CN1031558A

CN1031558A - The method of catalytic dewaxing

Info

Publication number: CN1031558A
Application number: CN88106112A
Authority: CN
Inventors: 埃默森·鲍斯; 弗里茨·阿瑟·史密夫
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1987-08-20
Filing date: 1988-08-19
Publication date: 1989-03-08
Also published as: KR890003926A; JPS6470594A; EP0304251A1; AU2013488A

Abstract

The lube stock that is difficult to dewax, especially paraffinic hydrocarbons weight percentage surpass 25% high waxy feeds or the catalytic dewaxing process of high nitrogen-containing material is divided into two stages.The condition of fs relatively relaxes, in order that prolong the life of catalyst of the dewaxing cycle between the reactivate of order, temperature keeps constant in the dewaxing cycle.Temperature improves gradually in each cycle of the dewaxing of subordinate phase, in order to guarantee the target pour point of product.Recommend to use the zeolite of adhesive-free to be catalyzer.In order to reduce the harsh degree in each stage, can adopt a plurality of pre-dewaxing stages, the stage that dewaxes in advance carries out under constant temperature.Adopt present method can prolong the cycle lie of the catalyzer of difficult dewaxing raw material.

Description

The method of catalytic dewaxing

The present invention relates to produce the catalytic dewaxing process of low pour point lubricating oil.

Dormant oils lubricating oil is by a series of courses of processing, extracts from various crude oil materials.In general, the purpose of the used course of processing be for obtain having suitable boiling point, the lubricant base of viscosity, viscosity index (VI) and other characteristic.Base oil generally adopts in atmospheric tower and vacuum distillation tower distillation, isolate steps such as undesirable aromatic hydrocarbons, dewaxing and post-treatment produces from crude oil.Because aromatic hydrocarbons causes high viscosity and extremely low viscosity index, so, do not recommend to adopt crude asphaltic petroleum, because after a large amount of aromatic components in the crude asphaltic petroleum are removed, the yield that can be used as lube stock is too low.Paraffinic hydrocarbons and naphthenic base crude are preferably, and still, the aromatic hydrocarbons separating step that removes undesirable aromatic hydrocarbons is still indispensable.Distillate cut for lubricating oil, their so-called neutral oil plants, for example heavy neutral oil, light neutral oil or the like, aromatic hydrocarbons is wherein extracted out with solvent-extraction process, and used solvent has the solvent of furfural, N-N-methyl-2-2-pyrrolidone N-, phenol or other energy selective extraction aromatic component.When lube stock oil is residual oil, need to remove wherein bituminous matter earlier with the propane deasphalting method, then, extract residual aromatic hydrocarbons out with solvent-extraction process again, produce a kind of lubricating oil, so-called bright stock.In the above two kinds of cases, all need the step that dewaxes usually, have satisfied pour point and cloud point, make its paraffinic components that does not cause low solubility at low temperatures solidify or be precipitated out to guarantee lubricating oil.

The known process for dewaxing of refining of petroleum industry has multiple, and solvent dewaxing is exactly a kind of of industrial widespread use, and used solvent has the mixture or the liquid propane gas of methylethylketone (MEK), methylethylketone and toluene.Recently proposed to produce lubricant base with catalytic dewaxing process, these methods have the unexistent many advantages of conventional solvent dewaxing flow process.The catalytic dewaxing process of being recommended be used in the middle of distillate distillate as the process for dewaxing of heated oil, jet fuel and kerosene, wherein many open in documents and materials, Oil and Gas Journal for example, on January 6th, 1975,69-73 page or leaf and United States Patent (USP) RE28398,3956102,4100056.These class methods normally are cracked into the selective paraffin of positive structure and low side chain the product of lower molecular weight, then, with the distillatory method it are removed from the lubricant base of higher again.Having recommended to be used for the catalyzer of this purpose, generally is the zeolite with certain pore size, and its aperture allows straight chain waxy normal paraffin to enter with low branched paraffin individually or only, still, does not allow highly branched component and naphthenic hydrocarbon to enter.United States Patent (USP) 3700585(Re28398), 3894938,3933974,4176050,4181598,4222855,4259170,4229282,4251499,4343692 and 4247388 zeolites of having narrated the process for dewaxing that is used for this purpose, ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38 and synthetic ferrierite.United States Patent (USP) 4259174 has been reported the process for dewaxing that uses the synthesizing Si-Al saspachite.According to Refining Process Handboek in 1986 and in September, 1986 Hydrocarbon Processing report, the commercialization of these class methods belongs to flying horse oil company lubricating oil dewaxing method.These data have been quoted herein as proof to introduce the method for various catalytic dewaxings.

Above-mentioned catalytic dewaxing process realizes that with the wax shape paraffinic components in the shape slective cracking raw material life-span that prolongs catalyst cycle with these class methods generally can not meet difficulty, and is still, quite different in some cases.For example, when containing the pollutent of influential catalyst activity in the dewaxing charging, will meet difficulty, but, this difficulty can be resolved these contaminant removal with the method for zeolite preadsorption.United States Patent (USP) 4357232 discloses this class methods, and United States Patent (USP) 4358363 discloses the waxy fuel oil treatment process similar to it.United States Patent (USP) 3956102 discloses the aging curve of intermediate pore size dewaxing catalyst, United States Patent (USP) 3894938 is pointed out, when directly using the straight run raw material, the cycle lie of intermediate pore size dewaxing catalyst may be longer than and use through hydrotreated material.When using the raw material in the lubricating oil boiling range, this class and some other difficulty be more normal running into just, and this causes difficulty all for the popularization of lubricating oil catalytic dewaxing method.Why so far Here it is (end of the year 1986) has hundreds of cover solvent dewaxing units to turn round, and only has seven cover lubricating oil catalytic dewaxing units to move.

As mentioned above, this class catalytic dewaxing process is selected cracking to realize the content of wax component in the charging.This just means, when containing higher content of wax component in the charging, has only when catalyzer and must just can obtain the product of target pour point when turning round under the exacting terms.Because under severe condition, when a large amount of paraffinic hydrocarbons cracking, can cause accelerating the sedimentation velocity of burnt matter on catalyzer, thereby accelerate the speed of catalyst deactivation, at this moment, in order to obtain target pour point product, will improve service temperature excessively, this just causes the shortening of twice running period between the continuous catalyst reactivate, and that yes is unwelcome for this.Because helping non-selective thermo-cracking and catalytic pyrolysis in too high service temperature, so, in any cycle, should avoid.In some cases, it is short in the extreme that cycle lie can become, even be as short as several hours, and that yes is unacceptable fully industrial for this.

By carrying out reactivate or regeneration continually, can keep activity of such catalysts, but, this method allows in laboratory scale research, and is not suitable for suitability for industrialized production, because, need more relatively more expensive dewaxing catalyst, like this, when dewaxing is carried out, can reactivate or another batch catalyzer of regenerating.

Have found that, for wax content at least greater than 25%(weight) usually at least greater than 35%(weight) and high waxy feeds can be satisfactorily with the dewaxing of catalytic dewaxing method, can adopt different the realizing of sequence of operations condition along continuous dewaxing step.Be exactly, in a step or pre-dewaxing of a few step step, under relatively than the demulcent condition, raw material partly dewaxed, in last dewaxing step, under the exacting terms product is being taken off the target pour point relatively again.In pre-dewaxing reactor, the pour point of not pursuing material drops to target value, still, in each cycle of pre-dewaxing, promptly between twice catalyzer was along continuous reactivate, it is constant that the temperature in of reactor keeps, and makes its numerical value can reach predetermined operational cycle time.Like this, the step that dewaxes is in advance carried out under relatively low, constant reactor inlet temperature, and the dewaxing condition of final step provides the required dewaxing degree of depth, makes product reach the target pour point.In the end in dewaxing reactor, in dewaxing cycle, do not require the maintenance homo(io)thermism, but the same with traditional method, in dewaxing cycle, in catalyst deactivation, little by little heat up, make the pour point of material reach target value.As a rule, only need a pre-dewaxing reactor, still, for some high waxy feeds, may need two or more pre-dewaxing reactors, each reactor is all operated under low relatively temperature, and in each dewaxing cycle, it is constant relatively that the temperature in of reactor keeps.

This working method is maintained fixed productive rate or fixedly the flow process of the catalytic dewaxing of pour point is different with general.In traditional operation, in each dewaxing cycle, when catalyzer because in burnt and the raw material when contained heteroatomic pollution and inactivation, the temperature in of reactor, thereby the average bed temperature of catalyzer need be in the temperature in scope of broad raises gradually, and this scope is generally greater than 40 °F (about 22 ℃).

The synoptic diagram of two-stage catalytic dewaxing device is provided by individual accompanying drawing.

The process for dewaxing that the present invention proposes is applicable to usually by hydrocarbon feed and produces the low pour point product.The boiling point of charging is generally greater than the boiling range of petroleum naphtha, that is, its initial boiling point is minimum to be about 330 °F (about 165 ℃) or higher, as greater than 385 °F (about more than 195 ℃).So, present method can be used for producing accordingly, having the product of better flowability from the distilled oil of jet fuel, diesel-fuel, heated oil and oil fuel, but is specially adapted to produce from the lubricating oil distillate hydrocarbon raw material lubricating oil of low pour point.As everyone knows, in order to prevent lubricating oil volatilization too much in use, its initial boiling point generally needs greater than 650 °F (about 343 ℃).Owing in any catalytic pyrolysis process, always produce some lower boiling split products, should contain in the raw material that boiling point approximates or greater than the component of 343 ℃ (650), also contain the component that is lower than 343 ℃ (650), but, do not say self-evident, these components will be removed in separating step subsequently, thereby these light constituents can not enter in the final dewaxed product.But, total hope separated these light constituents, because these light constituents only can increase the weight of the load of reactor and influence the dewaxing efficiency of high boiling range raw material before the dewaxing step.It is distillate (neutral oil) or de-asphalting residual oil (bright stock) that the final boiling point of charging depends on used, and usually at 750 °F (about 400 ℃) to the scope more than 1050 (about 565 ℃).General do not wish to contain in the raw material Residual oil material that a large amount of high boiling points, un-extracted are crossed, because they generally all contain burnt matter parent more, that can shorten the dewaxing catalyst cycle lie, still, feed end point itself is not significant.

As embodiment, the neutral oil lube stock that present method is used neutral oil on the lenient side begins, promptly the viscosity 40 ℃ the time from 21 centistokes (100 Saybolt second) to 150 centistokes (700 Saybolt second) till the bright stock.The initial boiling point of typical light extremely medium neutral oil plant is less than 650 °F (about 343 ℃) (ASTM D-2887), final boiling point is less than 1000 °F (about 540 ℃), the boiling range of heavier neutral oil generally is 650 °～1050 °F (about 343～565 ℃, ASTM D-1160,10 mmhg), typical case's boiling range is 750～1050 °F (about 400-565 ℃, ASTM D-1160).The boiling point of resid feed is generally greater than 750 °F (about 400 ℃), and its 50% recovered temperature is greater than 850 (about 455 ℃) (ASTM D-1160-1,1 mmhg).

The lube oil feedstocks of present method processing belongs to high wax feed, and the content of its waxy component is at least in 25%(weight) more than, generally at least in 35%(weight) more than.Waxy component is meant the paraffinic hydrocarbons of normal paraffin and low side chain and the paraffinic hydrocarbons that contains a large amount of monomethyls.Content of wax shape component is so high to mean that charging has paraffin attribute and the characteristic that high pour point is arranged, and under many circumstances, is solid-state during room temperature.Typical this class charging is from highly paraffinic crude oil, as South East Asia crude oil.

The residue cut of pulling out after the low boiling component with normal pressure and underpressure distillation can be used to produce lubricating oil.Wherein, can be used to produce distilled oil or neutral lubricating oil greater than the cut of 343 ℃ (greater than 650), the residue of VACUUM TOWER BOTTOM after diasphaltene, can be used to produce bright lubricating oil.Aromatic hydrocarbons can adopt the method for solvent extraction to remove from distillate (neutrality) oil, and used solvent has phenol, furfural, N-methyl-pyrrolidone or other alternative to remove the material of aromatic hydrocarbons.Pitch in the vacuum distillation tower residue, available traditional diasphaltene technology removes, and method is a propane deasphalting preferably.Remove the material behind the pitch, can be further remove aromatic hydrocarbons with the method for traditional, identical with handling neutral oil solvent extraction.Also can replace solvent extraction that aromatic hydrocarbons is saturated and remove such as heteroatomss such as nitrogen, sulphur with the method for hydrotreatment.Hydrotreatment is generally under high pressure carried out, so that improve the saturation ratio of aromatic hydrocarbons as much as possible, as a rule, pressure should be greater than 1000 pounds/inch ²Gauge pressure (7000 kPas), more typical pressure needs greater than 2000 pounds/inch ²Gauge pressure (14000 kPas), for example 2500 pounds/inch ²Gauge pressure (17340 kPas).The temperature of hydrotreatment then should remain on lower numerical value, because the hydrogenation of aromatic hydrocarbons is a strong exothermic reaction, low temperature helps the carrying out of hydrogenation.Hydrogen-oil ratio decides with the degree of depth of requirement with arene engaging scraping according to the concentration of aromatic hydrocarbons in the charging, and generally (356 standard liters rise its numerical value greater than 2000 standard cubic feet per barrels ^-1), often (712 standard liters rise greater than 4000 standard cubic feet per barrels ^-1), (800 standard liters rise 4500 standard cubic feet per barrels according to appointment ^-1).Typical hydrogenation air speed is 0.25～5, and often the liquid hourly space velocity of using (LHSV) is 0.5～1 hour ^-1Traditional hydrogenation catalyst all can adopt, and comprises the single component or the multi-component hydrogenation component that are fixed on the solid porous carrier.Typical metal (hydrogenation) component is table the VI A family or a VIII A family metal in the period of element, as nickel, cobalt, molybdenum, tungsten or vanadium, when content of heteroatoms is very low in the not excessive charging, can use precious metal, as platinum and palladium.Because the purpose of hydrogenation is that aromatic hydrocarbons is saturated, is converted into naphthenic hydrocarbon and paraffinic hydrocarbons, rather than aromatic hydrocarbons is cracked into lower-molecular-weight component, so in order to limit cracking severity, the normal use hanged down acid active carrier.But, need limited open loop effect, slight acidity to be still hope in order to remove heteroatoms.

The highly paraffinic charging of available the inventive method processing is from North Sea crude oil, through 343～454 ℃ of (650～850) (demarcation) vacuum gas oils of hydrotreatment in typical embodiment, and its composition is listed in table 1:

Table 1

The North Sea of hydrotreatment (North Sea) raw material

The nominal boiling range, ℃ (°F) 345-455(650-850)

Api gravity, 31.0

Hydrogen, %(weight) 13.76

Sulphur, %(weight) 0.012

Nitrogen, ppm weighs 34

Pour point, ℃ (°F) 32(90)

Kinematic viscosity, 100 ℃ of millimeters ²Second ^-14.139

Paraffinic hydrocarbons/naphthenic hydrocarbon/aromatic hydrocarbons %(weight)

Paraffinic hydrocarbons 30

Naphthenic hydrocarbon 42

Aromatic hydrocarbons 28

The highly paraffinic raw material that is more suitable for this course of processing is that its composition is shown in following table 2 from the vacuum gas oil of 343 °-540 ℃ (650 °-1000) (nominals) of Mi Nasi (Minas) (Indonesia) crude oil preparation,

Table 2

Mi Nasi gas oil (Gas Oil)

The nominal boiling range, ℃ (°F) 345-540(650-1000)

Api gravity 33.0

Hydrogen, %(weight) 13.6

Sulphur, %(weight) 0.07

Nitrogen, ppm weighs 320

Alkali nitrogen, ppm weighs 160

Kang Shi carbon residue, 0.04

Form %(weight)

Paraffinic hydrocarbons, 60

Naphthenic hydrocarbon, 23

Aromatic hydrocarbons, 17

The bromine valency, 0.8

Kinematic viscosity, 100 ℃ of centistokes 4.18

Pour point, ℃ (°F) 46(115)

95% recovered temperature, ℃ (°F) 510(950)

By hydrotreatment, as shown in the table 2, the paraffinicity in the stock oil can improve, and that following table is listed is composition (the hydrotreatment Ni-Mo/Al of Mi Nasi (MiNas) vacuum gas oil of hydrotreatment ₂O ₃Hydrotreating catalyst, 5620 kPas (800 pounds/inch ²Gauge pressure) hydrogen, 377 °-390 ℃ (710 °-735 °F), liquid hourly space velocity is that 1,712 mark rises, and rises ^-1Hydrogen and raw material ratio).

Table 3

The Mi Nasi of hydrotreatment (Minas) raw material

The nominal boiling range, ℃ (°F) 345-510(650-950)

Api gravity, 38.2

Hydrogen, %(weight) 14.65

Sulphur, %(weight) 0.02

Nitrogen, ppm weighs 16

Pour point, ℃ (°F) 38(100)

100 ℃ of millimeters of kinematic viscosity ²Second ^-13.324

Paraffinic hydrocarbons/naphthenic hydrocarbon/aromatic hydrocarbons %(weight)

Paraffinic hydrocarbons 66

Naphthenic hydrocarbon 20

Aromatic hydrocarbons 14

Other raw material that is applicable to present method comprises Ke Er Cook (Iraq) the lube stock oil that is difficult to process, and for example light (100 Saybolt second) (SUS) and medium (400 Saybolt second) neutral oil plant and bright stock is listed in the table below in 4.

Table 4

Ke Er Cook (Kirkuk) stock oil

The light medium neutral oil bright stock of neutral oil

API 33.8 31.1 26.9

Proportion 0.8621 0.8702 0.8933

Pour point, ℃ (°F) 21(70) 46(115)＞49(＞120)

Flash-point, ℃ (°F) 184(363) 256(498) 316(601)

38 ℃ of kinematic viscosity, centistoke 8.657 27.36 N/A

100 ℃, centistoke 3.268 7.856 26.62

149 ℃, centistoke 1.551 3.253 8.610

Saybolt second (SUS)

38 ℃ (calculating) 77.9 245

99 ℃ (calculating) 37.3 52.6 131.2

Sulphur, %(weight) 0.75 0.51 1.18

Alkali nitrogen, ppm 35 34 135

Total nitrogen, ppm 46 27 151

Bromine valency 1.8 1.3 2.5

Neutralization value.Milligram potassium hydroxide/gram 0.22 0.15 0.18

Aniline point, ℃ (°F) 206

Hydrogen, %(weight) 13.89 14.02 13.37

Oil-contg, %(weight) 83.76 80.61 70.95

70 ℃ 1.4530 1.45876 1.47318 of refractive index

Boiling range, ℃ (°F)

Method D2887 D1160 D1160 D1160

（10mmHg）（10mmHg）（1mmHg）

Initial boiling point 283(541) 422(792 413(776 317(602)))

5 317（603） 362（652） 440（824） 519（967）

10 367（629） 353（667） 448（839） 534（993）

30 368（695） 377（710） 461（862） 564（1047）

50 393（740） 396（745） 474（885） 587（1088）

70 416（781） 413（776） 488（911）（597（1106）@60％）

90 440（825） 433（811） 512（954）

95 449（841） 440（824） 521（971）

Do 328(885) 447(836) 544(1011)

Remove after the aromatic hydrocarbons with solvent extraction or with the method for hydrotreatment, raw material adopts and carries out catalytic dewaxing as the dewaxing step of feature of the present invention.Catalytic dewaxing is under the dewaxing condition of high temperature and high pressure raw material to be contacted with catalyzer, removes to catalyst selectivity waxy component (normal paraffin, the paraffinic hydrocarbons of the paraffinic hydrocarbons, particularly monomethyl of low side chain) from raw material.Dewaxing generally is to carry out in the presence of hydrogen.When dewaxing catalyst contains the zeolite of intermediate pore size, during as ZSM-5, ZSM-11, ZSM-22, ZSM-23 or synthetic ferrierite (for example ZSM-35 or ZSM-38), removing of waxy component is by selecting the shape cracking.Be to remove waxy component when dewaxing catalyst contains beta-zeolite by isomerization.Use ZSM-5 to be used for the oil plant dewaxing and to be disclosed by selecting the shape cracking, for example United States Patent (USP) RE28398,3956102,3894938,4357232,4599162,4490242,4437976,4357232,4358363,4372839,4283271,4283272,4292166 and in various other publications comprises the catalyzer comment: Sci.Eng.28 185-264 page or leaf (1986).Relation between the zeolite structured characteristic and the zeolite structured and shape selective catalysis active relation that dewaxes was discussed in J.Catalysis 86 24-31 pages or leaves (1984).List these patents and other publication detailed content of these class methods for your guidance herein.Beta-zeolite is used for catalytic dewaxing and is disclosed in United States Patent (USP) 4,419, in 220 and 4,501,926.

When dewaxing catalyst or use the silicon oxide caking agent or during the zeolite catalyst of better use adhesive-free, the catalyst life of expection all is good.Have been found that when zeolite is the extrudate of adhesive-free, can reach unexpected low rate of ageing.This speed ratio is made the catalyzer of caking agent with aluminum oxide rate of ageing hangs down 5 to 10 times, and it is also obviously good to make the resulting catalyzer of caking agent than those with silicon oxide.Adhesive-free can improve the actual effectively quantity of component one of the reactor charge zeolite-dewaxing of intended size except reducing this advantage of rate of ageing.This has realized that effectively prolongation running period, its reason are that the zeolite of greater amt is reduced to the deactivation component that can hold more semi-invariants before the level of not allowing, (coke, catalyzer poison) in activity.At present general dewaxing catalyst is typically and has used 35%(weight) caking agent, thereby compare with this class catalyzer, the quantity of the zeolite in the existing reactor of can packing into has approximately improved half (100/65).Expect that also can increase accordingly its cycle time, but have been found that in the recovery of twice order and handle (being typically hydrogenation resurrection or oxidation regeneration), between the prolongation degree of dewaxing cycle be greater than this numerical value, this mainly is the result owing to alumina-free.Though the aluminum oxide caking agent that catalyzer uses is no acidic in nature, therefore do not participate in non-shape selective catalysis scission reaction, however, it contains deleterious effects really, and the not bonding zeolite catalyst of the application of the invention has just overcome this deleterious effects.Similarly, although known silicon oxide is better than aluminum oxide in some aspects, as United States Patent (USP) 4,013, in 732 narration like that, not bonding catalyzer of the present invention is better, and this is not easy to explain.

Used not bonding (or another kind of saying, self the is bonding) dewaxing catalyst of present method is suitable for extruding production with the method for narration in the United States Patent (USP) 4,582,815.When introducing this method and extruded product thereof with reference to this patent.Here the method for narration can enough common extrusion equipments be extruded the product of high crushing strength, so this method is specially adapted to produce catalyzer of the present invention, and this catalyzer is (because the content of the silicon oxide in zeolite and the caking agent) that is rich in silicon oxide.As United States Patent (USP) 4,582, described in 815, this catalyzer zeolite and water in 0.25 to 10(% weight) alkaline substance such as oxygen sodium oxide (calculating) by the alkali solid thing in the total solid matters in the presence of grind to form contain 25-75%(weight) solid prepare.United States Patent (USP) 4,582 has further been done to be described in detail in 815.

Used catalyzer is the particle of extrusion molding, and particle can be cylindric or Polygons, can be square as the cross section, rectangle, sexangle, or other any shape that is suitable for the method production of extrusion molding.Foliated particularly useful, as trilobal (Herba Medicaginis leaf) or quatrefoil, have minimal diffusion apart from being not more than the catalyzer of extruding that 0.02 inch (0.63 millimeter) preferably is not more than 0.02 inch (0.51 millimeter) in any case preferentially select for use.This class catalyzer is specially adapted to residual oil dewaxing, is at least 700 °F (370 ℃) as the initial boiling point of raw material, and the 50%(volume) boiling point be at least 900 °F (480 ℃).The wax that the catalyzer that uses this class to be shaped is used for removing the high boiling point raw material is at U.S. Patent application 938,214, and (application on December 5th, 1986) and apply for EU1 accordingly is described in 681,146, and the details of this method can be applied for reference to this.Use the quatrefoil catalyzer at United States Patent (USP) 4,016, narration is arranged in 067.The use of trilobe-shaped catalyst is at United States Patent (USP) 3,674, is described in 680.And (Polyobular) catalyzer of various other leafy shapes is at United States Patent (USP) 4,118, narration all arranged in 310,4,028,227,3,764,565 and 3,966,644.The use of hollow granules of catalyst is at United States Patent (USP) 4,441, is described in 990.Can be used for the detailed content of the catalyzer that this class of present method is shaped, can be with reference to these publications.

Do directly more bonding the showing with identical zeolite component self bond catalysts that dewaxes of raw material with typical heavy neutral oil and can reduce the initial stage rate of ageing of about 67-75% with self bonding catalyzer, therefore, the zeolite content difference in the catalyzer (being generally 65% to 100%) has constituted about 1/3rd to 1/2nd of the benefit that observes directly.When with weight hourly space velocity (WHSV) being basis when comparing, benefit has reduced a coefficient, and this is because self bonding catalyzer is compared the cause with big charge weight ratio with bonding catalyzer.Typically, when proportion approximately was 0.65 grams per milliliter (self is bonding) and 0.56 grams per milliliter (bonding), this coefficient approximately was 10%.But benefit is still noticeable, but can not be fully from considering that the related reaction path of dewaxing process is illustrated.The improvement degree of following embodiment 2 explanation rate of ageings surpassed since catalyzer from bonding to the improvement that the non-bonding caused variation that takes place with respect to the air speed degree of zeolite of variation can bring.

Can reasoning, when not existing when having active caking agent, agine mechaism is the obstruction at random of zeolite pore, before shape selective changes, even before activity descends rapidly, allow to hold a large amount of cokes, (do not reach the condition of the top temperature in cycle, but finally be inevitable).Can also reasoning, if the space velocity of dewaxing process greater than certain critical range, obstruction at random is not " at random ", tendency takes place to connect to be stopped up, near the surface rather than be deep into crystals.Under low spatial speed, by attemperation transformation efficiency is remained unchanged, can think, stop up material or their precursor redispersion and spread all over inside and outside the zeolite crystal.Equally, except stopping up, also can be too big and compound that can not enter zeolite is produced the small molecules product by molecule in the raw material, equilibrium distribution also easily takes place in these small molecules.

No matter be to use the zeolite of intermediate pore size such as ZSM-5 selects the shape cracking or by isomerization, may follow some cracking as using the β float stone, dewax when reacting, coke is deposited on the activity of such catalysts center can cause catalyzer inactivation gradually.Require the quantity of catalyst removal wax big more, coking and deactivation is fast more so, and with the high waxy feeds oil of narrating as the front, the problem of coking and deactivation is with especially severe.Catalyzer inactivation gradually is to adopt to improve its dewaxing service temperature gradually compensated in the dewaxing cycle process.Yet heating up has the boundary of a qualification, can improve temperature and can not quicken non-selective thermally splitting or catalytic cracking within boundary, and these reactions can reduce the oxidation stability of productive rates or quality, particularly lube product.Therefore on a certain temperature spot, want terminating operation, and handle catalyzer recovering its dewaxing activity and selectivity, or at high temperature bring back to life and handle, or recover the dewaxing ability of catalyzer with other technology commonly used with hydrogen.Hydrogen treat is brought back to life catalyzer and normally is used between the twice successive oxidation regeneration, oxygen-containing gas is burnt the coke on catalyzer gradually in oxidative regeneration process, preferably use the hydrogen regeneration techniques as much as possible, this is to reduce catalyst activity owing to oxidation regeneration can cause metal component sintering on catalyzer (particularly noble metal component).Oxidation regeneration makes reactivation of catalyst be actually in use the inverse process of the inactivation that takes place, and as purpose of the present invention, it is taken as be " reactivate ".

In the method for the invention, dewaxing is to carry out the operational condition that each reactor is had nothing in common with each other again in two reactors at least.Pre-dewaxing is that in a plurality of reactors carries out, and under relative demulcent condition, makes the coke that is deposited on the catalyzer remain on a low level.A common pre-dewaxing reactor can meet the demands, but extreme waxy feeds can be used two or more pre-dewaxing reactors, each is all being operated under the demulcent condition relatively, this can prolong the on-stream time of catalyzer, can not expect only just to meet the requirements of pour point with pre-dewaxing, the pre-dewaxing is to operate under the condition of long cycle life, and because the pour point of pre-dewaxed product is unessential, the temperature of pre-dewaxing is not improved owing to catalyst deactivation in operating process.Therefore in the operational cycle between reactivation of catalyst, pre-dewaxing is worked under constant substantially reactor inlet temperature, and keeps low relatively level.Temperature in changes lessly can make in the reactor average bed temperature variation low, and this helps compensating the variation of stock oil component or some compensation is done in catalyst aging.Yet important consideration is to make the harsh degree of first reactor and temperature maintain relative low and constant substantially level in dewaxing cycle.Temperature in can control among a small circle in change, for example temperature rise is no more than 40 °F (about 22 ℃) or is no more than 25 °F (about 14 ℃) in cycleoperation.

Appropriate temperature selects to depend on the time that wax content, target pour point and acceptable each cycle in the stock oil continues.To the raw material of higher wax content, promptly paraffinic hydrocarbons is 50%(weight at least), the Mi Nasi of foregoing hydrotreatment (Minas) vacuum gas oil, temperature should be lower.First section temperature generally is no more than about 400 ℃, and should be lower than 380 ℃ in many instances.To approximately containing the raw material of 50% paraffinic hydrocarbons more than 650 °F, the cycle lie that temperature reaches when being 370 ℃ surpasses one month in typical operation, and this is considered to satisfied.Simultaneously, when the stable operation temperature that the pour point of oil has dropped to device from 60 ℃ of stock oil is no more than 370 ℃ 25 ℃, these conditions show that cycle lie can further prolong.Use typical dewaxing catalyst, first section temperature is from 625 °F to 725 °F, in each cycle in case reach the temperature that marks after, temperature maintenance is constant in the cycle.It is typical using hydrogen pressure in the catalytic dewaxing process, because no matter select shape cracking or isomerization, do not need hydrogen from the chemical equilibrium dewaxing, only needs low hydrogen pressure, generally is lower than 1000 pounds/inch ², gauge pressure (7000 kPas), more general is that pressure is lower than 500 pounds/inch ², gauge pressure (3550 kPas).Space velocity generally be the 0.25-5 liquid hourly space velocity (hour ^-1) 0.5-2 liquid hourly space velocity more usually.Moreover because do not need hydrogen from the angle of chemical equilibrium, hydrogen-oil ratio can be relatively low, and (about 770 marks rise generally to be lower than 4000 standard cubic feet per barrels ^-1), normally (approximately 180-535 standard liter rises at the 1000-3000 standard cubic feet per barrel ^-1).

The function of pre-dewaxing step is to be issued to the part dewaxing at the constant again severity of mitigation, and makes the cycle stretch-out of catalyzer in this step.No matter this means it is to operate in a reactor or in a plurality of reactors, the product of pre-dewaxing section is the dewaxing of process part only, and can not satisfy the pour point requirement of target product.Final dewaxing also will carry out and make its pour point in specification limit, and the operational condition in this step should make dewaxing reach the required degree of depth.But because carried out pre-dewaxing, in second section dewaxing, even in order to reduce pour point and under higher severity, to operate, also can prolong the cycle lie of catalyzer to the level that requires.Catalyzer is because of the carbon distribution inactivation in cycleoperation, for the pour point of keeping product within specification limit, need to improve the temperature of final dewaxing section.Therefore the feature of second section dewaxing is to operate under the condition that heats up gradually between twice reactivate of catalyzer.Generally between 250 ℃ to 425 ℃, the cycle typically is 275 ℃ when beginning to the temperature in of last reactor approximately, and the temperature of end cycle typically reaches 400 ℃, and this depends on the degree of depth in pre-dewaxing stage and the requirement of target pour point.

Opposite with the pre-process for dewaxing of the low-temperature working situation that does not change temperature substantially, it is aging with compensate for catalyst to improve temperature gradually second section dewaxing, make its dewaxed product satisfy the pour point specification, second section temperature in will improve in a quite wide scope, bigger than first section inlet rangeability, therefore will improve at least 25 °F (about 14 ℃) to second section dewaxing reactor temperature in, be typically at least 40 °F (about 22 ℃).Under many circumstances, in the cycleoperation process, need tangible raising, for example from 500 °F (about 260 ℃) to about 670 °F (about 355 ℃), promptly improve 170 °F (about 95 ℃).Sometimes about 100 of minimum raising (about 55 ℃), more generally, the temperature of second section dewaxing reactor inlet improves 120 °F (about 67 ℃) at least.

Other condition and the conditional likelihood that uses in pre-dewaxing section, as hydrogen pressure, space velocity, and hydrogen cycle rate.

The intermediate section of lighting end is from can carrying out between two dewaxing stages, and it not only helps to remove inorganic heteroatoms and also can avoid increasing load to second reactor.

After second section dewaxing, dewaxed product can be carried out the alkene in the saturated lubricating oil boiling range scope that is produced by cracking of hydrotreatment and be made product stable, also will remove any residual coloring matter and saturated aromatic hydrocarbons.Hydrotreatment can be carried out under low relatively temperature and hydrogen pressure under relative demulcent condition.Temperature is lower than 300 ℃, and hydrogen pressure is lower than 1000 pounds/inch ²Gauge pressure (7000 kPas) is normally suitable, because promptly do not want undue cracking this moment, also need not too make aromatic hydrocarbons saturated.Space velocity is typically from 0.25 to 5,0.5 to 2 liquid hourly space velocity that the most frequently used is (hour ^-1).Because low relatively hydrogen consumption, the cycle rate of hydrogen are that (approximately 90-535 standard liter rises 500 to 3000 standard cubic feet per barrels ^-1), owing to cracking need be reduced to minimum, also take off owing to most of heteroatoms, the catalyzer of hydrotreatment contains low relatively acidity usually, can adopt noble metal hydrogenation component such as platinum or palladium, but other metal such as VI A and VIII A family can adopt also in base metal such as nickel, cobalt, tungsten etc. or the periodictable.Carrier can be used through steam treatment to low acid (α value) or exchange to the zeolite such as the ZSM-5 of the intermediate pore size of necessary acidity through basic metal.Also can use high oxidation silicon: alumina ratio, this carrier such as unformed aluminum oxide, silicon oxide or silica-alumina as the hydrotreating catalyst of low tart zeolite or common usefulness, but also should be low tart.

Embodiment 1-3

These embodiment illustrate and adopt single hop wax fractionation process production lube product.

Wax shape raw material is the heavy neutral oil of being produced through furfural treatment by a kind of China's Mainland crude oil, and its character is listed in table 5.

Table 5

Heavy neutral raffinate oil

Proportion (15/4 ℃) 0.8618

Color, ASTM L5.0

Pour point, °F (℃) 140(60.0)

Table 5(is continuous)

Heavy neutral raffinate oil

Flash-point, °F (℃) 532(278)

Kinematic viscosity (centistoke)

100℃ 10.0

150℃ 4.23

Total nitrogen (ppm is heavy) 160

Basic nitrogen (ppm is heavy) 140

Sulphur (ppm is heavy) 450

Arsenic (ppm is heavy) 0.10

Hydrogen (heavy %) 14.00

Carbon (heavy %) 85.98

Conradson carbon residue (heavy %) 0.17

Refractive index, 70 ℃ 1.4558

Oleaginousness (heavy %) 51.0

Aniline point (℃) 126.4

Distillation (D-1160)

Initial boiling point/5% 731/874

10/20 910/941

30/40 967/981

50/60 998/1019

70/80 1034/1065

Raw material carries out catalytic dewaxing containing on the ZSM-5 dewaxing catalyst of 1% nickel under three kinds of conditions that table 6 is listed.

Table 6

Heavy neutral oil dewaxing

Embodiment numbers 123

Hydrogen pressure, pound/inch ²Gauge pressure 400(2860) 2000(13890 2000(13890))

(kPa absolute)

Liquid hourly space velocity, hour ^-10.5 0.5 0.25

The hydrogen circulation, the standard foot ³/ bucket

(the standard liter rises ^-1) 2,500 5,000 5000

Average each temperature, 625-675 620-675 580-660

（℃）（330-357）（327-357）（304-349）

The dewaxing after product is through hydrotreatment (the cyanogen ammonia HDN-30 of company, NiMo/Al ₂O ₃Catalyzer, 268 ℃, 400 pounds/inch ²Gauge pressure hydrogen, 0.5 liquid hourly space velocity, 2500 standard feet ³/ bucket hydrogen: oil) make alkene saturated.

In each case, temperature rises to maximum by the Schwellenwert of listing when catalyst aging, once attempts obtaining the dewaxing lubricant product that a kind of pour point is 16 (9 ℃).In all cases, the rate of ageing of catalyzer just can not satisfy the requirement of target pour point greatly after only turning round one day.When reaching the top temperature of listing in the table in each case, available pour point is 60 °F (15 ℃).Embodiment 1,2 and 3 experiment have just stopped after turning round 4,2 and 6 days respectively, because under the acceptable temperature of reactor, can not reach the target pour point.

Embodiment 4

Dewaxing in advance under low severity, steady temperature condition is adopted in the present embodiment explanation, dewaxes to the process for dewaxing of target pour point in conjunction with second section.

The configuration of reactor is shown among the figure.For the simple and clear hydrogen of expressing circulates.Raw material enters in advance (first section) reactor, carries out the part dewaxing in dewaxing cycle under the condition of basic maintenance steady temperature.The fractionation in intersegmental knockout tower 11 of part dewaxed product, the higher cut of boiling point enters second section reactor and dewaxes to the target pour point, and the temperature of rising reactor is with the compensate for catalyst inactivation in this cycle.The product that has dewaxed then enters hydrotreating reactor 13, and the alkene in the saturated lubricating oil boiling range makes product stable.The product of hydrotreatment and dewaxing enters product separation tower 14, removes the product that boiling point is lower than the lubricating oil boiling range.Knockout tower 11 and 14 recovered temperature can be given as required.Typically, they can remove naphtha fraction and lighting end at least in knockout tower 11, and the part of (about 315 ℃) or 650 (about 345 ℃) also can be removed but be lower than 600 °F in heavier cut such as the middle distilled oil.But because the rate of ageing that alkene can accelerator activator, and they are mainly in being lower than 330 cuts (165 ℃) below, remove the requirement that this cut just can satisfy second section operation usually intersegmental.The recovered temperature of knockout tower 14 is given with the root product specification, as by the cut of removing (about below 345 ℃) below 650 in the lube product.Only the purpose in order to demonstrate is fixed on 330 °F (165 ℃) in the present embodiment, and obviously, other numerical value also is suitable in normal running.

Raw material be solvent-refined heavy neutral raffinate oil with embodiment 1-3 in use identical.

Raw material with embodiment 1-3 in dewax 400 pounds/inch of hydrogen pressures on the identical 1%NiZSM-5 dewaxing catalyst ²Gauge pressure (2860 kPas, absolute), 0.5 liquid hourly space velocity, hydrogen: the ratio of oil is 2500 standard feet ³(445 standard liters rise/bucket ^-1).Reactor inlet temperature marks at 370 ℃, produces pour point consistently and be 26 ° to 29 ℃ part dewaxed product in 6-53 days.The analytical data of the part dewaxed product of (more than 165 ℃) is listed in the table below in 7 more than 330 °F.

Table 7

The single hop dewaxed product

Proportion, (15/4 ℃) 0.8737

Color, ASTM 4.5

Pour point, °F (℃) 79(26.0)

Flash-point, °F (℃) 345(174)

Kinematic viscosity (centistoke)

100℃ 9.96

150℃ 4.03

Nitrogen ppm weighs 203

Basic nitrogen ppm weighs 185

Sulphur ppm weighs 440

The heavy % 86.15 of carbon

The heavy % 13.67 of hydrogen

The heavy % 0.24 of Lan Shi carbon residue

Refractive index, 70 ℃ 1.4623

The heavy % 76.3 of oleaginousness

Aniline point, °F (℃) 246(119.0)

Distillation (D-1160)

Initial boiling point (°F) 389

5% 665

10 834

20 903

Table 7(is continuous)

The single hop dewaxed product

30 931

40 952

50 974

60 993

70 1011

80 1029

The product of (more than 165 ℃) more than 330 of part dewaxing is carried out second section dewaxing, and hydrogen pressure is 400 pounds/inch ²Gauge pressure (2860 kPas, absolute), 0.5 liquid hourly space velocity, 2500 standard feet ³(445 standard liters rise/bucket ^-1) hydrogen: oil.

Running through 8 days, reactor inlet temperature rises to 380 ℃ by 290 ℃ (cycle begins temperature), 11 days (temperature is inclined by 1 ℃/1 ℃ and is normalized to-9 ℃ product pour point) then turns round under this temperature, to start normalized 11 ℃ of/day rate of ageings, behind second section dewaxing reactor, product flows into alkene (the cyanogen ammonia HDN-30 of company, the NiMo/Al in the saturated lubricating oil boiling range of hydrotreating reactor downwards ₂O ₃Catalyzer, 268 ℃, 400 pounds/inch ²Gauge pressure, 0.5 liquid hourly space velocity, 2500 standard feet ³/ bucket hydrogen: oil).Hydrotreatment does not influence the result of dewaxing.Turning round, the product pour point is 6 ℃ after 7 days, is 16 ℃ after 11 days, compares with single hop dewaxing operation, shows that the product pour point also has significant improvement in the dewaxing cycle significant prolongation.In addition, owing to still can turn round satisfactorily through first section catalyzer after one long period, only second reactor needs reactivate, thereby can produce the economic benefit of some reactivate aspects.

The analytical data of second section (more than 165 ℃) product more than 330 after 7 days and 11 days is listed in the table below in 8.

Table 8

Lube product after the dewaxing

Proportion (15/4 ℃) 0.8765 0.8750

Kinematic viscosity, 40 ℃ (centistoke) 70.1 70.1

100 ℃ (centistoke) 9.53 9.66

Pour point, °F (℃) 43(6.0) 61(16.0)

Cloud point, °F (℃) 50(10.0) 64(18.0)

Color, ASTM L2 L2

Lan Shi carbon residue (heavy %) 0.19 0.19

Aniline point (℃) 117.0 118.0

70 ℃ 1.4640 1.4640 of refractive index

Bromine number 0.6 0.5

Neutralization value (milligram KOH/ gram) less than 0.05 less than 0.5

Flash-point, °F (℃) 180(82) 174(79)

Hydrogen (heavy %) 13.63 13.63

Sulphur (ppm) 230 190

Nitrogen (ppm) 230 210

Basic nitrogen (ppm) 167 166

Distillation (D-1160)

Initial boiling point (°F) 306 327

5/10 705/798 723/826

20/30 880/916 886/917

Table 8(is continuous)

Lube product after the dewaxing

40/50 936/958 939/960

60/70 973/991 979/998

80/90 1016/1048 1018/1052

95/ final boiling point-/--/-

Claims

1, a kind of with initial boiling point minimum be 343 ℃, wax content is minimum to be the method for the wax shape hydrocarbon lube stock catalytic dewaxing of 25% (weight), this method comprises:

(i) raw material reactor inlet temperature in the presence of hydrogen and in dewaxing cycle keeps under the constant condition substantially, contacts with a kind of dewaxing catalyst, makes the catalytic material dewaxing, produces a kind of product of part dewaxing;

(ii) the product of part dewaxing under the progressively intensification condition, is contacting with a kind of dewaxing catalyst in the presence of the hydrogen and in dewaxing cycle, further makes the product dewaxing of part dewaxing, produces a kind of product of predetermined pour point.

2, a kind of with initial boiling point minimum be 343 ℃, wax content is minimum to be 25%(weight) the method for wax shape hydrocarbon lube stock catalytic dewaxing, this method comprises:

(ⅰ) raw material is under hydrogen existence and dewaxing condition, be no more than under 40 the situation in temperature rise in high reactor inlet temperature and the dewaxing cycle between the order reactivate, in pre-dewaxing reactor, contact with a kind of zeolite dewaxing catalyst of intermediate pore size, optionally the waxy component in the cracking stock is produced the product of part dewaxing;

(ⅱ) product of part dewaxing is in the presence of hydrogen, under the dewaxing condition, the high temperature of reactor inlet progressively raises and but thereby the inactivation of the speed compensate for catalyst that raises is kept under the situation of target pour point of product in dewaxing cycle, contact with a kind of dewaxing catalyst of intermediate pore size, make the product of part dewaxing in second dewaxing reactor, reach the target pour point, produce the dewaxed product of low pour point.

3, according to the method for claim 1 or 2, wherein the temperature in of second dewaxing reactor raises in dewaxing cycle 22 ℃ at least.

4, according to the method for above each claim, wherein raw material contains the waxy component of 35% weight at least.

5, according to the method for above each claim, wherein raw material contains the heavy basic nitrogen of 100ppm at least.

6, according to the method for above each claim, wherein (ⅰ) and (ⅱ) dewaxing catalyst in each section contain a kind of zeolite of intermediate pore size.

7, according to the method for above each claim, wherein (ⅰ) and (ⅱ) dewaxing catalyst in each section contain ZSM-5.

8, according to the method for above each claim, wherein dewaxing catalyst contains ZSM-23, or a kind of by the synthetic offretite of selecting among ZSM-35 and the ZSM-38.

9, according to the method for above each claim, wherein raw material carries out hydrotreatment before dewaxing or after the dewaxing.

10, according to the method for above each claim, wherein raw material comprises a kind of lube stock of distilled oil, deasphalting Residual oil or solvent-refined raffinate oil.

11, according to the method for above each claim, wherein the initial boiling point of raw material is not less than 399 ℃.

12, according to the method for claim 11, wherein the initial boiling point of raw material is not less than 24 ℃, and 50% recovered temperature is not less than 454 ℃.

13, according to the method for above each claim, wherein dewaxing catalyst comes down to extrude by a kind of zeolite that particle constitutes.

14, according to the method for claim 13, its mesolite contains ZSM-5.