Furfural residue recycling method and system

Abstract

The invention discloses a method for recycling furfural residues. The method comprises the following steps: S1, conveying the furfural residues discharged by a hydrolysis kettle to a stirring kettle in a furfural production process; s2, blowing a proper amount of powdery calcium oxide into a stirring kettle containing the furfural residues by using an air blower; S3, dehydrating the furfural residues to be neutral after full stirring reaction; s4, taking the furfural residue after the reaction as a biomass boiler fuel; and S5, furnace ash obtained after combustion is treated as organic fertilizer, the temperature of the furfural residues entering the hydrolysis kettle in the step 1 is 60-85 DEG C, and the water content in the furfural residues in the step 1 is 40%-55%. According to the invention, the neutralized furfural residue is sent to the flue gas generated by combustion without desulfurization treatment basically, so that the treatment cost is reduced, and the environmental influence in the tail gas treatment process is improved; the moisture in the furfural residues is reduced, the heat value is increased, and the production economic benefits are increased; the stove ash is rich in elements such as N and P and can be used as organic fertilizer.

Description

Technical Field

[0001] The invention relates to the technical field of furfural residue recovery, and in particular to a method and a system for recovering furfural residue. Background Art

[0002] Furfural is scientifically known as α-furfurylaldehyde, with a molecular formula of C4H3O·CHO. It is an important organic chemical raw material and chemical solvent widely used in the petroleum industry, chemical industry, medicine, food, synthetic rubber, synthetic resin and other industries. There are more than 1,600 chemical products directly and indirectly synthesized with it, including furfuryl alcohol, maleic anhydride, tetrahydrofuran, furan resin, furfural resin, furfural ketone resin, etc. China produces a huge amount of furfural slag every year. For every ton of furfural produced, about 12-15 tons of furfural slag are produced, and the annual emission of furfural slag in my country reaches 2.4 million to 3 million tons. Furfural slag is a waste generated in the process of biomass hydrolysis. It has a high salt content and is acidic. Its large accumulation will pollute the atmosphere, soil and rivers.

[0003] With the development of the chemical industry, the demand for furfural is increasing, and the discharge of furfural residue is also increasing. As a kind of biomass waste, furfural residue contains a large amount of cellulose, hemicellulose and lignin, and has good recycling value. Therefore, the rational resource utilization of furfural residue, eliminating its pollution to the environment, increasing the economic added value of furfural residue, achieving zero discharge of pollutants in the production process of furfural, and achieving the purpose of clean production and recycling are the problems that need to be solved in the resource utilization of furfural.

[0004] At present, furfural slag is directly sent for combustion. In the process of combustion, not only a large amount of sulfur is produced, resulting in high cost of flue gas desulfurization, but also the treatment of ash requires cost, and it will also have a certain adverse impact on the environment. Based on the existing furfural slag treatment methods, calcium oxide is used for neutralization. The flue gas generated by sending the neutralized furfural slag for combustion basically does not need desulfurization treatment, and the ash can also be used as organic fertilizer. It not only increases the profit of furfural production, but also greatly improves the environmental impact of furfural slag treatment.

[0005] At present, the commonly used methods for treating furfural residue are: 1. Furfural residue is directly transported to the warehouse for storage through a belt; 2. After cooling and drying, it is directly put into the furnace for combustion; 3. The ash is entrusted for disposal as general solid waste. Although this method uses furfural residue as fuel for biomass boilers, resources are reasonably utilized and the emission of furfural residue is reduced, it also increases the cost of tail gas treatment in the process, and the ash is not fully utilized, and true zero pollution, clean production, and recycling are not achieved. Summary of the invention

[0006] The purpose of the present invention is to reduce the cost of tail gas treatment after combustion of furfural slag, achieve zero discharge of furfural slag, maximize resource utilization, and reduce the impact on the ecological environment during the treatment of furfural slag. The present invention provides a method and system for recycling furfural slag.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for recycling furfural residues comprises the following steps:

[0009] S1: During the furfural production process, the furfural residue discharged from the hydrolysis reactor is transported to the stirring tank;

[0010] S2: using a blower to blow an appropriate amount of powdered calcium oxide into the stirring kettle containing furfural residue;

[0011] S3: After sufficient stirring and reaction, the furfural residue is dehydrated and neutralized;

[0012] S4: The furfural residue after the reaction serves as fuel for the biomass boiler;

[0013] S5: The ash obtained after combustion is used as organic fertilizer.

[0014] Preferably, in step 1, the temperature of the furfural residue entering the hydrolysis reactor is 60-85°C.

[0015] Preferably, the moisture content of the furfural residue in step 1 is 40%-55%.

[0016] Preferably, in step 2, the powdered calcium oxide is directly sprayed onto the surface of the furfural residue and is fully mixed by stirring.

[0017] Preferably, the moisture content of the furfural residue after sufficient reaction in step 3 is 20%-32%.

[0018] Preferably, the furfural residue after sufficient reaction in step 3 can be put into the furnace for combustion when the pH value is about 7-8.

[0019] A furfural residue recycling system comprises a stirring kettle, wherein a discharge port is arranged at the bottom of the stirring kettle, a furfural residue feed port and a calcium oxide addition port are arranged on the side of the stirring kettle, and a stirring mechanism is arranged inside the stirring kettle.

[0020] Preferably, the calcium oxide addition port is connected to an annular distribution pipe surrounding the outside of the stirring tank, and the inner circle of the annular distribution pipe is provided with a plurality of feed pipes connected to the stirring tank.

[0021] Preferably, two cylinders are fixed to the top of the stirring kettle, a support plate is fixed between the output shafts of the two cylinders, the stirring mechanism includes a lifting rod, the bottom end of the lifting rod is movably extended to the interior of the stirring kettle, and the top end of the lifting rod is rotatably connected to the support plate, a mixing disk is fixed to the outside of the lifting rod, and a plurality of through holes are opened on the mixing disk.

[0022] Preferably, a horizontal bar is fixed on the fixed part of the cylinder, a guide rod is fixed on the horizontal bar, a guide groove is provided on the outside of the lifting rod, the guide groove extends spirally, and one end of the guide rod extends into the guide groove.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The flue gas generated by sending the neutralized furfural slag for combustion basically does not need desulfurization treatment, which reduces the treatment cost and improves the environmental impact during the tail gas treatment process; reduces the moisture in the furfural slag, increases the calorific value, and increases the economic benefits of production; the ash is rich in N, P and other elements and can be used as an organic fertilizer.

[0025] 2. Through the design of the stirring mechanism, the lifting rod drives the mixing disk to move up and down, and the furfural residue and calcium oxide pass through the through holes on the mixing disk, thereby achieving the purpose of efficient mixing. During the lifting and moving of the lifting rod, the guide rod extends into the guide groove, thereby driving the lifting rod to rotate, and then driving the mixing disk and the stirring branch to rotate, which can further improve the mixing effect, thereby accelerating the reaction and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a first-view stereoscopic view of the stirring kettle of the present invention;

[0028] Figure 2 A second perspective stereoscopic view of the stirring kettle of the present invention;

[0029] Figure 3 This is a third perspective stereogram of the stirring kettle of the present invention;

[0030] Figure 4 for Figure 3 A zoomed-in detail of position A in the middle;

[0031] Figure 5 It is the front view of the stirring kettle of the present invention;

[0032] Figure 6 It is a cross-sectional view of a stirred tank of the present invention;

[0033] In the figure: 1 a stirring kettle, 101 a furfural residue feed port, 102 a discharge port, 2 a calcium oxide addition port, 201 annular distribution pipe, 202 a feed pipe, 3 a cylinder, 303 an output shaft, 4 a support plate, 401 a lifting rod, 402 a guide groove, 403 a horizontal bar, 404 a guide rod, 405 a mixing plate, 406 a through hole, and 407 a stirring branch. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A method for recycling furfural residues comprises the following steps:

[0037] S1: transport the furfural residue discharged from the hydrolysis kettle during the furfural production process to a 5m 3 The internal temperature of the furfural residue in the stirring kettle was 70°C and the moisture content was 52%;

[0038] S2: using a blower to blow 100 kg of powdered calcium oxide into the stirred tank containing furfural residue within 30 minutes;

[0039] S3: After sufficient stirring and reaction, the furfural residue was sampled and analyzed to have a moisture content of 29% and a pH of 7.5;

[0040] S4: The furfural residue after the reaction is discharged to the belt conveyor and directly transported to the biomass boiler for combustion as biomass boiler fuel;

[0041] S5: The ash obtained after combustion can be used as organic fertilizer, which has a good effect on the growth of crops.

[0042] Example 2

[0043] A method for recycling furfural residues comprises the following steps:

[0044] S1: transport the furfural residue discharged from the hydrolysis kettle during the furfural production process to a 5m 3 The internal temperature of the furfural residue in the stirring kettle was 85°C and the moisture content was 50%;

[0045] S2: Using a blower, 150 kg of powdered calcium oxide was blown into the stirred tank containing furfural residue within 30 minutes;

[0046] S3: After sufficient stirring and reaction, the furfural residue was sampled and analyzed to have a moisture content of 25% and a pH of 7.8;

[0047] S4: The furfural residue after the reaction is discharged to the belt conveyor and directly transported to the biomass boiler for combustion as biomass boiler fuel;

[0048] S5: The ash obtained after combustion can be used as organic fertilizer, which has a good effect on the growth of crops.

[0049] Example 3

[0050] A method for recycling furfural residues comprises the following steps:

[0051] S1: transport the furfural residue discharged from the hydrolysis kettle during the furfural production process to a 5m 3 The internal temperature of the furfural residue in the stirring kettle was 65°C and the moisture content was 45%;

[0052] S2: using a blower to blow 200 kg of powdered calcium oxide into the stirred tank containing furfural residue within 30 minutes;

[0053] S3: After sufficient stirring and reaction, the furfural residue was sampled and analyzed to have a moisture content of 22% and a pH of 8.1;

[0054] S4: The furfural residue after the reaction is discharged to the belt conveyor and directly transported to the biomass boiler for combustion as biomass boiler fuel;

[0055] S5: The ash obtained after combustion can be used as organic fertilizer, which has a good effect on the growth of crops.

[0056] Example 4

[0057] A method for recycling furfural residues comprises the following steps:

[0058] S1: transport the furfural residue discharged from the hydrolysis kettle during the furfural production process to a 5m 3 The internal temperature of the furfural residue in the stirring kettle was 60°C and the moisture content was 43%;

[0059] S2: using a blower to blow 200 kg of powdered calcium oxide into the stirred tank containing furfural residue within 30 minutes;

[0060] S3: After sufficient stirring and reaction, the furfural residue was sampled and analyzed to have a moisture content of 20% and a pH of 7.9;

[0061] S4: The furfural residue after the reaction is discharged to the belt conveyor and directly transported to the biomass boiler for combustion as biomass boiler fuel;

[0062] S5: The ash obtained after combustion can be used as organic fertilizer, which has a good effect on the growth of crops.

[0063] Example 5

[0064] Reference Figure 1-6 A furfural residue recycling system comprises a stirring kettle 1, a discharge port 102 is arranged at the bottom of the stirring kettle 1, a furfural residue feed port 101 and a calcium oxide addition port 2 are arranged on the side of the stirring kettle 1, and a stirring mechanism is arranged inside the stirring kettle 1.

[0065] Among them, the calcium oxide addition port 2 is connected to an annular distribution pipe 201, which surrounds the outside of the stirring tank 1, and the inner circle of the annular distribution pipe 201 is provided with multiple feeding pipes 202, which are connected to the stirring tank 1. The blower is started to blow the powdered calcium oxide evenly into the stirring tank through the annular distribution pipe 201 of the calcium oxide addition port 2. The design of the annular distribution pipe 201 enables the calcium oxide to be evenly distributed along the circumference of the stirring tank to avoid local excess or deficiency.

[0066] Among them, two cylinders 3 are fixed on the top of the stirring tank 1, and a support plate 4 is fixed between the output shafts 303 of the two cylinders 3. The stirring mechanism includes a lifting rod 401, the bottom end of the lifting rod 401 is movably extended to the inside of the stirring tank 1, and the top end of the lifting rod 401 is rotatably connected to the support plate 4, and a mixing disk 405 is fixed on the outer side of the lifting rod 401, and a plurality of through holes 406 are opened on the mixing disk 405;

[0067] When the lifting rod 401 drives the mixing plate 405 to move up and down, the mixing plate 405 is driven to move up and down, and the furfural residue and calcium oxide pass through the through hole 406 on the mixing plate 405, thereby achieving the purpose of efficient mixing.

[0068] Among them, a horizontal bar 403 is fixed on the fixed part of the cylinder 3, and a guide rod 404 is fixed on the horizontal bar 403. A guide groove 402 is opened on the outside of the lifting rod 401, and the guide groove 402 extends spirally, and one end of the guide rod 404 extends into the guide groove 402. A stirring branch 407 is also provided on the outside of the lifting rod 401. During the lifting and moving process of the lifting rod 401, since the guide rod 404 extends into the guide groove 402, it can drive the lifting rod 401 to rotate, and then drive the mixing disk 405 and the stirring branch 407 to rotate, which can further improve the mixing effect, thereby accelerating the reaction and improving efficiency.

[0069] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for recycling furfural residues, characterized in that: The following steps are involved: S1: During the furfural production process, the furfural residue discharged from the hydrolysis reactor is transported to the stirring tank (1); S2: using a blower to blow an appropriate amount of powdered calcium oxide into the stirred tank (1) containing furfural residue; S3: After sufficient stirring and reaction, the furfural residue is dehydrated and neutralized; S4: The furfural residue after the reaction serves as fuel for the biomass boiler; S5: The ash obtained after combustion is used as organic fertilizer.

2. The method for recycling furfural residue according to claim 1 is characterized in that: In the step 1, the temperature of the furfural residue entering the hydrolysis reactor is 60-85°C.

3. A method for recycling furfural residues according to claim 1, characterized in that: In the step 1, the moisture content of the furfural residue is 40%-55%.

4. A method for recycling furfural residues according to claim 1, characterized in that: In step 2, the powdered calcium oxide is directly sprayed onto the surface of the furfural residue and is fully mixed by stirring.

5. The method for recycling furfural residue according to claim 1, characterized in that: The moisture content of the furfural residue after sufficient reaction in step 3 is 20%-32%.

6. The method for recycling furfural residue according to claim 1, characterized in that: After the furfural residue is fully reacted in step 3, the pH value of the residue is about 7-8 and can be put into the furnace for combustion.

7. A furfural residue recycling system, applied to the furfural residue recycling method according to any one of claims 1 to 6, characterized in that: The stirring kettle (1) comprises a discharge port (102) at the bottom of the stirring kettle (1), a furfural residue feed port (101) and a calcium oxide addition port (2) are provided on the side of the stirring kettle (1), and a stirring mechanism is provided inside the stirring kettle (1).

8. The furfural residue recycling system according to claim 7, characterized in that: The calcium oxide addition port (2) is connected to an annular distribution pipe (201) surrounding the outside of the stirring tank (1), and the inner circle of the annular distribution pipe (201) is provided with a plurality of feed pipes (202), and the feed pipes (202) are connected to the stirring tank (1).

9. A furfural residue recycling system according to claim 8, characterized in that: Two cylinders (3) are fixed on the top of the stirring kettle (1), a support plate (4) is fixed between the output shafts (303) of the two cylinders (3), the stirring mechanism comprises a lifting rod (401), the bottom end of the lifting rod (401) is movably extended to the inside of the stirring kettle (1), and the top end of the lifting rod (401) is rotatably connected to the support plate (4), and a mixing disk (405) is fixed on the outer side of the lifting rod (401), and a plurality of through holes (406) are opened on the mixing disk (405).

10. A furfural residue recycling system according to claim 9, characterized in that: A horizontal bar (403) is fixed on the fixed part of the cylinder (3), a guide rod (404) is fixed on the horizontal bar (403), a guide groove (402) is provided on the outside of the lifting rod (401), the guide groove (402) extends spirally, and one end of the guide rod (404) extends into the guide groove (402).

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