DE1917357B2 - Process for the pretreatment of used lubricating oils containing active additives prior to regeneration - Google Patents

Description

of Petroleum, 1962, London, p. 452, stated that if the bleaching earth is treated at too high a temperature and for too long a time, oils with a deteriorated color are obtained and certain cracking inevitably occurs. In the publication MAFKl Köziemei.yek 7, Müszaki Könyvkiado, Budapest, 1966, p. 145, it is described in connection with the hot contact process that the color of the oils treated in the presence of air in a closed system deteriorates with increasing temperatures and above 250 ⁰ C the oils become darker than untreated oils. In fact, experts in the field of regeneration of waste oils or the pretreatment for regeneration have taken a different route and used methods that have nothing in common with the heating method according to the invention. In known processes, for example, the pretreatment is carried out by removing solids from the oil by settling, filtering, centrifuging and neutralizing with dry or wet alkalis, which is followed by a washing process (German Auslegeschrift 1 182 377 and Belgian patent 570155). According to a further process, the actual regeneration by hydrogenation is preceded by a low-temperature distillation and filtration of the distillation residue (US Pat. No. 2,339,717). In the publications by K ehse in Chemie-Ingenieur Technik 1963, No. 2, pp. 95 to 98 and by WP Rietsch and Hoffmann, Maschinenbautechnik, 1964, Issue 8, pp. 434b to 438, there are also several different treatments for separating the disruptive components from waste oils described, which include filtration, sulfuric acid refining, bleaching earth treatment, etc. These publications show that hitherto the possibility of pretreatment by mere heating has not been recognized.

The invention is based on the problem of eliminating the disadvantages of the known methods to make a simple process accessible by which the pretreatment of active additives containing used lubricating oils before regeneration in continuous operation with high product yields takes place without the formation of useless or harmful by-products.

The invention is based on the knowledge that to solve this problem, the pretreatment of Used lubricating oils can be carried out prior to regeneration by removing the used lubricating oil to be regenerated is subjected to a heat treatment in a temperature range of 260 to 360 ° C. These This finding is surprising, since lubricating oils are known to be at temperatures above 200 ° C. as a result of cracking processes and polymerization processes are damaged and deteriorate in quality.

The invention relates to a process for the pretreatment of active additives Used lubricating oils before regeneration, which is characterized in that the used oil to be regenerated at a temperature between 260 and 360 ° C, preferably between 280 and 340 ° C, 15 to 110 minutes is subjected to a heat treatment for a long time and the solid impurities of the so heat-treated Used oil is separated off in a manner known per se, preferably by filtration or centrifugation will.

From the used lubricating oils containing active additives treated in this way, under Use of the known lubricating oil refining process secondary raffinates (regenerated lubricating oils) of excellent quality. According to the invention it is possible to achieve a substantial increase in the yield compared to known processes.

To achieve a successful pre-cleaning in the mentioned temperature range, the length of time

ίο the heat treatment by increasing the temperature shortened, or by lowering the temperature, the duration of the heat treatment can be extended will.

The heat treatment is expediently carried out at atmospheric pressure or at a pressure corresponding to the resistance of the device. In the case of increasing the pressure, it is expedient to reduce the time duration and / or the temperature of the Wärmebehandfung.

The pretreatment method according to the invention is for the pre-cleaning of any internal combustion engine system originating, active additives containing used lubricating oil suitable, and on this Product obtained in a wise manner can be particularly successful and economical with the hydroregeneration technology be regenerated.

The effectiveness of the pretreatment method according to the invention is not influenced by the degree of wear, mechanical contamination, still influenced by the water and soot content of the waste oils. The method can of course be used when the engine oil is still with others petroleum-derived lubricating oils (turbine oil, spindle oil, transformer oil, etc.) or with motor fuels (Petrol, gas oil) is diluted.

Impurities can be removed from the heat-treated waste oil through sedimentation, centrifugation, Filter, or can be removed by combining them. In the filtering process, the presence was revealed one of the cheap filtration aids added to the waste oil before the heat treatment (e.g.

Bentonite, fuller's earth, fuller's earth) in an amount of 1 to 2 percent by weight of particularly good effect.

A major advantage of the method according to the invention is that the viscosity index the lubricating oil components in the used oil are not deteriorated during the process, and if the subsequent refining is carried out with the hydroregeneration technique, it will be Index even improved.

An example of an embodiment for carrying out the method according to the invention serving device is described with reference to the drawing.

The figure shows the schematic technological work scheme of the process according to the invention.

From the raw material container 1, the collected waste oil reaches the stirred tank 2 with the help of a pump, that from the feeder 3 is also a cheap filtration aid in an amount of 1 to 2 percent by weight can be fed. The feeding and premixing of the bleaching earth and the waste oil takes place continuously. The mixture obtained is passed through the heat exchanger 9 with the aid of a pump, then the oil preheated in this way is put into the tube furnace for the purpose of the actual heat treatment 4 brought from which the oil mixture in the

Scheider 5 arrives, where the water pollution and the light hydrocarbon fraction of the oil from Separate the lubricating oil part and pass through the water cooler 10 into the tank 6 collecting the distillate. The aqueous phase which separates out is drained off at the bottom of this container; their amount depends on the respective Depends on the water content of the used oil. From the middle part of the distillate collection Container 6, the light hydrocarbon fraction is derived.

The heat-treated waste oil passes from the separator 5 into the heat exchanger 9, where it is used Most of it is cooled, and from here into the filter 7. The filtered, soot and other mechanical Used oil that no longer contains impurities is passed through the water cooler 10 into the storage container 8, then passed into the regenerating device, not shown in the figure.

For the characterization of the waste oil subjected to the heat treatment according to the invention as well as the secondary raffinates produced from this by hydroregeneration are in the subsequent

o the table below gives four examples. That for The waste oil used in the experiments came from a gasoline engine. The final product was made with the following Key figures gained:

example

Color (ASTM)

Viscosity at 50 ^° C., cSt

Viscosity index

Sulfur content, ° / ₀

Conradson number, percent by weight

Acid number, mg KOH / g

Oxidation stability:

Viscosity quotient, VJV ₁

Conradson difference, C ₂ - C ₁

Heat treatment temperature, ⁰ C

Hydrogenation temperature, ⁰ C

Heat treatment time, minutes .... Yield,%

38.6

86 0.11 0.03 0.00

1.47 0.38 270 300 75 80 1.5
36.5
85
0.10
0.04
0.00

1.42
0.40
295
310
100
81

2.5 2.5 35.3 36.2 87 87 0.10 0.10 0.04 0.04 0.00 0.00 1.53 1.55 0.42 0.45 320 350 320 290 55 20th 80.5 79

The yield calculated on the original waste oil was with otherwise almost identical product key figures 25% lower on average if regeneration takes place after pretreatment Hydrogenation with furfural extraction and subsequent final refining with sulfuric acid bleaching earth took place.

The main advantages of the method according to the invention can be summarized as follows:

a) It ensures a much higher yield than the known pre-cleaning methods.

b) The product contains all lubricating oil components of high boiling point and excellent Quality, or even all unsaturated compounds that are effective in the known Pretreatment processes are lost, but by means of hydro-regeneration in lubricating oil components can be converted.

c) There are practically no losses in the valuable lubricating oil components.

d) The formation of the by-products that can otherwise be used for heating is minimal.

e) The operating costs are extremely low.

f) No chemicals are needed.

g) In the device used for the execution there is no need for special construction material.

1 sheet of drawings

Claims (3)

Quality that reaches that of the primary Rafnnate, in claims: usually used in combination. Another disadvantage of vacuum distillation 1. Process for the pretreatment of active method consists in the fact that these old lubricating oils, which do not contain a good yield of additives, are secured before the 5, namely because of the sediment regeneration, which results in considerable losses due to the waiting net that the old oil to be regenerated in the case of a lubricating oil component. In addition, the old temperature between 260 and 360 ⁰ C, preferably lubricating oil, must be centrifuged for 15 to 110 minutes and / or subjected to a mild heat treatment and io chemical treatment before pre-cleaning by vacuum between 280 and 340 ^{0 C,} otherwise the solid impurities of the so heat-treated in the vacuum distillation device - due to the th waste oil in a known manner, preferably suspended in the waste oil or at temperature by filtering or centrifuging, are separated out in solid form. impurities - cross-section constrictions very quickly 2. The method according to claim 1, characterized thereby 15 would occur. This precedes the vacuum distillation, that before the heat treatment or ongoing operations, a filtration aid (10 to 12%) is also associated with the waste oil, which is considerable afterwards,
preferably fuller's earth is added. The chemical cleaning processes and the 3. The method according to claim 1 or 2, characterized in solvent extraction methods are also economic, that the heat treatment in the 20 borrowed very expensive; the one hand will be considerable substantial amounts of chemicals consumed at atmospheric pressure, on the other hand to be led. are the payback and maintenance costs of the Applied devices very high. It was also known that waste oils were obviously 25 Hch were free of active additives by treating with fuller's earth or silica at increased The invention relates to a method for pretreatment temperature and subsequent filtration of old preparations containing active additives. In this way, waste oils were reconditioned, Lubricating oils before regeneration. which in addition to solid impurities such as dust, soot, As is well known, old lubricating oils can also after various metal parts originating from wear which processes are regenerated. The regeneration decomposition products of the oil contained, as for example generally consists of two or more wise resins, oxidation products, asphalts, acidic Stages, of which the first stage is usually a pre-decomposition product and possibly water. That act represents. The only purpose was to heat the oil to be processed For the pretreatment of used lubricating oils before the 35th addition, treatment with silica or fuller's earth Regeneration will be improved to the greatest extent possible in order to better respond to the zer process applied: settlement products of the oil with the active centers to achieve the bleaching earth (German patent specification a) Sedimentieren, 738 224 and German patent 748 924). From the b) Centrifugation, 40 British Patent 413 537 was the regeneration c) Filtration, of used oil by heating with anhydrous aluminum d) vacuum distillation chloride to a temperature of 130-350 ⁰ C. e) chemical treatment (known as acidic and / or alkaline) Treatment), aluminum chloride and heating the decomposition f) Treatment with solvents. 45 Settlement products of the lubricating oil polymerize and deposit. These deposited products can These methods are usually combined then along with the solid impurities through applied. Filtration or otherwise separated from the oil A common disadvantage of the known Vorbe- be. treatment method consists in the fact that they are 50 These known methods of regeneration significant losses of valuable lubricating oil compo- a waste oil, in which the heating to improve nenten as well as for the formation of difficult or even the actual treatment is carried out, However, unusable or often even harmful cannot indicate the possibility Lead by-products. Another disadvantage of giving before regenerating after another chemical pretreatment consists in the fact that it only requires pretreatment by mere heating to be performed from expensive construction materials. built devices can be carried out. In addition, the well-known Regene- In addition, the unsaturated oils are also subjected to a spoilage treatment, which is openly Resin-prone compounds removed, which was visibly free of active additives by means of. One would have Hydroregeneration in lubricating oil components must therefore fear that the heating of a leads can be. Used oil containing active additives has an accelerated rate Another common disadvantage the known decomposition of the oil would cause so much more than Pretreatment methods is that, when used alone, the literature indicates that oils are used in none of them is suitable for pre-cleaning at temperatures above 250 to 300 ⁰ C as a result of cracking the degree of which damages the undisturbed execution of the 65 processes and polymerisation processes enables further regeneration stages. Become demented and suffer a deterioration in quality, The above-mentioned pre-cleaning procedures, for example, are used by E.B. Evans, “Modem Methods for Obtaining Reclaimed Material, Their Petroleum Technology, "Third Edition, The Institute