DE1098129B - Cyclic adsorption process for the separation of the constituents of petroleum products boiling above 300 ° C - Google Patents

Description

GERMAN

The invention relates to a cyclic adsorption process for separating the constituents at temperatures above 300 ° C boiling petroleum products, the less adsorbable saturated and the moderately adsorbable lower aromatic hydrocarbons with a maximum of two 5 rings (hereinafter referred to as "aromatic" for short) also strongly adsorbable compounds, such as condensed polycyclic aromatics and / or sulfur, oxygen or Contain nitrogen compounds (hereinafter referred to as "resinous" for short).

The purpose of the invention is to provide an easily, economically and relatively quickly executable ad and To create desorption cycle, which is in one and the same column without an intermediate treatment of the initially filled adsorbent can be repeated very often (at least 200 to 300 times).

In the previously known cyclic adsorption process for the separation of petroleum fractions The above composition became the adsorbent after adsorption by a strongly polar Solvents, e.g. B. alcohol, eluted, which is hot afterwards with blown hot air or blown through Gases had to be removed in order to regenerate the adsorbent for one repetition of the cycle. That Blowing through required the use of a coarse-grained adsorbent, which was undue effort Adsorbents and solvents resulted.

The invention is based on the new idea of using a solvent with a temperature gradient as the eluent the adsorbability to use, which is flatter than the temperature gradient of the adsorbability the resinous constituents of the starting material. From the group of such solvents is one as Eluent chosen, its adsorbability the two conditions, the resinous at elevated temperature Components to be eluted economically and at room temperature by a little adsorbable solvent to be economically displaced is sufficient.

In order to enable a precise comparison of the adsorbabilities of the various substances, is used as a measure the specific heat of wetting with respect to the adsorbent is chosen as the basis for adsorbability.

The specific heats of wetting Q of the compounds that are to be separated here as constituents of the feed mixture as diluents and displacers and as eluents can be found in the list below.

Q cal / m ² Components of the feed mixtures Spindle oil, saturated ingredients 0.0180 to 0.0190 aromatic ingredients 0.0350 to 0.0380 resinous ingredients 0.0420 to 0.0450

50

Cyclic adsorption process

for separating the components of petroleum products boiling above 300 ° C

Applicant:

"LICENCIA"

Talälmanyokat Ertekesitö Vällalat, Budapest

Representative: Dr. G. W. Lotterhos

and Dr.-Ing. H. W. Lotterhos, patent attorneys,

Frankfurt / M., Lichtensteinstr.

Claimed priority: Hungary from April 19, 1955

Dr. Mihaly Freund, Dr. Gyula Nyul

and Endre Vamos, Budapest, have been named as inventors

Engine lubricating oil, saturated ingredients ... aromatic ingredients. resinous constituents.

Aids

Carbon tetrachloride

Technical pentane

n-heptane

Aromatic-free light petrol

Technical xylene

toluene

α-methylnaphthalene

benzene

Thiophenol

Thiophene

Dichloroethane

acetone

Ethanol

Methanol

Q cal / m ²

0.0200 to 0.0230 0.0400 to 0.0430 0.0450 to 0.0480

0.0138 0.0140 to 0.0160

0.0164 0.0150 to 0.0170

0.0249

0.0319

0.0351

0.0387

0.0415

0.0415

0.0425

0.0472

0.0529

0.0538

This information was given on silica gel of medium porosity with a specific surface area of 530 m ² / g and an average pore radius of 17 to 22 Å

109 507/454

3 4

determined; but they also apply to silica gels calculated differently, in the process according to the invention in general

structure and, according to some measurements, mine is also higher.

Aluminum oxide and aluminum silicate gels, but not yield and quality of the separated products

for activated carbon, bleaching earth, permutite, bauxite or bentonite. in the method according to the invention as desired

The invention consists in regulating a cyclic process 5 during the process. Will be included in a cycle

to separate the components of over 300 ° C boiling application of the same amount of adsorption and

Petroleum fractions which, in addition to the poorly adsorbable solvents, contain less feed mixture in the column

saturated (A) and the moderately adsorbable lower one, the quality of the main product increases,

aromatic hydrocarbons (B) also strongly adsorbed while increasing the feed mixture of the

bable compounds (C) such as condensed polycyclic ^ io yield can be increased with modest quality.

Aromatics and / or sulfur, oxygen or stick with the same amount of feed mixture and adsorbent

Contain substance compounds by adsorption of the in can be increased by increasing the diluent

a light hydrocarbon (a) dissolved output - higher yield of weaker quality, by

material on silica gel or on one of the usual reduction of the diluent a lower yield

Then achieve aluminum oxide or aluminum silicate gels of better quality.

Occasionally it happens that the yield of saturated solution remaining by the same product after about 150 cycles decreases considerably. Solvent (a) and subsequent elution begins with one. In such cases it is advisable to use the temperature intensifier adsorbable eluent (δ), thereby reducing the temperature of the eluent and the adsorption column z. B. indicates that the adsorption of the solvent (α) ao from 100 to 120 ° C to increase. This increases the dissolved mixture and the subsequent displacement first of all the extract yield, but after about two cycles of the same through the solvent (a) at about room temperature, the initial yield at saturated temperature and the subsequent elution by the product is restored. If after about a hundred more eluents (δ) at at least 100 ° C and the number of cycles again a deterioration in the yield true displacement of the eluent (δ) by 25 increases, then by increasing the solvent (a) again at about room temperature, elution temperature, for example, to 150 ° C the number of cycles and the solvent («) a hydrocarbon is increased to at least three hundred before the column is filled with fresh adsorbent

O ~ O (D must.

Ya, ~ YA \) _3o -Qj _e ^ ₆ J _1n method obtained according to the invention

and as an eluent (δ) a solvent extracts can be used for the purposes of the chemical industry

is used that the condition as starting materials or directly, such as. B. as cable

0a + Qc insulating material or as a plasticizer in the rubber, leather oil + 0.02 _; Qb ! _ - (II) and plastics industry can be used.

2 35 Some examples of the practical implementation of the invention

is sufficient and its temperature gradient of the adsorption is shown below with reference to the drawing, a

availability is flatter than that of the strongly adsorbable Be schematic representation of a for performing the

constituents (C) of the starting material, where Q describes the equipment suitable for the process.

Specific heat of wetting measured at 20 ° C in cal / m ² -d · · 1 ι

means on the adsorbent used. 40

Compliance with the above with (II) designated loading A heavy engine oil distillate with viscosity index35

condition ensures that on the one hand (right side of the should in (A) saturated, (B) aromatic and (C) resinous

Condition) the elution at elevated temperature and components are broken down. The specific wetting

on the other hand (unke side of the condition) warm the displacement (Q cal / m ² ) for the components to be separated

of the eluent were effective at room temperature 45 in this case: Qa = 0.0230, Q _B = 0.0420,

and can be carried out economically. Qc = 0.0480. Accordingly, the solution and

Because the relatively weak Desorp- displacer is an aromatic-free light petrol

tion ability of the eluent by increasing the selects its specific heat of wetting according to the above

Desorption temperature is compensated, the directory is also smaller than Qa. The specific wetting

Range of applicable eluants expanded so that 50 heat Q _{b of} the eluent could according to the invention

when choosing the eluant, different values from the minimum value are used

Aspects such as corrosion, hygiene and boiling point Q _A _ | _ Q ₀ 0.023 + 0.048

and stability can be more considerate. Qt> min = - - = - = 0.0355

If so, the more strongly adsorbable portion of the feed mixture of several differently adsorbable 55 an up to the maximum value

Components, these can also be fractionated q = Q _a + 0.02 = 0.023 + 0.02 = 0.043
eluted and collected by having the eluant first at room temperature, then at elevated temperatures. As an eluent, dichloroethane was allowed to act at the temperature. specific heat of wetting 0.0425 selected and that

Since the adsorbent used against water 60 separation process is carried out as follows,

and coarse contaminants are sensitive, we recommend 22 cm ^{3 of} the heavy engine

it is, the adsorption column a significantly smaller, oil distillate through valve 2 and 20 cm ³ aromatic-free

Auxiliary column filled with adsorbent waste, petrol introduced as solvent through valve 3,

switch. The solution thus prepared was through valve 4 and

The main products of the process are quality 65 line 5 in the surrounded with a heating jacket 8

(premium grade) oils, which are also introduced into adsorption column 7 with a diameter of 20mm for lubrication purposes,

high loads are suitable and viscosity- The filling of the column 7 consisted of 100 g of silica gel

index and oxidation stability due to solvent medium porosity and an average grain size

riffination products are at least equivalent in size of 0.07 mm and were mixed with light petrol.

are, but the yield, on the same quality 70 tet. To heat or cool the column, in

the jacket space 8 water vapor can be introduced through valve 9 or water through valve 10. The heating steam could be diverted through valve 9 ', the cooling water through valve 10'. In the container 1 could through line 11 and valve 11 'also inert nitrogen gas ί to regulate the flow rate in the Column 7 are initiated. The flow rate of the solution was adjusted so that the adsorbent related space velocity 801 per hour was not exceeded.

After the level of the solution introduced in the column had sunk to the surface of the silica gel, 30 cm ^{3 of} light gasoline were introduced into the container 1 as a displacement agent (a) and pressed through the column 7. The fractions of the oil solution and of the displacement agent (light gasoline) which had flowed through the column were collected separately through the valve 13. Afterwards, 40 cm ^{3 of} dichloroethane as eluent (b) were poured into the second container 14 through line 15 and valve 16, pressed through column 7 and also drawn off through valve 13, but collected separately. Since the specific heat of wetting Q _{b of} the dichloroethane at room temperature is somewhat higher than Qb, but far below Qc , only the aromatic constituents (B) of the starting mixture were eluted in this first evaluation. Meanwhile, a further 60 cm ^{3 of} dichloroethane were introduced into the third container 18 through valve 17 and heated to 100 ° C. by means of the electric heater 19 in order, after the cold dichloroethane had flowed out of the column 7, to be passed into the column preheated by steam heating. Both the cold and the warm eluent were forced through the column by the inert gas in line 11 at the same rate as the oil solution and the displacer previously were. The warm extract containing the resinous constituents (C) of the starting mixture was collected through valve 20 after flowing through cooler 21 in container 22 to be emptied through valve 23.

During the warm elution, a gas line 24 opening into the upper part of the container 22 was used the gas pressure in the column is increased to prevent the volatilization of the warm dichloroethane. Of course, the pressure in the upper part of the column must remain higher than in the lower part.

After the warm eluent had drained from the column, the column jacket was switched from steam heating to water cooling and then a further 20 cm ^{3 of} light gasoline from container 1 was forced through the column to force out the dichloroethane remaining in the adsorption column in the cold state. The cycle ended in this way could easily be repeated very often.

The products obtained in several cycles were combined according to quality and the solvents through Distillation regenerated to be reused in subsequent cycles.

The quality and quantity data of the separation products are in Table 1 in comparison with those of the starting mixture summarized.

Tabel

Raffinate more aromatic more resinous 1.002 1.040 Feed oil 0.904 extract - - 0.937 240 - - 240 78.2 - --- 170 10.4 - - 21 +72 1.5665 1.6670 +35 0.12 - 32 1.2 1.4958 - > 100 1.5187 - Dark green black - - 19th 11 - yellow Dark green 70

Density if

Flash point, ⁰ C

Viscosity, cSt, 50 ° C

Viscosity, E / 50

Viscosity index

Conradson number

Refractive index n ² g

Softening point, ring and ball test, ° C

Ductility at 15 ° C, cm

colour

Yield, percent by weight

If the aromatic and resinous extracts are not separated from one another, the elution can be carried out entirely at 100 ° C. with 80 cm ^{3 of} dichloroethane.

Example 2

55

In order to obtain a cosmetic white oil from a dewaxed spindle oil by separating off the aromatic and resinous constituents, a technical pentane was selected as the solvent and displacement agent according to the invention, the specific heat of wetting (Q _a = 0.0160 cal / m ² ) was lower than that of the saturated components of the locker ¹ oil (^ ₁ = 0.0190). Since the specific heat of wetting of the highly adsorbable resinous constituents of the spindle oil was Qc - 0.0430 cal / m ² , eluents with specific heats of wetting came within the limits according to the invention

70 into consideration. Benzene with a specific heat of wetting 0.0387 cal / m ^{2 was} selected.

Using the same equipment as in Example 1, 30 cm ^{3 of} spindle oil dissolved in 30 cm ^{3 of} pentane was forced through the column at a specific space velocity not higher than 120 liters per hour. ^{40 cm 3 of} pentane were replenished as displacement center] (a) for the solution. While this amount of pentane was flowing off, 40 cm ^{3 of} benzene were heated in the container 18 with the electrical heating device in order to be forced through the preheated column after the pentane had drained off. Afterwards, the system switched from steam heating to water cooling, and the pentane residues were displaced from the column ^{by 25 cm 3 of cold pentane.} The cold and warm fractions were collected separately in the same way as in Example 1. The cycle could also be repeated in the same way and just as often. The quality and quantity data for Example 2 are summarized in Table 2 in a manner similar to that in Table 1 for Example 1.

Tabel

Feed oil

White oil

extract

Density ä ™

Flash point, ⁰ C

Viscosity, cSt

20 ° C

50 ° C

E / 20

E / 50

Viscosity index

Conradson number

Refractive index nf

colour

Winkler's iodine number

Yield, percent by weight

Example 3

In order to obtain a product with a particularly high viscosity index, when treating an engine lubricating oil, the oil solution was displaced from the column with a reduced amount of solvent and the extractants were first eluted at room temperature, then at 100 ° C and finally at 150 ° C, 0.902
165

40.0
10.9

5.3

1.9
+46

0.01

1.4970
Brown

2.51

0.876
165

32.0

9.4

4.3

1.8
+72

0.0

1.4799
colorless

0.12
78

0.970
168

95.0
16.4
12.5

2.5
-58

0.20

1.5820
Dark brown

3.85
22nd

so that three extracts were obtained. The product obtained showed a reduced stability against oxidation and an increased tendency to corrosion. By admixture of the eluted fraction at 100 ° C to extract the extracted oil with the solvent in an amount of 1.5 ° / _0, based on the oil, these adverse properties have been fixed according to the table 3 without significant reduction in the viscosity index.

TabeUe main product
originally + 1.5% extract

Viscosity, cSt, 50 ° C

Viscosity index

Conradson number

After oxidation according to the British Air Ministry test

Difference in the Conradson numbers C ₂ -C ₁

Viscosity quotient VJV ₁ at 50 ° C

Acid number, mg KOH / g

corrosion

Claims (4)

Claims: 45 1. Cyclic process for separating the constituents of petroleum fractions boiling above 300 ° C, which, in addition to the poorly adsorbable saturated (A) and the moderately adsorbable lower aromatic hydrocarbons (B), also strongly adsorbable compounds (C) such as condensed polycyclic aromatics and / or sulfur - Contain oxygen or nitrogen compounds, by adsorption of the starting material dissolved in a light hydrocarbon (a) on silica gel or on one of the usual aluminum oxide and aluminum silicate gels, subsequent displacement of the solution remaining between the grains of the adsorbent by the same solvent (a) and subsequent elution with a more strongly adsorbable eluent (b), characterized in that the adsorption of the mixture dissolved in the solvent (a) and the subsequent displacement of the same by the solvent (a) at about room temperature, the subsequent elution by the eluent ittel (b) at at least 100 ° C and the subsequent displacement of the eluent (b) by the solvent (a) take place again at about room temperature and a 70.4 as solvent (a)
90
0.12 0.90 1.2 4.6 positive 72.1
88.6
0.16 0.95 1.2 1.3 corresponding Hydrocarbon is used that meets the condition- Qa ~ Qa (I) and as eluant (b) a solvent is used that of the condition Qa + Qc Q _A + 0.02 ^ Qb ^ (II) is sufficient and its adsorbability temperature gradient is flatter than that of the strongly adsorbable constituents (C) of the starting material, where Q is the specific heat of wetting measured at 20 ° C in cal / m ² on the adsorbent used. 2. The method according to claim 1, characterized in that the eluent first at room temperature, then at a higher temperature by the Column is driven and the extracts obtained at different temperatures are collected separately. 3. The method according to claim 1 or 2, characterized in that at an advanced number of cycles allows the eluent to act at a higher temperature than in the previous cycles. 4. The method according to any one of claims 1 to 3, characterized in that one for displacement. of the warm eluent, warm solvent used and then displaced with cold solvent. Documents considered: German Patent No. 862 450; 129 Swiss Patent No. 220 754; British Patent No. 714,614; U.S. Patent Nos. 2,554,908, 2,585,490; Petroleum, 1932, No. 7, pp. 4, 5; Oil and Coal, 1937, p. 964; Analytic, Chem., 28, pp. 876-881, 1950. 1 sheet of drawings