Composition for treating waste plastic oil, application of composition and method for removing impurities in waste plastic oil

Abstract

The invention relates to the field of waste plastic oil recycling, and discloses a composition for treating waste plastic oil, application of the composition and a method for removing impurities in the waste plastic oil. Based on the total amount of the composition, the composition contains the following components which are stored independently or stored in a mixed manner: 30-45wt% of a carboxylic acid polymer, 5-10wt% of hydroximic acid, 5-20wt% of a polyether imidazoline compound and 5-10wt% of a demulsifying agent, wherein the carboxylic acid polymer, the hydroximic acid, the polyether imidazoline compound and the demulsifying agent are stored in a mixed manner; wherein the polyether imidazoline compound is alkyl phenolic resin polyether imidazoline. When the composition provided by the invention is used for treating waste plastic oil, the removal rates of iron and calcium are respectively more than 58% and more than 65%, and the removal rate of chlorine is more than 40% and can reach 45.5% at most, so that the composition has better demetallization and dechlorination effects. In addition, under the preferable condition, the reaction conditions are more mild.

Description

Technical Field

[0001] The invention relates to the field of recycling of waste plastic oil, and in particular to a composition for treating waste plastic oil and an application thereof, and a method for removing impurities from the waste plastic oil. Background Art

[0002] While plastics bring convenience to human society, they also cause many environmental problems, becoming white garbage that pollutes the environment and endangers human health. According to statistics, more than 60% of waste plastics worldwide are landfilled or incinerated because they cannot be used reasonably.

[0003] Common waste plastics include: polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polycarbonate (PC), polylactic acid (PA), nylon (Nylon), fiberglass reinforced plastics (FRP), and polylactic acid film (BOPLA).

[0004] Waste plastics can be converted into recycled oil under high temperature or catalyst, called plastic oil or waste plastic oil. Plastic oil can be used as fuel or chemical raw material, or it can be converted into high value-added products such as diesel, low-carbon olefins and high-octane gasoline under appropriate process conditions. Preparing plastic oil from waste plastics and then using plastic oil as raw material to make high value-added products can achieve chemical recycling of waste plastics. It is a promising technology that has received widespread attention at home and abroad.

[0005] The methods for cracking and oiling waste plastics include: thermal cracking, catalytic cracking, thermal cracking-catalytic modification, catalytic cracking-catalytic modification, etc. The catalysts used include solid acid catalysts, alkali metal catalysts (such as CaO, BaO, Al2O3), molecular sieves (ZSM-5), etc.

[0006] Due to the large variety of waste plastics and the large number of additives contained in waste plastics, the impurity content in plastic oil is generally high, and the main impurities include chlorine and metals.

[0007] Metals in plastic oil, such as calcium and iron, have a great impact on subsequent processing. These metals mainly come from the catalysts used in the catalytic cracking of plastics. Metals such as calcium and iron can exist in the form of fine particles, or combine with acidic substances in plastic oil to form oil-soluble compounds.

[0008] The chlorine in plastic oil will have a relatively large impact on subsequent processing. The chlorine in plastic oil mainly comes from HCl released by the decomposition of PVC. It has been reported in the literature that PVC begins to dechlorinate at 200°C and completes dechlorination before 350°C. HCl can add to other olefins or alkyne compounds produced by cracking to form chlorinated alkanes or chlorinated olefin compounds. HCl can react with PET decomposition products to form chlorinated ester compounds. Chlorinated hydrocarbon compounds and ester compounds will release HCl again during the processing of plastic oil, causing corrosion and salt formation of equipment. Therefore, the technology of many plastic oil companies has strict requirements on the content of PVC and PET in waste plastic raw materials. However, due to the wide source of waste plastics and the difficulty of sorting, the actual prepared plastic oil still has the problem of excessive chlorine content. For example, the chlorine content of plastic oil produced by some companies is 0.25%-0.48%, which has a relatively large impact on subsequent processing.

[0009] There is no good method to remove impurities such as metals and chlorine from plastic oil. We can only learn from the methods of dechlorination of distillate oil and demetallization of crude oil.

[0010] CN101392184A discloses a method for removing metals from hydrocarbon oil using phytic acid, the method comprising: fully mixing hydrocarbon oil, phytic acid, demulsifier and water, separating oil phase and water phase, and extracting metals in the oil phase into the water phase for removal. The molar ratio of phytic acid to calcium in the raw oil is 0.01-10:1, so as to achieve the removal of metals such as calcium, iron, magnesium, manganese, etc. in the hydrocarbon oil.

[0011] CN101314728A discloses a method for deironing hydrocarbon raw oil. The method adopts a deironing agent prepared by mixing nitrogen-containing compounds and organic acids, which has stronger iron ion chelating ability and can achieve better deironing effect in a shorter reaction time and at a lower reaction temperature.

[0012] CN1760340A and CN1760341A respectively disclose a method for removing metals from hydrocarbon oils using carboxylic acid homopolymers or carboxylic acid copolymers. The methods respectively use unsaturated carboxylic acid homopolymers or unsaturated carboxylic acid copolymers as hydrocarbon oil demetallizing agents, and are particularly effective in removing metals such as calcium and iron, especially calcium, in the form of cyclopentaneates in hydrocarbon oils. The methods have the characteristics of small dosage and high removal efficiency, and are suitable for hydrocarbon oils containing excessive amounts of calcium.

[0013] The methods for demetallizing crude oil are relatively mature, and there are many corresponding existing technologies. However, since the existence forms of metals such as calcium and iron in plastic oil are different from those in crude oil, the catalyst added during the plastic pyrolysis oil production process adsorbs the acidic substances in the plastic oil on the surface during the pyrolysis process and becomes oil-soluble metals. The metal removal rate is low when adding demetallizing agents in the process of simulating electrical desalination. Therefore, the methods for demetallizing crude oil are not applicable to the metal removal of plastic oil.

[0014] At present, the main methods for removing organic chlorine include catalytic hydrogenation, advanced oxidation, metal reduction, nucleophilic substitution, electrochemical dechlorination and biological dechlorination, etc. Among these methods, the catalytic hydrogenation method has the highest dechlorination efficiency (greater than 90%), while the removal rates of other methods are relatively low (less than 40%).

[0015] The catalytic hydrogenation method is that hydrogen and organic chloride generate HCl and corresponding hydrocarbons on the surface of the catalyst. CN104492480A and CN111171865A disclose catalytic hydrodechlorination methods, but the reaction temperature in the existing methods is relatively high (greater than 300°C), the reaction pressure is greater than 2.5MPa, and high-temperature and high-pressure equipment is required, and the equipment investment and operating costs are relatively high. In addition, the HCl produced by catalytic hydrodechlorination will cause equipment corrosion, seriously affecting operational safety. Summary of the invention

[0016] The purpose of the present invention is to overcome the problem that the existing method for removing impurities from waste plastic oil has poor removal effect of metal and chlorine.

[0017] In order to achieve the above object, the first aspect of the present invention provides a composition for treating waste plastic oil, which comprises the following components stored separately or in a mixture of two or more thereof, based on the total amount of the composition:

[0018] 30-45wt% of a carboxylic acid polymer, 5-10wt% of a hydroxamic acid, 5-20wt% of a polyether imidazoline compound and 5-10wt% of a demulsifier; wherein the polyether imidazoline compound is an alkylphenol-formaldehyde resin polyether imidazoline having a general structure shown in Formula I:

[0019]

[0020] In the formula, R is nonyl or octyl; a is 2-10; x is 1-2; and y is 5-8.

[0021] The second aspect of the present invention provides use of the composition described in the first aspect in treating waste plastic oil.

[0022] A third aspect of the present invention provides a method for removing impurities from waste plastic oil, the method comprising:

[0023] In the presence of a reaction solvent, the waste plastic oil is contacted with the components in the composition described in the first aspect to react, and then the obtained reaction product is subjected to electrical desalination treatment, and then the product obtained by the electrical desalination treatment is subjected to oil-water separation.

[0024] Through the above technical scheme, the composition provided by the present invention is used to treat waste plastic oil, and the removal rates of iron and calcium are respectively above 58% and above 65%, and the removal rate of chlorine is above 40%, and can reach up to 45.5%, with good demetallization and dechlorination effects. In addition, in a preferred case, the reaction conditions are also more moderate. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise 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, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] In the present invention, unless otherwise stated, the pressures described are gauge pressures.

[0027] As mentioned above, the first aspect of the present invention provides a composition for treating waste plastic oil. Based on the total amount of the composition, the composition contains the following components which are stored separately or in a mixture of two or more:

[0028] 30-45wt% of a carboxylic acid polymer, 5-10wt% of a hydroxamic acid, 5-20wt% of a polyether imidazoline compound and 5-10wt% of a demulsifier; wherein the polyether imidazoline compound is an alkylphenol-formaldehyde resin polyether imidazoline having a general structure shown in Formula I:

[0029]

[0030] In the formula, R is nonyl or octyl; a is 2-10; x is 1-2; and y is 5-8.

[0031] According to some embodiments of the present invention, preferably, the carboxylic acid polymer is at least one of an acrylic acid polymer, a hydrolyzed polymaleic anhydride, an acrylic acid-maleic anhydride copolymer, an acrylic acid-acrylate copolymer, and an acrylic acid-2-acrylamide-2-methylpropyl sulfonic acid (AMPS) copolymer, preferably an acrylic acid-acrylate copolymer. The acrylic acid-acrylate copolymer may be a binary copolymer or a ternary copolymer.

[0032] According to some embodiments of the present invention, preferably, the acrylic acid-acrylate copolymer is at least one of acrylic acid-methyl acrylate copolymer, acrylic acid-hydroxyethyl acrylate copolymer, acrylic acid-hydroxypropyl acrylate copolymer, acrylic acid-hydroxyethyl methacrylate copolymer, acrylic acid-hydroxypropyl methacrylate copolymer and acrylic acid-hydroxypropyl acrylate-methyl acrylate terpolymer, preferably acrylic acid-hydroxypropyl acrylate copolymer. The acrylic acid-acrylate copolymer of the above preferred embodiment is used in combination with the components in the composition, which is conducive to obtaining a better removal effect of impurities such as metals (such as calcium, iron) and chlorine.

[0033] According to some embodiments of the present invention, preferably, the weight average molecular weight of the acrylic acid-acrylate copolymer is 1000-50000 g / mol, preferably 2000-40000 g / mol.

[0034] According to some embodiments of the present invention, preferably, in the acrylic acid-acrylate copolymer, the molar ratio of the acrylic acid structural unit to the acrylate structural unit is 0.1-20:1, preferably 0.5-10:1.

[0035] The acrylic acid-acrylate copolymer of the above preferred embodiment is used in combination with the components in the composition to achieve a better removal effect of impurities such as metals (such as calcium and iron) and chlorine.

[0036] According to some embodiments of the present invention, the polyether imidazoline compound is an alkylphenol-formaldehyde resin polyether imidazoline having a general structure shown in Formula I:

[0037]

[0038] In the formula, R is nonyl or octyl, preferably nonyl; a is 2-10, preferably 4-6; x is 1-2; y is 5-8;

[0039] Preferably, the polyether imidazoline compound is a nonylphenolic resin polyether imidazoline, that is, R is a nonyl group in Formula I. The above preferred embodiment is advantageous for obtaining a better removal effect of impurities such as metals (such as calcium and iron) and chlorine.

[0040] According to some embodiments of the present invention, the polyether imidazoline compound can be commercially available or prepared by itself.

[0041] According to some embodiments of the present invention, preferably, the polyether imidazoline compound is prepared by a method comprising the following steps:

[0042] (S1) contacting an alkylphenol-formaldehyde resin polyether with succinic anhydride to perform a first reaction to obtain a carboxylated polyether; the first reaction is a carboxylation reaction;

[0043] (S2) contacting the carboxylated polyether with diethylenetriamine to carry out a second reaction; the second reaction includes an amidation reaction and a cyclization reaction.

[0044] According to some embodiments of the present invention, preferably, in step (S1), the alkylphenol-formaldehyde resin polyether has a general structure shown in Formula II:

[0045]

[0046] Wherein, R, a, x, and y are defined and selected as above and will not be described in detail here;

[0047] Preferably, the alkylphenol-formaldehyde resin polyether is nonylphenol-formaldehyde resin polyether.

[0048] According to some embodiments of the present invention, the alkylphenol-formaldehyde resin polyether can be commercially available or prepared by itself.

[0049] According to a preferred embodiment of the present invention, the alkylphenol-formaldehyde resin polyether is prepared by a method comprising the following steps:

[0050] 1) Under an inert atmosphere, an alkylphenol-formaldehyde resin and a base I are contacted with propylene oxide to react to obtain an intermediate product; wherein:

[0051] The base I is sodium hydroxide and / or potassium hydroxide; the mass ratio of the alkylphenol-formaldehyde resin, the base I and the propylene oxide is 50-240:1:35-200;

[0052] The reaction conditions include: temperature of 125-135°C, pressure of 0.1-0.5MPa, and time of 15min-2h;

[0053] 2) under an inert atmosphere, contacting the intermediate product and base II with ethylene oxide to react to obtain an alkylphenol-formaldehyde resin polyether; wherein:

[0054] The base II is sodium hydroxide and / or potassium hydroxide; the mass ratio of the intermediate product, the base II and the ethylene oxide is 100:1-2:10-30;

[0055] The reaction conditions include: temperature of 115-125° C., pressure of 0.1-0.5 MPa, and time of 15 min-2 h.

[0056] Preferably, in step 1), the alkylphenol-formaldehyde resin can be obtained commercially or prepared by itself. The preparation method thereof may include:

[0057] In the presence of a catalyst, the alkylphenol and formaldehyde are subjected to a condensation reaction. The catalyst may be an acid or a base. The specific reaction conditions are well known to those skilled in the art and will not be described in detail herein.

[0058] Preferably, in step 1), the degree of polymerization of the alkylphenol-formaldehyde resin is 2-10, preferably 4-6; the weight average molecular weight is 440-2200 g / mol, preferably 880-1320 g / mol.

[0059] According to some embodiments of the present invention, preferably, the weight average molecular weight of the alkylphenol-formaldehyde resin polyether is 440-2200 g / mol, preferably 880-1320 g / mol; the hydroxyl value is 25.5-127 mgKOH / g, preferably 42.4-63.6 mgKOH / g.

[0060] According to some embodiments of the present invention, preferably, in step (S1), the mass ratio of the alkylphenol-formaldehyde resin polyether to the succinic anhydride is 90-150:8, preferably 100-120:8, and more preferably 100-110:8.

[0061] According to some embodiments of the present invention, in step (S1), the first reaction is a carboxylation reaction. The equation of the first reaction is as follows:

[0062]

[0063] Preferably, the conditions of the first reaction include: temperature of 100-120°C, preferably 105-115°C; time of 1-8h, preferably 2-6h.

[0064] According to some embodiments of the present invention, preferably, in step (S2), the mass ratio of the carboxylated polyether to the diethylenetriamine is 11-15:1, preferably 12-14:1.

[0065] According to some embodiments of the present invention, in step (S2), the second reaction includes an amidation reaction and a cyclization reaction. The equation of the second reaction includes:

[0066]

[0067] Preferably, in step (S2), the contacting step comprises: first mixing the carboxylated polyether with diethylenetriamine at a temperature of 140-160°C, preferably 145-155°C, and then heating to 230-250°C, preferably 235-245°C, until no water is generated.

[0068] According to some embodiments of the present invention, the inert atmosphere is provided by at least one inert gas selected from the group consisting of nitrogen, argon, neon and helium.

[0069] According to some embodiments of the present invention, preferably, the hydroxamic acid is salicylic hydroxamic acid.

[0070] According to some embodiments of the present invention, preferably, the demulsifier is at least one of fatty alcohol polyoxypropylene polyoxyethylene ether, polyol polyoxypropylene polyoxyethylene ether, polyethylene polyamine polyoxypropylene polyoxyethylene ether, alkylphenol polyoxypropylene polyoxyethylene ether, and alkylphenol amine polyoxypropylene polyoxyethylene ether.

[0071] According to some embodiments of the present invention, preferably, the composition further comprises a solvent, and the solvent is water and / or ethanol. Preferably, based on the total amount of the composition, the content of the solvent is 35-65wt%, preferably 40-60wt%.

[0072] The second aspect of the present invention provides use of the composition described in the first aspect in treating waste plastic oil.

[0073] A third aspect of the present invention provides a method for removing impurities from waste plastic oil, the method comprising:

[0074] In the presence of a reaction solvent, the waste plastic oil is contacted with the components in the composition described in the first aspect to react, and then the obtained reaction product is subjected to electrical desalination treatment, and then the product obtained by the electrical desalination treatment is subjected to oil-water separation.

[0075] According to some embodiments of the present invention, preferably, the mass ratio of the waste plastic oil to the composition is 100:0.1-0.5.

[0076] According to some embodiments of the present invention, preferably, in the waste plastic oil, the mass ratio of the total content of iron and calcium, calculated as elements, to the amount of the composition is 1:5-10.

[0077] According to some embodiments of the present invention, preferably, in the waste plastic oil, the total content of iron and calcium, calculated as elements, is 1-800 μg / g.

[0078] According to some embodiments of the present invention, preferably, the waste plastic oil has an organochlorine content of 50-5000 μg / g, calculated as the element.

[0079] According to some embodiments of the present invention, preferably, the reaction solvent is water.

[0080] According to some embodiments of the present invention, preferably, the mass ratio of the waste plastic oil to the reaction solvent is 100:10-50.

[0081] According to some embodiments of the present invention, preferably, the reaction conditions include: reaction temperature of 80-110° C., preferably 90-110° C.; reaction time of 1-10 h, preferably 1-3 h.

[0082] According to some embodiments of the present invention, preferably, the conditions of the electrical desalination treatment include: temperature of 80-130°C, preferably 80-120°C; electric field strength of 100-300V / cm, preferably 150-250V / cm; time of 0.5-3h, preferably 1-2h.

[0083] The present invention will be described in detail below through examples.

[0084] In the following examples and comparative examples, unless otherwise specified, all raw materials used are commercially available.

[0085] Acrylic acid-hydroxypropyl acrylate copolymer was purchased from Linhua Water Stabilizer Factory; wherein the molar ratio of acrylic acid structural unit to acrylate structural unit is 2:1, and its weight average molecular weight is 3000 g / mol; it is provided in the form of a 50wt% aqueous solution;

[0086] Salicylic hydroxamic acid was purchased from Innochem Reagents;

[0087] Demulsifier RP-2 (polyol polyoxypropylene polyoxyethylene ether) was purchased from Beijing Linhua Water Stabilizer Factory;

[0088] The properties of waste plastic oil are shown in Table 1, and the composition of its chlorine-containing compounds is shown in Table 2. These chlorine-containing hydrocarbons come from the addition of HCl produced by the decomposition of polyvinyl chloride and olefins or alkynes produced by the decomposition of plastics such as polyethylene (PE) and polypropylene (PP):

[0089] Table 1

[0090] project Crude Oil A Crude oil B <![CDATA[Density (20 °C) / (kg / m 3 )]]> 850.2 863.4 Oxygen mass fraction / % - 3.4 Mechanical impurities / wt% ＜0.005 ＜0.005 Fe / (μg / g) 164 9.3 Ca / (μg / g) 234 0.2 Na / (μg / g) 7.6 ＜0.1 <![CDATA[Total chlorine (calculated as Cl - ) / wt%]]> 0.38 0.24 Total acid value / (mgKOH / g) 0.8 20.11

[0091] Table 2

[0092]

[0093]

[0094] The following preparation examples are used to illustrate the polyether imidazoline compounds and preparation methods thereof provided by the present invention.

[0095] Wherein, the nonylphenol-formaldehyde resin polyether is prepared by a method comprising the following steps:

[0096] 1) Preparation of nonyl phenolic resin

[0097]

[0098] 100 g of nonylphenol (molecular weight 220) was added into a three-necked flask, immersed in a 75° C. constant temperature water bath, a certain amount of concentrated hydrochloric acid (37 wt %) was added to make the solution pH 3-5, 38.9 g of formaldehyde (35 wt %) (molecular weight 30) was added dropwise with stirring, the formaldehyde addition speed was controlled to be 1 drop / s, and the addition was completed within 1 h, the polymerization temperature did not exceed 80° C., the supernatant was removed from the product, and the product was washed with water to obtain a nonylphenol-formaldehyde resin (whose weight average molecular weight was 970 g / mol and degree of polymerization was 4);

[0099] 2) Preparation of nonylphenolic resin polyether

[0100]

[0101] 110 g of the obtained nonylphenolic resin and 1.1 g of potassium hydroxide were added to an autoclave, purged with nitrogen to exclude air, evacuated, stirred, heated to 130° C., and then 132 g of propylene oxide (molar ratio 6) was added dropwise at 0.3 MPa and 135° C. After the addition was completed, the reaction was continued for 0.5 h, and the temperature was lowered to obtain an intermediate product;

[0102] 100 g of the intermediate product and 1.86 g of potassium hydroxide were added to a high-pressure reactor, purged with nitrogen and evacuated, stirring was started and the temperature was raised to 120°C, and then 19 g of ethylene oxide was added dropwise at a pressure of 0.3 MPa and a temperature of 125°C. After the addition was completed, the reaction was continued for 0.5 h, and the material was cooled and discharged to obtain nonylphenolformaldehyde resin polyether (whose weight average molecular weight was 1244 g / mol and hydroxyl value was 45 mgKOH / g).

[0103] Preparation Example 1

[0104] (S1) In a three-necked flask, 100 g of an alkylphenol-formaldehyde resin polyether is contacted with succinic anhydride to carry out a first reaction to obtain a carboxylated polyether; wherein:

[0105] The alkylphenol-formaldehyde resin polyether is the nonylphenol-formaldehyde resin polyether obtained above;

[0106] The mass ratio of alkylphenol-formaldehyde resin polyether to succinic anhydride is 100:8;

[0107] The first reaction is a carboxylation reaction; the conditions of the first reaction are: temperature 110°C, time 6 hours; wherein, after the reaction is carried out for 1 hour, the acid value is measured every 0.5 hours until the acid value no longer changes;

[0108] (S2) In a three-necked flask, 108 g of the above carboxylated polyether is contacted with diethylenetriamine to carry out a second reaction to obtain a nonylphenolic resin polyether imidazoline Z1; wherein:

[0109] The mass ratio of carboxylated polyether to diethylenetriamine is 108:8.3;

[0110] The second reaction includes an amidation reaction and a cyclization reaction; the contacting steps are: first, at a temperature of 150° C., diethylenetriamine is added dropwise to the carboxylated polyether to mix, the generated water is continuously condensed and separated to an acid value equilibrium, and then the temperature is raised to 240° C. until no water is generated, and the reaction is stopped.

[0111] Preparation Example 2

[0112] According to the method of Preparation Example 1, the difference is that in step (S1), the mass ratio of the amount of alkylphenol-formaldehyde resin polyether to succinic anhydride is 100:6, and the rest are the same, to obtain nonylphenol-formaldehyde resin polyether imidazoline Z2.

[0113] The following examples are used to illustrate the composition for treating waste plastic oil and the method for removing impurities from waste plastic oil provided by the present invention.

[0114] Example 1

[0115] In the presence of a reaction solvent, waste plastic oil (100 g) is contacted with a composition for treating waste plastic oil to react under reflux conditions, and then the obtained reaction product is subjected to electrical desalination treatment, and then the product obtained by the electrical desalination treatment is subjected to oil-water separation to obtain a water phase and an oil phase; wherein:

[0116] The waste plastic oil is raw material oil A; the types and amounts of the components in the composition for treating waste plastic oil are shown in Table 3; the mass ratio of the waste plastic oil to the composition is 100:0.3;

[0117] The reaction solvent is water; the mass ratio of the waste plastic oil to the reaction solvent is 100:20;

[0118] The reaction conditions are: reaction temperature is 105°C; reaction time is 1h;

[0119] The conditions for the electrical desalination treatment were: temperature 90°C; electric field strength 200 V / cm; time 1 h;

[0120] The obtained oil phase was analyzed for its metal and total chlorine contents. The results are shown in Table 4.

[0121] Example 2

[0122] The method of Example 1 is followed, except that the amount of each component in the composition for treating waste plastic oil is specifically shown in Table 3; the rest is the same, and a water phase and an oil phase are obtained; the obtained oil phase is taken to analyze its metal and total chlorine content, and the results are shown in Table 4.

[0123] Example 3

[0124] The method of Example 1 is followed, except that the amount of each component in the composition for treating waste plastic oil is specifically shown in Table 3; the rest is the same, and a water phase and an oil phase are obtained; the obtained oil phase is taken to analyze its metal and total chlorine content, and the results are shown in Table 4.

[0125] Example 4

[0126] The method of Example 1 is different from that of Example 1:

[0127] The types and amounts of the components in the composition for treating waste plastic oil are shown in Table 3;

[0128] The mass ratio of the waste plastic oil to the composition is 100:0.2;

[0129] The mass ratio of waste plastic oil to reaction solvent is 100:10;

[0130] The reaction conditions are: reaction temperature is 90°C; reaction time is 1h;

[0131] The conditions for the electrical desalination treatment were: temperature 90°C; electric field strength 200 V / cm; time 1 h;

[0132] The rest are the same, and the water phase and the oil phase are obtained;

[0133] The obtained oil phase was analyzed for its metal and total chlorine contents. The results are shown in Table 4.

[0134] Example 5

[0135] According to the method of Example 1, except that the waste plastic oil is raw material oil B, and the rest is the same, a water phase and an oil phase are obtained;

[0136] The obtained oil phase was analyzed for its metal and total chlorine contents. The results are shown in Table 4.

[0137] Comparative Example 1 (without reflux treatment)

[0138] The method of Example 1 is different in that the waste plastic oil is treated by a conventional electrical desalination method, as follows:

[0139] 100 g of waste plastic oil is taken, preheated at 95° C., mixed with a composition for treating waste plastic oil and a reaction solvent using a waring mixer for 30 seconds, and then the obtained oil-water mixture is subjected to electrical desalination treatment, and then the product obtained by the electrical desalination treatment is subjected to oil-water separation; wherein:

[0140] The mass ratio of the waste plastic oil to the composition is 100:0.3;

[0141] The reaction solvent is water; the mass ratio of the waste plastic oil to the reaction solvent is 100:20;

[0142] The conditions for the electrical desalination treatment were: temperature 90°C; electric field strength 200 V / cm; time 1 h;

[0143] The obtained oil phase was analyzed for its metal and total chlorine contents. The results are shown in Table 4.

[0144] Comparative Example 2

[0145] The method of Example 1 is followed, except that the composition for treating waste plastic oil does not contain salicylic hydroxamic acid and polyether imidazoline compounds. The types and amounts of the components are shown in Table 3. The rest are the same, and a water phase and an oil phase are obtained. The oil phase is taken and analyzed for its metal and total chlorine content. The results are shown in Table 4.

[0146] Table 3

[0147]

[0148] Table 4 (wherein, the oil before degreasing refers to the waste plastic oil, and the oil after degreasing refers to the obtained oil phase)

[0149]

[0150] It can be seen from the above results that when the composition provided by the present invention is used to treat waste plastic oil, the removal rates of iron and calcium are respectively above 58% and above 65%, and the removal rate of chlorine is above 40%, and can reach up to 45.5%, with good demetallization and dechlorination effects.

[0151] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition for treating waste plastic oil, characterized in that: Based on the total amount of the composition, the composition contains the following components which are stored separately or two or more components are stored in a mixture: 30-45wt% of a carboxylic acid polymer, 5-10wt% of a hydroxamic acid, 5-20wt% of a polyether imidazoline compound and 5-10wt% of a demulsifier; wherein the polyether imidazoline compound is an alkylphenol-formaldehyde resin polyether imidazoline having a general structure shown in Formula I: In the formula, R is nonyl or octyl; a is 2-10; x is 1-2; and y is 5-8.

2. The composition according to claim 1, wherein The carboxylic acid polymer is at least one of acrylic acid polymer, hydrolyzed polymaleic anhydride, acrylic acid-maleic anhydride copolymer, acrylic acid-acrylate copolymer, acrylic acid-2-acrylamide-2-methylpropyl sulfonic acid copolymer, preferably acrylic acid-acrylate copolymer; Preferably, the acrylic acid-acrylic acid ester copolymer is at least one of acrylic acid-methyl acrylate copolymer, acrylic acid-hydroxyethyl acrylate copolymer, acrylic acid-hydroxypropyl acrylate copolymer, acrylic acid-hydroxyethyl methacrylate copolymer, acrylic acid-hydroxypropyl methacrylate copolymer and acrylic acid-hydroxypropyl acrylate-methyl acrylate terpolymer; Preferably, the weight average molecular weight of the acrylic acid-acrylate copolymer is 1000-50000 g / mol, preferably 2000-40000 g / mol; Preferably, in the acrylic acid-acrylate copolymer, the molar ratio of the acrylic acid structural unit to the acrylate structural unit is 0.1-20:1, preferably 0.5-10:

1.

3. The composition according to claim 1, wherein In Formula I, R is nonyl; a is 4-6; Preferably, the polyether imidazoline compound is prepared by a method comprising the following steps: (S1) contacting an alkylphenol-formaldehyde resin polyether with succinic anhydride to perform a first reaction to obtain a carboxylated polyether; the first reaction is a carboxylation reaction; (S2) contacting the carboxylated polyether with diethylenetriamine to carry out a second reaction; the second reaction includes an amidation reaction and a cyclization reaction.

4. The composition according to claim 3, wherein In step (S1), the mass ratio of the alkylphenol-formaldehyde resin polyether to the succinic anhydride is 90-150:8, preferably 100-120:8, more preferably 100-110:8; Preferably, the conditions of the first reaction include: temperature of 100-120°C, preferably 105-115°C; time of 1-8h, preferably 2-6h.

5. The composition according to claim 3 or 4, wherein In step (S2), the mass ratio of the carboxylated polyether to the diethylenetriamine is 11-15:1, preferably 12-14:1; Preferably, in step (S2), the contacting step comprises: firstly mixing the carboxylated polyether with diethylenetriamine at a temperature of 140-160°C, preferably 145-155°C, and then heating to 230-250°C, preferably 235-245°C.

6. The composition according to any one of claims 1 to 5, wherein The hydroxamic acid is salicylic hydroxamic acid; Preferably, the demulsifier is at least one of fatty alcohol polyoxypropylene polyoxyethylene ether, polyol polyoxypropylene polyoxyethylene ether, polyethylene polyamine polyoxypropylene polyoxyethylene ether, alkylphenol polyoxypropylene polyoxyethylene ether, and alkylphenol amine polyoxypropylene polyoxyethylene ether; Preferably, the composition further comprises a solvent, and the solvent is water and / or ethanol; based on the total amount of the composition, the content of the solvent is 35-65wt%, preferably 40-60wt%.

7. Use of the composition described in any one of claims 1 to 6 in treating waste plastic oil.

8. A method for removing impurities from waste plastic oil, the method comprising: In the presence of a reaction solvent, waste plastic oil is contacted with each component in the composition according to any one of claims 1 to 6 for reaction, and then the obtained reaction product is subjected to electrical desalination treatment, and then the product obtained by the electrical desalination treatment is subjected to oil-water separation.

9. The method according to claim 8, wherein: The mass ratio of the waste plastic oil to the composition is 100:0.1-0.5; Preferably, in the waste plastic oil, the total content of iron and calcium, calculated as elements, is in a mass ratio of 1:5-10 to the amount of the composition; Preferably, the total content of iron and calcium in the waste plastic oil is 1-800 μg / g, calculated as elements; Preferably, the waste plastic oil contains 50-5000 μg / g of organic chlorine in terms of element.

10. The method according to claim 8 or 9, wherein: The reaction solvent is water; Preferably, the mass ratio of the waste plastic oil to the reaction solvent is 100:10-50; Preferably, the reaction conditions include: reaction temperature of 80-110°C, preferably 90-110°C; reaction time of 1-10h, preferably 1-3h; Preferably, the conditions of the electrical desalination treatment include: a temperature of 80-130°C, preferably 80-120°C; The electric field strength is 100-300 V / cm, preferably 150-250 V / cm; the time is 0.5-3 h, preferably 1-2 h.

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