CN-121988074-A - Separation method and separation device for organic silicon in waste oil

CN121988074ACN 121988074 ACN121988074 ACN 121988074ACN-121988074-A

Abstract

The invention discloses a separation method and a separation device of organic silicon in waste oil, wherein the separation method of the organic silicon in the waste oil comprises the following steps of mixing the waste oil containing the organic silicon, a surfactant and water, stirring and emulsifying to obtain emulsified mixed liquid; and demulsifying the emulsified mixed solution to separate phases of the mixed solution to obtain an upper purified oil layer, a middle oil-water interface layer containing organic silicon and a lower water layer, namely separating the organic silicon in the waste oil. The separation method is different from the traditional processes such as a solvent extraction method, an oxidation decomposition method, an alkaline washing method, a hydrogenation removal method, an adsorption removal method and the like, and the method does not generate solid hazardous waste, reduces energy consumption and effectively realizes the recycling of the waste oil.

Inventors

DU JINZE
CONG HAIFENG
CAI MIAOMIAO
CAO YAN
Mao Linhan
LI YAN

Assignees

天津大学浙江研究院
浙江省宁波市威欧思能源科技发展有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (12)

1. The method for separating the organic silicon in the waste oil is characterized by comprising the following steps of: mixing the waste oil containing the organic silicon, a surfactant and water, stirring and emulsifying to obtain an emulsified mixed solution; And demulsifying the emulsified mixed solution to separate phases of the mixed solution to obtain an upper purified oil layer, a middle oil-water interface layer containing organic silicon and a lower water layer, namely separating the organic silicon in the waste oil.
2. The method for separating organic silicon from waste oil according to claim 1, wherein the water is used in an amount of 3% -32% of the mass of the waste oil.
3. The method for separating organic silicon from waste oil according to claim 1, wherein the amount of the surfactant is 0.1-20% of the total mass of water and waste oil, or 0.5-60 times of the mass of silicon element in waste oil.
4. The method for separating silicone from waste oil according to claim 1, wherein the surfactant is at least one of an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, a natural emulsifier, and a polymeric emulsifier; Wherein the anionic surfactant is at least one of a fatty acid salt surfactant, a sulfonate surfactant, a sulfate surfactant and a phosphate surfactant; the cationic surfactant is at least one of alkyl quaternary ammonium salt surfactant and benzyl quaternary ammonium salt surfactant; The nonionic surfactant is at least one of polyol fatty acid ester, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether and block polyether; The amphoteric surfactant is at least one of betaine surfactant, imidazoline surfactant and amino acid surfactant; The natural emulsifier is at least one of phospholipid emulsifier, polysaccharide emulsifier, protein emulsifier and saccharide derivative emulsifier; the high molecular emulsifier is at least one of polyacrylate emulsifier and polyurethane emulsifier.
5. The method for separating organic silicon from waste oil according to claim 1, wherein the stirring speed of the emulsification is 200r/min-1200r/min, and the stirring time is 15min-120min.
6. The method for separating organic silicon from waste oil according to claim 1, wherein the demulsification adopts at least one of centrifugal demulsification, demulsification and textile filtration demulsification; wherein the centrifugal demulsification is carried out by adopting a continuous centrifuge, the centrifugal time is 10s-120s, the separation factor is 1000-30000, or the centrifugal demulsification is carried out by adopting an intermittent centrifuge, the centrifugal time is 2min-30min, and the separation factor is 800-20000; the mixed solution emulsified by adopting fabric filtration is demulsified, the filtration pressure is 0.1MPa-0.5MPa, and the surface flow rate is 0.5m 3 /（m 2 ·h）-5m 3 /（m 2 h); and mixing the demulsifier with the emulsified mixed solution to carry out demulsification, wherein the adding amount of the demulsifier is 0.01-2% of the mass of the mixed solution.
7. The method for separating silicone from waste oil according to claim 1, wherein the upper layer of purified oil, the surfactant and water are mixed, and emulsification, demulsification and phase separation are repeated.
8. The method for separating organic silicon from waste oil according to claim 7, wherein the upper purified oil layer obtained after repeated emulsification, demulsification and phase separation is subjected to alkali washing, adsorption, filtration and rectification.
9. The method for separating organic silicon from waste oil according to claim 1, wherein the organic silicon-containing middle layer oil-water interface layer, the surfactant and the water are mixed, and emulsification, demulsification and phase separation are repeated.
10. The method for separating organic silicon from waste oil according to claim 1, wherein the waste oil containing the organic silicon is subjected to primary centrifugation, the lower liquid is removed, the upper liquid is collected, and then the upper liquid, the surfactant and the water are mixed and stirred for emulsification; Wherein the mass of the removed lower liquid is 1.25-25 times of that of the silicon element in the waste oil.
11. A separation device of organic silicon in waste oil, which is applied to the separation method of organic silicon in waste oil according to claim 1, and comprises the following steps: the emulsifying unit comprises a mechanical stirring tank and is used for mixing, stirring and emulsifying the waste oil containing the organic silicon, the surfactant and the water; And the demulsification unit is communicated with the mechanical stirring tank and is used for receiving the emulsion and performing demulsification and phase separation on the emulsion.
12. The apparatus for separating silicone from waste oil according to claim 11, wherein the demulsification unit comprises a centrifuge in communication with a mechanical agitation tank, or, The demulsification unit comprises a phase separator which is communicated with a mechanical stirring tank, or, The demulsification unit comprises a filter, and the filter is communicated with the mechanical stirring tank.

Description

Separation method and separation device for organic silicon in waste oil Technical Field The invention belongs to the technical field of waste oil treatment, and particularly relates to a separation method and a separation device for organic silicon in waste oil. Background The recycling of waste oil becomes an important direction in the fields of environmental protection and energy. The organic silicon in the waste oil mainly originates from defoamers, additives and the like, is mostly in the form of siloxane, has extremely strong thermal stability and chemical stability, and is difficult to remove by the conventional refining process. The organosilicon in the waste oil not only can cause irreversible poisoning of the hydrogenation catalyst and shorten the operation period of the device, but also can influence the quality of regenerated oil, and becomes a core bottleneck for restricting the high-value utilization of the waste oil, and the research and development of the efficient desilication technology is important for improving the comprehensive utilization rate of the waste oil. At present, the method mainly comprises an adsorption method, a hydrodesiliconizing method, a catalytic conversion method, a chemical treatment method and a pyrolysis treatment method aiming at the removal of the organic silicon in the waste oil, wherein the adsorption method is the most widely applied desilication pretreatment technology, and the core principle is that Van der Waals force, hydrogen bond or coordination effect is formed between the surface active site of the adsorbent and the organic silicon molecules to realize selective separation. The hydrodesiliconizing method is a mainstream technology for realizing deep desilication of waste oil, is mostly used for producing regenerated base oil with high added value, and is based on the principle that Si-C bonds in organic silicon molecules are broken under the action of hydrogen atmosphere and a catalyst, so that silicon is converted into SiO 2 for deposition or volatile silicon compounds are removed. The catalytic conversion method takes non-hydrogen condition as core advantage, promotes the decomposition and isomerization of organic silicon through a catalyst, converts the organic silicon into a solid form which is easy to separate, and is suitable for the treatment of waste plastic oil and heavy waste oil with high silicon content. The chemical treatment method is mainly used for pretreatment or auxiliary desilication of small-scale waste oil by virtue of the characteristics of simple equipment and mild reaction conditions, and mainly comprises three types of alkali liquor washing, oxidative decomposition and solvent extraction. The pyrolysis treatment method is mainly applied to waste plastic pyrolysis oil, and the principle is that a silicon collector, such as granular alumina, is added in the pyrolysis process of waste plastic, so that organic silicon is directly converted into solid silicon compounds during pyrolysis, the organic silicon is prevented from entering the pyrolysis oil, and the silicon content in the pyrolysis oil is enabled to be less than 5 mu g/g. Although the method can realize the removal of the organic silicon impurities in the waste oil, the method has the problems of high energy consumption, low economy and low environmental protection, and needs to be further perfected. Disclosure of Invention The invention aims to provide a separation method and a separation device for organic silicon in waste oil, which have the characteristics of low treatment cost, environmental protection and energy saving, are suitable for separating the organic silicon in the recovered waste oil such as waste engine oil, white oil, hydraulic oil, fuel oil, transformer oil and the like. In order to achieve the above object, a specific embodiment of the present invention provides the following technical solution: A method for separating organic silicon from waste oil, which comprises the following steps: mixing the waste oil containing the organic silicon, a surfactant and water, stirring and emulsifying to obtain an emulsified mixed solution; And demulsifying the emulsified mixed solution to separate phases of the mixed solution to obtain an upper purified oil layer, a middle oil-water interface layer containing organic silicon and a lower water layer, namely separating the organic silicon in the waste oil. In one or more embodiments of the invention, the water is used in an amount of 3% to 32% of the mass of the used oil. In one or more embodiments of the invention, the surfactant is used in an amount of 0.1% -20% of the total mass of water and used oil, or in an amount of 0.5-60 times the mass of elemental silicon in used oil. In one or more embodiments of the present invention, the surfactant is at least one of an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, a natural emulsifier, and a polymeric emulsifier; Wherein the