JPS6120600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for alkylating waxes to liquid substances whose boiling points are primarily within the lubricating oil range.
More particularly, the present invention provides a method for treating normally solid waxy hydrocarbons and low molecular weight olefins such as ethylene at elevated temperatures and pressures with a catalyst containing one or more secondary alcohols of _C2 to _C5 carbon atoms. The present invention relates to a process for alkylating waxy hydrocarbons by contacting them into liquid hydrocarbons with boiling points primarily within the lubricating oil range.

It is well known in the art to dewax mineral oils containing wax, particularly lubricating oil fractions of petroleum oils, to remove at least a portion of the wax to obtain a dewaxed oil with a reduced pour point. For many years, this wax has been removed by various solvent dewaxing methods. In the solvent dewaxing method,
The temperature of the wax-containing oil is lowered sufficiently to precipitate the wax as solid crystals of wax. At the same time, solvents are added to the wax-containing oil to improve its flowability and reduce its viscosity, so that various filtration methods can be used to separate the wax from the dewaxed oil. Generally, the wax supertemperature should be about 10 or 20° (5.6 or 11.1°C) lower than the pour point of the dewaxed oil due to a phenomenon known as flow-supertemperature conversion.

Recently, certain zeolite-type materials, such as hydrogen-type mordenite (commonly referred to in the art as decationized or H-mordenite), have been used for catalytic dewaxing of petroleum fractions, such as lubricating oil fractions. and certain ZSM type crystalline aluminosilicates were found to be effective. Thus, U.S. Pat. No. 3,516,925 and U.S. Pat. No. 3,539,498 disclose the catalytic dewaxing of lubricating oil fractions with hydrogen-form mordenite, whereas U.S. Pat. No. 3,700,585 ZSM-5 and ZSM for catalytic dewaxing of hydrocarbon fractions
Discloses the use of type-8 crystalline aluminosilicate. These catalytic dewaxing processes are particularly useful for producing particularly low pour point lubricating oils required for certain specialty applications such as transformer oils, refrigeration oils, and aviation turbine oils. However, the disadvantages associated with these catalytic dewaxing methods are that they consume significant amounts of hydrogen (which must be added to the reaction zone) and that the wax is heated at room temperature and atmospheric pressure. Mention is made of the fact that it is usually decomposed into gaseous low molecular weight fractions. These processes thus consume significant amounts of hydrogen and convert wax to relatively worthless gaseous by-products. Furthermore, these catalysts are susceptible to poisoning and the catalytically dewaxed oil is substantially lower than that of the feedstock oil. It would be valuable if it were possible to catalytically dewax a lubricating oil fraction and simultaneously convert the wax to a useful lubricating oil product. Additionally, it would be beneficial to be able to convert petroleum waxes into generally useful lubricating oil products.

One such method is by an alkylation reaction consisting of reacting the wax with a low molecular weight olefin such as ethylene in the presence of a halogen-containing catalyst such as chloroform to produce useful lubricating oil products from the wax. U.S. Patent No. 1 for a process for producing lubricating oil from normally solid wax-containing hydrocarbons.
Disclosed in No. 2741649. However, the introduction of halogens into the process (even though these halogens are present in halogen-containing hydrocarbons such as chloroform) can lead to severe corrosion problems in refinery process equipment, and if residual halogen-containing materials are created. If present in materials, this can cause severe corrosion problems in use. Therefore, methods using such halogen-containing catalysts are undesirable from both process and product quality points of view.

Isomerization using noble metal catalysts has been found to be somewhat effective in refined waxes, but not in waxes in the presence of oil. Thus providing a catalytic dewaxing process with the requisite selectivity for converting wax molecules to lubricating oil components in the presence of oil molecules without generating or introducing corrosive substances into either the process equipment or the product. It is desirable to do so.

Thus, in the present invention, wax and low molecular weight olefins are contacted with a catalyst containing one or more C ₂ -C ₅ carbon atom secondary alcohols at elevated temperatures and pressures to relatively reduce a substantial portion of the wax. A process has now been discovered for alkylating normally solid waxy hydrocarbons to liquid hydrocarbons with boiling points within the range of conventional lube oils, which consists of converting them to high, low pour point lube oil components. Additionally, the process of the present invention has been found to be useful for alkylating waxes to lubricating oil components even when the wax is in the presence of lubricating oil fractions. Thus, the present invention is also useful for at least partially dewaxing a lubricating oil fraction, thereby lowering its pour point.

The waxy hydrocarbon to be reacted with the olefin may be any waxy hydrocarbon that is solid at room temperature and derived from various petroleum distillates, natural crude oils, or synthetic lubricating oils. Included in this category are various petroleum distillates derived from tar sands, coal, shale oil and the like, paraffin waxes, microcrystalline waxes, petrolatum and slut waxes obtained from natural and synthetic crude oils. It will be done. When reducing the wax content of a lubricating oil fraction using the method of the present invention, the lubricating oil fraction is primarily paraffinic;
and is understood to have a boiling point within a wide range of about 500-1300° (260-704°C), preferably between about 550-1200° (288-649°C). These lubricating oil fractions include any crude oil derived from Aramco, Kuwait, Panhandle, Louisiana, Alberta, North Sea, etc., as well as crude oil derived from Athabas Qatar Sands, Petroleum, Sierra Oil and the like. It can be produced from paraffinic crude oil.

Olefin reactants useful in this invention are monoolefins containing 2 to 10 carbon atoms in the molecule. Ethylene, propylene, butene
2 in molecules such as 1, butene-2 and isobutene.
Preference is given to using normally gaseous monoolefins containing ~5 carbon atoms. These olefins can be used either singly or as a mixture. Particularly preferred is ethylene.
Other examples of olefin reactants that can be used either alone or in combination with other olefins in the process of the invention include pentene-1, pentene-2, 2-methylbutene-1, cyclopentene, cyclohexene, 3 -methylbutene-1,
2-methylbutene-2, hexene-1, 3-methylpentene-2, heptene-1, octene-1,
Octene-2, decene-1 and decene-2 are mentioned.

Catalysts useful in this invention include low molecular weight secondary alcohols having 3 to 5 carbon atoms in the molecule, such as isopropanol, sec-butanol, 2-pentanol, 3-pentanol, and the like.

In carrying out the alkylation reaction of the present invention between a wax and an olefin, the ratio of olefin to wax in the reaction zone should be
About 1 to 100 olefins per mole, preferably 2 to 10
It may be within the molar range. used in reaction zone
The amount of secondary alcohol catalyst of _C2 - _C5 carbon atoms is
It ranges from about 0.1 to 10% and preferably from about 0.5 to 5% by weight of the wax in the reaction zone. It will, of course, be understood that the amount of catalyst used in the reaction zone will vary depending in part on the nature of the reactants as well as the particular alcohol or alcohol mixture used as a catalyst. Suitable alkylation reaction conditions include approximately 100-5000 psig (7-352 Kg/
^cm2 gauge) preferably 200-1000 psig (14-70
Kg/cm ² gauge) more preferably 700 to 900 psig (48
300 at pressures within the range of ~63Kg/ ^cm2 gauge)
~1000psig (149~538℃) preferably 450~850〓
(232~454℃) More preferably 600~750℃〓(316
~399°C). Although these pressures are usually provided in large part by the gaseous olefin reactants in the reaction zone, nitrogen, carbon dioxide, hydrogen, methane, ethane or other gases that are inert to the feedstock, products and reaction are used. can be used to provide a portion of the pressure in the reaction zone. The reaction time or residence time in the reactor is between about 1 and 30 hours, preferably between 15 and 20 hours.

The alkylation reaction of the present invention is essentially a liquid phase reaction and therefore stirring of the reaction mixture may prove beneficial. The reaction can be carried out batchwise, semi-continuously or continuously in a manner well known to those skilled in the art. However, it is important to avoid too high a concentration of olefin in the reaction zone at some point in order to minimize the disadvantageous competing reaction of olefin polymerization. Therefore, the amount of olefin charged to the reaction zone at any particular time is in the range of about 5 to 40%, preferably about 10 to 20%, by weight of the total olefin charged at any given time. . Therefore, if the reaction is carried out continuously, an elongated reaction zone is used and the olefin is added to the zone continuously in portions along its length as the reaction mixture progresses through the zone; This preferably avoids too high a concentration of olefin at any point within the reactor. For convenience, the reaction product will be referred to hereinafter as "alkylate oil." When the feedstock to the reaction zone is wax, the alkylated product from the reaction zone may be combined with small amounts (i.e., up to about 4 or 5% by weight) of various other materials such as unreacted wax, cracked wax, etc. 70-90 together
% wax-olefin alkylate lubricating oil and about 10-30% olefin polymer. Alkylate oils have pour points in the range of about 50-100°C (10-38°C) and close to that of the feedstock. Wax feedstocks typically produce alkylate oils with a molecular weight of about 130-150, whereas wax-containing oils produce alkylate oils with a molecular weight lower than that. The viscosity of the alkylate oil is generally about the same as that of the feedstock after stripping the product oil to remove light fractions whose boiling point is below the initial boiling point of the feedstock. It should be understood, of course, that the pour point of the lubricating oil fraction dewaxed by the method of the present invention will depend on the extent of the alkylation reaction as well as the pour point of the initial waxy feedstock.

In any event, the reaction product, together with any lubricating oil initially present in the feed, is first sent to a gas separation zone where gaseous components such as unreacted olefins are removed and passed into the reaction zone. recirculated;
These are then sent to a hydrorefining zone to remove residual unsaturations in the oil and purify it to obtain color and oxidative stability, after which it is subjected to storage or additional dewaxing operations. can be sent to. Alternatively, the reaction product can be further dewaxed prior to hydrorefining.

The following examples illustrate the operation of the present invention.

Example 1 In this example, the wax-containing feedstock oil has a boiling point of about 800-1050〓 (427-566 °C) at atmospheric pressure and a pour point of 130〓 (54 °C) and a viscosity of 64SUS at 210〓 (99 °C). It was a solvent-extracted lifenate from Western Canadian crude oil. 100 g of this oil and 2 g of isopropanol were placed in an autoclave equipped with a stirrer, and ethylene was added to it at 1200 psig (84 Kg/cm ^{2 ).}
gauge) was introduced at the initial pressure. autoclave
Set the temperature to 650〓(343℃), and increase this temperature to 5
After maintaining the ethylene pressure for 400 psig (28
Kg/cm ² gauge). The total liquid product recovered from the autoclave (116 parts by weight) was atmospherically distilled (topping) to remove light substances with a boiling point below 650〓 (343 °C), thus reducing the boiling point to 210〓 (99 °C).
The boiling point is 650〓 with a viscosity of 61.4SUS
(343° C.) 90 parts by weight of product were obtained. Both the feedstock and product were dewaxed with a ketone solvent to a pour point of 25°C (-4°C). The wax removed is then measured and shows that the feedstock oil
20% by weight, but only 4% by weight of the dewaxed product. Furthermore, the viscosity of the dewaxed oil is the viscosity of the raw material oil (at 210〓 (99℃)
Although it was only slightly lower than 64SUS),
The viscosity index was increased to 94 compared to 88 when the same stock was dewaxed with a ketone solvent.

Example 2 In this example, the alkylation reaction was carried out in one continuous tube reactor using the same feed oil and catalyst and feed oil to catalyst ratio as in Example 1. The space velocity of the feedstock oil through the reactor is 800 psig (56
675〓 under an ethylene pressure of Kg/cm ² gauge) and a flow rate of 0.34 standard ft ³ (0.0096 m ³ ) of ethylene per hour.
It was 0.04V/V/hr at a temperature of (357°C). 120 parts of liquid product per 100 parts of feedstock oil were removed from the reactor. Distillation or topping of this liquid product to remove materials with boiling points below 700°C (371°C) yielded 90 parts of alkylated product per 100 parts of feedstock oil. The product was hydrorefined with a nickel catalyst at a temperature of 500°C (260°C) to saturate the residual olefins remaining in the product. The hydrorefined product was prepared as in Example 1 at 25〓(-4
Solvent dewaxing to a pour point of
It was found that the amount was 4% by weight in proportion to .

Example 3 In this example, the wax-containing feedstock was a sludge wax obtained from an Arabian crude oil fraction with a boiling point of about 800-1000°C (427-538°C) at atmospheric pressure. 100 parts of this slurry wax containing 2% by weight of isopropanol was introduced into a stirred autoclave and heated to 1100 psig (77 Kg/cm ² gauge).
was contacted with ethylene at a pressure of . If the autoclave temperature is maintained at 670° (354°C) for 6 hours, the ethylene pressure will increase to approximately 200 psig (14
Kg/ ^cm2 gauge). 120 g of liquid product per 100 g of wax-containing feedstock was removed from the autoclave and topped at 700°C (371°C), yielding 94 g of alkylate oil per 100 g of waxy feedstock. Alkylate product is 0
When dewaxed with solvent at (-18℃), 210〓(99
Viscosity of 49SUS at ℃), viscosity index of 140 and
44 g of oil with a pour point of 10° (-12°C) was produced. Thus, 44 of the Slatswax feedstock
% was converted to useful alkylate oil.

Claims (1)

[Claims] 1. Normally solid waxy hydrocarbons and low molecular weight olefins at elevated temperature and pressure.
boiling waxy hydrocarbons by contacting them with a catalyst containing one or more _C2 to _C5 atom secondary alcohols to convert a substantial portion of the wax to a relatively high, low pour point lubricating oil component. A method of alkylation into liquid hydrocarbons, primarily within the lubricating oil range. 2. The method of claim 1, wherein the olefin is selected from the group consisting of _C2 to _C10 carbon atom olefins and mixtures thereof. 3. The method of claim 2, wherein the olefin is selected from the group consisting of olefins of _C2 to _C5 carbon atoms and mixtures thereof. 4. A process according to claim 1, which comprises obtaining waxy hydrocarbons from natural or synthetic petroleum. 5 Elevated temperature and pressure are respectively 300 ~
1000〓 (149~538℃) and 100~5000psig (7~
352 Kg/cm ² gauge). 6. The method of claim 1, wherein the ratio of catalyst to waxy hydrocarbon is within the range of 0.1 to 10% by weight of waxy hydrocarbon. 7 Elevated temperature and pressure 450-850 respectively
〓 (232~454℃) and 200~1000psig (14~70
6. The method according to claim 5, wherein the method is within the range of Kg/cm ² gauge). 8. The method of claim 1, wherein the amount of olefin is within the range of 2 to 10 moles of olefin per mole of wax. 9. The method of claim 1, wherein the amount of catalyst is in the range of 0.5 to 5% by weight of the wax. 10. Contacting a wax-containing lubricating oil feedstock and an olefin of _C2 to _C10 carbon atoms with a secondary alcohol catalyst of _C2 to _C5 carbon atoms at elevated temperature and pressure in a reaction zone to convert a portion of the wax into a lubricating oil. 1. A process for dewaxing a wax-containing lubricating oil feedstock comprising converting a wax-containing lubricating oil feedstock into a lubricating oil feedstock having a reduced wax content and a reduced pour point. 11 The elevated temperature and pressure in the reaction zone are 300-1000〓 (149-538℃) and 100-
11. The method of claim 10, wherein the pressure is within the range of 5000 psig (7-352 Kg/cm ^<2> gauge). 12 Claim 10 in which the olefin is a monoolefin having _C2 to _C5 carbon atoms
The method described in section. 13. The method according to claim 10, wherein the raw material is lubricating oil roughinate.