Composition for treating waste grease raw material, application of composition and pretreatment method of waste grease raw material

Abstract

The invention relates to the field of biomass energy pretreatment, and discloses a composition for treating a waste grease raw material, application of the composition and a pretreatment method of the waste grease raw material. The composition contains a demulsifier, oligomeric alkylphenol polyoxyethylene ether and a phase transfer agent which are stored independently or stored in a mixed mode of two or more of the components, and the demulsifier, the oligomeric alkylphenol polyoxyethylene ether and the phase transfer agent. Wherein the oligomeric alkylphenol polyoxyethylene ether has a structure as shown in a formula I: # imgabs0 #, in the formula, a is 2 to 15, and n is 7 to 30. When the composition is used as a grease purifying agent, metal, chlorine, phosphorus and other impurities in a waste grease raw material can be further removed into a water phase to be separated, a better impurity removal effect is obtained, a purified grease raw material is provided for a hydrogenation device for subsequently producing alkyl biodiesel, and the stable operation period of a fixed bed hydrogenation device can be prolonged.

Description

Technical Field

[0001] The present invention relates to the field of biomass energy pretreatment, and particularly to a composition for treating waste oil raw materials, its application, and a pretreatment method for waste oil raw materials. Background Art

[0002] Bio-renewable energy has always been the most important energy research topic due to the stability of its source and environmental friendliness. Among bio-renewable energies, biodiesel is one that is relatively mature in research and most widely used.

[0003] Currently, biodiesel has developed to the second generation. For the second-generation biodiesel, on the premise that the acid value meets the requirements, attention also needs to be paid to the contents of oxygen, sulfur, chlorine elements, and metal ions in biodiesel. Excessive chlorine element content will corrode alloy steel and cause equipment loss; the presence of metal ions will damage the carrier of the catalyst and affect catalysis. The common problem existing in currently produced biodiesel is that the high contents of oxygen, sulfur, chlorine elements, and metal ions affect the catalyst carrier, reducing the service life of the catalyst. In addition, the existing hydrotreating unit for alkyl biodiesel adopts a fixed-bed hydrotreating process after non-hydrogen pretreatment of the raw materials, which has the problem of inability to operate in a long cycle, seriously affecting economic benefits and posing a huge potential safety hazard. The reason is that the raw materials used mainly include waste cooking oils such as swill oil, hot pot oil, and frying oil, and are also doped with animal fats, soybean (or palm) acidified oils, etc. The extremely high contents of metal elements, salts, phospholipids, etc. in the raw materials are a huge test for the fixed-bed reactor. Therefore, in order to avoid the rapid increase in the bed pressure drop of the hydrotreating unit and extend the operation cycle of the unit, how to reduce the content of impurity elements in the biodiesel oil raw materials has become an urgent problem to be solved.

[0004] CN1931963A discloses a pretreatment production process for preparing biodiesel from waste animal and vegetable oils. In this method, water, salt, or sulfuric acid is added to the raw material oil for hydration, salting-out, or acid precipitation, followed by standing for separation and drying, and then through filtration, vacuum evaporation, distillation, or a combination process of evaporation and distillation to obtain two main components, fatty acids and glycerides. Although this method has high yield and good product quality, the water washing process is prone to emulsification, the separation of oil and water by standing is difficult, pollutants are likely to remain in the oil phase, and the evaporation and distillation processes require high temperatures, which are difficult to control, have poor adaptability, and are also energy-consuming.

[0005] CN109536202A discloses a pretreatment method for preparing raw materials for biodiesel from waste grease of cold rolling oil. In this method, the cold rolling oil is heated and then filtered to obtain filtered oil, a demulsifier is added for demulsification, a flocculant is added for flocculation, and then centrifugal separation is carried out to obtain oil, wastewater, and residue respectively. Finally, the oil is collected to obtain the raw material for biodiesel. The demulsifier used in this method is composed of sodium chloride, calcium chloride, magnesium chloride, aluminum sulfate, and water. Even if a trace amount of the demulsifier remains in the oil phase during the treatment process, it will greatly increase the metal content in the collected oil product; the flocculant used is cationic polyacrylamide, and its residual macromolecular network structure in the oil product will greatly affect the quality of the raw material for biodiesel and the subsequent hydrogenation process. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems of poor impurity removal effect and harsh process conditions in the existing grease pretreatment methods, and to provide a grease purifying agent that is not likely to remain in the oil phase. Even if a trace amount remains, it will not affect the properties of the oil product, nor will it affect the stable operation of the subsequent hydrogenation treatment device.

[0007] To achieve the above purpose, the first aspect of the present invention provides a composition for treating waste grease raw materials, and the composition contains the following components stored independently or in a mixture of two or more:

[0008] Demulsifier, oligomeric alkylphenol polyoxyethylene ether, and phase transfer agent;

[0009] Among them, the oligomeric alkylphenol polyoxyethylene ether has the structure shown in Formula I:

[0010]

[0011] In the formula, a is 2 - 15, and n is 7 - 30.

[0012] The second aspect of the present invention provides the application of the composition described in the first aspect in treating waste grease raw materials for producing alkyl biodiesel.

[0013] The third aspect of the present invention provides a pretreatment method for waste grease raw materials, and the pretreatment method includes the following steps:

[0014] In the presence of a solvent, the waste grease raw materials are contacted with a grease purifying agent for electro - desalting treatment, and then the obtained product is subjected to oil - water separation;

[0015] Among them, the grease purifying agent is the composition described in the first aspect.

[0016] Through the above technical solutions, the present invention has the following advantages:

[0017] 1. The composition provided by the present invention contains an oligomeric alkylphenol polyoxyethylene ether with a specific structure. When used in combination with a demulsifier and a phase transfer agent, and taking the composition as an oil purification agent, it can further remove impurities such as metals, chlorine, and phosphorus in the waste oil raw material to the aqueous phase for separation, obtaining a better impurity removal effect, providing a purified oil raw material for the subsequent hydrogenation unit for producing alkyl biodiesel, and being able to extend the stable operation period of the fixed-bed hydrogenation unit.

[0018] 2. The pretreatment method for the waste oil raw material provided by the present invention is simple and flexible in operation and has mature equipment during the process of treating the waste oil raw material. By contacting the waste oil raw material with the oil purification agent in the presence of a solvent for electro - desalting treatment, and then separating the resulting product into oil and water phases, it is beneficial to transfer various impurities in the waste oil raw material from the oil phase to the water phase, achieving a better impurity removal effect.

[0019] In addition, under preferred conditions, the pickling treatment before electro - desalting treatment can reduce the impurities and emulsifiable substances in the waste oil raw material, greatly reducing the difficulty of electro - desalting treatment and reducing the consumption of chemicals. Further, combined with the adsorption treatment after electro - desalting treatment, it can not only further improve the impurity removal effect, but also extend the service life of the adsorbent and reduce the solid waste discharge. And using the waste refining catalyst as the adsorbent realizes the effective utilization of waste resources, which is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the electrospray mass spectrum of the intermediate prepared in Preparation Example 1;

[0021] Figure 2 is the mass spectrum of the oligomeric alkylphenol polyoxyethylene ether prepared in Preparation Example 1;

[0022] Figure 3 is the electrospray mass spectrum of the intermediate prepared in Preparation Example 2;

[0023] Figure 4 is the mass spectrum of the oligomeric alkylphenol polyoxyethylene ether prepared in Preparation Example 2;

[0024] Figure 5 is the electrospray mass spectrum of the intermediate prepared in Preparation Example 3;

[0025] Figure 6 is the mass spectrum of the oligomeric alkylphenol polyoxyethylene ether prepared in Preparation Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0026] The endpoints and any values in the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0027] In the present invention, unless otherwise stated, "first" and "second" do not represent the order of precedence, nor do they limit each material or operation. They are only used to distinguish each material or operation. For example, "the first reaction" and "the second reaction" are only used to distinguish and indicate that these are not the same reaction.

[0028] As described above, the first aspect of the present invention provides a composition for treating waste grease raw materials, and the composition contains the following components stored independently or mixed with two or more of them:

[0029] Demulsifier, oligomeric alkylphenol polyoxyethylene ether and phase transfer agent;

[0030] Wherein, the oligomeric alkylphenol polyoxyethylene ether has the structure shown in Formula I:

[0031]

[0032] In the formula, a is 2 - 15, and n is 7 - 30.

[0033] The inventors of the present invention found during the research process that the composition contains an oligomeric alkylphenol polyoxyethylene ether with a specific structure. When used in combination with a demulsifier and a phase transfer agent, and taking the composition as an oil purification agent, it can further remove impurities such as metals, chlorine, and phosphorus in the waste grease raw materials to the aqueous phase for separation, obtaining a better impurity removal effect, providing a purified oil raw material for the subsequent hydrogenation device for producing alkyl biodiesel, and being able to extend the stable operation period of the fixed-bed hydrogenation device.

[0034] According to some embodiments of the present invention, in Formula I, a represents the degree of polymerization of the oligomeric alkylphenol polyoxyethylene ether, a is 2 - 15, preferably 3 - 10, more preferably 4 - 7; n represents the number of polyoxyethylene ether monomers, n is 7 - 30, preferably 10 - 20. By adopting the above preferred embodiments, in Formula I, a and n satisfy the above preferred ranges, which is beneficial to improving the metal removal efficiency of the oil raw material and has a better impurity removal effect.

[0035] According to some embodiments of the present invention, the oligomeric alkylphenol polyoxyethylene ether can be obtained by commercial purchase or can be prepared by itself.

[0036] According to a preferred embodiment of the present invention, the oligomeric alkylphenol polyoxyethylene ether is prepared by a method comprising the following steps:

[0037] (a) In the presence of an organic solvent and an acidic catalyst, nonylphenol is contacted with paraformaldehyde to carry out a first reaction to obtain an intermediate; wherein, the acidic catalyst is selected from at least one of oxalic acid, citric acid, p-toluenesulfonic acid, and linear alkylbenzenesulfonic acid, preferably p-toluenesulfonic acid;

[0038] (b) In the presence of a basic catalyst, the intermediate is contacted with ethylene oxide to carry out a second reaction.

[0039] According to some embodiments of the present invention, preferably, in step (a), the mass ratio of the amount of p-toluenesulfonic acid to the amount of nonylphenol is 1:20 - 100.

[0040] According to some embodiments of the present invention, preferably, in step (a), the molar ratio of the amount of nonylphenol to the amount of paraformaldehyde is 1 - 2:1, preferably 1.1 - 1.5:1, more preferably 1.15 - 1.35:1.

[0041] According to some embodiments of the present invention, preferably, in step (a), the organic solvent is xylene; preferably, the mass ratio of the amount of nonylphenol to the amount of the organic solvent is 1:1 - 3.

[0042] According to some embodiments of the present invention, preferably, in step (a), the contact includes: first mixing the nonylphenol, the p-toluenesulfonic acid, and the organic solvent, and then adding the paraformaldehyde to the resulting mixture to carry out the first reaction; preferably, the temperature of the mixture is 40 - 50°C. There is no particular limitation on the device or equipment for carrying out the first reaction. For example, it can be carried out in a three-necked flask equipped with a reflux condenser.

[0043] According to some embodiments of the present invention, preferably, in step (a), the first reaction is a phenolic aldehyde condensation reaction. The equation of the first reaction is as follows:

[0044]

[0045] According to some embodiments of the present invention, preferably, in step (a), the conditions of the first reaction include: the reaction temperature is 60 - 90°C; the reaction time is 4 - 10 h.

[0046] According to some embodiments of the present invention, preferably, in step (a), the intermediate has the structure shown in formula II:

[0047]

[0048] According to some embodiments of the present invention, preferably, in step (b), the basic catalyst is KOH.

[0049] According to some embodiments of the present invention, preferably, in step (b), the mass ratio of the basic catalyst to the intermediate is 0.3 - 1:100.

[0050] According to some embodiments of the present invention, preferably, in step (b), the molar ratio of the intermediate to the ethylene oxide is 1:20 - 250. Since ethylene oxide inevitably undergoes self - polymerization during the synthesis process, the amount of ethylene oxide used needs to be slightly more than the theoretical value.

[0051] According to some embodiments of the present invention, preferably, in step (b), the contacting includes: first mixing the intermediate with the basic catalyst, and then adding the ethylene oxide to the obtained mixture to carry out the second reaction; preferably, the temperature of the mixture is 60 - 80 °C. There is no particular limitation on the device or equipment for carrying out the second reaction. For example, it can be carried out in a high - pressure reactor.

[0052] According to some embodiments of the present invention, preferably, in step (b), the second reaction is an addition reaction.

[0053] According to some embodiments of the present invention, preferably, in step (b), the conditions of the second reaction include: the reaction temperature is 120 - 140 °C; the reaction time is 3 - 8 h; the reaction pressure is 0.2 - 0.4 MPa.

[0054] According to some embodiments of the present invention, preferably, step (b) further includes aging the product obtained from the second reaction; the aging time can be 2 - 4 h.

[0055] According to some embodiments of the present invention, preferably, the first reaction and the second reaction are carried out under an inert atmosphere. The inert atmosphere is provided by at least one inert gas among nitrogen, argon, neon, and helium.

[0056] According to some embodiments of the present invention, preferably, the demulsifier is a water - soluble polyether, preferably a polyether with a branched structure, and more preferably at least one of polyether polyamines, phenolic resin polyethers, and phenolic amine resin polyethers.

[0057] According to some embodiments of the present invention, preferably, the phase transfer agent is at least one of PEG - 400, PEG - 600, polyethylene glycol monomethyl ether, and polyethylene glycol monomethyl ether acrylate.

[0058] According to some embodiments of the present invention, preferably, in the composition, the mass ratio of the oligomeric alkylphenol polyoxyethylene ether, the demulsifier and the phase transfer agent is 1:0.1 - 1:0.3 - 1, preferably 1:0.2 - 0.5:0.3 - 0.8. Adopting the above preferred embodiments is beneficial to further improve the impurity removal effect of the waste oil raw material.

[0059] The second aspect of the present invention provides an application of the composition described in the first aspect in treating waste oil raw materials for producing alkyl biodiesel.

[0060] The third aspect of the present invention provides a pretreatment method for waste oil raw materials, and the pretreatment method includes the following steps:

[0061] In the presence of a solvent, the waste oil raw material is contacted with an oil purification agent for electro - desalting treatment, and then the obtained product is subjected to oil - water separation;

[0062] wherein, the oil purification agent is the composition described in the first aspect.

[0063] According to some embodiments of the present invention, preferably, in step (1), relative to 1 L of the waste oil raw material, the dosage of the oil purification agent is 20 - 500 mg, preferably 50 - 300 mg. Adopting the above preferred embodiments is beneficial to further improve the impurity removal effect of the pretreatment method.

[0064] According to some embodiments of the present invention, the waste oil raw material can be any oil raw material conventionally used in the art suitable for producing alkyl biodiesel, especially waste oil raw materials, such as including but not limited to at least one of waste oil raw materials such as acidulated oil (such as palm acidulated oil, soybean acidulated oil), restaurant waste oil, etc. Preferably, the density of the waste oil raw material at 20 °C is 860 - 950 kg / m 3 ; the total metal content is 30 - 800 μg / g; the chlorine content is 5 - 40 μg / g; the phosphorus content is 2 - 20 μg / g.

[0065] According to some embodiments of the present invention, preferably, in step (1), the temperature of the waste oil raw material is 60 - 90 °C, preferably 70 - 80 °C. The temperature of the waste oil raw material can be made to meet the above range by heat - exchanging the waste oil raw material. Adopting the above preferred embodiments is beneficial to improving the material fluidity and enhancing the separation efficiency.

[0066] According to some embodiments of the present invention, preferably, before the electro - desalting treatment in step (1), the waste oil raw material is further contacted with an acidifying agent for pickling treatment. Adopting the above preferred embodiments is beneficial to further improve the impurity removal effect of the pretreatment method.

[0067] Preferably, the acidic agent is at least one of phosphoric acid, maleic acid and citric acid. Preferably, the acidic agent is provided in the form of an aqueous solution. Preferably, in the aqueous solution, the mass fraction of the acidic agent is 1-10%.

[0068] Preferably, the mass ratio of the acidic agent to the waste oil raw material is 0.01-1:100.

[0069] Preferably, the time of the pickling treatment is 5-30 min, preferably 10-20 min.

[0070] Preferably, step (1) further includes performing (oil-water-solid) three-phase separation on the product obtained by the pickling treatment to obtain oil phase I. The three-phase separation can be carried out in a conventional manner in the art, and there is no particular limitation thereto. Preferably, the method of the three-phase separation is centrifugal separation. Preferably, the conditions of the centrifugal separation include: the rotation speed is 2000-4500 r / min; the time is 5-15 min. There is no particular limitation on the equipment used for the centrifugal separation, for example, it can be a three-phase horizontal screw centrifuge.

[0071] According to a preferred embodiment of the present invention, step (1) includes: contacting the waste oil raw material with an acidic agent for pickling treatment, and then performing three-phase separation on the obtained product to obtain oil phase I; in the presence of a solvent, contacting oil phase I with an oil purification agent for electro-desalting treatment, and then performing oil-water separation on the obtained product.

[0072] By adopting the above preferred embodiment, first, the emulsifiable substances and impurities in the waste oil raw material are chemically reacted through pickling treatment, then the emulsified substances and impurities in the oil phase are further removed through three-phase separation, and then the obtained oil-water mixture is subjected to electro-desalting treatment in combination with an oil purification agent. Under the action of an electric field, oil-water separation is carried out, and under the combined action of the oil purification agent and the residual acid solution, impurities such as metals, chlorine and phosphorus in the oil-water mixture are further removed to the water phase for separation, so as to obtain a better impurity removal effect.

[0073] According to some embodiments of the present invention, preferably, in step (1), the conditions of the electro-desalting treatment include: the temperature is 110-150 °C, preferably 120-140 °C; the electric field strength is 200-2000 V / cm, preferably 500-1500 V / cm; the time is 0.1-1 h, preferably 0.2-0.5 h.

[0074] According to some embodiments of the present invention, preferably, in step (1), the solvent is water;

[0075] Preferably, based on the total mass of the waste oil raw material, the amount of the solvent is 5-15 wt%.

[0076] According to some embodiments of the present invention, when the relevant indicators of the oil phase II obtained by the oil-water separation do not meet the hydrogenation requirements for the subsequent production of alkyl biodiesel, an adsorbent can be used to further purify the oil phase II.

[0077] According to some embodiments of the present invention, preferably, step (2) further includes: contacting the oil phase II obtained by the oil-water separation with an adsorbent for adsorption treatment;

[0078] Preferably, the adsorbent is at least one of clay, kaolin, and waste refinery catalyst.

[0079] Adopting the above preferred embodiments is beneficial to further improve the impurity removal effect of the pretreatment method, and using the waste refinery catalyst as an adsorbent can achieve the effective utilization of waste resources, which is economical and environmentally friendly.

[0080] According to some embodiments of the present invention, the pretreatment method by contacting the oil phase II obtained by the oil-water separation with an adsorbent for adsorption treatment is beneficial to further obtain a purified raw material with a lower impurity content.

[0081] The present invention will be described in detail below through examples.

[0082] In the following examples and comparative examples, unless otherwise specified, various raw materials and equipment used are commercially available products. Among them:

[0083] Mass spectrometry analysis method

[0084] Test instrument: 15T SolariX XR type Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS), Bruker Daltonics company, and the ion source is an electrospray ionization source (ESI + ) in the positive ion mode.

[0085] Test conditions: The samples are all dissolved in a toluene / methanol (volume ratio 1:1) mixed solvent, and 2.5% formic acid is added to the sample to be measured as an auxiliary ionization reagent. The nebulizing gas and the drying gas are both high-purity nitrogen (99.999%), the nebulizing gas flow rate is 1.0 L / min, the drying gas flow rate is 4.0 L / min, and the drying gas temperature is 200 °C. The m / z detection range of the sample is 100-3000, the flight time (TOF) is 1.2 ms, the sampling memory is 8 Mb, and the scan is 128 times;

[0086] The metal and other elements in the raw material are determined by inductively coupled plasma emission spectrometry;

[0087] Paraformaldehyde and phase transfer agent are both chemical reagents, purchased from InnoChem Co., Ltd.;

[0088] The demulsifiers are industrial products, all purchased from Jiangsu Innovation Co., Ltd. Among them: the model / brand of phenolic resin polyether is RP616; the model / brand of phenolic amine resin polyether is RP404;

[0089] Waste cooking oil and soybean acidulated oil are provided by Anhui Yisheng New Energy Co., Ltd.;

[0090] The types and properties of the waste oil raw materials are shown in Table 1.

[0091] Table 1

[0092]

[0093] The following preparation examples are used to illustrate the oligomeric alkylphenol polyoxyethylene ether and its preparation method

[0094] Preparation Example 1

[0095] This preparation example is used to prepare the oligomeric alkylphenol polyoxyethylene ether Z1, where a = 2 and n = 10;

[0096] The specific preparation method is as follows:

[0097] (a) Preparation of intermediate:

[0098] In the presence of an organic solvent and p-toluenesulfonic acid, nonylphenol (11 g) is contacted with paraformaldehyde for the first reaction to obtain an intermediate, whose electrospray mass spectrum is as Figure 1 shown. It is determined by electrospray mass spectrometry to be a dimer intermediate (yield 85 wt%); among them:

[0099] The mass ratio of p-toluenesulfonic acid to nonylphenol is 1:55;

[0100] The molar ratio of nonylphenol to paraformaldehyde is 2:1;

[0101] The organic solvent is xylene; the mass ratio of nonylphenol to the organic solvent is 11:18;

[0102] The specific contact step is: add nonylphenol, p-toluenesulfonic acid, and xylene into a three-necked flask equipped with a reflux condenser, then pass nitrogen for protection, heat up to 60 °C and stir evenly, and then add paraformaldehyde to carry out the first reaction;

[0103] The first reaction is a phenolic condensation reaction; the conditions of the first reaction are: reaction temperature is 70 °C; reaction time is 6 h;

[0104] After the first reaction, water and xylene in the product are removed, and the product is separated and purified by silica gel column chromatography to obtain the above intermediate;

[0105] (b) Preparation of oligomeric alkylphenol polyoxyethylene ether: In the presence of a basic catalyst, the above intermediate is contacted with ethylene oxide for a second reaction; wherein:

[0106] The basic catalyst is KOH; the mass ratio of the basic catalyst to the intermediate is 0.5:100;

[0107] The molar ratio of the intermediate to ethylene oxide is 1:22;

[0108] The specific steps of the contact are as follows: Add the above intermediate into a high-pressure reactor, then add the basic catalyst, seal the reactor body, displace the air in the high-pressure reactor, the feed tank and the feed pipe with dry nitrogen, start heating and stirring, and at the same time evacuate with a vacuum pump. Stop evacuating when the temperature rises to 100 °C; Add ethylene oxide into the feed tank, pressurize to the reaction pressure, and then open the feed valve to start feeding to carry out the second reaction;

[0109] The second reaction is an addition reaction; the conditions of the second reaction are: the reaction temperature is 130 °C; the reaction time is 6 h; the reaction pressure is 0.4 MPa;

[0110] After the ethylene oxide in the reactor has reacted completely, continue aging for 1 h, the pressure in the reactor drops to a constant value, cool and discharge the material, neutralize the reaction product with acetic acid, and the mass spectrum of the obtained product is as Figure 2 shown. It is determined by mass spectrometry to be oligomeric alkylphenol polyoxyethylene ether Z1 (yield 75% by weight).

[0111] Preparation Example 2

[0112] This preparation example is used to prepare oligomeric alkylphenol polyoxyethylene ether Z2, wherein, a = 4, n = 15;

[0113] According to the method of Preparation Example 1, the difference is:

[0114] In step (a), the molar ratio of nonylphenol to paraformaldehyde is 4:3, and the rest are the same;

[0115] The obtained intermediate, its electrospray mass spectrum is as Figure 3 shown. It is determined by electrospray mass spectrometry to be a tetramer intermediate (yield 83% by weight);

[0116] In step (b), the molar ratio of the intermediate to ethylene oxide is 1:66, and the rest are the same;

[0117] The mass spectrum of the obtained product is as Figure 4 shown. It is determined by mass spectrometry to be oligomeric alkylphenol polyoxyethylene ether Z2 (yield 75% by weight).

[0118] Preparation Example 3

[0119] This preparation example is used to prepare oligomeric alkylphenol polyoxyethylene ether Z3, where a = 7 and n = 30;

[0120] According to the method of Preparation Example 1, the difference is:

[0121] In step (a), the molar ratio of nonylphenol to paraformaldehyde is 7:6, and the rest are the same;

[0122] The obtained intermediate, its electrospray mass spectrum is as Figure 5 shown, and it is determined to be a heptamer intermediate (yield 80% by weight) by electrospray mass spectrometry;

[0123] In step (b), the molar ratio of the intermediate to ethylene oxide is 1:231, and the rest are the same;

[0124] The mass spectrum of the obtained product is as Figure 6 shown, and it is determined to be oligomeric alkylphenol polyoxyethylene ether Z3 (yield 71% by weight) by mass spectrometry testing.

[0125] The following examples are used to illustrate the composition for treating waste grease raw materials and the pretreatment method of waste grease raw materials

[0126] Example 1

[0127] (1) Contact the waste grease raw material (100 g) with an acid agent for pickling treatment, and then perform three-phase separation on the obtained product to obtain oil phase I; where:

[0128] The waste grease raw material is waste cooking oil; the temperature of the waste grease raw material is 80 °C;

[0129] The acid agent is citric acid, which is provided in the form of a 1 wt% aqueous citric acid solution;

[0130] The mass ratio of the acid agent to the waste grease raw material is 0.1:100;

[0131] The pickling treatment time is 10 min; the separation method for three-phase separation is centrifugal separation, and the conditions for centrifugal separation are: rotation speed is 4000 r / min; time is 5 min;

[0132] (2) In the presence of a solvent, contact the above oil phase I with a grease purifying agent for electro-desalting treatment, and then perform oil-water separation on the obtained product to obtain oil phase II; where:

[0133] The types and content mass ratios of the components in the grease purifying agent are shown in Table 2;

[0134] Relative to 1 L of waste grease raw material, the dosage of the grease purifying agent is 200 mg;

[0135] The solvent is water; based on the total mass of the waste oil raw material, the dosage of the solvent is 10 wt%.

[0136] The conditions for electro - desalting treatment are: temperature is 120 °C; electric field strength is 1200 V / cm; time is 30 min.

[0137] (3) When the temperature of the oil phase II drops to 80 °C, 10 wt% of it is taken for analysis, and the rest is continuously subjected to adsorption treatment with an adsorbent to obtain a purified raw material; among them, the adsorbent used is clay.

[0138] Example 2 - 3

[0139] According to the method of Example 1, the difference is that in step (1), the types of oligomeric alkylphenol polyoxyethylene ethers in the oil purification agent are different, as shown in Table 2 specifically; the rest are the same.

[0140] Example 4

[0141] According to the method of Example 2, the differences are as follows:

[0142] In step (1), the waste oil raw material is soybean acidulated oil; the temperature of the waste oil raw material is 70 °C.

[0143] The acidulant is phosphoric acid, which is provided in the form of a 1 wt% aqueous phosphoric acid solution.

[0144] The mass ratio of the acidulant to the waste oil raw material is 0.3:100.

[0145] The time for pickling treatment is 20 min; the separation method for three - phase separation is centrifugal separation, and the conditions for centrifugal separation are: rotational speed is 2500 r / min; time is 10 min.

[0146] The rest are the same, and oil phase I is obtained.

[0147] In step (2), the types and mass ratio of the components in the oil purification agent are shown in Table 2.

[0148] Relative to 1 L of the waste oil raw material, the dosage of the oil purification agent is 50 mg.

[0149] The solvent is water; based on the total mass of the waste oil raw material, the dosage of the solvent is 5 wt%.

[0150] The conditions for electro - desalting treatment are: temperature is 130 °C; electric field strength is 500 V / cm; time is 20 min.

[0151] The rest are the same, and oil phase II is obtained.

[0152] In step (3), when the temperature of the second oil phase drops to 80 °C, 10 wt% of it is taken for analysis, and the remaining part continues to be treated with the adsorbent to obtain the purified raw material. The adsorbent used is a mixture of kaolin and waste refining catalyst, and in this mixture, the mass ratio of kaolin to waste refining catalyst is 1:1.

[0153] Example 5

[0154] According to the method of Example 2, the difference is that in step (2), relative to 1 L of waste grease raw material, the dosage of the grease purifying agent is 20 mg; the rest are the same, and the purified raw material is obtained.

[0155] Example 6

[0156] According to the method of Example 2, the difference is that in step (2), the content mass ratio of each component in the grease purifying agent is different, as shown in Table 2 specifically, and the rest are the same, and the purified raw material is obtained.

[0157] Example 7

[0158] According to the method of Example 2, the difference is that step (1) is not carried out, but in the presence of a solvent, the waste grease raw material is directly contacted with the grease purifying agent for electro - desalting treatment; the rest are the same, and the purified raw material is obtained.

[0159] Comparative Example 1

[0160] According to the method of Example 2, the difference is that in step (2), no grease purifying agent is added; the rest are the same, and the purified raw material is obtained.

[0161] Comparative Example 2

[0162] According to the method of Example 2, the difference is that in step (2), the grease purifying agent does not contain a demulsifier; the rest are the same, and the purified raw material is obtained.

[0163] Comparative Example 3

[0164] According to the method of Example 2, the difference is that in step (2), the grease purifying agent does not contain a phase transfer agent; the rest are the same, and the purified raw material is obtained.

[0165] Table 2

[0166]

[0167]

[0168] In each example and comparative example, the content of each element in the oil phase and the grease raw material is shown in Table 3.

[0169] Table 3

[0170]

[0171] As can be seen from the above results, the composition and pretreatment method provided by the present invention can significantly reduce the contents of impurities such as metals, chlorine, and phosphorus in waste oil raw materials. Especially for waste oil raw materials with high metal contents (such as restaurant waste oil), which are difficult to treat and prone to emulsification, when using the composition and pretreatment method provided by the present invention, the total metal removal rate before adsorption treatment (oil phase II) reaches over 90%, and can be up to 94.3% at most (see Example 2); the impurity removal effect of using the composition provided by the present invention as an oil purification agent is remarkable. Using the composition and pretreatment method provided by the present invention, the total metal content of restaurant waste oil can be reduced to a minimum of 5.5 μg / g, the phosphorus content can be reduced to a minimum of 0.8 μg / g, and the chlorine content can be reduced to a minimum of 0.8 μg / g, and the impurity removal effect is very obvious. For soybean acidified oil with relatively low metal content, the composition and pretreatment method provided by the present invention also have good treatment effects. In addition, under preferred circumstances, first contacting the waste oil raw material with an acid agent for pickling treatment is beneficial to further improving the total metal removal rate of the waste oil raw material and can obtain a better impurity removal effect.

[0172] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A composition for treating waste grease raw materials, characterized in that, The composition contains the following components stored independently or in combination of two or more: Demulsifier, oligomeric alkylphenol polyoxyethylene ether, and phase transfer agent; Among them, the oligomeric alkylphenol polyoxyethylene ether has the structure shown in Formula I: In the formula, a is 2 - 15, and n is 7 - 30.

2. The composition according to claim 1, wherein, In Formula I, a is 3 - 10, preferably 4 - 7; n is 10 - 20; Preferably, the oligomeric alkylphenol polyoxyethylene ether is prepared by a method comprising the following steps: (a) In the presence of an organic solvent and an acidic catalyst, nonylphenol is contacted with paraformaldehyde for a first reaction to obtain an intermediate; wherein, the acidic catalyst is selected from at least one of oxalic acid, citric acid, p-toluenesulfonic acid, and linear alkylbenzene sulfonic acid, preferably p-toluenesulfonic acid; (b) In the presence of a basic catalyst, the intermediate is contacted with ethylene oxide for a second reaction.

3. The composition according to claim 2, wherein In step (a), the mass ratio of the p-toluenesulfonic acid to the nonylphenol is 1:20 - 100; Preferably, in step (a), the molar ratio of the nonylphenol to the paraformaldehyde is 1 - 2:1, preferably 1.1 - 1.5:1, more preferably 1.15 - 1.35:1; Preferably, in step (a), the organic solvent is xylene; the mass ratio of the nonylphenol to the organic solvent is 1:1 - 3.

4. The composition according to claim 2, wherein, In step (a), the first reaction is a phenolic aldehyde condensation reaction; the conditions of the first reaction include: the reaction temperature is 60 - 90 °C; the reaction time is 4 - 10 h; Preferably, in step (a), the intermediate has the structure shown in Formula II:

5. The composition according to claim 2, wherein In step (b), the basic catalyst is KOH; Preferably, in step (b), the mass ratio of the basic catalyst to the intermediate is 0.3 - 1:100; Preferably, in step (b), the molar ratio of the intermediate to the ethylene oxide is 1:20 - 250; Preferably, in step (b), the second reaction is an addition reaction; the conditions of the second reaction include: the reaction temperature is 120 - 140 °C; the reaction time is 3 - 8 h; the reaction pressure is 0.2 - 0.4 MPa; Preferably, the first reaction and the second reaction are carried out under an inert atmosphere.

6. The composition according to any one of claims 1-5, wherein The demulsifier is a water-soluble polyether, preferably a polyether with a branched structure, more preferably at least one of polyamine polyether, phenolic resin polyether, and phenolic amine resin polyether; Preferably, the phase transfer agent is at least one of PEG - 400, PEG - 600, polyethylene glycol monomethyl ether, and polyethylene glycol monomethyl ether acrylate; Preferably, in the composition, the mass ratio of the oligomeric alkylphenol polyoxyethylene ether, the demulsifier, and the phase transfer agent is 1:0.1 - 1:0.3 - 1, preferably 1:0.2 - 0.5:0.3 - 0.

8.

7. Use of the composition according to any one of claims 1 - 6 in treating waste oil raw materials for producing alkyl biodiesel.

8. A pretreatment method for waste oil raw materials, characterized in that, The pretreatment method comprises the following steps: In the presence of a solvent, the waste oil raw material is contacted with an oil purification agent for electro - desalting treatment, and then the obtained product is subjected to oil - water separation; Among them, the oil purification agent is the composition described in any one of claims 1 - 6.

9. The pretreatment method according to claim 8, wherein, Relative to 1 L of the waste oil raw material, the dosage of the oil purification agent is 20 - 500 mg, preferably 50 - 300 mg; Preferably, the density of the waste grease raw material at 20 °C is 860-950 kg / m 3 ; the total metal content is 30-800 μg / g; the chlorine content is 5-40 μg / g; the phosphorus content is 2-20 μg / g.

10. The pretreatment method according to claim 8 or 9, wherein Before carrying out the electro - desalting treatment, it further includes contacting the waste oil raw material with an acid agent for pickling treatment; Preferably, the acid agent is at least one of phosphoric acid, maleic acid and citric acid; Preferably, the mass ratio of the acid agent to the waste oil raw material is 0.01 - 1:100; Preferably, the time of the pickling treatment is 5 - 30 min, preferably 10 - 20 min; Preferably, the temperature of the waste oil raw material is 60 - 90 °C, preferably 70 - 80 °C.

11. The pretreatment method according to any one of claims 8-10, wherein, The conditions of the electro - desalting treatment include: temperature is 110 - 150 °C, preferably 120 - 140 °C; electric field strength is 200 - 2000 V / cm, preferably 500 - 1500 V / cm; time is 0.1 - 1 h, preferably 0.2 - 0.5 h.

12. The pretreatment method according to any one of claims 8-11, wherein, The solvent is water; based on the total mass of the waste oil raw material, the dosage of the solvent is 5 - 15 wt%.

13. The pretreatment method according to any one of claims 8-12, wherein, The pretreatment method further includes: contacting the oil phase II obtained by the oil - water separation with an adsorbent for adsorption treatment; Preferably, the adsorbent is at least one of clay, kaolin and waste refining catalyst.

Images