RU2133262C1 - Method of regenerating exhausted lubricating oils - Google Patents

Abstract

FIELD: lubricating materials. SUBSTANCE: exhausted lubricating oil is treated on heating to 80-90 C at stirring with aqueous solution of alkali metal salt taken in quantity 0.2 to 0.6% based on oil weight for 15 to 30 min maintaining temperature 80-90 C. Then, aqueous solution of soap (0.3- 0.5% of oil weight) is added. Mixture is agitated for 15-30 min to complete emulsification. After settling and cooling, oil is separated from sludge and distilled. Proposed method can be applied on low-scale production plants where separate collection of different-quality oils is provided. EFFECT: essentially simplified technology. 2 tbl

Description

 The invention relates to the restoration of the properties of waste lubricating oils and can be used in oil refineries and regeneration plants.

A known method of purification of waste lubricating oils (ed. St. USSR N 1567615, C 10 M 175/02, publ. 30.05.90) by treating them with a demulsifier based on a block copolymer of ethylene oxide and propylene with stirring and heating to 85-97 ^o C, in the presence of an aqueous solution of alkali or ammonia, taken in an amount of 0.5-1.0% by weight of the oil, followed by separation of the sludge. Despite the sufficient degree of purification of oil from impurities, such a cleaning process is associated with the use of hazardous and harmful auxiliary materials - concentrated alkali, ammonia.

A known method of purification of waste oils, which is adopted as a prototype, comprising the following stages: heating the waste oil to 65.5-95 ^o C, contacting the oil with an aqueous solution of an alkali metal salt, which has a concentration of 3-10% by weight of salt, water separation and solid impurities from the oil, the introduction of a demulsifier into the mixture, while heating and stirring, until the mixture is completely demulsified, after settling for 12-24 hours at 37.7-82 ^° C, fine particles and the remaining suspended water are separated from the oil, vacuum distillation of the oil and repeated about Cleaning the metal from impurities (U.S. Patent N 4431524, C 10 M 11/00, publ. 02.14.84). This process is carried out in stages, while metal impurities are removed in several stages, which is associated with increased energy costs. There is a problem of waste disposal. As indicated in the description of the patent, when burning sludge, harmful emissions are generated, and when re-cleaning, waste is generated that goes to the storage tanks.

 The objective of the invention is to increase the yield of regenerated lubricating oils, increase the efficiency of the process, improve the environmental parameters of the regeneration process.

 The problem is achieved in that the proposed method for the regeneration of used lubricating oils includes: heating the oil, treating with an aqueous solution of an alkali metal salt with heating and stirring. Moreover, the used lubricating oil is subjected to treatment with an aqueous solution of an alkali metal salt, taken in an amount of 0.01-0.60% by weight of the oil, adding 0.01-0.50% of the mass of the oil, an aqueous solution of soap, and then a coagulant of 0.01- 0.30% by weight of the oil in the form of an aqueous solution, followed by separation of the sludge and the release of oil.

According to the proposed method, the spent lubricating oil heated to 80-90 ^° C is contacted with 0.01-0.60% (by weight of the oil) aqueous solution of an alkali metal salt with stirring. At the same time, metallic contaminants, polar compounds, solid particles are released from the used oil, and the acids present in the oil are neutralized.

Continuing stirring and maintaining a temperature of 80-90 ^o C, a 0.01-0.50% aqueous soap solution is added to the mixture, which adsorbs resinous substances contained in the used oil in a medium of weak electrolyte and also transfers fine particles stabilizing the emulsion deep into the volume . The coagulant, which is supplied in the form of an aqueous solution to a mixture with a temperature of 80-90 ^o C with stirring in an amount of 0.01-0.30% by weight of the oil, is prone to lower gelatinization temperatures in the presence of metal salts.

 After settling and cooling, the mixture is divided into four phases; mechanical particles, water, sludge, oil. Mechanical particles, together with the sorbent worked out after percolation, make up 0.3-1.5 wt.%, After burning, they are sent to the dump. Water is 4-8 wt.%, Has a pH of 9-11, after cleaning through a filter it can be reused in the regeneration process or for washing parts. The sludge is 2-8 wt.%, Is a colloidal mass, including oil, fine particles of carbon, resinous substances, soap, products of the degradation of additives, polymer particles, water. Due to its properties it can be used for the lubrication of rails, crane tracks, turnouts, for the impregnation of sleepers, poles, bridge beams. The oil is 85-96 wt. %, is subjected to separation, distillation of low-boiling components (water, fuel), and then percolation by known methods and after adding additives (alloying components) is sent to a commodity container. Obtained after distillation from diesel engine oils gas oil (3-10 wt.%) Can be used as heating oil.

With this method for the regeneration of used lubricating oils, emissions to the atmosphere are limited by fumes from oil heated to 90 ^° C and exhaust from a vacuum pump, after cleaning from oil mist, they meet the requirements for the residential area of the adjacent areas of the city.

 Industrial use case N 1.

Example 1.1 770 kg of spent diesel oil M-14-B2, preheated to 85 ^o C in a batch reactor, is contacted with stirring with 4.5 kg of alkali metal salt (in the form of an aqueous solution of sodium hydroxyborohydride with a concentration of 2%) for 25 minutes. Continuing mixing and maintaining a temperature of 85 ^o C in the mixture, add 2.5 kg of soap (in the form of an aqueous solution of potassium stearate with a concentration of 15%). The reaction time is 30 minutes Maintaining the temperature of the mixture at 85 ^° C. and stirring into the mixture, 2.3 kg of coagulant are introduced (in the form of an aqueous solution of polyacrylamide with a concentration of 10%). The reaction time is 25 minutes The resulting mixture settles for 18 hours at 75 ^o C. Mechanical particles, water, sludge are discharged from the bottom of the reactor into the sludge collector. The oil phase is subjected to separation, distillation of diesel fuel in a rotary film evaporator, percolation and after the introduction of additives (alloying components) is sent to a commodity tank.

 In the table. 1 presents the main physico-chemical parameters of spent diesel oil before and after regeneration of the proposed method.

 The yield of products: regenerated oil - 721 kg, mechanical particles - 5 kg, sludge - 45 kg, gas oil - 18 kg, spent adsorbent - 4 kg, the rest is water.

Example 1.2 1250 kg of used diesel oil M-14-B2, preheated to 85 ^o C in a batch reactor, is contacted with stirring with 6.3 kg of alkali metal salt (in the form of an aqueous solution of calcium carboxylate with a concentration of 8%) for 35 minutes. Continuing mixing and maintaining a temperature of 85 ^o C, 2.8 kg of soap (in the form of an aqueous solution of lithium stearate with a concentration of 10%) are added to the mixture. The reaction time is 40 minutes Maintaining the temperature of the mixture at 85 ^° C. and stirring, 3.0 kg of coagulant is introduced into the mixture (in the form of an aqueous solution of carboxymethyl cellulose with a concentration of 10%). The reaction time is 25 minutes The resulting mixture settles for 18 hours at 75 ^o C. Mechanical particles, water, sludge are discharged from the bottom of the reactor into the sludge collector. The oil phase is subjected to separation, distillation of diesel fuel in a rotary film evaporator, percolation and after the introduction of additives (alloying components) is sent to a commodity tank.

 In the table. 1 presents the main physico-chemical parameters of spent diesel oil before and after regeneration of the proposed method.

 Product yield: regenerated oil - 1170 kg, mechanical particles - 10 kg, sludge - 80 kg, gas oil - 29 kg, spent adsorbent - 7 kg, the rest is water.

 Industrial use case N 2.

Example 2.1 561 kg of spent TP-22s turbine oil, preheated to 80 ^o C in a flow-through heater, when pumped to the “ring” in a stream, is successively contacted with 0.058 kg of alkali metal salt (in the form of an aqueous solution of sodium metasilicate with a concentration of 6%) at intervals of 20 minutes ), 0.080 kg of soap (in the form of an aqueous solution of sodium stearate with a concentration of 20%) and 0.060 kg of coagulant (in the form of an aqueous solution of neonol K 2125-20 with a concentration of 5%). The resulting mixture settles for 8 hours. Mechanical particles, water, sludge are discharged into a sludge collector. The oil phase is subjected to separation, drying in a vacuum tank, filtration. After the introduction of additives is sent to a commodity tank.

 In the table. 2 presents the main physico-chemical parameters of spent turbine oil before and after regeneration of the proposed method.

 Yield: regenerated oil - 542 kg, mechanical particles - 1.5 kg, sludge - 20 kg, the rest is water.

Example 2.2 660 kg of spent Tp-22s turbine oil, preheated to 80 ^o C in a flowing electric heater, when pumped to the ring in a stream, is successively contacted with 0.070 kg of an alkali metal salt (in the form of an aqueous solution of sulfonated sodium borohydride with a concentration of 2 %), 0.10 kg of soap (in the form of an aqueous solution of potassium stearate with a concentration of 20%) and 0.080 kg of coagulant (in the form of an aqueous solution of polyacrylamide with a concentration of 10%). The resulting mixture settles for 8 hours. Mechanical particles, water, sludge are discharged into a sludge collector. The oil phase is subjected to separation, drying in a vacuum tank, filtration. After the introduction of additives is sent to a commodity tank.

 In the table. 2 presents the main physico-chemical parameters of spent turbine oil before and after regeneration of the proposed method.

 Product yield: regenerated oil - 638 kg, mechanical particles - 2, sludge - 22 kg, the rest is water.

 The proposed method can be used in installations used for small-scale production (directly at the enterprise, in the depot or in the workshop), where the collection of used oils by brands (grades) is provided, significantly simplifying, cheapening and environmentally safer providing the regeneration of used oils.

Claims (1)

 The method of regeneration of used lubricating oils, including heating them, treatment with an aqueous solution of an alkali metal salt by heating and stirring, followed by separation of the sludge and oil recovered, characterized in that the treatment is carried out with an alkali metal salt solution taken in an amount of 0.01-0.60% by weight of the oil, after which an aqueous soap solution is added in an amount of 0.01-0.50% by weight of the oil, and then an aqueous solution of a coagulant in an amount of 0.01-0.30% by weight of the oil.

Images