Method for refining waste vehicle lubricating oil using a solvent containing additives

Abstract

The present invention relates to the field of waste oil regeneration technology, and discloses a method for refining waste vehicle lubricating oil using a solvent containing an additive. The method pre-treats the waste vehicle lubricating oil in a rotary evaporator, then mixes and stirs the pre-treated waste vehicle lubricating oil, an extractant solvent, an extraction aid, and a surfactant for solvent extraction. After extraction, the oil product is separated, and finally, vacuum filtration is performed through medium-pore filter paper to obtain refined oil. The method preferably uses N-methylpyrrolidone (NMP) as the extractant, N-N-dimethylformamide (DMF) as the extraction aid, and sodium ethoxylated alkyl sulfate as the extraction aid, which is beneficial for improving yield and achieving significant results in various indicators such as viscosity index, acid value, ash content, and sulfur content. The method has broad application prospects in the refining of waste lubricating oil.

Description

Technical Field

[0001] The present invention relates to the technical field of waste oil regeneration, and provides a method for refining waste vehicle lubricating oil using a solvent containing an additive. Background Art

[0002] With the rapid development of the economy and the automotive industry, waste vehicle lubricants have become a major source of environmental pollution. They contain a large number of toxic and hazardous substances, such as heavy metals, polycyclic aromatic hydrocarbons, and organochlorine, posing a serious threat to the environment and human health. Therefore, the recycling of waste vehicle lubricants is an effective way to address environmental pollution and resource shortages.

[0003] Conventional additives, such as solvents and decolorants, are often used in the traditional solvent refining process for waste vehicle lubricant oil. However, these additives present several challenges, including severe environmental pollution and low recycling efficiency. To address these issues, a new additive with high efficiency, environmental friendliness, and cost-effectiveness is needed.

[0004] Therefore, the present invention proposes a surfactant additive. The selected surfactant additive is used in the solvent refining of waste vehicle lubricating oil, demonstrating its high efficiency, environmental friendliness, and economical nature. This additive can effectively separate sulfur-containing substances and high-viscosity components from waste vehicle lubricating oil, thereby increasing the reuse rate and utilization value of waste vehicle lubricating oil while reducing environmental pollution and resource waste. Summary of the Invention

[0005] The present invention aims to address the current low recycling efficiency of waste vehicle lubricant oil by proposing a method for refining waste vehicle lubricant oil solvent using an additive. This method can both increase the yield of refined vehicle lubricant oil and reduce environmental pollution.

[0006] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is that an additive is used in the solvent refining method of waste vehicle lubricating oil, and its raw materials are calculated by weight as follows: 1000 parts of waste vehicle lubricating oil, 1000-3000 parts of extraction agent, 50-300 parts of extraction aid, and 1-10 parts of surfactant.

[0007] Furthermore, the preferred extractant is N-methylpyrrolidone (NMP); the extraction aid is N-dimethylformamide (DMF); and the surfactant is ethoxylated sodium alkyl sulfate.

[0008] Furthermore, the raw materials are calculated by weight as follows: 1000 parts of waste vehicle lubricating oil, 2000 parts of NMP, 200 parts of DMF, and 5 parts of sodium ethoxylate alkyl sulfate.

[0009] A method for refining waste vehicle lubricating oil using a solvent containing an additive, comprising the following steps:

[0010] a. Pretreatment: The lubricating oil is treated in a rotary evaporator to remove water and some volatile light hydrocarbons;

[0011] b. Solvent extraction: A mixture of 1000 parts of waste vehicle lubricating oil, 2000 parts of an extractant solvent, 200 parts of an extraction aid and 5 parts of an ethoxylated sodium alkyl sulfate surfactant was stirred at a speed of 300 to 1200 r / min for 1 to 2 hours at a stirring temperature of 348 to 388K.

[0012] c. Separation: Allow to stand for at least 1 hour. Pass the resulting extract through a separatory funnel for initial separation to obtain the extract phase (refined oil) and the raffinate phase (extractant-extraction aid-surfactant mixture). Wash with hot distilled water at least 6 times to remove the solvent from the extract and raffinate phases. Dry over anhydrous calcium chloride.

[0013] d. Filtration: The extract phase (refined oil) described in step c was passed through commercially available medium-pore filter paper (10 μm) and vacuum filtered at 298K.

[0014] Preferably, in step a, in order to retain the effective components and remove water and some light hydrocarbons in the waste vehicle lubricating oil, the evaporation temperature of the rotary evaporator is 333K and the environment is vacuum.

[0015] The refined oil obtained by single solvent extraction, N-methylpyrrolidone refined oil has a high viscosity index and low sulfur content. In order to further improve the refining efficiency of lubricating oil, the preferred extraction agent is N-methylpyrrolidone (NMP), a commercially available product.

[0016] Preferably, in step b, the refined oil obtained by compounding solvent extraction, the refined oil obtained by compounding N-methylpyrrolidone and NN dimethylformamide has a high viscosity index and low sulfur content. In order to further improve the refining efficiency of the lubricating oil, the preferred extraction aid is NN dimethylformamide (DMF), a commercially available product.

[0017] Preferably, in step b, the compound solvent is added to the refined oil obtained by extraction, and N-methylpyrrolidone, NN dimethylformamide, and ethoxylated sodium alkyl sulfate are compounded. The resulting refined oil has a high viscosity index and a low sulfur content. In order to further improve the refining efficiency of the lubricating oil, the surfactant ethoxylated sodium alkyl sulfate is preferably a commercially available product.

[0018] Preferably, in step b, the waste vehicle lubricant oil sample is waste gear oil, which is mainly characterized by a low viscosity index (143) and a high sulfur content (9.1 mg / Kg).

[0019] The present invention has the following advantages:

[0020] Compared with the refined oil obtained by solvent refining with conventional active additives (sodium ethoxylated dodecylbenzene sulfonate, sodium ethoxylated palmitic acid, sodium ethoxylated lauryl sulfate) as auxiliary agents, the refined oil obtained by adding solid surfactant sodium ethoxylated alkyl sulfate has the characteristics of high viscosity index, high yield, low sulfur content, etc.

[0021] Compared with compound solvents, the addition of surfactants yields higher refined oil yields, and the viscosity index, acid value, and ash content of the refined oil are superior to compound solvents. Furthermore, sodium ethoxylated alkyl sulfate is widely used in human care products such as shampoo and body wash, posing minimal harm to the environment and human health, thus meeting environmental protection requirements.

[0022] This method combines solvent compounding with surfactants, conducting compounding experiments with various solvents and ethoxylated anionic surfactants. Experiments have demonstrated that, compared to traditional surfactant additives (such as sodium ethoxylated dodecylbenzene sulfonate, sodium ethoxylated palmitate, and sodium ethoxylated lauryl sulfate), sodium ethoxylated alkyl sulfate as a compounding solvent additive significantly improves the viscosity index of vehicle lubricants, exhibits greater selectivity for sulfur-containing components in the oil, and yields higher refined oils. The resulting refined oil exhibits improved thermal stability, maximizing the utilization of waste vehicle lubricants and possessing significant research and utilization value.

[0023] Explanation of the attached table:

[0024] In order to better illustrate the embodiments of the present invention, the following is a brief introduction to the appendix used in the embodiments.

[0025] Table 1 Product properties of waste vehicle lubricants

[0026]

[0027] DETAILED DESCRIPTION

[0028] In order to facilitate industrial production, the present invention is further described in detail below through specific examples.

[0029] Example 1:

[0030] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, 200kg of N-dimethylformamide (DMF) as extraction aid, and 5kg of sodium ethoxylated alkyl sulfate as surfactant;

[0031] A method for refining solvent of waste vehicle lubricating oil using an additive, comprising the following steps:

[0032] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0033] b solvent extraction: a mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, 200kgDMF and 5kg of ethoxylated alkyl sodium sulfate was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0034] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP-DMF-ethoxylated alkyl sodium sulfate solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Then, dry them over anhydrous calcium chloride.

[0035] d. Filtration: The refined oil c was passed through medium-pore filter paper (10 μm) and vacuum filtered at 298 K to obtain 942 kg of light yellow transparent refined oil.

[0036] Example 2:

[0037] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, and 200kg of dimethylformamide (DMF) as extraction aid;

[0038] A method for refining solvent of waste vehicle lubricating oil using an additive, comprising the following steps:

[0039] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0040] b. Solvent extraction: A mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, and 200kgDMF was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0041] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP-DMF solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0042] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 801 kg of a light yellow transparent refined oil.

[0043] Example 3:

[0044] 1000kg of waste vehicle lubricating oil and 2200kg of extraction agent N-methylpyrrolidone (NMP);

[0045] A novel additive is used in a solvent refining method for waste vehicle lubricating oil, comprising the following steps:

[0046] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0047] b. Solvent extraction: A mixture of 1000kg of waste vehicle lubricating oil and 2200kgNMP was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0048] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0049] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 720 kg of a light yellow transparent refined oil.

[0050] Example 4:

[0051] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, 200kg of N-dimethylformamide (DMF) as extraction aid, and 10kg of sodium ethoxylated alkyl sulfate as surfactant;

[0052] A novel additive is used in a solvent refining method for waste vehicle lubricating oil, comprising the following steps:

[0053] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0054] b. Solvent extraction: A mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, 200kgDMF and 10kg of ethoxylated sodium alkyl sulfate was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0055] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP-DMF-ethoxylated alkyl sodium sulfate solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0056] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 943 kg of a light yellow transparent refined oil.

[0057] Example 5:

[0058] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, 200kg of N-dimethylformamide (DMF) as extraction aid, and 1kg of sodium ethoxylated alkyl sulfate as surfactant;

[0059] A novel additive is used in a solvent refining method for waste vehicle lubricating oil, comprising the following steps:

[0060] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0061] b. Solvent extraction: A mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, 200kgDMF and 1kg of sodium ethoxylated alkyl sulfate was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0062] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP-DMF-ethoxylated alkyl sodium sulfate solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0063] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 920 kg of a light yellow transparent refined oil.

[0064] Example 6:

[0065] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, 200kg of N-dimethylformamide (DMF) as extraction aid, and 5kg of sodium ethoxylate palmitate as surfactant;

[0066] A novel additive is used in a solvent refining method for waste vehicle lubricating oil, comprising the following steps:

[0067] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0068] b solvent extraction: a mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, 200kgDMF and 5kg of sodium ethoxylate palmitate was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0069] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is the lubricating oil, and the lower liquid raffinate phase is the NMP-DMF-ethoxylated sodium palmitate solution). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0070] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 844 kg of a light yellow transparent refined oil.

[0071] Example 7:

[0072] 1000kg of waste vehicle lubricating oil, 2000kg of N-methylpyrrolidone (NMP) as extraction agent, 200kg of N-dimethylformamide (DMF) as extraction aid, and 5kg of ethoxylated sodium lauryl sulfate as surfactant;

[0073] A novel additive is used in a solvent refining method for waste vehicle lubricating oil, comprising the following steps:

[0074] a. Pretreatment: The lubricating oil is treated in a rotary evaporator and vacuum filtered at 298K to remove water and some volatile light hydrocarbons;

[0075] b. Solvent extraction: A mixture of 1000kg of waste vehicle lubricating oil, 2000kgNMP, 200kgDMF and 5kg of ethoxylated sodium lauryl sulfate was stirred at a stirring speed of 500r / min, a stirring time of 1h, and a stirring temperature of 358K;

[0076] c. Separation: Let stand for 1 hour, then pass the resulting sample through a separatory funnel for initial separation (the upper liquid extract phase is lubricating oil, and the lower liquid raffinate phase is NMP-DMF-ethoxylated sodium lauryl sulfate). Wash with hot distilled water six times to remove the solvent from the extract and raffinate phases. Next, dry with anhydrous calcium chloride.

[0077] d. Filtration: The refined oil in step c was passed through a medium-pore filter paper (10 μm) and vacuum filtered at preferably 298K to give 806 kg of a light yellow transparent refined oil.

[0078] Table 2 Properties of the recycled oil products obtained in Examples 1 to 7

[0079]

[0080] The above are representative properties of the refined oils obtained from the experiments in each example. Example 1, as a preferred option, outperforms Examples 2-7 in terms of yield, viscosity index, acid value, ash content, and sulfur content. Further additions beyond 5% significantly improve lubricant extraction. For economic reasons and extraction effectiveness, the preferred surfactants are sodium ethoxylated alkyl sulfate, 5% surfactant addition, and 298K vacuum filtration temperature. The preferred extraction aid, NN dimethylformamide (DMF), is used in waste vehicle lubricants at a mass fraction of 20%. Above 20%, viscosity shows no significant change, but rather fluctuates.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various changes and variations may be made within the spirit and principles of the present invention. These equivalent variations or replacements are all included in the scope of protection of the present invention.

Claims

1. A method for refining waste vehicle lubricating oil using a solvent containing an additive, characterized in that: The waste vehicle lubricant and solvent containing additives are calculated as follows by weight: 1000 parts of waste vehicle lubricant, 1000-3000 parts of extractant solvent, 50-300 parts of extractant auxiliary, and 1-10 parts of additive; wherein the additive is ethoxylated sodium alkyl sulfate surfactant; wherein the extractant solvent is N-methylpyrrolidone; and the extractant auxiliary is NN dimethylformamide; a. Pretreatment: The waste vehicle lubricating oil is pretreated in a rotary evaporator to remove water and volatile light hydrocarbons; b. Solvent extraction: 1000 parts of pretreated waste vehicle lubricating oil, 1000 to 3000 parts of extractant solvent, 50 to 300 parts of extractant aid, and 1 to 10 parts of ethoxylated sodium alkyl sulfate surfactant were mixed and stirred for solvent extraction; c. Separation: After standing for a period of time, the extracted sample in step b was separated by a separatory funnel to obtain an extract phase and a raffinate phase, respectively, which were washed several times with hot distilled water to remove the solvent from the extract phase and the raffinate phase, and dried with anhydrous calcium chloride; d. Filtration: The extracted phase after washing in c is passed through medium-pore filter paper and vacuum filtered to obtain refined oil.

2. The method for refining waste vehicle lubricating oil using a solvent containing an additive according to claim 1, characterized in that: In step a, the evaporation temperature of the rotary evaporator is 333K, and the evaporation environment is vacuum.

3. The method for refining waste vehicle lubricating oil using a solvent containing an additive according to claim 1, wherein: The mixing and stirring conditions are as follows: a rotation speed of 300~1200r / min, a stirring time of 1~2h, and a stirring temperature of 348~388K.

4. The method for refining waste vehicle lubricating oil using a solvent containing an additive according to claim 1, wherein: The solvent extraction conditions in step b are as follows: 1000 parts of pretreated waste vehicle lubricating oil, 2000 parts of extractant solvent, 200 parts of extractant auxiliary agent, and 5 parts of ethoxylated sodium alkyl sulfate surfactant are mixed and stirred to perform solvent extraction.

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