SU732362A1 - Method of purifying mineral oil distillates - Google Patents

Description

I

The invention relates to oil refining, in particular to a method for the purification of mineral oils from undesirable components using selective solutions; architects., J

High-boiling oil fractions, used as raw material for the production of lubricating oils, contain undesirable impurities that degrade the EC (the operational properties of oils, in particular the viscosity index, which reduce their stability. Undesirable components of oils are heterocyclic compounds (high molecular weight thiophene derivatives , pyridine, furan, and so on. p-,), asphalt-resinous substances and polycyclic aromatic hydrocarbons. The total content of hetero-elements in the oil fractions is comparatively small. The higher stability of heterocyclic compounds (in particular, furan and thiophene derivatives), as compared with carbocyclic compounds, is primarily due to thermal

physical and thermal oxidative stability of oils. All of this applies to both aophalty resinous and polycyclic hydrocarbons. In addition, the oxidation of sulfur-containing compounds in the process of exploitation of sulfur leads to the formation of sulfuric acid and its derivatives, which increases the corrosiveness of oils, therefore, to obtain lubricating oils with high operating

10 characteristics to remove unwanted components from them. I Known method of purification of distillates of mineral oils by extraction using as a selective

ts phenol solvent {i or more effective furfural 2.

Phenol, which has a relatively high dissolving ability with an average selectivity, provides almost complete removal of polycyclic hydrocarbons and resins and significantly improves the performance properties of oils. However, phenol is distinguished by low selectivity in order to increase which 5-10% water is added to it. The strong toxicity of phenol, its high freezing temperatures also complicate its use as a selective solvent, furfural has a higher selectivity, high density, less toxic than phenol, (The main disadvantage of furfural is its low dissolution ability and, moreover, low stability, which causes great losses in nponeccei. The purpose of the invention is to increase the degree of purification of oil, in particular from heterocyclic compounds, asphalt-smolite substances and polycyclic aromatic substances. The goal is achieved by using N-acetyloxazolidine or its mixture with water as a selective solvent. N-Acetyloxazolidine is a colorless liquid with a viscosity of 2.9 cSt at 30 ° C. The boiling point of N-acetyloxazolidine is 23 O ° C under normal pressure, density d5 .O 4 1,141, refractive index 1 pp N -Acetyloxazolini 1,4700 dyn, can be obtained by simple synthesis from available raw materials - mono ethanolamine, formaldehyde and acetic anhydride. This solvent has a more successful combination of two main extraction properties — selectivity and dissolving ability — than furfur. To regenerate M-acetyloxazolidine, it is possible to use the distillation of its oil fraction components (rectification or steam distillation), reextraction of the hydrocarbon portion of the extract medium using low molecular weight hydrocarbons (pentane, hexane, heptane, etc.), washing the solvent with water. The extraction properties of the selective solvent are studied on an artificial mixture of tridecane-c, methylnaphthalene and massed fractions. Example. 2.91 g of M-acetyloxazolidine and 1.95 g of raw materials containing 35% by weight of O4-methylnaphthalene and 65% by weight of tridecane are loaded into a hermetic container with a magnetic stirrer. The mixture is thermostated at ZO C for 30 min with vigorous stirring. After settling, the extract phase is withdrawn with a syringe. The weight of the extract phase is 3.42 g, weight. the raffinate phase was 1.44 g. The composition of both phases was analyzed by chromatography. The composition of the extract phase: solvent 84.2%, TrVDecane 1.4%, C-methylnaphthalene 14 ,. The composition of the raffinate phase: solvent 1.8%, tridecane 85.5%, ° C-methylnaphthalene 12.7%. The composition of the raffinate: tridecane 87.1%, o4 -metstinnaphthalin 12.9% The composition of the extract: tridecane 8.1%, cC-methylnaphthalene 91.9%. The degree of extraction of tridecane is 96.2% of the potential content in the raw material. Since the target component goes into the raffinate phase when cleaning oils, the comparison of solvents is carried out by its properties. The results of a single-stage extraction of an artificial mixture of tridecane (TD) with oC-methylnaphthalene (MN) at 3A and the ratio of solvent: raw materials - 1.5: 1 by weight are presented in Table. 1. Table 1

16.8 28.5 Furfural 65.0 86.8 Phenol + 6% 65.0 82.928.8 15.0 N-Acetyloxazolidine 65.0 87.1 8.1 43.1 1.14 92.2 73.4 32.5 0.80 85.9 66.2 12.0 1.13 96.2 73.0 48.7 As can be seen from the table. 1, H-acetyloxazopidane exceeds phenol and furfural in almost all indicators. As a result of single-stage extraction, the content of tridecane and its degree of extraction are highest with N-acetyloxazolidine. To compare the properties of solvents during oil purification, a single extraction was carried out. Furfural 0.8579 1.4718 .6.95 Phenol + 6% H, 0 0.8579 1.4726 7.11 -Acetyloxazolydine0.85921.4728 7.34 - acetyl - oxazolidine + 2.7%, 8610 1.4750 6.73 As can be seen from the table. 2, the use of D / -acetyl-xazolicin allows to obtain purified oil of approximately the same quality, but with a higher yield. To compare the properties of solvents under conditions approaching industrial, at 28 ° -40 ° C, a five-step extraction of the fraction of the Stavropol oil mixture in the separatory funnel system is carried out with the following physical-chemical Furfurol 94.0 0.8447 1.47O9 10.27 3 , 56 111

N-Acetylke bzolidine 9 6, O 0.8463 1.472O 1O, ZO 3.58 il3

As can be seen from the table. 3, 1Ч-acetylox bzoli din provides an opportunity to get refined nat better quality and with higher yield. In addition, the properties of the extracts (table. 2, 3) indicate that when using | H-acetyloxazolidine

1.5424

undesirable components are better removed.

Claims (3)

Invention Formula The method of purification of distillates of mineral oils by extraction with the use of an oil having the following physicochemical properties: density q 0.8668, refractive index 11 1.481 O, viscosity 7.55 cSt), -, 2.65 cSt. The extraction is carried out at 50 ° C and the solvents content is 1.5: 1 according to Becy.v 2., Tbl and c a 2 2.52 2.76 87.01.014545 2.52 2.82 82, O1.5138 2.54 2.89 91, O1.5589 2.54 2.65 94.0 - ---- t - - -. -J. Cescian properties: E 0.8566, refractive index 1.48 O6, kinematic viscosity O 10.88 cSt, 3.63 cSt, melting point 36 ° C. The temperature at the inlet of the raw material is 72C, at the inlet of the solvent. O solvent solvents ratio, 54: 1 by weight, Q The results obtained are presented; in tab. 3. Table h X ..7323628    “.. ... V calling selectively, on t-Sources -information, l and h and y and so that, with the aim of being taken into account in the examination increase the degree of purification, as - 1; Chemistry and technology of fuels and masoprotective solvent use Sel, 1970, № 6, p. 22-26. N-acetyloxazolidum or its mixture with s 2. Chemistry and fuel technology and mavodoy. Sel, 1967, No. 12, p. 6Q-61 (prototype);