RU2198201C2 - Method for production of high-index and waxy extract - Google Patents

Abstract

FIELD: petroleum processing. SUBSTANCE: lube fractions are deparaffinated according to integrated three-step filtration, third-step filtrate being withdrawn in the form of a separate stream and second-step filtrate returned into the beginning of process. Deparaffinated oil is subjected to extraction by N- methylpyrrolidone. Process gives oils with pour point below -15 C and waxy extract with pour point below -25 C. EFFECT: increased yield of oils with viscosity index above 100 and enabled production of waxy extract. 10 tbl, 5 ex

Description

 The invention relates to oil refining, and more specifically to the production of oils and paraffins in oil refineries in Russia.

 The domestic technology of oil and paraffin production involves the production of oil distillates from the vacuum column of the AVT-M units, the production of deasphalts from the tar of the vacuum column in the process of propane deasphalting, the selective purification of distillates and deasphalts by phenol in installations for the selective purification of oils, dewaxing of raffinates in a solution of ketone-aromatic solvents production of dewaxed oils, de-oiling of gachas and petrolatums on paraffin plants to obtain pa Athens and ceresin. Scheme of technological processes for the production of oils and paraffins and their sequence are presented in the book (D.O. Golberg, S.E. Krein. Lubricating oils from oils of eastern deposits. - M .: Chemistry, 1972, - p. 37).

 In the process of improving the technology of oils and paraffins in the process of dewaxing, the conventional technology was replaced by a combined one at the Novo-Ufa Oil Refinery. Combined dewaxing differs from the usual three-stage filtration scheme and the output of stage III filtrate in a separate stream through the solvent regeneration system. The absence of recirculation of the low-viscosity filtrate into the raw suspension of the crystallization block made it possible to obtain marketable paraffin instead of pumping gach (Ways to intensify the main processes of the oil refining industry in connection with the prospects for its development. Materials of the meeting. - M.: CNITENeftegaz, 1964, - p. 359-363 .).

 In the process of improving the technology of oils and paraffins at the Novo-Ufa Oil Refinery, the phenolic refining of oils was replaced by the process of refining deasphaltsates and distillates with N-methylpyrrolidone. N methylpyrrolidone is a more selective solvent than phenol. With all other things being equal, the yield of raffinates when treated with N-methylpyrrolidone increases by 3.5-4.5%. N-methylpyrrolidone is a non-toxic solvent (Karakuts V.N., Makhov A.F., Kushnir I.L. et al. Operational experience of the selective oil purification unit 37/1 on N-methylpyrrolidone. Oil refining and petrochemicals. 1991, 1, p. .9-11).

 As a prototype of the technology for the production of oils and paraffin, we select the technology for purifying distillates and deasphalts with N-methylpyrrolidone and the technology for combined dewaxing of raffinates with the simultaneous production of dewaxed oils and marketable paraffins on the same installation.

 The advanced technology adopted for the prototype is not without a number of disadvantages. In the process of producing oils and paraffins using this technology, highly refined oils with a viscosity index above 100 cannot be obtained and low-setting extracts cannot be obtained. Isoparaffin hydrocarbons with a viscosity index of 130-140 go together with extracts and slop-vox and are only partially involved in dewaxed oils, low-melting paraffins of normal structure with a melting point.

 The objective of the invention is to create a method by which it is possible to obtain highly purified oils with a viscosity index above 100 and at the same time low-setting extracts.

The problem is solved by a method in which oil distillates are dewaxed according to a combined scheme in three stages of filtration with the output of the filtrate of the third stage in a separate stream and the filtrate of the second stage is returned to the raw material, and then the crude dewaxed oil is subjected to extraction with N-methylpyrrolidone. Get oil with solidification minus 15 ^o C and a low-setting extract with a pour point below minus 25 ^o C.

Example 1: Deparaffinization in a direct sequence in three stages of filtration, the filtrate of the III stage are not returned to the feed, and in the form of slop wax, they are discharged in a separate stream (combined dewaxing). The distillate of fraction III is purified by N-methylpyrrolidone in a ratio of 1.5: 1 in countercurrent in three stages at temperatures of 50 ... 55 ... 60 ^o C. The resulting raffinate is subjected to dewaxing in three stages of filtration in a solution of ketone-aromatic solvent (methyl ethyl ketone 60%, toluene 40%). At the first stage, the temperature is -23 ...- 24 ^o С, total dilution with a solvent and filtrate of the II stage is 3.5: 1 (vol.); at the second stage, the temperature is -13 ^o C, dilution with a solvent of 6: 1 (vol.); at the third stage, the temperature is +2 ^o С, dilution with a solvent of 6: 1 (vol.). The results are shown in Table 1 and 2. As a raw material, distillate of the third fraction was taken from a mixture of Tuymazinskaya and Tyumen oil.

 Material balance of technology, taking into account losses.

 Taken: distillate of the III fraction of 100%.

Received,%:
Dewaxed Oil - 47.85
Paraffin - 5.5
Extract - 34.0
Slop Vox - 7.6
Total - 94.95
Useful components that make up the calculated product,%:
Dewaxed Oil - 47.85
Paraffin - 5.5
Total - 53.35
Example 2: The dewaxing in direct sequence in three stages of filtration, the filtrate of the III stage does not return to the raw material, and in the form of slop wax is discharged in a separate stream (combined dewaxing).

The distillate of fraction III is purified by N-methylpyrrolidone in a ratio of 1.4: 1 in countercurrent in three stages, at temperatures of 50 ... 55 ... 60 ^o C. The resulting raffinate is subjected to dewaxing in three stages of filtration in a solution of ketone-aromatic solvent (methyl ethyl ketone 60 %, toluene 40%). At the first stage, the temperature is -23 ...- 24 ^o С, the total dilution with a solvent and filtrate is 3.5: 1 (vol.); at the second stage, the temperature is -13 ^o C, dilution with a solvent of 6: 1 (vol.); at the third stage, the temperature is +2 ^o С, dilution with a solvent of 6: 1 (vol.). The results in table 3 and 4.

 Material balance of technology, taking into account losses.

Taken: distillate III fraction 100%
Received,%:
Dewaxed Oil - 47.2
Paraffin - 6.2
Extract - 29.8
Slop Vox - 9.5
Total - 92.7
Useful components that make up the calculated product,%:
Dewaxed Oil - 47.2
Paraffin - 6.2
Total - 53.4
Example 3: Deparaffinization (combined) in the reverse sequence in three stages of filtration with the return of the filtrate of the II stage in the feed and with the conclusion of the filtrate of the III stage in a separate stream. The dewaxing of the distillate in a ketone-aromatic solvent containing 60% methyl ethyl ketone, 40% toluene. At the first stage, the temperature is -23 ...- 24 ^o С, the total dilution with a solvent and filtrate is 3.5: 1 (vol.); at the second stage, the temperature is -13 ^o C, dilution with a solvent of 6: 1 (vol.); at the third stage, the temperature is +2 ^o С, dilution with a solvent of 6: 1 (vol.). The crude dewaxed oil was purified by N-methylpyrrolidone at temperatures of 50 ... 55 ... 60 ^o C and the ratio of solvent to raw material 1.3: 1 (vol.). The results are in table 5 and 6.

 As a raw material, distillate of the third fraction was taken from a mixture of Tuymazinskaya and Tyumen oil.

 Material balance of technology, taking into account losses.

Taken: distillate III fraction 100%
Received,%:
Dewaxed Oil - 48.9
Paraffin - 7.5
Extract - 32.7
Slop Vox - 5.0
Total - 94.1
Useful components that make up the calculated product,%:
Dewaxed Oil - 48.9
Paraffin - 7.5
Total - 55.4
Low curing extract 32.7%
The low-curing extract can be used as a flavored coolant oil (AMT-300), as a low-curing flavored additive in road bitumen, for the production of special soot materials and other products.

Example 4: The distillate of Tyumen oil was taken as a raw material. Deparaffinization (combined) in the reverse sequence in three stages of filtration with the return of the filtrate of the second stage to the feed and the withdrawal of the filtrate of the third stage in a separate stream. The dewaxing of the distillate in a ketone-aromatic solvent containing 60% methyl ethyl ketone, 40% toluene. At the first stage, the temperature is -23 ...- 24 ^o C, the total dilution with a solvent and filtrate is 3.5: 1 (vol.); at the second stage, the temperature is -13 ^o C, dilution with a solvent of 6: 1 (vol.); at the third stage, the temperature is +2 ^o С, dilution with a solvent of 6: 1 (vol.).

The crude dewaxed oil was purified by N-methylpyrrolidone at temperatures of 50 ... 55 ... 60 ^o C and the ratio of solvent to raw material 1.3: 1 (vol.). The results in table 7 and 8.

 Material balance of technology, taking into account losses.

Taken: distillate III fraction 100%
Received,%:
Dewaxed Oil - 50.0
Paraffin - 7.5
Extract - 33.2
Slop Vox - 5.0
Total - 95.7
Useful components that make up the calculated product,%:
Dewaxed Oil - 50.0
Paraffin - 7.5
Total - 57.5
Low-hardening extract - 33.2
Example 5: Combined dewaxing in reverse sequence in three stages of filtration with the return of the filtrate of the second stage to the feed and the output of the filtrate of the third stage in a separate stream.

The dewaxing of the distillate in a ketone-aromatic solvent containing 60% methyl ethyl ketone, 40% toluene. At the first stage, the temperature is -23 ...- 24 ^o С, the total dilution with a solvent and filtrate is 3.5: 1 (vol.); at the second stage, the temperature is -13 ^o C, dilution with a solvent of 6: 1 (vol.); at the third stage, the temperature is +2 ^o С, dilution with a solvent of 6: 1 (vol.).

The crude dewaxed oil was subjected to deeper purification with N-methylpyrrolidone at temperatures of 50 ... 55 ... 60 ^o With a ratio of solvent to raw material of 1.5: 1 (vol.).

 The results in table 9 and 10.

 Material balance of technology, taking into account losses.

Taken: distillate III fraction 100%
Received,%:
Dewaxed Oil - 48.1
Paraffin - 8.1
Extract - 34.6
Slop Vox - 5.6
Total - 96.4
Useful components that make up the calculated product,%:
Dewaxed Oil - 48.1
Paraffin - 8.1
Total - 56.2
Low curing extract - 34.6
All other things being equal, with the technology in the reverse order, high-index oils with VI above 100 were obtained. The yield of the calculated products is 1-2% higher than with the technology in the direct sequence. At the same time, low-hardening extracts were obtained.

 There is one drawback: lower filtration rates, especially in the first stage.

Claims (1)

 A method of obtaining a high index oil and a low setting extract by dewaxing oil distillates according to a combined scheme in three stages of filtration with the output of the filtrate of the third stage in a separate stream and returning the filtrate of the second stage to the feedstock, followed by purification of the dewaxed oil with N-methylpyrrolidone.

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