RU2804769C1 - Method for regenerating used turbine oil - Google Patents

Abstract

FIELD: chemical technology.

SUBSTANCE: method for regenerating used turbine oil by passing it through an adsorbent bed. In this case, NaX zeolite is used as an adsorbent, on the surface of which potassium hydroxide is deposited. The rate of passage of used turbine oil through the adsorbent layer is from 1 to 2 m/h.

EFFECT: simplification of the purification process and, through the use of a modified adsorbent, a high degree of purification.

2 cl, 6 ex

Description

The present invention relates to chemical technology for processing turbine oils that have failed as a result of operation and discloses a method for their regeneration by passing the oil through a sorbent layer at a speed of no more than 2 m/h. The sorbent is a NaX zeolite with a non-continuous layer of potassium hydroxide deposited on the surface. The ratio of potassium hydroxide to NaX zeolite ranges from 1:20 to 1:10. Thus, potassium hydroxide effectively reduces the acid number of oil, neutralizing low molecular weight organic acids, and zeolite dries and concentrates the products of oxidative polymerization of oil components on its surface. The technical result of the present invention is to simplify the cleaning process and, through the use of a modified adsorbent, to achieve a high degree of purification.

There is a known method for cleaning used oil by preheating the oil and subsequent separation of contaminants, while a mixture of isopropyl alcohol and urea is added to the oil in a 1:1 ratio, taken in an amount of 1.0%, based on dry urea by weight of the oil being purified (RU No. 2554357).

The disadvantage of this method is the use of urea, which, due to the fact that it is a weak base, does not effectively neutralize low molecular weight organic acids. Also, heating in air promotes further oxidation of the oil.

There is a known method for regenerating used oil by mixing preheated oil to 80-100°C with an aqueous solution of urea and subsequent separation of the regenerated oil, while mixing the oil is carried out with an aqueous solution consisting of 30-50 wt. % urea, 4-6 wt. % monoethanolamine and 2-4 wt. % aluminum chloride, taken in an amount of 0.5-1.0 vol. % of the volume of used oil (RU No. 2600726).

The disadvantage of this method is the use of a control reagent of complex chemical composition, as well as high energy consumption for preheating the oil.

There is a known method for regenerating used lubricating oil, which contains successive stages: a stage in which a 5% aqueous solution of sodium carbonate is added to the used lubricating oil and mixed at a temperature of 50-56°C; a step of cooling the resulting mixture to room temperature, followed by separating the aqueous layer from the organic layer; a step of extracting the organic layer with water; a step of adding anhydrous sodium sulfate to the organic layer and mixing them; a step of obtaining a filtered organic layer by filtering the resulting mixture through a filter; the stage at which the filtered organic layer is distilled in vacuum (RU No. 2736715).

The main disadvantage of this method is the complexity and large number of stages of processing used oil, which naturally will have a negative impact on the cost of cleaning.

There is a known method for regenerating used synthetic motor oils by treating with amino alcohol in a mixture with aliphatic alcohol, followed by stirring the resulting mixture while heating, removing sediment, while 2 vol. % amino alcohol - amine monoethanol and 2 vol. % isopropyl alcohol based on the starting raw material, the mixture is heated to 130-150°C and the precipitate is removed by centrifugation (RU No. 2556221).

The disadvantage of this method is the need to heat to high temperatures and the use of an additional centrifugation station.

There is a known method for the regeneration of used transformer oils, in which the used oil is sequentially passed through three layers, while in the first layer calcium carbide of grades KM or 2/25 or screening of calcium carbide is used, in which acidic impurities are dried and neutralized. In the second layer, a mixture of quartz sand, fine fractions with particle sizes from 0.1 to 0.63 mm, with alumina or fine-grained silica gel of MSKG or ASKG grades is used in a mass ratio (1-10): 1, in which adsorption and filtration are carried out. In the third layer, coarse silica gel of the KSKG brand or its mixture with coarse quartz sand with a particle size of 1.6 to 7 mm is used, in which, simultaneously with percolation, degassing is carried out using a vacuum, which continues in a thin layer of oil until the purified oil is collected (RU No. 2433165).

The disadvantages of this method are the complexity of preparation for work and subsequent regeneration/disposal of a multilayer regenerating cartridge.

The closest analogue to the claimed method is a method for regenerating used motor oil by mixing it together with an adsorbent in a capacitive apparatus, characterized in that NaX zeolite is used as an adsorbent, on the surface of which sodium hydroxide is applied, and the contact time of used motor oil with the adsorbent is not less than 1 hour. (RU No. 2769605).

The disadvantages of this method are the need to use capacitive equipment with a mixing device and the difficulty of unloading spent adsorbent from it.

The technical objective of this invention is to simplify the process of regenerating used turbine oil with a high degree of purification through the use of a one-stage chemical technological process at room temperature using a complex sorbent, which is NaX zeolite with a continuous layer of potassium hydroxide applied to its surface.

The technological problem is solved by passing used turbine oil through a layer of modified adsorbent. As a result, a layer of potassium hydroxide neutralizes low molecular weight organic acids, and the zeolite dries and concentrates the products of oxidative polymerization of waste oil components on its surface. Blocks with adsorbent can be manufactured in the form of quick-detachable elements for quick and easy replacement with ones containing fresh adsorbent and sending spent blocks for regeneration - for applying a layer of potassium hydroxide.

Let's consider examples of the implementation of a method for regenerating used turbine oil.

Example 1

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 2.5 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 0.99 mg/g and final water content 0.01% wt.

Example 2

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 5.0 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 1.07 mg/g and final water content 0.01% wt.

Example 3

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 10.0 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 1.11 mg/g and final water content 0.01% wt.

Example 4

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 12.5 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 1.32 mg/g and final water content 0.01% wt.

Example 5

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 15.0 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 3.23 mg/g and final water content 0.03% wt.

Example 6

100 g of NaX zeolite, on the surface of which potassium hydroxide was applied, was loaded into a glass tube with an internal diameter of 22 mm and a length of 250 mm. A mineral wool swab 15 mm long was installed at the outlet of the tube. 1 L of used turbine oil was pumped through a layer of modified adsorbent using a peristaltic pump at a flow rate of 20.0 ml/min. For the starting oil, the initial acid number was measured to be 6.5 mg/g and the initial water content was 0.15 wt%. The oil that passed through the tube was collected in a flask and analyzed. Final acid value 3.92 mg/g and final water content 0.05% wt.

Claims (2)

1. A method for regenerating used turbine oil by passing it through an adsorbent layer, characterized in that NaX zeolite is used as an adsorbent, on the surface of which potassium hydroxide is applied, and the speed of passage of used turbine oil through the adsorbent layer is from 1 to 2 m/h. 2. The method for regenerating used oil according to claim 1, characterized in that the ratio of potassium hydroxide to NaX zeolite is in the range from 1:20 to 1:10 wt.