Kitchen waste grease deacidification process

Abstract

The invention relates to the technical field of waste grease treatment, and provides a kitchen waste grease deacidification process which comprises the following steps: S1, activating activated carbon, uniformly mixing the activated carbon with chitosan, and grinding to obtain chitosan modified activated carbon; s2, uniformly mixing the chitosan modified activated carbon with a sodium hydroxide solution, filtering and drying to obtain solid alkali; and S3, uniformly mixing the solid alkali with the kitchen waste grease, and carrying out suction filtration, washing and centrifugation to obtain a deacidified oil phase. According to the technical scheme, the problem of low deacidification rate of a kitchen waste grease deacidification process in related technologies is solved.

Description

Technical Field

[0001] The invention relates to the technical field of waste grease treatment, and in particular to a process for deacidification of waste kitchen grease. Background Art

[0002] Waste cooking oil refers to waste edible oil, which is derived from edible oil made from a variety of biological resources. It has the characteristics of dark color, high viscosity, high acidity, etc. Its composition is very complex, and it is a mixture of various organic substances, mainly composed of fatty acid glycerides. If waste kitchen oil is discharged directly without treatment, it will cause great harm to the environment and human body. Its various oil compounds will cause serious pollution to the atmosphere, soil, water sources, etc. after mixing with waste water; waste oil contains unstable chemical substances, which will produce by-products when exposed to the environment, and the white smoke and stench produced by waste oil will seriously harm human health after being inhaled by the human body.

[0003] The unsaturated fatty acids in waste oils undergo oxidation and acidification, causing the acid value in the waste oils to exceed the standard and the generated peroxides are free fatty acids. If free fatty acids are consumed by humans, they can cause human poisoning and even induce diseases such as cancer and atherosclerosis. Therefore, it is necessary to strengthen the treatment of waste oils from catering. Waste oil deacidification refers to the process of removing free fatty acids and other organic acids from waste oils by physical or chemical methods. Through waste oil deacidification, the quality and utilization rate of waste oils can be improved and the occurrence of the above-mentioned hazards can be reduced. However, the deacidification rate of the current waste cooking oil deacidification process needs to be further improved. Therefore, a waste cooking oil deacidification process with a high deacidification rate is urgently needed. Summary of the invention

[0004] The invention provides a process for deacidification of waste kitchen oil, which solves the problem of low deacidification rate in the process for deacidification of waste kitchen oil in the related art.

[0005] The technical solution of the present invention is as follows: The present invention provides a process for deacidification of waste cooking oil, comprising the following steps: S1, after the activated carbon is activated, it is evenly mixed with chitosan and ground to obtain chitosan-modified activated carbon; S2, mixing chitosan modified activated carbon and sodium hydroxide solution evenly, filtering, and drying to obtain solid alkali; S3. Evenly mix the solid alkali and the kitchen waste oil, filter, wash and centrifuge to obtain the deacidified oil phase.

[0006] As a further technical solution, the activation treatment steps are: mixing the activated carbon and the hydrochloric acid solution evenly, filtering, washing, and drying.

[0007] As a further technical solution, the chitosan is modifier-modified chitosan, and the modifier in the modifier-modified chitosan is 4-aminodiphenylmethane.

[0008] In the present invention, chitosan is limited to be modified by a modifier, thereby further improving the deacidification rate of the kitchen waste oil deacidification process.

[0009] As a further technical solution, the raw materials for modifying chitosan with the modifier include 4-aminodiphenylmethane and chitosan in a mass ratio of 2 to 5:40.

[0010] As a further technical solution, the mass ratio of 4-aminodiphenylmethane to chitosan is 3-4:40.

[0011] In the present invention, the mass ratio of 4-aminodiphenylmethane to chitosan is limited to 3-4:40, thereby further improving the deacidification rate of the kitchen waste oil deacidification process.

[0012] As a further technical solution, the raw materials of the chitosan-modified activated carbon include modifier-modified chitosan and activated carbon in a mass ratio of 1 to 5:30.

[0013] As a further technical solution, the mass ratio of the modifier-modified chitosan and the activated carbon is 2~3:30.

[0014] In the present invention, the mass ratio of the chitosan modified by the modifier and the activated carbon is limited to 2-3:30, thereby further improving the deacidification rate of the kitchen waste oil deacidification process.

[0015] As a further technical solution, the preparation method of the modifier-modified chitosan comprises the following steps: The modifier is dissolved in a solvent, chitosan is added and mixed evenly, and the mixture is dried to obtain the modifier-modified chitosan.

[0016] As a further technical solution, the mass ratio of the solid alkali to the waste cooking oil is 10-15:100.

[0017] As a further technical solution, the temperature during mixing in S3 is 60-70° C. and the time is 20-30 min.

[0018] The working principle and beneficial effects of the present invention are: In the present invention, chitosan-modified activated carbon loaded with sodium hydroxide is used as a solid base in the process of deacidification of waste kitchen oil. Chitosan is an environmentally friendly adsorbent with a natural structure. By loading sodium hydroxide on chitosan-modified activated carbon, the content of fatty acids in the waste oil is effectively reduced. At the same time, the deacidification rate of the process of deacidification of waste kitchen oil is greatly improved by adjusting the content of each component and optimizing the process parameters in the process of deacidification of waste kitchen oil. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0020] In the following examples and comparative examples, the parameters of the raw materials are as follows: The particle size of activated carbon is 200 mesh; Chitosan is chitosan nanoparticles, which are prepared by the following method: ① Weigh a certain amount of chitosan with a deacetylation degree of 85.61% and dissolve it in a 1% glacial acetic acid solution to prepare a 0.75 mg / mL chitosan solution. Stir for 1 h, adjust the pH value to 5.0, and filter with a 0.45 μm filter membrane to obtain a chitosan stock solution. ② Prepare a sodium tripolyphosphate aqueous solution with a concentration of 0.75 mg / mL, filter it through a 0.45 μm filter membrane to obtain a sodium tripolyphosphate stock solution. Transfer 6.0 mL of chitosan stock solution into a 50 mL round-bottom centrifuge tube, add 1.0 mL of sodium tripolyphosphate stock solution at a speed of 600 r / min, continue stirring for 10 min, obtain a chitosan nanoparticle suspension, and spray dry to obtain chitosan nanoparticles. Spray drying conditions are: flow rate 120 mL / h, drying gas flow rate 0.35 m 3 / min, the spray pressure was 130 kPa, the inlet temperature was 121 °C, and the outlet temperature was 65 °C.

[0021] Example 1 A process for deacidification of waste cooking oil comprises the following steps: S1. Mix 30 parts of activated carbon and 100 parts of 0.5 mol / L dilute hydrochloric acid, filter, wash with deionized water to pH = 7, dry, mix with 1 part of chitosan, grind, and obtain chitosan-modified activated carbon; S2. According to the equal volume method, chitosan-modified activated carbon was added into 10 g / L sodium hydroxide solution, stirred for 12 h, filtered, and dried to obtain a solid base; S3. Mix 10 parts of solid alkali with 100 parts of kitchen waste oil at 60° C. for 20 minutes, filter, wash with deionized water until pH=7, and centrifuge to obtain a deacidified oil phase.

[0022] Example 2 A process for deacidification of waste cooking oil comprises the following steps: S1. Mix 30 parts of activated carbon and 100 parts of 0.5 mol / L dilute hydrochloric acid, filter, wash with deionized water until pH = 7, dry, mix with 5 parts of chitosan, grind, and obtain chitosan-modified activated carbon; S2. According to the equal volume method, chitosan-modified activated carbon was added into 10 g / L sodium hydroxide solution, stirred for 12 h, filtered, and dried to obtain a solid base; S3. Mix 15 parts of solid alkali and 100 parts of kitchen waste oil at 70° C. for 30 minutes, filter, wash with deionized water until pH=7, and centrifuge to obtain a deacidified oil phase.

[0023] Example 3 A process for deacidification of waste cooking oil comprises the following steps: S1, dissolving 2 parts of 4-aminodiphenylmethane in 60 parts of methanol, adding 40 parts of chitosan, mixing evenly, and drying to obtain modifier-modified chitosan; S2. According to the equal volume method, chitosan-modified activated carbon was added into 10 g / L sodium hydroxide solution, stirred for 12 h, filtered, and dried to obtain a solid base; S3, mixing 30 parts of chitosan-modified activated carbon and 100 parts of 10 g / L sodium hydroxide solution, filtering, and drying to obtain a solid base; S4. Mix 10 parts of solid alkali with 100 parts of kitchen waste oil at 60° C. for 20 minutes, filter, wash with deionized water until pH=7, and centrifuge to obtain a deacidified oil phase.

[0024] Example 4 The difference from Example 3 is only that: 5 parts of 4-aminodiphenylmethane.

[0025] Example 5 The difference with Example 3 is only: 3 parts of 4-aminodiphenylmethane.

[0026] Example 6 The difference with Example 3 is only that: 4 parts of 4-aminodiphenylmethane.

[0027] Example 7 The only difference from Example 6 is that 5 parts of chitosan are modified by the modifier.

[0028] Example 8 The only difference from Example 6 is that 2 parts of chitosan are modified by a modifier.

[0029] Example 9 The only difference from Example 6 is that 3 parts of chitosan are modified by the modifier.

[0030] Comparative Example 1 A process for deacidification of waste cooking oil comprises the following steps: S1. Mix 30 parts of activated carbon and 100 parts of 0.5 mol / L dilute hydrochloric acid, filter, wash with deionized water to pH = 7, dry, add to 10 g / L sodium hydroxide solution according to the equal volume method, stir for 12 hours, filter, and dry to obtain a solid base; S2. Mix 10 parts of solid alkali and 100 parts of kitchen waste oil at 60° C. for 20 minutes, filter, wash with deionized water until pH=7, and centrifuge to obtain a deacidified oil phase.

[0031] Comparative Example 2 A process for deacidification of waste cooking oil comprises the following steps: S1. Mix 30 parts of activated carbon and 20 parts of clay with 100 parts of 0.5 mol / L dilute hydrochloric acid, filter, wash with deionized water to pH = 7, and dry to obtain activated activated carbon and activated clay; S2, after 6 parts of activated activated carbon and 4 parts of activated clay are mixed evenly, according to the equal volume method, put into 10g / L sodium hydroxide solution, stir for 12h, filter, and dry to obtain a solid base; S3. Mix 10 parts of solid alkali with 100 parts of kitchen waste oil at 60° C. for 20 minutes, filter, wash with deionized water until pH=7, and centrifuge to obtain a deacidified oil phase.

[0032] Test example The acid value of the waste cooking oil before and after deacidification treatment using the waste cooking oil deacidification process of Examples 1 to 9 and Comparative Examples 1 to 2 was measured with reference to the standard of the first method in GB 5009.229-2016, and the deacidification rate was calculated according to the following formula: Deacidification rate = (acid value of waste oil before treatment - acid value of waste oil after treatment) ÷ acid value of waste oil before treatment × 100%; The results are shown in Table 1.

[0033] Table 1 Deacidification test results of Examples 1 to 9 and Comparative Examples 1 to 2

[0034] Compared with Comparative Examples 1-2, Example 1 uses chitosan-modified activated carbon in the process of deacidification of waste kitchen oil. As a result, the deacidification rate of Example 1 is greater than that of Comparative Examples 1-2, indicating that the activated carbon used is chitosan-modified activated carbon, which can improve the deacidification rate of the process of deacidification of waste kitchen oil.

[0035] The deacidification rates of Examples 3 to 6 are greater than that of Example 1, indicating that chitosan is a modifier-modified chitosan, which further improves the deacidification rate of the kitchen waste oil deacidification process.

[0036] The deacidification rates of Examples 5 to 6 are greater than those of Examples 3 to 4, indicating that the mass ratio of 4-aminodiphenylmethane to chitosan is 3 to 4:40, which further improves the deacidification rate of the deacidification process for waste cooking oil.

[0037] The deacidification rates of Examples 8 to 9 are greater than those of Examples 6 to 7, indicating that the mass ratio of the modifier-modified chitosan to the activated carbon is 2 to 3:30, which further improves the deacidification rate of the kitchen waste oil deacidification process.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for deacidification of waste cooking oil, characterized in that: The following steps are involved: S1, after the activated carbon is activated, it is evenly mixed with chitosan and ground to obtain chitosan-modified activated carbon; S2, mixing chitosan modified activated carbon and sodium hydroxide solution evenly, filtering, and drying to obtain a solid base; S3. Evenly mix the solid alkali and the kitchen waste oil, filter, wash and centrifuge to obtain the deacidified oil phase.

2. A process for deacidification of waste cooking oil according to claim 1, characterized in that: The activation treatment steps are: uniformly mixing the activated carbon and the hydrochloric acid solution, filtering, washing and drying.

3. A process for deacidification of waste cooking oil according to claim 1, characterized in that: The chitosan is modifier-modified chitosan, and the modifier in the modifier-modified chitosan is 4-aminodiphenylmethane.

4. A process for deacidification of waste cooking oil according to claim 3, characterized in that: The raw materials of the modifier-modified chitosan include 4-aminodiphenylmethane and chitosan in a mass ratio of 2 to 5:

40.

5. A process for deacidification of waste cooking oil according to claim 4, characterized in that: The mass ratio of 4-aminodiphenylmethane to chitosan is 3-4:

40.

6. A process for deacidification of waste cooking oil according to claim 5, characterized in that: The raw materials of the chitosan-modified activated carbon include modifier-modified chitosan and activated carbon in a mass ratio of 1 to 5:

30.

7. A process for deacidification of waste cooking oil according to claim 6, characterized in that: The mass ratio of the modifier-modified chitosan to the activated carbon is 2-3:

30.

8. A process for deacidification of waste cooking oil according to any one of claims 3 to 7, characterized in that: The preparation method of the modifier-modified chitosan comprises the following steps: The modifier is dissolved in a solvent, chitosan is added and mixed evenly, and the mixture is dried to obtain the modifier-modified chitosan.

9. The process for deacidification of waste cooking oil according to claim 1, characterized in that: The mass ratio of the solid alkali to the kitchen waste oil is 10-15:

100.

10. The process for deacidification of waste cooking oil according to claim 1, characterized in that: The temperature during mixing in S3 is 60-70° C. and the time is 20-30 min.

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