JPS6018576A - Removal of peroxide from degraded oil - Google Patents

Abstract

PURPOSE:To reclaim a degraded oil efficiently, by immersing clay minerals of hydrous silicate in an alkali solution to give clay minerals of hydrous silicate with low silicate cntent, bringing the degraded oil into contact with the clay minerals of hydrous silicate with low silicate content to adsorb peroxides on them, removing the clay minerals. CONSTITUTION:Clay minerals of hydrous silicate (preferably attapulgite, sepiolite, or talc) are immersed in an alkali aqueous solution having preferably 0.01- 10 normal alkali concentration at normal temperature for 1hr-6 days to give clay minerals of hydrous silicate with low silicate content, powder or the clay minerals of hydrous silicate with low silicate content having 0.01-20mum particle diameters is immersed in a degraded oil (e.g., lubricating oil of car, linseed oil, etc.) for 5min-1hr, brought into contact with it, peroxides in the degraded oil are adsorbed on the clay minerals, and the clay minerals are removed. 5-20wt% clay minerals are preferably immersed in the degraded oil. EFFECT:The process has improved decoloring properties, and a reclaimed oil having increased transparency is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating degraded oil by removing peroxides therein using an active adsorbent.

In general, deterioration of oils such as mineral oils and vegetable oils occurs due to the effects of oxidation, thermal decomposition, or mechanical shear stress during use, resulting in the formation of peroxides in the base oil and impurities (organic content such as pigments, solid substances). It is due to the contamination of Peroxides in degraded oil are produced in large quantities in base oil, promoting corrosion and wear of metals, and in the case of lubricating oils for machines, for example, they degrade the functionality of machines due to corrosion and the like. In addition, peroxide is a harmful substance to the human body, and when vegetable oil, which is used as edible oil, deteriorates and contains a large amount of peroxide, it cannot be used and is discarded.

Therefore, many methods have been proposed to remove peroxides from deteriorated oil to produce recycled oil. Among these methods, the one that is low cost and requires few processing steps is the method that uses adsorption.This method involves immersing an adsorbent in degraded oil and allowing the adsorbent to adsorb and remove impurities from the coconut oil. It is an attempt to reproduce the . The adsorbents include alumina gel, silica gel, and activated reactivation.

There are inorganic substances such as clay, and organic substances such as ion exchange resins and surfactants.

However, although the conventional adsorbents mentioned above are effective in removing impurities mixed in from the outside, they have poor adsorption ability for peroxides in the base oil, which are degradation products, and white clay, which is commonly used for 9%, cannot be used. lack of personal ability.

Although sulfuric acid treatment and the like are sometimes carried out to improve the adsorption capacity, the adsorption capacity for peroxides is not sufficient.

Furthermore, as adsorbents with high adsorption capacity, there are hydrous silicate clay minerals such as attapulgite and sepiolite.
This mineral has a large specific surface area and is said to be able to adsorb peroxides, so it is used to regenerate degraded oil. However, even with this mineral, the amount of M absorbed by peroxide in oil is small, the regeneration rate of degraded oil is low, and there are problems in terms of industrial cost.

The present invention overcomes the above-mentioned conventional problem of low adsorption capacity, increases the adsorption of peroxide in degraded oil by using an active adsorbent, and easily and efficiently removes peroxide. The aim is to completely regenerate degraded oil by removing impurities such as:

That is, 1. The method for removing peroxides from deteriorated oil according to the present invention is as follows:
An alkali treatment step in which the hydrated silicate clay mineral is immersed in a total alkaline solution to form a hydrated silicate clay material with less silicic acid, and the alkali-treated hydrated silicate clay material is a deterioration product of oil. This method is characterized by comprising an adsorption step in which peroxide is adsorbed, and a removal step in which the hydrated silicate clay material is removed.

According to the present invention, the hydrous silicate clay mineral used as an adsorbent has been subjected to alkali treatment, so it has a large surface area.
It has high adsorption activity and can adsorb and remove a large amount of peroxide in deteriorated oil, as well as adsorb and remove impurities such as moisture and solid matter other than peroxide, efficiently regenerating deteriorated oil. can do.

In addition, all the peroxide in the oil can be adsorbed and removed simply by bringing the degraded oil into contact with the hydrous silicate clay material that has been treated with alkali, so the processing steps are very few and all the peroxide can be removed at low cost. Can be removed.

In the method of the present invention, the target oil that can be regenerated is:
Either mineral oil or vegetable oil may be used. The mineral oils include vehicle lubricating engine oil, turbine oil, etc., and the vegetable oils include dry oils such as linseed oil and tung oil, non-drying oils such as olive oil and peanut oil, and semi-dry oils such as sesame oil and rapeseed oil. There is.

Hydrous silicate clay mineral has a specific surface area of 260 to 260 n
It has a large diameter of 1/fir, has a fiber-like structure, and has long tunnel-like pores. The reason why the effects of the present invention can be obtained by performing an alkali treatment of immersing the hydrated silicate clay mineral in an alkaline solution is thought to be due to the following phenomenon occurring. That is, a part of the silicic acid on the inner surface of the mineral is eluted into the alkaline solution, increasing the surface area and increasing the adsorption property. The alkali-treated hydrated silicate clay material with low silicic acid content (
The substance (hereinafter referred to as "the substance") has an overall negative charge, so it has the property of selectively physically and chemically adsorbing all substances that hold cations and functional groups, and it also has adsorption properties on hydrocarbon substances. Naphthenic hydrogen, which is the main component of the oil, is not adsorbed by the substance because of the lack of hydrogen. Due to this property, it selectively adsorbs all impurities such as peroxides that are the cause of deterioration in deteriorated oil.
Can regenerate degraded oil.

Such hydrous silicate clay minerals include Attapulgite and Seviolite (fEep).
i, olj-te), talc (Ta1e), etc. are used. The particle size of the mineral is preferably made as small as possible in order to increase the surface area and improve the reactivity.

The alkali treatment step in the present invention is a step in which the above clay mineral is immersed in an alkaline solution and left to stand for a certain period of time to obtain the material with low silicic acid content. By the alkali treatment,
The silicic acid content on the inner surface of the clay mineral is eluted and the surface area increases. after that.

The clay mineral is removed from the total alkaline solution by a method such as filtration, and the adhering alkaline solution is removed by washing with water or the like to obtain the substance with a low silicic acid content. The material has a large surface area, is very active, and can adsorb all the peroxides in the aged oil.

In order to add the substance before deterioration and to efficiently adsorb degraded oil, it is preferable to crush it into powder. The particle size of the material powder should be made as small as possible in order to increase the surface area and improve the adsorption property (,0,[J
A range of 1 to 20 μm is desirable. The substance may also be formed into granules or plates.

Examples of the alkaline solution include aqueous solutions of substances represented by MOH (alkali metals such as M, NfL, or bases such as ammonia) such as sodium hydroxide and ammonium hydroxide, alcoholic solutions, and water-soluble organic solvent solutions. , or a mixture of two or more W+ is used. The alkaline concentration of the alkaline solution is preferably in the range of 0.01 to 10 normal.

When the alkali concentration is Q, 01Nm, the action of the alkali is weak and the reaction 9 does not proceed sufficiently, so that the treatment takes a long time. On the other hand, when the alkali concentration is 10N or higher, the reaction between silicic acid and alkali is promoted, making it difficult to adjust the amount of silicic acid eluted into the alkaline solution, and requiring neutralization treatment after treatment. I need. In addition, even if the alkali concentration is within the above range, if the amount of silicic components eluted is small, in order to accelerate one reaction, after soaking the hydrated silicate clay mineral in an alkaline solution for two times, the alkaline solution a
The alkaline solution may be stirred or refluxed, and the alkaline solution may be further heated.

The above-mentioned immersion time is not necessarily determined depending on the concentration and temperature of the alkaline solution, but is preferably 1 hour to 6 days at room temperature, for example. Soak for less than 1 hour.

If the reaction does not proceed sufficiently and if the clay mineral is immersed for more than 6 days, there is a risk that all the silicic acid content contained in the clay mineral will be eluted.

In addition, the alkaline dissolved Wlft adhering to the alkali-treated hydrated silicate clay material is removed by washing with water or the like, and then the adhering water is removed by drying. In this drying process, it is preferable to heat and maintain the product at a temperature ranging from room temperature to 650° C. for 3 to 120 hours in a sudden draft or an inert gas atmosphere.

Next, the substance is brought into contact with degraded oil to adsorb peroxides in the degraded oil. The method for bringing the substance into contact with the degraded oil is preferably a method of immersing and holding powder or granules of the substance in the degraded oil, or a method of passing the degraded oil through a plate-shaped body made of the substance. For this process,
Peroxides in the degraded oil are adsorbed by the substance and can purify the degraded oil. In the method of immersing the substance, the substance may be immersed in the degraded oil and then stirred to promote peroxide adsorption. Furthermore, by heating the entire degraded oil to lower its viscosity, the agitation properties of the adsorbed substance are increased and the adsorption time is shortened. This seems to be because the probability of contact between the deteriorated oil and the substance increases.

It is desirable that the substance be immersed in the degraded oil in an amount of 5 to 20% by weight (hereinafter referred to as wt%). When the immersion ratio is 5 wt%.

The adsorption of peroxides in deteriorated oil is reduced, and on the other hand, 20
If the total wt% is exceeded, a large amount of the substance will be mixed into the oil and the overall viscosity will stop, resulting in a decrease in the recovery rate of recycled oil.

The above immersion time varies depending on the immersion ratio.

For example, it is desirable for 5 minutes to 1 hour. If the soaking time is less than 5 minutes, the amount of peroxide adsorbed is small, and if the soaking time exceeds 9.1 hours, a commensurate adsorption effect cannot be obtained.

Next, after allowing the substance to sufficiently adsorb the peroxide in the oil,
A step is performed to separate and remove the substance from the oil and obtain recycled oil. Through this step, substances that have adsorbed impurities such as peroxides that cause deterioration are completely separated from the recycled oil. The obtained recycled oil not only contains less peroxide, but also other impurities are adsorbed and removed, and once it is decolorized and becomes transparent, it can be used again for various purposes.

The method for removing this substance from oil is by qualitative F paper.

Or a filtration method such as by vacuum filtration.

Alternatively, the substance may be separated by centrifugation. Further, when the plate-like body made of the alkali-treated substance is used as a filter plate.

By passing the degraded oil through this filter plate, peroxides in the degraded oil can be adsorbed and recycled oil can be separated at the same time.

Hereinafter, the non-invention will be explained in detail.

Example 1 Attapulgite powder (particle size 1.0 to 20 μm) was used as the hydrated silicate clay mineral, and the powder was immersed in an aqueous solution of 6N hydroxide at a temperature of 109°C for 10 minutes.
After perfusion for a period of time, the mixture was allowed to stand for 60 minutes and subjected to tFJ. The material obtained by filtration was washed with water and dried at 80°C for 48 hours.
A hydrous acid salt clay material with low silicic acid content according to the present invention was obtained.

Next, the powder was immersed in the degraded oil at a weight ratio of 8:1 to the powder obtained by completely pulverizing the above substance, and the powder was stirred and mixed at room temperature for 10 minutes.
Filtered to obtain regenerated oil.

In addition, for comparison, we performed the same operations as above for the case where conventionally used white clay was immersed in degraded oil as an adsorbent, and the case where the same attapulgite powder as above was immersed in degraded oil without alkali treatment. I made 1 recycled oil.

Infrared analysis of the above three types of recycled oil.

The amount of residual peroxide in the oil was determined as absorbance from the absorption spectrum peak. The results are shown in FIG.

The absorbance of peroxide in degraded oil is 4.1X10-2, whereas that of the oil treated with conventional white clay is A8X10-2.
The value of A2×10'' for the athanolulgite treated without alkali treatment was as low as 2.6×10'-2 for the one according to the present invention. In other words, it can be seen that the peroxide adsorption capacity of the alkali-treated attapulgite of the present invention is large.

Furthermore, the decolorization property of the degraded oil was measured by measuring the light transmittance of the purified oil using a spectrophotometer. The results are shown in FIG. From Figure 2, the transmittance of the purified oil treated with white clay is 54%, and that of the oil treated with attapulgite without alkali treatment is 80%, whereas the transmittance of the purified oil treated with the present invention is as high as 90%. The results show that the present invention can also adsorb and remove impurities such as dyes, and has a large effect on decolorization.

Example 2 Seviolite powder (particle size 1
．． Example-treated oils and Seviolite-treated oils without alkali treatment were prepared in the same manner, except that 0-20 μm) was used.

As in Example 1, the amount of residual peroxide in the recycled oil was determined as absorbance from the absorption spectrum peak by infrared analysis. The results are shown in FIG. Figure 3 shows that the alkali-treated Seviolite of the present invention has a large adsorption capacity. Furthermore, the light transmittance of the recycled oil was measured using a spectrophotometer.

The results are shown in FIG. From FIG. 4, it can be seen that the method of the present invention has a greater decolorizing effect.

Example 3 Seviolite powder (particle size 1.0 to 20 μm) - A powder of the substance treated with alkali under the same conditions as in Example 1 was press-molded into a plate shape to produce a temporary plate according to the present invention. The filter plate is used to filter the degraded oil so that the weight ratio of the degraded oil to the filter plate is 1=8, and the peroxides in the oil are adsorbed to produce recycled oil. Obtained. In addition, as a comparison, the sepiolite powder was molded into a filter plate in the same manner as above without being subjected to the gold alkali treatment, and the degraded oil was filtered using the filter plate to prepare recycled oil.

The amount of residual peroxide in the recycled oil of the above two spears was determined by infrared analysis, and the results are shown in FIG. Figure 5: 1: It can be seen that the filter plate of the present invention has a greater peroxide removal effect. Also, as in the nine examples,
By forming the adsorbent into a t-filter plate or the like, there is an advantage that the t-1 step can be a two-step process of adsorption and t-filtration when regenerating degraded oil.

The results of measuring the absorbance and light transmittance of objects are shown in Figure 1.
Figure 2 shows the measurement results of the absorbance and light transmittance of peroxide in Example 1, Figure 3, Toyota Central Research Institute, Ltd. Figure 7, Figure 2, Figure 5.

Claims (3)

[Claims] (1) An alkali treatment step in which hydrated silicate clay minerals are immersed in an alkaline solution to form a hydrated silicate clay material with less silicic acid, and the degraded oil content is converted into a hydrated silicate clay material that has been subjected to the alkali treatment. Deterioration characterized by comprising an adsorption step of contacting the hydrated silicate clay material to adsorb peroxide, which is a degradation product of oil, and a removal step of removing the hydrated silicate clay material. How to remove peroxide from oil. (2) The above-mentioned hydrated silicate clay mineral is attapulgite,
The method for removing peroxide from deteriorated oil according to claim (1), which is at least one of Seviolite and talc. (3) The above alkaline solution has an alkaline concentration of α01~1
The method for removing peroxides from degraded oil according to claim (1), which is a 0N solution.