JPS6059951B2 - Simultaneous deasphalt extraction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for simultaneously deasphalting and extracting asphalt-containing mineral oil and recovering the extraction solvent.

In particular, the present invention provides simultaneous solvent deasphalting and extraction of mineral oil containing asphaltic and aromatic components in a combined zone, in which the mineral oil is combined with light hydrocarbons and N-methyl-2-pyrrolidone (hereinafter referred to as N for simplicity
(referred to as MP) to produce a ruffinate phase and an extract phase, separating the solvent from the ruffinate phase, and recycling the separated solvent to a dual purpose zone. . More particularly, the present invention provides a method for simultaneously solvent deasphalting and extracting petroleum containing asphaltic components and aromatic components, in which said petroleum is treated in a combined zone with: (a) at least one liquid; The desired oil, most of the hydrocarbon solvent and producing a roughinate phase containing some NMP and an extract phase, heating the solvent-containing roughinate and then brushing off most of the hydrocarbon solvent, and then cooling the hydrocarbon solvent-depleted roughinate to form the M2 and roughinate. Separating NMP from the oil by creating lump-liquid immiscibility with the oil;
and to a method consisting of recycling NMP into a dual-use band. It is well known to those skilled in the art to deasphalt asphalt-containing mineral oils with light or low molecular weight hydrocarbons such as propane, particularly in the production of lubricating oils from residual oils and crude oils.

In this method, an oil feedstock or stream containing asphaltic components is mixed with a light hydrocarbon, such as liquid propane, under conditions of temperature and pressure, thereby precipitating the asphaltic components. After separation of the asphaltic components from the deasphalted oil, each stream is treated in a well-known manner to recover the solvent. Additionally, certain oil feedstocks, particularly distillate lube oil feedstocks, can be used to separate relatively aromatic and polar components with low VI from relatively paraffinic components with high I. Treatment with suitable solvents is also well known to those skilled in the art. Examples of conventional extraction solvents useful in such methods include solvents such as phenol, various resols, furfural, sulfur dioxide, and, more recently, NMP with a small amount of water. In extraction operations such as contact with solvents such as In the actual stage, the oil to be treated is usually introduced at one end of the countercurrent treatment zone and the solvent or solvent mixture at the other end. The solvent and oil flow countercurrently under temperature and pressure conditions to form a ruffinate phase and an extract phase. A solvent-rich extract phase is withdrawn from one end of the countercurrent processing zone, containing a large proportion of relatively low V aromatic and polar components, as opposed to high VI paraffins. The oily or solvent-poor roughinate phase containing system components is removed from the other end of the processing zone. Each stream is then processed in a known manner to separate and recover the solvent. Other methods well known to those skilled in the art include the Duo-Sol process (DuO-SOI) for extracting high I, light colored, low carbon residual lube base stocks from residual or distillate lube feedstocks.
PrOcess).

This is a simultaneous deasphalt extraction process that derives its name from the use of two solvents. The solvents used are propane and a mixture of cresol and phenol. Propane selectively dissolves relatively high VI paraffinic lubricating base stocks from the feedstock, whereas cresol and phenol selectively dissolve asphalt, undesirable aromatics, polar materials, and colors as extracts from it. dissolve in The combination lubrication process disclosed in U.S. Pat. No. 3,291,718 incorporates a duosol extraction deasphalting operation in which a suitable feedstock, such as an aromatic residue, is placed in the center of the deasphalting extraction zone. whereas propane is fed at the bottom and phenol is fed at the top to form a deasphalt troughinate phase (from which a high VI lubricating oil is made) which is relatively low in aromatics and polar substances. generate. Recently, M-containers have been proposed as useful for de-asphalting and for simultaneous de-asphalting solvent purification. In U.S. Pat. No. 3,779,895, for the deasphalting of an aqueous dispersion of heavy petroleum fractions pretreated with high temperature steam, NMP ranges from -3 to
Low molecular weight paraffin containing 10 carbon atoms, NM
It has been proposed as one of a number of groups of solvents consisting of P and furfural. Finally, U.S. Patent No. 3,779
, 896 and 3,816,295, lubricating oils are prepared by using either furfural or NMP as a deasphaltizing and refining solvent in a resid-containing petroleum fraction and most preferably with a large thermal stability. Due to its properties and solvent capacity, it is produced by simultaneous de-asphalto solvent purification using NMP. Later, according to the prior art, it was proposed to use NMP in combination with light hydrocarbon solvents to simultaneously deasphalt and extract asphalt-containing oils. However, in addition, the roughinate produced by this method contains an excess amount of NIl! 4P
This provides a method for separating NMP from the ruffinate phase and recycling the NMP to the combined deasphalt extraction zone to make the combined process economically viable. It means that you had to find out. The present invention provides a method for simultaneously solvent deasphalting and extracting a mineral oil feedstock containing an asphaltic component and an aromatic component, comprising: ．． NMP containing V% water
(b) in contact with a solvent consisting of a mixture of one or more liquid, low molecular weight hydrocarbons of C2 to ClO carbon atoms;
forming two layers or phases: an upper raffinate phase containing the desired oil, most of the hydrocarbon solvent and some NMP, and a lower extract layer or phase containing the asphalt and most of the NMP; (2) removing the raffinate from the dual purpose zone and heating it to a temperature within the range of 180-450°F; (3) sending the hot raffinate from step (2) to a flash zone from which the majority of the hydrocarbon solvent is vaporized; and (4) removing said hydrocarbon solvent-depleted roughinate as sufficient to cause mass-liquid immiscibility between the ruffinate oil and the NMP. Cooling to as low a temperature as possible, thereby creating two phases or layers: a light phase rich in oil and containing most of the NMP and some oil present in the roughinate produced in step (1) above. (5) separating an oil-rich phase from an NMP-rich phase; and (6) sending said NMP-rich phase to said combined zone. It's a method.

The oil-rich light phase containing the desired ruffinate oil can then be further processed. The deasphalt extraction solvent used in the present invention comprises (a) hydrocarbons ranging from ethane or ethylene to decane and mixtures thereof ranging from C2 to ClO carbon atoms and (b) from 0 to 5L. Consisting of a liquid mixture of NMP containing V% water.

It is possible to have small amounts of other hydrocarbons present in the solvent without materially affecting the overall efficiency of the process.
Preferably the hydrocarbons consist of 3 carbon atom hydrocarbons such as low molecular weight paraffins containing 3 to 1 carbon atoms and mixtures thereof and most preferably propane. Particularly preferred solvents are based on M2 content of about 0
~2L. A mixture of propane and NMP containing V% water. The volume ratio of light low molecular weight hydrocarbon to NMP is:
In the range of 211-6 based on hydrocarbon and oil feedstock. Non-limiting examples include (a)1
(b) a mixture of NMP containing LV% water and (b) propane, such that the volume ratio of propane to NMP is 2.5 ha. The amount of deasphaltized extraction solvent used and the operating temperature and pressure used will depend on the particular solvent composition used to obtain a deasphalted extracted oil with the desired viscosity, aromatics content, and Conradson residual carbon content. must be controlled to suit the product and oil feedstock being processed. Generally speaking, the amount of light hydrocarbon used will be about 50 to 800 L. of the feedstock.
V%, whereas M2 is in the range of 50 to 400 L% of the feedstock in the presence or absence of water. More preferably, the light hydrocarbon comprises 4 of the feedstock.
00~600L, ■% and NMP is 1
50-2501, V%. 4 “Middle East (
Particularly preferred solvents for the feedstock include propane as the light hydrocarbon solvent and NMP with V% water as the polar solvent.

Thus, ゜“Arab Light”
When using 600'F+ residual oil as feedstock,
Propane throughput is preferably 500LV% and N
The MP processing amount is approximately 200L, V%. The contacting step is conducted at a temperature greater than about 50 DEG F. but below the temperature of complete miscibility of the feedstock in the solvent and below the critical temperature of the light hydrocarbon. This temperature is approximately 10~
About 600PS1g, preferably about 180 to about 500pSi
Generally, the pressure is within the range of about 70 to 350 degrees Fahrenheit, preferably about 120 to about 190 degrees Fahrenheit. Ru. The exact conditions required will, of course, depend on the type of solvent used and the solvent/feed ratio. Additionally, although not absolutely necessary for the operation of the present invention, the feedstock may be introduced near the middle of the dual-purpose contacting zone (i.e., the deasphalt extraction tower), and the light hydrocarbons may be introduced into the zone. Preferably, the NMP with or without water is introduced at the bottom and the NMP with or without water is introduced at the top. This results in a countercurrent flow of solvent and oil, which under appropriate temperature and pressure conditions undergoes phase separation into two liquid layers or phases, i.e., the hydrocarbon solvent along with the desired oil. and a lower layer or extract containing the majority of NMP and water together with asphatenes and most of the aromatic and polar components of the oil. The raffinate drawn from the top of the de-asphalt extraction zone contains the desired lubricating oil along with a large portion of the hydrocarbon solvent and an appreciable amount of NMP, and its M2 makes the process practical and It must then be removed and recycled to the dual-use band to be economically worthwhile.

Thus, the roughinate may contain as much as 65% by weight NMP. This roughinate is heated and sent to a flash zone where most of the light hydrocarbon solvents contained are brushed away as vapor. Thus, the raffinate is heated from a temperature within the range of about 180 to 450 degrees Fahrenheit, and the flash zone is about 4
Operates at pressures from 0 to 500 pSig. The light hydrocarbon solvent-depleted raffinate liquid produced in the flash zone contains less than about 25% by weight light hydrocarbon solvent, preferably less than about 15% by weight, with the remainder being NMP and It's oil. The hydrocarbon solvent-depleted roughinate liquid is then cooled to a temperature low enough to create mass-liquid immiscibility between the NMP-rich phase and the lighter phase containing the desired lubricant. be done. The temperature at which the hydrocarbon solvent-depleted raffinate liquid is cooled is generally in the range of about 80-2500F, and the cooled liquid is then passed to a separation zone;
There, two phases may separate and exist in both the light upper layer or oil-rich phase containing the majority of the lubricating oil and the raffinate and hydrocarbon solvent-depleted raffinate removed from the combined zone. This results in a heavy phase or lower layer containing most of the NMP. Generally, the light phase contains at least 50% oil and no more than 35% NMP, and the lower phase contains at least 70% NMP with the balance being small amounts of oil and light hydrocarbon solvents. The heavy phase, mostly NMP, is then recycled directly back to the dual purpose zone as a solvent. The method of the present invention includes:
All mineral oil feedstocks containing both asphaltenes and aromatics can be used to simultaneously deasphaltize.

Suitable feedstocks include from about 500 to about 1,100'F.
Examples include crude oils, atmospheric distillation residues and vacuum distillation residues having an initial boiling point (at atmospheric pressure) of . Thus, atmospheric distillation residues having boiling points greater than about 700'F and about 1,050'
Both vacuum distillation residues having a boiling point higher than F can be treated by the process of the invention. The feedstock used for this process is Arabian, Ligil, etc.
t) or Heavy crude oil, Kuwaiti (Kuw)
ait), Venezuelan and Western Canadian crude oils such as Cold Lake
e) and Athabasca, Bitumen, Bachaquer O, etc. Particularly suitable feedstocks include atmospheric and vacuum distillation residues from AramcO, Safaniya, and Vaquero, and synthetic feedstocks derived from the Athabasca tar sands. The contact between the feedstock and the deasphalting and extraction solvent is carried out at 1
It can be carried out in two or more mixer-settler units or in one or more countercurrent liquid-liquid contacting columns. In the latter case, the feedstock enters the column near the middle, the light hydrocarbon solvent enters near the bottom and M2 with or without water enters near the top. The column is equipped with internal components such as a backing, angled and staggered rows of iron rods, rotating disc contactors, liquid-liquid contact trays, etc. to provide sufficient contact between the solvent and the feedstock. It will be done. The asphaltic or extract phase passes through the column countercurrently to the majority of the upward flow of propane and exits the bottom of the column. The raffinate phase containing the desired deasphalted oil passes upwardly through the column countercurrently to most of the downstream NMP and exits at the top of the column. Referring in detail to the accompanying drawings, an oily feedstock containing asphalt and aromatics is fed via line 10 to the central portion of dual use zone 12.

The top of zone 12 is connected to O-? via lines 14 and 16. ■%
An NMP solvent containing water of
C2 to Cl are supplied to the bottom of the tank through a pipe 18. A liquid hydrocarbon of carbon atoms is introduced. The extract, which contains the bulk of the NMP, asphalt and aromatic components of the oily feedstock, exits the bottom of zone 12 via line 20. The ruffinate containing the desired lubricating oil with a majority of hydrocarbons of C2 to ClO carbon atoms and some NMP is heated at a temperature of about 120 to 190 degrees Fahrenheit and about 180 to 500 degrees Fahrenheit.
It exits the top of zone 12 via line 22 at a pressure of pSig and passes through heat exchanger 24 where it is
'F and then passed via line 26 to flash zone 28. Flash band 28 is approximately 40-5
00 PSig, and most of the C2 to ClO carbon atom hydrocarbons present in the roughinate are brushed in this zone and exit as vapor via line 30, which is then replaced by C2 to ClO carbon atoms. hydrocarbon solvents result in reduced roughinate formation. The hydrocarbon solvent-depleted roughinate exits zone 28 via line 32 and is passed through heat exchanger 34 where it is
It is cooled to a temperature of ~250'F, which causes mass-liquid immiscibility between the raffinate oil and the NMP;
Two phases are thus formed: a light oil-rich phase containing the desired roughinate lubricant and a heavy phase that is mostly NMP. After passing through the cooler 34, the two-phase liquid enters the settling zone 3
8, where the light oil-rich phase separates from the heavy NMP-rich phase to produce an upper oil-rich layer and a lower NMP-rich layer. The oil-rich upper layer flows from zone 38 to line 40.
for solvent recovery and/or further processing, whereas the NMP-rich phase is removed from zone 38 and recycled directly to zone 12 via lines 42 and 16. The invention will now be understood more clearly by reference to the Examples.

Example 1 This example is a computer simulation of the NMP recovery and recirculation portion of the accompanying drawings.

With reference to the drawings, a ruffinate having the composition shown in Table 1 is passed through a heat exchanger 24 at a temperature of 170°F and a pressure of 500 PSig where it is heated to 325°F; and to a flash zone 28 operating at a pressure of 275 pSig. band 28
In this, most of the propane is brushed as steam from the roughinate to produce a propane-depleted la finate. Propane vapor is removed via line 30, cooled and recycled to zone 12 by means not shown. The vapor flow and composition of the propane-depleted ruffinate are shown in Table 1. The propane-depleted raffinate (approximately 44.5% by weight of the raffinate entering zone 28 via line 26) is then sent via line 32 to heat exchanger 34 where it is cooled to a temperature of 150°F. It is then sent via line 36 to settling zone 38. Cooling the propane-depleted raffinate to 150'F produces two immiscible liquid phases, an oil-rich phase and an NMP-rich phase having the compositions shown in Table 2. The amounts of oil-rich and NMP-rich phases formed were 66.2 and 33.2% for the propane-depleted ruffinate, respectively.
Heel volume %. The amounts of these phases formed and their compositions are according to R. H. Perry. 4℃Hemi
A ternary diagram for raffinate oil, propane and NMP was obtained from the practice of standard techniques as described in calEngineerlsHandbOOk'5, 5th edition, page 15-1.

The raffinate oil used was purified according to the invention by pilot plant treatment with propane and NMP.
The sample was produced from rabLight'680'F+residue. In the settling zone 38, the oil-rich phase containing the desired roughinate oil separates from the NMP-rich phase and, being lighter, rises to the top as a layer and flows through line 4.
0 and sent for solvent recovery and/or further processing. The NMP-rich phase settles as a lower layer, is removed via line 42 and recycled to zone 12 via lines 42 and 16. Thus, 51.74% of the NMP solvent in Raffinate 1 produced in Zone 12 is recycled to the de-asphalto-extraction zone without the need to separate it from the Raffinate by vaporization or distillation operations.

EXAMPLE 2 In this example, a pilot plant experiment was carried out on an Arab Light V atmospheric distillation resid having an initial boiling point of 750'F+ and an API gravity of 16.

This feedstock is fed to the center of a solvent deasphalt extraction column, propane is fed to the bottom of the column, and propane is fed to the bottom of the column and propane is selected from the group consisting essentially of phenol, NMP or M2 containing 2L, V% water. A polar solvent was fed to the top of the column. The operating conditions in the column are as shown in Table 3.
The pressure was 0PS1g and the temperature was about 131-167F. This produced a deasphalted oil ruffinate and an asphaltic extract, with the raffinate being removed from the top of the column and the extract being removed from the bottom. The solvent was removed from the resulting ruffinate and asphaltic extract. The characteristics of the recovered solvent-free deasphalted oil and asphalt are
Shown in the table. These results demonstrate that not only is less solvent required when using the 7° pan/NMP solvent, but the yield of deasphalted oil is surprisingly higher than that obtained using phenol; This shows that the asphalt produced was hard. Therefore, valuable heavy lubricating oil was not lost to the asphalt as in the case of propane/phenol. Example 3 In this experiment, the feedstock was 6'LiglltAr'Ab processed batchwise using NMP and propane/NMP as solvent for simultaneous de-asphalto extraction.
It was 680°F + residual oil from atmospheric distillation.

The feedstock and solvent-free deasphalting characteristics are listed in Table 4. 3 of each 200LV% (based on feedstock) for a total throughput of 600L% NMP
NMP deasphalt extraction was performed using two treatments.

Propane/Nr! The deasphalt extraction performed with 4P was 550 L. based on the feedstock. Only one treatment with a total solvent throughput of V% (propane + NMP) was used. The data in Table 4 shows that when using propane/NMP, even if the total solvent throughput and number of treatments are at least
It shows that high quality deasphalted oil was obtained in high yield compared to the use of NMP alone.

Example 4 This example illustrates the utility of the present invention for removing aromatics from oils.

In this experiment, propane and propane/Nr! 4P (which NMP contains 21,V% H2O) was used to deasphalt the ArabLightV 750F+ resid and simultaneously solvent extract it. The properties of the feedstock and solvent-free deasphalted extracted oil are listed in Table 5. Data are based on feedstock propane/(NMP+
shows that simultaneous deasphalting and extraction with a 2L, V% H2O) solvent produced a raffinate oil with an aromatic content of 3% by weight compared to the aromatic content of 4% by weight in the feedstock. .

[Brief explanation of the drawing]

The accompanying drawing is a flow diagram of a preferred embodiment of the present invention, and the reference numerals representing the main parts are as follows. 12: Asphalt removal/extraction zone, 24, 34: Heat exchanger, 28: Flashing zone, 38: Sedimentation zone.

Claims (1)

Claims: 1. A method for simultaneously solvent deasphalting and extracting a mineral oil feedstock containing an asphaltic component and an aromatic component, comprising: (a) treating said feedstock in a combined deasphalting-extraction zone; NMP containing 0-5LV% water and (ii) one or more liquids with low molecular weight C_2~
In contact with a solvent consisting of a mixture with a hydrocarbon of C_1_0 carbon atoms, two layers or phases are formed: an upper raffinate phase containing the desired oil, a majority of the hydrocarbon solvent and some NMP, and a majority of asphalt and NMP. (b) extracting the roughinate from the dual-purpose zone and heating it to 180~
(c) step (b);
(d) directing the hot raffinate from the .
The hydrocarbon solvent-depleted raffinate is cooled to a temperature low enough to create mass-liquid immiscibility between the raffinate oil and NMP, thereby forming two phases or layers, i.e. producing an oil-rich light phase and an NMP-rich heavy phase containing most of the NMP and some oil present in the roughinate produced in step (a) above; and (e) an NMP-rich phase. separating an oil-rich phase from the NMP-rich phase, and (f) sending said NMP-rich phase to said dual-purpose zone;
A method consisting of each step. 2. The contacting step is carried out at a temperature of about 70 to about 350 degrees Fahrenheit and about 100 degrees Fahrenheit.
2. The method of claim 1, comprising operating at a pressure of ~600 psig. 3 The contact step is about 50-800LV% for hydrocarbons.
3. The method of claim 1 or 2, wherein NMP is carried out at a solvent to oil ratio within the range of about 50-400 LV%. 4. A method according to any one of claims 1 to 3, wherein the mineral oil is a petroleum having an initial boiling point of about 500 to about 1,050 degrees Fahrenheit at normal pressure. 5 Approximately 180 before sending roughinate to flash band
5. A method as claimed in any one of claims 1 to 4, comprising heating to a temperature of -450°F. 6. The method of any of claims 1-5, wherein the flash zone operates at a temperature of about 180 to 450 degrees Fahrenheit and a pressure of about 40 to 500 psig. 7. Claims 1-7 comprising cooling the hydrocarbon solvent-depleted roughinate produced in the flash zone to a temperature below about 250° F. before passing it to the settling zone.
The method described in any of Section 6. 8. The method of any one of claims 1-7, wherein the oil is a residual oil having an initial boiling point within the range of about 700°F+ to about 1,100°F+ at normal pressure. 9. The method according to any one of claims 1 to 8, wherein the hydrocarbon solvent is propane. 10. A method according to any of claims 1 to 9, wherein the NMP contains about 0-2 LV% water.