A is obtained.

[0073] (2) Intermediate material A enters the high-pressure pyrolysis reactor 2 through the homogenization outlet 14, the high-pressure pyrolysis feed pipe 9 and the high-pressure pyrolysis feed port. The fresh steam delivered by the steam feed pipe 7 also enters the high-pressure pyrolysis reactor 2 through the fresh steam inlet. The second stirring paddle includes a stirring shaft and stirring blades. A discharge trough 12 is set on one side of the stirring blades. The discharge trough 12 is used to place the pretreatment agent. The fresh steam, pretreatment agent and intermediate material A are mixed and treated at 1.6 MPa and 140℃ for 40 min to obtain intermediate material B.

[0074] (3) Under the pressure difference between intermediate material B and the high-pressure pyrolysis reactor 2, the steam flows into the flash reactor 3 by gravity through the high-pressure pyrolysis outlet 14, the high-pressure pyrolysis outlet pipe 10 and the flash inlet. The intermediate material B is cooled to 110°C and reduced to atmospheric pressure in the flash reactor 3 and then flows out from the flash outlet 14. After being filtered through a filter screen with a pore size of 10 mm, the pretreated material 2# is obtained. The waste steam in the flash reactor 3 flows out from the waste steam outlet to the waste steam inlet of the homogenizing reactor 1.

[0075] Pre-treated material #3

[0076] The difference between pretreatment material #3 and pretreatment material #2 lies in the preparation of the pretreatment agent; the remaining steps are the same as for pretreatment material #2. The specific preparation of the pretreatment agent is as follows:

[0077] S1: 4 parts of chitosan were dissolved in 120 parts of acetic acid solution to swell, and alumina with a particle size of 11 mm was added as a carrier. After heating to 60℃, 200 parts of liquid paraffin and 5 parts of sorbitan monooleate were added for emulsification. Then, 10 parts of formaldehyde solution with a mass concentration of 40% and 25 parts of 2,4-dihydroxybenzaldehyde solution with a mass concentration of 70% were added. After adjusting the pH to 10, the reaction was carried out for 30 min. The mixture was filtered, washed with water until neutral, extracted, and dried to obtain the intermediate.

[0078] S2: The intermediate was added to 100 parts of copper nitrate solution with a copper ion concentration of 600 mg / L. The reaction was carried out at 30°C and pH 3 for 5 hours. After filtration and drying, the pretreatment agent was obtained.

[0079] Pre-treated material #4

[0080] The difference between this pretreatment material 4# and pretreatment material 2# is that the preparation of the pretreatment agent does not include step S2, that is, the intermediate in step S1 is the pretreatment agent, and the remaining steps are the same as those of pretreatment material 2#.

[0081] Pre-treated material #5

[0082] The difference between this pretreatment material 5# and pretreatment material 2# is that 2,4-dihydroxybenzaldehyde solution was not added in step S1 of the preparation of the pretreatment agent; the remaining steps are the same as those of pretreatment material 2#.

[0083] Test Example 1

[0084] The sulfur ions, calcium ions, sulfate ions, and carbonate ions in the pretreated material prepared in Example 2 were detected. The concentrations of sulfur ions, calcium ions, sulfate ions, and carbonate ions in pretreated material 1# were used as the original values. The removal rates of the above ions in pretreated materials 2#-5# were calculated. For example, the removal rate of sulfur ions in pretreated material 2# = (sulfur ion content in pretreated material 1# - sulfur ion content in pretreated material 2#) / sulfur ion content in pretreated material 1# * 100. The results are shown in Table 1 below.

[0085] Table 1

[0086]

[0087] Test Example 2

[0088] The pretreated material prepared in Example 2 was subjected to anaerobic treatment. The residence time and biogas production during the operation were statistically analyzed, and the biogas production rate was calculated. The untreated initial organic slurry (particle size of 10 mm, water content of 85%, and oil content of 1%), which was the same as that in Example 2, was used as a control group. The residence time and biogas production during the operation of the control group were statistically analyzed, and the biogas production rate was calculated. The results are shown in Table 2 below.

[0089] Table 2

[0090]

[0091] The H2S content in pretreated materials 2#-5# in the table above is lower than that in pretreated material 1#, but the decrease is less than the sulfur ion removal rate in Table 1. This is because some of the sulfate ions remaining in the organic slurry will also react to generate H2S during anaerobic treatment.

[0092] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0093] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A pretreatment device for a kitchen organic slurry, characterized by, It comprises: A homogenate reactor, which is provided with a homogenate feed inlet, a waste steam inlet and a homogenate discharge outlet, and the kitchen organic slurry enters the homogenate reactor through the homogenate feed inlet, and the homogenate reactor is provided with a first stirring paddle, and the particle size of the kitchen organic slurry is ≤10mm, the water content is 85-95%, and the oil content is ≤1%; A high-pressure cracking reactor, which is provided with a high-pressure cracking feed inlet, a new steam inlet and a high-pressure cracking discharge outlet, the high-pressure cracking feed inlet is connected with the homogenate discharge outlet through a high-pressure cracking feed pipeline, the new steam inlet is connected with a steam feed pipeline, and the high-pressure cracking reactor is also provided with a second stirring paddle; A flash reactor, which comprises a flash feed inlet, a flash discharge outlet and a waste steam outlet, the flash feed inlet is connected with the high-pressure cracking discharge outlet through a high-pressure cracking discharge pipeline, the flash discharge outlet is connected with a flash discharge pipeline, and the waste steam outlet is connected with the waste steam inlet through a waste steam pipeline; The second stirring paddle comprises a stirring shaft and a stirring blade, one side of the stirring blade is provided with a discharge groove, and the discharge groove is used for placing a pretreatment agent; The discharge groove is square, the inside of the discharge groove is hollow to form a containing cavity for containing the pretreatment agent, the top of the discharge groove is provided with a movable cover plate, the movable cover plate is opened to place the pretreatment agent in the containing cavity, and the bottom of the discharge groove is provided with a discharge port; The preparation method of the pretreatment agent is as follows in terms of weight parts: S1: 2-4 parts of chitosan are dissolved in 100-120 parts of acetic acid solution to swell, and aluminum oxide with a particle size greater than 10mm is added as a carrier, then 100-200 parts of liquid paraffin and 1-5 parts of sorbitan monooleate are emulsified after being heated to 60℃, then 10-20 parts of formaldehyde solution and 15-25 parts of 2,4-dihydroxybenzaldehyde solution are added, the pH value is adjusted to 7-10, and then the reaction is carried out for 30min, and then the intermediate is obtained by filtering, washing to neutral, extracting and drying; S2: the intermediate is added to 100-120 parts of copper nitrate solution, and the reaction is carried out at 30-40℃ and pH 3-5 for 2-5h, and then the pretreatment agent is obtained by suction filtration and drying.

2. The pre-treatment device of claim 1, wherein The bottom of the discharge groove is inverted trapezoidal, and the discharge port is arranged at the lowermost part of the bottom.

3. The pre-treatment device of claim 1, wherein It also comprises a preheating feed pipeline, and the kitchen organic slurry enters the homogenate reactor through the preheating feed pipeline and the homogenate feed inlet.

4. The pre-treatment device of claim 1, wherein The homogenate reactor, the high-pressure cracking reactor and the flash reactor are all provided with a temperature sensor, a pressure sensor and a liquid level sensor. It is carried out by using the pretreatment device for kitchen organic slurry in any one of claims 1-4, comprising the following steps:

5. A method for pretreatment of a kitchen organic slurry, characterized by, ​ (1) the kitchen waste organic slurry with particle size ≤10 mm, water content of 85-95%, and oil content ≤1% is transported into the homogenizing reactor through the homogenizing feed inlet, the waste steam from the flash reactor flows into the homogenizing reactor through the waste steam inlet, the waste steam heats the kitchen waste organic slurry in the homogenizing reactor, the kitchen waste organic slurry is heated to 80-90℃ by the first stirring paddle, and after 20-30 min of treatment, intermediate material A is obtained; (2) the intermediate material A enters into the high-pressure pyrolysis reactor through the homogenizing outlet, the high-pressure pyrolysis feed pipeline, and the high-pressure pyrolysis feed inlet, the new steam transported by the steam feed pipeline also enters into the high-pressure pyrolysis reactor through the new steam inlet, under the stirring of the second stirring paddle, the new steam and the intermediate material A are mixed, and after at least 30 min of treatment at 0.6-1.6 MPa and 140-160℃, intermediate material B is obtained; (3) the intermediate material B and the steam in the high-pressure pyrolysis reactor flow into the flash reactor through the high-pressure pyrolysis outlet, the high-pressure pyrolysis outlet pipeline, and the flash feed inlet under the action of the pressure difference between the flash reactor, the intermediate material B is cooled to 110-120℃ and reduced to normal pressure in the flash reactor, and then flows out from the flash outlet to obtain pretreated material, and the waste steam in the flash reactor flows out from the waste steam outlet to the waste steam inlet of the homogenizing reactor; the second stirring paddle comprises a stirring shaft and stirring blades, one side of the stirring blades is provided with a discharge groove, the discharge groove is used for placing a pretreatment agent, in step (2), under the stirring of the second stirring paddle, the new steam, the pretreatment agent, and the intermediate material A are mixed, and after at least 30 min of treatment at 0.6-1.6 MPa and 140-160℃, intermediate material B is obtained, and in step (3), the material flowing out from the flash outlet is filtered to obtain the pretreated material; the preparation method of the pretreatment agent is as follows: S1: 2-4 parts of chitosan are dissolved in 100-120 parts of acetic acid solution to swell, and aluminum oxide with a particle size greater than 10 mm is added as a carrier, then 100-200 parts of liquid paraffin and 1-5 parts of sorbitan monooleate are emulsified after being heated to 60℃, then 10-20 parts of formaldehyde solution and 15-25 parts of 2,4-dihydroxybenzaldehyde solution are added, the pH value is adjusted to 7-10, and then reacted for 30 min, filtered, washed with water to neutral, extracted, and dried to obtain an intermediate; S2: the intermediate is added to 100-120 parts of copper nitrate solution, and reacted at 30-40℃ and pH 3-5 for 2-5 h, then filtered and dried to obtain the pretreatment agent.

6. The pre-treatment method according to claim 5, characterized in that, The mass concentration of 2,4-dihydroxybenzaldehyde in the 2,4-dihydroxybenzaldehyde solution is 50%-70%, and the mass concentration of formaldehyde in the formaldehyde solution is 35%-40%.

7. The pre-treatment method of claim 5, wherein, The concentration of copper ions in the copper nitrate solution is 500-600 mg / L.

Images