阅读说明：本技术 一种利用餐厨废油制备液体皂的方法 (Method for preparing liquid soap by using kitchen waste oil ) 是由 王春铭 林培彬 吴淇 黄焯燊 李晓天 汤有千 林昌权 于 2021-07-20 设计创作，主要内容包括：本发明属于环境保护废弃物资源化利用技术领域,公开了一种利用餐厨废油制备液体皂的方法。该方法包括步骤：将餐厨废油处理得到的清澈餐厨油脂加热至70-110℃,取碱性溶液分多次加入其中进行皂化反应,当pH值达到碱性,皂化反应完全时,盐析1-3次,排出底层的废水,将皂基取出风干,制得固体皂；将固体皂与水混合,加入10％-60％固体皂质量的增溶降粘助剂,再加入0.5-55％固体皂质量的表面活性剂和0.01-1％固体皂质量的螯合剂；搅拌至固体皂溶解后,干燥通风静置,于25-55℃恒温保存12-48小时,取出后冷却至室温即可得到稳定的含表面活性剂液体皂。(The invention belongs to the technical field of environmental protection waste resource utilization, and discloses a method for preparing liquid soap by using kitchen waste oil. The method comprises the following steps: heating clear kitchen grease obtained by treating kitchen waste oil to 70-110 ℃, adding alkaline solution into the kitchen grease for multiple times for saponification reaction, salting out for 1-3 times when the pH value reaches alkalinity and the saponification reaction is complete, discharging waste water at the bottom layer, taking out soap base, and air drying to obtain solid soap; mixing solid soap with water, adding a solubilizing and viscosity-reducing auxiliary agent accounting for 10-60% of the mass of the solid soap, and then adding a surfactant accounting for 0.5-55% of the mass of the solid soap and a chelating agent accounting for 0.01-1% of the mass of the solid soap; stirring until the solid soap is dissolved, drying, ventilating and standing, storing at the constant temperature of 25-55 ℃ for 12-48 hours, taking out, and cooling to room temperature to obtain the stable liquid soap containing the surfactant.)

1. A method for preparing liquid soap by using kitchen waste oil is characterized by comprising the following steps:

s1, heating the treated clear kitchen grease to 70-110 ℃, taking alkaline solution, adding the alkaline solution into the alkaline solution for multiple times for saponification, when the pH value reaches alkalinity, completely performing saponification, salting out, discharging waste water at the bottom layer, taking out soap base, and air-drying to obtain solid soap; the mass ratio of the alkaline solution to the clear grease is 1: 1-3;

s2, mixing the solid soap with water, adding 10-60% of a solubilizing viscosity-reducing auxiliary agent by mass of the solid soap, and then adding 0.5-55% of a surfactant by mass of the solid soap and 0.01-1% of a chelating agent by mass of the solid soap; stirring until the solid soap is dissolved, drying, ventilating and standing, storing at the constant temperature of 25-55 ℃ for 12-48 hours, taking out, and cooling to room temperature to obtain the stable liquid soap containing the surfactant.

2. The method for preparing the liquid soap by using the kitchen waste oil as claimed in claim 1, wherein the method comprises the following steps: the clear kitchen grease in S1 is prepared according to the following method: removing impurities and water from the kitchen waste oil; heating to 50-95 deg.C, adding water, stirring to fully mix oil and water, standing for layering, and removing water layer to obtain raw oil; heating the obtained raw oil to 50-80 deg.C, sequentially adding activated clay and hydrogen peroxide solution, stirring, heating to 70-110 deg.C, decolorizing, and collecting the upper clear oil.

3. The method for preparing liquid soap by using waste kitchen oil, according to claim 2, is characterized in that: the kitchen waste oil is obtained by separating kitchen grease by pretreating kitchen waste with 60-250 ℃ water heat; the step of removing impurities and water is to filter and centrifuge the kitchen waste oil to remove the impurities and water; the adding amount of the activated clay is 5-15% of the mass of the raw material oil, and the using amount of the hydrogen peroxide solution is 2-5% of the mass of the raw material oil; the mass fraction of the hydrogen peroxide in the hydrogen peroxide solution is 20-35%; the decolorization time is 15-40 min.

4. The method for preparing the liquid soap by using the kitchen waste oil as claimed in claim 1, wherein the method comprises the following steps: in the step S1, the alkaline solution is one or more than two of sodium hydroxide, sodium carbonate and potassium hydroxide, and the mass fraction of the alkaline solution is 25-35%; the pH value reaching alkalinity means that the pH value reaches 9;

the salting-out is carried out by adopting one or more than two of ammonium sulfate, sodium chloride and sodium sulfate neutral salts; when the neutral salt is ammonium sulfate, sodium chloride and sodium sulfate, the three are prepared according to the mass ratio of (18-32) to (45-60) to (13-35); when two neutral salts are used, mixing and preparing according to the respective mass ratio;

the mode that the alkaline solution is added for a plurality of times is as follows: firstly, adding an alkaline solution with the mass of 1/5-1/3, and stirring to ensure that the grease is dispersed in the alkaline solution in an emulsified state for 30-80 min; at the moment, the saponification reaction is accelerated, and an alkaline solution with the mass of 1/3-1/2 is added for reaction for 60-180 min; finally adding the residual alkaline solution, and reacting for 30-90 min; stirring continuously during the process of adding the alkali liquor.

5. The method for preparing the liquid soap by using the kitchen waste oil as claimed in claim 1, wherein the method comprises the following steps: the mass ratio of the solid soap to the water in the step S2 is 1: 0.2-5; the solubilizing and viscosity-reducing auxiliary agent is one or more than two of ethanol, isopropanol, sodium toluene sulfonate and urea.

6. The method for preparing liquid soap by using waste kitchen oil, according to claim 5, is characterized in that: when the solubilizing and viscosity-reducing auxiliary agents are four types, namely ethanol, isopropanol, sodium toluenesulfonate and urea, the four types are prepared according to the mass ratio of (30-55) to (25-40) to (11-35) to (5-33); and when the solubilizing and viscosity-reducing auxiliary agent is two or three of ethanol, isopropanol, sodium toluene sulfonate and urea, mixing and preparing according to the respective mass ratio.

7. The method for preparing the liquid soap by using the kitchen waste oil as claimed in claim 1, wherein the method comprises the following steps: in the step S2, the surfactant is one or more of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid.

8. The method for preparing liquid soap by using waste kitchen oil according to claim 7, wherein the method comprises the following steps: when the surfactant is six of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid, the six are prepared according to the mass ratio of (9-29): (15-30): (20-35): 13-33): 3-25): 16-38; when the surfactant is two to five of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid, the components are mixed according to the respective mass ratio.

9. The method for preparing the liquid soap by using the kitchen waste oil as claimed in claim 1, wherein the method comprises the following steps: in step S2, the chelating agent is one or more of ethylenediaminetetraacetic acid, tartaric acid, citric acid, and nitrilotriacetic acid.

10. The method for preparing liquid soap by using waste kitchen oil according to claim 9, wherein the method comprises the following steps: when the chelating agent is four of ethylenediamine tetraacetic acid, tartaric acid, citric acid and nitrilotriacetic acid, the chelating agent is prepared according to the mass ratio of (20-50) to (18-40) to (25-45) to (3-35); when two or three kinds are used, the mixture is prepared in the above respective mass ratios.

Technical Field

The invention belongs to the technical field of environmental protection waste resource utilization, and particularly relates to a method for preparing liquid soap by using kitchen waste oil.

Background

With the development of catering industry, the yield of kitchen waste oil in China is increased day by day, and a plurality of environmental and food safety problems are promoted. Researches and discusses comprehensive recycling technology of the kitchen waste oil, and changes the kitchen waste oil into valuables is the best way to solve the problems. In a plurality of resource ways of preparing fatting agents, release agents, stearic acid, oleic acid, biodiesel, biofuel oil, soap and the like by using the kitchen waste oil, the process is simpler, and the soap is prepared from the kitchen waste oil. The liquid soap containing the surfactant prepared from the kitchen waste oil can be used for cleaning articles which are not in direct contact with human bodies, such as furniture, vehicles, fabrics and the like, so that the raw material cost for preparing the liquid soap is reduced, the kitchen waste oil is comprehensively utilized, and the problems of environmental pollution and sanitary safety are solved. However, the related technology for preparing the liquid soap containing the surfactant by using the waste kitchen oil is almost blank at present, and an identifiable technical method for realizing the efficient conversion of the waste kitchen oil is difficult to find.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention mainly aims to provide a method for preparing liquid soap by using waste kitchen oil in a two-step method.

The purpose of the invention is realized by the following technical scheme:

a method for preparing liquid soap by using kitchen waste oil comprises the following steps:

s1, heating the treated clear kitchen grease to 70-110 ℃, taking alkaline solution, adding the alkaline solution into the alkaline solution for multiple times for saponification, when the pH value reaches alkalinity, completely performing saponification, salting out, discharging waste water at the bottom layer, taking out soap base, and air-drying to obtain solid soap; the mass ratio of the alkaline solution to the clear grease is 1: 1-3;

s2, mixing the solid soap with water, adding 10-60% of a solubilizing viscosity-reducing auxiliary agent by mass of the solid soap, and then adding 0.5-55% of a surfactant by mass of the solid soap and 0.01-1% of a chelating agent by mass of the solid soap; stirring until the solid soap is dissolved, drying, ventilating and standing, storing at the constant temperature of 25-55 ℃ for 12-48 hours, taking out, and cooling to room temperature to obtain the stable liquid soap containing the surfactant.

The clear kitchen grease in S1 is prepared according to the following method: removing impurities and water from the kitchen waste oil; heating to 50-95 deg.C, adding water, stirring to fully mix oil and water, standing for layering, and removing water layer to obtain raw oil; heating the obtained raw oil to 50-80 deg.C, sequentially adding activated clay and hydrogen peroxide solution, stirring, heating to 70-110 deg.C, decolorizing, and collecting the upper clear oil.

Preferably, the kitchen waste oil is kitchen grease separated after kitchen waste is pretreated by 60-250 ℃ water heat; the step of removing impurities and water is to filter and centrifuge the kitchen waste oil to remove the impurities and water; the adding amount of the activated clay is 5-15% of the mass of the raw material oil, and the using amount of the hydrogen peroxide solution is 2-5% of the mass of the raw material oil; the mass fraction of the hydrogen peroxide in the hydrogen peroxide solution is 20-35%; the decolorization time is 15-40 min.

Preferably, in step S1, the alkaline solution is one or more of sodium hydroxide, sodium carbonate and potassium hydroxide, and the mass fraction of the alkaline solution is 25-35%; the pH value reaching alkalinity means that the pH value reaches 9;

the salting-out is performed by adopting one or more than two neutral salts such as ammonium sulfate, sodium chloride, sodium sulfate and the like, wherein saturated sodium chloride is preferably used for salting-out; when the neutral salt is ammonium sulfate, sodium chloride and sodium sulfate, the three are prepared according to the mass ratio of (18-32) to (45-60) to (13-35); when two neutral salts are used, mixing and preparing according to the respective mass ratio;

the mode that the alkaline solution is added for a plurality of times is as follows: firstly, adding an alkaline solution with the mass of 1/5-1/3, and stirring to ensure that the grease is dispersed in the alkaline solution in an emulsified state for 30-80 min; at the moment, the saponification reaction is accelerated, and an alkaline solution with the mass of 1/3-1/2 is added for reaction for 60-180 min; finally adding the residual alkaline solution, and reacting for 30-90 min; stirring continuously during the process of adding the alkali liquor.

Preferably, the mass ratio of the solid soap to water in step S2 is 1: 0.2-5;

preferably, the solubilizing and viscosity-reducing auxiliary agent in step S2 is one or more of ethanol, isopropanol, sodium toluene sulfonate and urea.

When the solubilizing and viscosity-reducing auxiliary agents are four types, namely ethanol, isopropanol, sodium toluene sulfonate and urea, the four types are mixed and prepared according to the mass ratio of (30-55): (25-40): (11-35): 5-33); and when the solubilizing and viscosity-reducing auxiliary agent is two or three of ethanol, isopropanol, sodium toluene sulfonate and urea, mixing and preparing according to the respective mass ratio.

Preferably, the surfactant in step S2 is one or more of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid.

When the surfactant is six of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid, the six are prepared according to the mass ratio of (9-29), (15-30), (20-35), (13-33), (3-25) and (16-38); when the surfactant is two to five of polyethylene glycol, alkyl glycoside, alcohol ether carboxylate, tea saponin, bamboo vinegar and polyaspartic acid, the components are mixed according to the respective mass ratio.

Preferably, the chelating agent in step S2 is one or more of ethylenediaminetetraacetic acid (EDTA), tartaric acid, citric acid, and nitrilotriacetic acid (NTA).

When the chelating agent is four of ethylenediamine tetraacetic acid, tartaric acid, citric acid and nitrilotriacetic acid, the chelating agent is prepared according to the mass ratio of (20-50) to (18-40) to (25-45) to (3-35); when two or three kinds are used, the mixture is prepared in the above respective mass ratios.

The solubilizing auxiliary agent not only has the viscosity reduction function, but also can enable the liquid soap to be more clear and transparent; but also promote the saponification reaction of the grease and improve the reaction rate.

The surfactant can obviously reduce the surface tension of the target solution, generate a foaming effect, realize surface modification and achieve the aims of cleaning and forming emulsion. Polyethylene glycol (PEG) is a nonionic surfactant, has no toxicity or irritation, has good water solubility, and can be dissolved in many organic substances; has excellent adhesion, moisture retention, lubricity, antistatic agent, dispersibility and the like. The tea saponin is a natural product, has good decontamination, foaming, moistening, dispersing and emulsifying functions, is a surfactant material which is hard to obtain in the daily chemical industry, and has the functions of sterilization, inflammation diminishing, itching relieving and the like. The alkyl glycoside (APG) is a novel nonionic surfactant, has good compounding performance and good foamability, and has much and mild foam; strong alkali and electrolyte resistance and good thickening performance; no toxicity, good biological degradability and biological safety. The alcohol ether carboxylate is non-toxic and safe to use, and has excellent solubilizing capability and good detergency, wettability, emulsibility, dispersibility and lime soap dispersibility. The tea saponin is easy to biodegrade, hard water resistant, acid and alkali resistant, electrolyte resistant, high temperature resistant, stable to hypochlorite and peroxide, good in compatibility and especially free of interference on conditioning performance of cations. The bamboo vinegar has good permeability and absorbability to plant and animal tissue, and has odor eliminating effect. The polyaspartic acid has good scale inhibition and dispersion performance, still has good scale inhibition effect in water with higher hardness or alkalinity, and is an anode type corrosion inhibitor.

Chelating agents enable metal ions to form chelates of completely different properties, which is the main method for reducing and controlling the concentration of metal ions. Ethylenediaminetetraacetic acid (EDTA), in addition to its ability to stabilize solutions and increase clarity, has antioxidant and preservative effects, and can reduce the formation of fatty acid salts of polyvalent metal ions by complexation and precipitation. Tartaric acid can complex with various metal ions. Citric acid improves the performance of the detergent product, rapidly precipitates metal ions, prevents the reattachment of contaminants to the fabric, maintains the alkalinity necessary for washing, disperses and suspends dirt and ash, enhances the performance of the surfactant, and is an excellent chelating agent. Nitrilotriacetic acid (NTA) is low in price and has a strong chelating effect on calcium and magnesium ions.

Because the components of the kitchen grease are complex and changeable and are difficult to control and utilize, the reports about preparing the kitchen grease into solid soap are less in the prior art; the report about preparing the kitchen grease into the liquid soap is more blank. In the few reported liquid soap preparation technologies at present, only a solubilizing viscosity-reducing auxiliary agent or a chelating agent is usually added, and the kitchen grease cannot be successfully prepared into the liquid soap according to the method, namely the kitchen waste oil cannot be prepared into flowable liquid with a cleaning function. So far, research on the development of a liquid soap formula aiming at the characteristics of complex components of kitchen grease is not found. Therefore, the invention provides a two-step method for preparing the kitchen grease into the liquid soap. Firstly, preparing solid soap by using kitchen grease; then, a solubilizing viscosity-reducing auxiliary agent, a surfactant and a chelating agent are added to prepare the solid soap into liquid soap, and the obtained liquid soap meets the relevant standard. Wherein, the surfactant is added to react with the solubilizing and viscosity-reducing auxiliary agent and the chelating agent together with the solid soap to prepare the liquid soap, which is the characteristic and innovation of the invention. At present, no relevant literature report is found.

Compared with the prior art, the invention has the following advantages and effects:

(1) the invention firstly provides a method for preparing the kitchen grease into the liquid soap by adopting a two-step method. Preparing a solid soap base by taking kitchen waste oil as a raw material, and compounding by adding a green and environment-friendly solubilizing and viscosity-reducing auxiliary agent, a surfactant and a chelating agent to obtain a green and environment-friendly composite liquid soap detergent; provides a new technical approach for the resource utilization of the kitchen waste oil, realizes the recycling of waste resources, and has important significance for realizing carbon neutralization.

(2) The method has the advantages of cheap and easily obtained raw materials, less used reagents, simple flow, convenient operation and wide application prospect.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1:

s1, hydrothermal pretreatment: and (3) carrying out hydrothermal pretreatment on the kitchen waste at the treatment temperature of 150 ℃, and separating out kitchen grease to obtain the kitchen waste oil.

S2, impurity removal and dehydration: filtering and centrifuging the kitchen waste oil, and removing impurities and water; and then heating the kitchen waste oil to 50 ℃, adding water, stirring to fully mix oil and water, standing for layering, and removing a water layer to obtain the raw oil.

S3, decoloring and deodorizing by adopting activated clay and hydrogen peroxide: heating raw oil to 50 ℃, sequentially adding activated clay 5% by mass of the raw oil and hydrogen peroxide solution 2% by mass of the raw oil (the mass concentration of the hydrogen peroxide solution is 25%), stirring, heating to 90 ℃, decoloring for 15min, centrifuging, and taking the upper clear kitchen grease.

S4, preparation of solid soap: heating clear kitchen grease to 90 ℃, adding sodium hydroxide solution into the clear grease for 3 times to carry out saponification reaction, when the pH value reaches 9, carrying out saponification reaction completely, salting out saturated sodium chloride for 1 time, discharging waste water at the bottom layer, taking out soap base, and air-drying to obtain the solid soap. Wherein the mass ratio of the sodium hydroxide solution to the clear grease is 1: 1.5. The sodium hydroxide solution was added as follows: firstly, adding sodium hydroxide solution with the mass of 1/4, and stirring to ensure that the grease is dispersed in the sodium hydroxide solution in an emulsified state for 30 min; at the moment, the saponification reaction is accelerated, sodium hydroxide solution with the mass of 1/2 is added, and the reaction is carried out for 60 min; finally, adding the rest sodium hydroxide solution, and reacting for 30 min; adding alkali liquor while stirring slowly to make clear oil and sodium hydroxide solution contact fully.

S5, preparation of liquid soap: mixing solid soap and water according to the mass ratio of 1:0.2, adding 10% of solubilizing viscosity-reducing auxiliary agent absolute ethyl alcohol based on the mass of the solid soap, then adding 0.5% of surfactant tea saponin based on the mass of the solid soap and 0.1% of chelating agent Ethylene Diamine Tetraacetic Acid (EDTA) based on the mass of the solid soap; stirring until the solid soap is dissolved, drying, ventilating and standing, storing at the constant temperature of 35 ℃ for 12 hours, taking out, and cooling to room temperature to obtain the stable liquid soap containing the surfactant.

Example 2

And S1, performing anhydrous thermal pretreatment, and separating the kitchen waste oil from the kitchen waste.

S2, impurity removal and dehydration: filtering and centrifuging the kitchen waste oil, and removing impurities and water; and then heating the kitchen waste oil to 95 ℃, adding water, stirring to fully mix oil and water, standing for layering, and removing a water layer to obtain the raw oil.

S3, decoloring and deodorizing by adopting activated clay and hydrogen peroxide: heating raw oil to 80 ℃, sequentially adding activated clay 15% by mass of the raw oil and hydrogen peroxide solution 5% by mass of the raw oil (the mass concentration of the hydrogen peroxide solution is 35%), stirring, heating to 110 ℃, decoloring for 40min, and taking the upper clear kitchen grease.

S4, preparation of solid soap: heating clear kitchen grease to 110 ℃, adding potassium hydroxide solution into the kitchen grease for 3 times to carry out saponification reaction, when the pH value reaches 9, completely saponifying, salting out saturated sodium chloride for 3 times, discharging waste water at the bottom layer, taking out soap base, and air-drying to obtain the solid soap. Wherein the mass ratio of the potassium hydroxide solution to the kitchen grease is 1: 3; the potassium hydroxide solution was added as follows: firstly adding 1/5 mass potassium hydroxide solution, stirring to make oil disperse in potassium hydroxide solution in emulsified state for 80 min; at the moment, the saponification reaction is accelerated, and a potassium hydroxide solution with the mass of 1/3 is added for reaction for 180 min; finally adding the rest potassium hydroxide solution, and reacting for 90 min; and continuously and slowly stirring while adding the potassium hydroxide solution to ensure that the kitchen grease is fully contacted with the potassium hydroxide solution.

S5, preparation of liquid soap: mixing the solid soap and water according to a mass ratio of 1:5, adding a solubilization viscosity-reducing auxiliary agent (the solubilization viscosity-reducing auxiliary agent is prepared from 55 mass percent of ethanol, 25 mass percent of isopropanol, 11 mass percent of sodium toluene sulfonate and 9 mass percent of urea) with the mass percent of 60 percent of the solid soap, then, a surfactant (the surfactant is prepared from 9 mass percent to 30 mass percent to 20 mass percent to 13 mass percent to 3 mass percent to 25 mass percent) with the mass of 55 percent of solid soap is added, and a chelating agent (the chelating agent is prepared from Ethylene Diamine Tetraacetic Acid (EDTA), tartaric acid, citric acid and nitrilotriacetic acid (NTA) with the mass percent of 1 percent of solid soap is added, wherein the chelating agent comprises the following components in percentage by mass: 40%: 25%: 15%, stirring until the solid soap is dissolved, drying, ventilating and standing, storing at constant temperature of 45 ℃ for 48 hours, taking out and cooling to room temperature to obtain the stable liquid soap containing the surfactant.

Example 3:

in the other operation steps, as in example 1, the solubilizing and viscosity-reducing auxiliary agent in the step S5 is prepared from ethanol and isopropanol in a mass ratio of 3:4, the surfactant is prepared from polyethylene glycol, alkyl glycoside and tea saponin in a mass ratio of 29:15:33, and the chelating agent is prepared from ethylenediaminetetraacetic acid (EDTA) and tartaric acid in a mass ratio of 25: 9.

Comparative example

The procedure was as in example 1. S5, the solubilizing viscosity-reducing auxiliary agent, the surfactant and the chelating agent are not added.

In the steps of decoloring and deodorizing, the texture of the kitchen grease becomes more transparent, so that the purpose of deodorizing is achieved in the examples 1, 2, 3 and comparative examples. Index parameters of the produced environmentally friendly liquid soap are shown in table 1.

TABLE 1 comparison of the quality of eco-friendly liquid soap produced in each example and comparative example

As can be seen from Table 1, the physical and chemical indexes of the environment-friendly liquid soap produced by the invention all reach the standards specified in soap lye (Q/LBJT 36-2017) of Guangzhou white Enterprise group Limited company.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.