Preparation method and application of environment-friendly potato residue compound binder

Abstract

The method comprises the following steps: heating the potato residues to a certain temperature in a water bath, adding a certain amount of a sodium hydroxide solution, stirring, adding a certain amount of a calcium hydroxide reagent, and stirring; and finally, adding a certain amount of polypropylene fiber and stirring to obtain the compound binder, and using the compound binder for preparing the semi-coke. The compound binder has the beneficial effects that by virtue of the multi-component synergistic effect of the potato residues and the generation of the cellulose calcium, and by combining the three-dimensional network effect of the polypropylene fibers, the compressive strength of the prepared shaped semi-coke breaks through 4000 N / ball or above, and the forming quality and the combustion efficiency are remarkably improved. The process is simple and raw material cost is low. By utilizing the waste potato residues, the environment pollution is reduced, and meanwhile, the efficient recycling of resources is realized. The method has economic benefits and environmental protection values, and provides an innovative solution for green upgrading of the semi-coke industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of binder preparation, and particularly relates to a method for preparing a compounded binder based on potato residue and application thereof. BACKGROUND

[0002] Lan carbon powder is generated by extrusion and abrasion between particles in the low-rank coal dry distillation process, and is also generated in the transportation and use process. The lan carbon technology solves the problems of low utilization rate of lan carbon powder, and some enterprises cannot handle it, which causes air pollution, water pollution, soil pollution, resource waste and the like for a long time.

[0003] At present, most binders have the problems of high cost and secondary pollution, so it is particularly important to select raw materials with wide sources and no pollution. Inorganic binders such as bentonite, silicate and various oxides cannot burn and do not release heat, so the calorific value of the briquette is reduced, which may not meet the demand of some users for high calorific value. In addition, the addition of inorganic binders will increase the ash content of the briquette.

[0004] The preparation method of the briquette binder disclosed in patent No. 202011184869.8 uses starch as raw material, and the starch is modified by sodium hydroxide, and the adhesion is improved under the action of calcium hydroxide and polypropylene fiber. At the same time, a large amount of cellulose similar to the reinforcing body in the composite material will connect the lan carbon powder together.

[0005] Therefore, it is particularly important to develop a new type of binder with low cost and green environmental protection. SUMMARY

[0006] In order to solve the technical problems of environmental pollution and high price of the existing binders, the present application discloses a method for preparing a compounded binder based on potato residue and application thereof. The compounded binder with environmental protection, economy and excellent performance is prepared by using potato residue as raw material and through physical treatment and chemical modification, and is applied to the preparation of lan carbon briquette.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A method for preparing a compounded binder based on potato residue, the following raw materials are used by weight: 20-24 parts of potato residue; 1-2 parts of polypropylene fiber; 0.5-0.6 parts of calcium hydroxide; 0.8-1 part of sodium hydroxide; 60-70 parts of water.

[0008] Further, the potato residue is sieved through a 100-mesh standard sieve.

[0009] Further, the specific steps are: a. A certain amount of water and potato residue is first placed in a three-necked flask, heated in a constant temperature water bath and magnetically stirred, and the temperature is monitored by a thermometer; b. When the temperature reaches 70-75 DEG C, add sodium hydroxide solid, heat and stir for 20 min to get gelatinized night; c. Add calcium hydroxide solid to the gelatinized liquid obtained in step b and continue to heat and stir for 15 min; d. Finally, add polypropylene fiber and stir for 10 min to obtain a compounded binder.

[0010] Further, in step a, the mass ratio of potato residue to water is 2-3:20.

[0011] Further, in step b, the mass ratio of potato residue to sodium hydroxide is 19:3-5.

[0012] Further, in step c, the mass of calcium hydroxide is 2 times that of sodium hydroxide.

[0013] Further, in step d, the mass of polypropylene fiber is 0.5 times that of sodium hydroxide.

[0014] The application also discloses a method for preparing shaped green coke by using the compounded binder. After screening, the green coke powder is mixed with a certain amount of 20-30 mL compounded binder, stirred uniformly, formed under a pressure of 6-8 MPa, dried at 60 DEG C for 18 h, and the shaped green coke is obtained.

[0015] Further, the particle size of the green coke powder is less than 6 mm, and the mass ratio of green coke powder to binder is (2-3):1.

[0016] In the application, the potato residue is used as raw material, and sodium hydroxide is added to the potato residue solution, which can destroy the cell wall, lignin and starch structure, so that the gelatinization reaction is carried out at a lower temperature, the crystallinity is reduced, and the intermolecular force is strengthened. The polypropylene fiber additive is added later to entangle the green coke powder to enhance the compressive strength of the shaped green coke.

[0017] In addition, the price of potato residue is much lower than that of starch, and the potato residue contains about 35% starch, a large amount of cellulose and pectin, which can better improve the adhesion of the binder and the stability of the shaped green coke.

[0018] The application has the following advantages compared with the prior art: 1. Excellent performance: The present application uses potato residue as the main raw material, which contains about 35% starch, 30% cellulose, pectin and other synergies. The alkali-treated cellulose is a complex enhancer-calcium cellulose. Adding an appropriate amount of polypropylene fiber additive to the coke powder can enhance the bonding force. The compressive strength of the shaped coke prepared by the binder reaches 4000N / ball, which can significantly improve the molding quality and combustion efficiency of the coke. At the same time, the industrial analysis results of the shaped coke meet the requirements of industrial and civilian fuels.

[0019] 2. Economic: The potato residue binder process is simple, widely available and low in price, effectively reducing the production cost of the binder. Preliminary estimate of the cost of 1t shaped coke binder produced from coke powder is about 33yuan.

[0020] 3. Environmental protection: The present application uses potato residue as the main raw material, which realizes the effective utilization of agricultural waste and promotes the high-value utilization of coke resources. It reduces waste emissions and environmental pollution, and meets the concept of green and sustainable development.

[0021] 4. Wide application: The shaped coke sample prepared by the present application has uniform size and high strength, and is suitable for various combustion equipment and transportation requirements, which has broad market application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the present application; DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] Example 1 A method for preparing a compounded binder based on potato residue, specifically: Put 200mL water, 30g potato residue and other raw materials into a three-necked flask, and heat and stir under the action of a magnetic stirrer in a constant temperature water bath. Insert a thermometer to accurately monitor the temperature.

[0025] When the temperature reaches 70~75℃, add 0.8~1% sodium hydroxide and heat and stir for 20min.

[0026] Add 0.5~0.6% calcium hydroxide to the obtained gelatinized liquid and heat and stir for 15min.

[0027] Finally, 1-2% polypropylene fiber is added and stirred for 10 minutes to prepare the compound binder.

[0028] The compound binder is used in the method for preparing the molded green coke, and specifically: 60g of 0-1mm green coke powder is selected, 20-30mL of the compound binder is added, and stirred uniformly. The mixture is dried in a constant temperature drying box at 60°C under a pressure of 6-8MPa for 18h.

[0029] The mechanical strength of the molded green coke is determined, and the compressive strength is 4262.2N / ball, 4337.7N / ball, and 4045.2N / ball.

[0030] Example 2 The difference between the raw materials of Example 1 is that 0.6-0.7% calcium hydroxide is added in the method for preparing the compound binder.

[0031] The preparation process of the molded green coke is the same as Step 1.

[0032] The mechanical strength of the molded green coke is determined, and the compressive strength is 3333N / ball, 3024.4N / ball, and 3220.4N / ball.

[0033] It is found by comparison that, in Example 2 compared with Example 1, excess calcium hydroxide is added in the gelatinization process, a certain amount of Ca 2+ is easy to form a complex with potato residue amylopectin, promoting the gelatinization of potato residue, but excess calcium hydroxide is easy to cause too much precipitate of the binder, reducing the compressive strength.

[0034] Example 3 The difference between the raw materials of Example 1 is that 1-2% sodium hydroxide is added in the method for preparing the compound binder.

[0035] The preparation process of the molded green coke is the same as Step 1.

[0036] The mechanical strength of the molded green coke is determined, and the compressive strength is 2523N / ball, 2368.1N / ball, and 2151N / ball.

[0037] It is found by comparison that, in Example 3 compared with Example 1, excess sodium hydroxide is added in the gelatinization process, which seriously damages pectin and starch in the gelatinization process, leading to a serious decrease in the binding effect and a decrease in the compressive strength.

[0038] Example 4 The difference between Example 1 is that the green coke powder is sieved, and 60g of 3.35-6mm is selected with a proportion of 100%.

[0039] The method for preparing the compound binder is the same as Example 1.

[0040] The mechanical strength of the above-mentioned shaped blue charcoal was determined, and the compressive strength was 2277.6 N / ball, 2106.9 N / ball, and 2403.5 N / ball.

[0041] It is found by comparison that, compared with Example 1, the specific surface area of the 3.35-6 mm large particle size particles in Example 5 is small, the contact area of the binder with the blue charcoal is low, and the inter-particle gap is large, resulting in poor compressive strength. At the same time, the stress distribution of the large particle size is uneven, and stress concentration is easily generated in the local part, resulting in difficulty in forming and demolding, and the compressive strength decreases.

[0042] Example 5 The difference between Example 1 is that: the blue charcoal powder is sieved, and 60g of 1-3.35mm accounts for 100%.

[0043] The preparation method of the compounded binder is the same as that in Case 1.

[0044] The mechanical strength of the above-mentioned shaped blue charcoal was determined, and the compressive strength was 2277.6 N / ball, 2106.9 N / ball, and 2403.5 N / ball.

[0045] It is found by comparison that, compared with Example 1, the specific surface area of the 3.35-6 mm large particle size particles in Example 5 is small, the contact area of the binder with the blue charcoal is low, and the inter-particle gap is large, resulting in poor compressive strength. At the same time, the stress distribution of the large particle size is uneven, and stress concentration is easily generated in the local part, resulting in difficulty in forming and demolding, and the compressive strength decreases.

[0046] Example 6 The difference between Example 1 is that: the blue charcoal powder is not sieved.

[0047] The preparation method of the compounded binder is the same as that in Case 1.

[0048] The mechanical strength of the above-mentioned shaped blue charcoal was determined, and the compressive strength was 2277.6 N / ball, 2106.9 N / ball, and 2403.5 N / ball.

[0049] It is found by comparison that, compared with Example 1, the specific surface area of the 3.35-6 mm large particle size particles in Example 5 is small, the contact area of the binder with the blue charcoal is low, and the inter-particle gap is large, resulting in poor compressive strength. At the same time, the stress distribution of the large particle size is uneven, and stress concentration is easily generated in the local part, resulting in difficulty in forming and demolding, and the compressive strength decreases.

[0050] The present application comprehensively covers the preparation method of the compounded binder of potato residues and all details of the application thereof, ensures the integrity and originality of the technology and the achievement, and lays a solid foundation for subsequent industrialization.

[0051] The present application first applies potato residues and inorganic compounded binders to blue charcoal forming, solves the problems of high cost and large pollution of traditional binders. It can effectively solve the problem of reusing blue charcoal powder, promote the transformation and upgrading of the blue charcoal industry, and meet the strategic guidance of the national sustainable development.

[0052] Of course, the above description is not a limitation on the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the spirit and scope of the present application should also be included in the protection scope of the present application.

Claims

1. A method for preparing a compounded binder based on potato pulp, characterized by, The following weight parts of raw materials are used: Potato residue 20~24 parts; Polypropylene fiber 1~2 parts; Calcium hydroxide 0.5~0.6 parts; Sodium hydroxide 0.8~1 part; Water 60~70 parts.

2. A method of preparing a compounded binder based on potato pulp as claimed in claim 2, wherein, The potato residue is passed through a 100-mesh standard sieve.

3. A method of preparing a compounded binder based on potato pulp as claimed in claim 1, wherein, The specific steps are: ​ a. A certain amount of water and potato residue is first placed in a three-necked flask, heated in a constant temperature water bath and magnetically stirred, and the temperature is monitored by a thermometer; b. When the temperature reaches 70~75℃, add sodium hydroxide solid, heat and stir for 20 min to get a gelatinized liquid; c. Add calcium hydroxide solid to the gelatinized liquid obtained in step b and continue to heat and stir for 15 min; d. Finally, add polypropylene fiber and stir for 10 min to get a compounded binder.

4. A method of preparing a compounded binder based on potato pulp as claimed in claim 3, wherein, In step a, the mass ratio of potato residue to water is 2~3:

20.

5. A method of preparing a compounded binder based on potato pulp as claimed in claim 4, wherein, In step b, the mass ratio of potato residue to sodium hydroxide is 19:3~5.

6. A method of preparing a compounded binder based on potato pulp as claimed in claim 5 wherein, In step c, the mass of calcium hydroxide is 2 times that of sodium hydroxide.

7. A method of preparing a compounded binder based on potato pulp as claimed in claim 6 wherein, In step d, the mass of polypropylene fiber is 0.5 times that of sodium hydroxide.

8. The method of preparing a green coke using the compounded binder as claimed in claim 7, characterized in that, The specific process is: After screening, the fine semi-coke is mixed with a certain amount of 20~30 mL compounded binder, stirred uniformly, formed under a pressure of 6~8 MPa, and dried at 60℃ for 18 h to get the shaped semi-coke.

9. The method of producing a preparation-grade blue water gas according to claim 8, characterized by, The particle size of the fine semi-coke is less than 6 mm, and the mass ratio of fine semi-coke to binder is (2~3):1.

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