Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
  • C10G45/58—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins
  • C10G45/60—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used
  • C10G45/64—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used containing crystalline alumino-silicates, e.g. molecular sieves
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/10—Lubricating oil

Definitions

• This invention relates to the hydroisomerization of waxy feeds including slack wax, slack wax isomerate, Fischer-Tropsch wax, Fischer- Tropsch hydroisomerate waxy raffinates, and waxy distillates to produce a lube oil basestock or blending stock. More specifically, this invention relates to the conversion of a waxy feed using a mixed catalyst having a preselected acidity capable of promoting the formation of a basestock having a predetermined (VI) within a range of VTs.
• Waxy feeds can be converted to liquid products using well known catalytic dewaxing catalysts; however, in these instances the selective cracking of paraffins typically results in a loss of viscosity (VI) which is undesirable.
• VI viscosity
• This invention relates to a method for hydroisomerizing a waxy feed to produce improved yield of a lube basestock which comprises: contacting the waxy feed under hydroisomerization conditions with a catalyst comprising a unitized mixed powdered pellet catalyst having (1) a first dewaxing component selected from 8, 10 and 12 ring molecular sieves and mixtures thereof; (2) a second isomerization component which is an amorphous inorganic oxide; and (3) at least one of a Group VLB and a Group VHI metal hydrogenation component, wherein the first and second components are present in a ratio such that when evaluated in the conversion of methyl cyclohexane at 320°C to 1,1-dimethylcyclopentane, 1,2-dimethylcyclopentane, 1,3-dimethylcyclopentane and ethylcyclopentane, the catalyst will provide a trans-l,2-/trans-l,3-dimethyl- cyclopentane ratio of less than 1 and a
• Figure 1 is a schematic drawing showing the conversion of methylcyclohexane to various cyclopentane compounds at 320°C. - 3 -
• the feed suitable in the practice of the present invention includes waxy hydrocarbon oils such as slack wax, slack wax isomerate, Fischer-Tropsch wax, Fischer-Tropsch isomerate waxy raffinates and waxy distillates. Typically, such feeds will have wax contents of 15% or more.
• the preferred feed will have a nitrogen and sulfur content each below about 20 wppm or more.
• the preferred feed will have a nitrogen and sulfur content each below about 20 wppm. Indeed, if the feed contains higher amounts of sulfur and nitrogen, the feed can be first subjected to hydrotreating under typical hydrotreating conditions to reduce the sulfur and nitrogen contents.
• any of the conventional hydrotreating catalysts can be employed like Ni/Mo on alumina, Ni/W on alumina Co/Mo on alumina.
• any of the Group VTB to Group VDI (The groups referred to here and hereinafter are those metals of the Periodic Table of Elements; Sargent- Welch Scientific Co.) on metal oxide refractory supports may be employed. Commercial examples of such are identified as HDN-30 and KF-840.
• Hydrotreating is conducted so as to lower the sulfur and nitrogen contents to levels of 20 wppm or less nitrogen or 20 wppm or less sulfur especially 10 ppm less nitrogen and 10 ppm or less sulfur and most preferably to levels below 5 ppm for nitrogen and 5 ppm or less for sulfur.
• Waxy feeds secured from natural petroleum sources contain quantities of sulfur and nitrogen compounds which are known to deactivate wax hydroisomerization catalysts. To prevent this deactivation it is preferred that the feed contain no more than 10 ppm sulfur, preferably less than 2 ppm sulfur and no more than 2 ppm nitrogen, preferably less than 1 ppm mtrogen. - 4 -
• the feed is preferably hydrotreated to reduce the sulfur and nitrogen content.
• Hydrotreating can be conducted using any typical hydrotreating catalyst such as Ni/Mo on alumina, Co/Mo on alumina, Co/Ni/Mo on alumina, e.g., KF-840, KF-843, HDN-30, HDN-60, Criteria C-411, etc.
• bulk catalysts comprising Ni/Mn/Mo or Cr/Ni/Mo sulfides as described in U.S. Patent 5,122,258 can be used.
• Hydrotreating is performed at temperatures in the range 280°C to 400°C, preferably 340°C to 380°C at pressures in the range 500 to 3000 psi, hydrogen treat gas rate in the range of 500 to 5000 SCF/bbl and a flow velocity in the range 0.1 to 5 LHSV, preferably 1 to 2 LHSV.
• the hydrotreated waxy oil is stripped to remove ammonia and H2S and then is subjected to the hydroisomerization process of the present invention.
• the catalyst employed in the hydroisomerization of waxy feeds in accordance with the present invention is a unitized mixed powdered pellet catalyst.
• unitized as used here and in the claims means that each pellet is one made by mixing together a powdered first component with a powdered second component and pelletizing the mixture to produce pellets each of which contain all of the powder components previously recited.
• the unitized catalyst can be prepared by starting with individual finished powdered components pulverizing and powdering such individual finished components, mixing the powdered materials together to form a - 5 -
• Pulverizing and powdering is to a consistency achievable using a ball mill or other such conventional powdering means to a particle size less than 100 microns.
• the first component is a catalytic dewaxing component including crystalline 8, 10 and 12 ring molecular sieves.
• Crystalline molecular sieves include metallo-, e.g., alumino silicates, alumino phosphates and sihco uminophosphates.
• crystalline alumino silicates include zeolites such as erionite, chabazite, ZSM-5, ZSM-11, ZSM-12, Theta-1 (ZSM- 22), ZSM-23, ZSM-35, ZSM-48 natural and synthetic ferrierites, ZSM-57, beta mordenite and offretite.
• Examples of crystalline alumino- and silicoalumino- phosphates include SAPO-11, SAPO-41, SAPO-31, MAPO-11 and MAPO-31. Preferred include ZSM-5, ZSM-22, ZSM-23, ferrierites, and SAPO-11.
• the second isomerization component can be any of the typical isomerization catalyst such as those comprising amorphous refractory metal oxide support base (e.g., umina, silica, zirconia, titania, silica-magnesia, silica- alumina, etc.) on which has been preferably deposited a catalytically active metal selected from Group VI B, Group VII B, Group VU3 metals and mixtures thereof, preferably Group VUI, more preferably noble Group VIE, most preferably Pt or Pd and optionally including a promoter or dopant such as yttria, rare earth oxides, from, e.g., La, Ce, etc., boria, magnesia, etc.
• amorphous refractory metal oxide support base e.g., umina, silica, zirconia, titania, silica-magnesia, silica- alumina, etc.
• the catalytically active metals are present in the range 0.1 to 5 wt%, preferably 0.1 to 3 wt%, more preferably 0.1 to 2 wt%, most preferably 0.1 to 1 wt%.
• the promoters and dopants are used to control the acidity of the isomerization catalyst.
• acidity of the resultant catalyst is reduced by addition of a basic material such as - 6 -
• yttria rare earth oxides, from e.g., La, Ce, etc., boria or magnesia or by controlling the ratio of silica.alumina in the sihca- umina.
• the metal hydrogenation component can be deposited on either the first dewaxing component, the second isomerization component or preferably on both the first and second components.
• the metal is selected from at least one of Group VIB and Group VHI, preferably Group VIII, more preferably Pt or Pd.
• the amount of metal can range from 0.1 to 30 wt%, based on catalyst. If the metal is Pt or Pd, the preferred amount is from 0.1 to 5 wt%, based on catalyst. In order to maximize catalyst utilization, it is preferred that the metal dispersion be at least 0.3 (on a scale where 100% metal dispersion is 1.0) if the metal is only on one component. If the metal is on both components, then it is preferred that the metal dispersion (D) times the metal concentration (C) (i.e., D x C) on one of the components be at least 0.08.
• the first and second components are combined in a ratio sufficient to promote wax isomerization and naphthene destruction without substantial decrease in VI.
• the zeolite to amorphous inorganic oxide ratios for catalysts according to the invention range from about 1: 1 to 1:20 by weight, subject to the MCH test described below.
• One technique for deteirnining the proper ratio of first and second components in the catalyst is based on an evaluation of the combined components containing about 0.5 wt% Pt in converting methylcyclohexane (MCH) to various cyclopentane compounds.
• Catalyst that at 320°C provide a ratio of trans 1,2-dimethylcyclopentane to trans-l,3-dimethylcyclopentane (trans- 1,2/trans- 1,3 DMCP) in the range of less than 1 have been found to - 7 -
• the second factor is when the catalyst, impregnated with about 0.5 wt% Pt and evaluated in converting methylcyclohexane to various cyclopentane compounds at 10% conversion, exhibits a selectivity for ethylcyclopentane (ECP) formation above at least 50%.
• ECP ethylcyclopentane
• the ratio of trans- 1,2-DCMP to trans-l,3-DCMP is adjusted to less than - 8 -
• amorphous isomerization component about 1 predominantly by controlling both the number and strength of the amorphous isomerization component. It is preferred to use lower acid strength amorphous components such as alumina.
• a catalyst that will maximize VI is produced by increasing the acid strength of the amorphous phase.
• it is preferred to use higher acid strength amorphous components such as silica-aluminas or modified sihca-aluminas.
• Another way of making such a catalyst is by changing the ratio of the microporous component to the amorphous component such that the unitized catalyst has a trans-l,2/trans-l,3 DMCP ratio of >1.
• the hydroisomerization process utilizing the catalyst of the present invention is conducted at temperatures between about 200°C to 400°C, preferably 250°C to 380°C, and most preferably 300°C to 350°C at hydrogen partial pressures between about 350 to 5,000 psig (2.41 to 34.6 mPa), preferably 1,000 to 2500 psig (7.0 to 17.2 mPa), a hydrogen gas treat ratio of 500 to 10,000 SCF H 2 /bbl (89 to 1780 ⁇ /m 3 ), preferably 2,000 to 5,000 SCF H 2 /bbl (356 to 890 m 3 /m 3 ) and a LHSV of 0.1 to 10 v/v/hr, preferably 0.5 to 5 v/v/hr, and more preferably 1 to 2 v/v/hr.
• the waxy feed is first subject to solvent dewaxing to a pour point of the order of +10°C or lower.
• the dewaxing solvent used may include the C3-C6 ketones such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), mixtures of MEK and MIBK, aromatic hydrocarbons like toluene, mixtures of ketones and aromatics like MEK/toluene, ethers such as methyl t-butyl ethers and mixtures of - 9 -
• MEK methyl ethyl ketone
• MIBK methyl isobutyl ketone
• the solvent employed will be an equal volume mixture of methyl ethyl ketone and methyl isobutyl ketone.
• the isomerate to solvent ratio will range between 1 to 10 and preferably will be about 1:3.
• This example illustrates the yield- VI trade-off on a hydrocracker distillate (Feed A) for catalysts with different degrees of acidity in the amorphous component.
• the physical properties of the hydrocracker distillate (Feed A) are shown in Table 1.
• the catalyst in Table 2 (column B) was made by combining the zeolite theta-1 (TON) in the powder form with alumina (BET Surface Area 190 m ⁇ lm?) in the powder form followed by intimate mixing so as to form a - 10 -
• the catalyst in Table 2 (column C) was made by combining the zeolite TON with silica-alumina (Si-Al) using the same technique as used in column A to produce a homogeneous powdered catalyst before forming into pellets.
• the palladium was loaded (as palladium teu-aamine dinitrate) on to the finished unitized catalyst by incipient wetness.
• Table 2 shows a comparison of activity and selectivity of these two catalysts for hydrodewaxing versus solvent dewaxing (column A).
• the acidity differences of each catalyst component and the corresponding finished unitized catalysts is also shown using the reaction of methylcyclohexane at 320°C.
• the table clearly shows the higher acidity (greater number and acid strength) silica- umina catalyst (column C) gives lower yield but much higher VI compared with the very low acidity associated with alumina (column B) which results in high yield but a debit in VI.
• This example further illustrates the yield- VI trade off and shows a comparison of activity and selectivity of two catalysts for hydrodewaxing a hydrocraker distillate (Feed B) versus solvent dewaxing.
• the physical properties of the hydrocracker distillate (Feed B) are shown in Table 3.
• Wax Content wt% 22.4
• This example further illustrates the yield- VI trade and shows a comparison of activity and selectivity of two catalysts for hydroisomerization a hydrocraker distillate (Feed B) versus solvent dewaxing.
• This example illustrates that by changing the relative amounts of microporous component to amorphous component the overall acidity of the unitized catalyst an be tailored to maximize yield or VI.
• Table 5 compares two unitized catalysts both of which have been made by combining the powdered ZSM-5 (Si Al ratio 110) with the powdered amorphous component in different ratios and then loading platinum by incipient wetness using platinum tetraamine dichloride.
• Table 5 shows a comparison of activity and selectivity for these catalysts for dewaxing hydrocracker distillate B, the physical properties of which are shown in Table 3, with solvent dewaxing.
• the catalyst in column B which has a trans-l,2/trans-l,3 DMCP ratio of less than 1 shows higher yield but lower VI than the catalyst in column C which has a trans-l,2/trans-l,3 DMCP ratio greater than 1.
• the metal in a mixed powdered catalyst can be dispersed on the microporous component or on the amorphous component.
• the catalysts in Table 6 were made by combining the zeolite theta- 1 (TON) in the powder form with alumina (BET Surface Area 190m 2 /m 3 ) in the powder form followed by intimate mixing so as to form a homogeneous powdered mixture and then forming into catalyst pellets by pressing in a die and sizing to the required mesh size.
• TON zeolite theta- 1
• BET Surface Area 190m 2 /m 3 alumina
• the TON in the catalyst in column A had been loaded with platinum tetramine dinitrate before being mtermixed with alumina.
• the catalyst in column D was made as described in Example 1.
• Table 6 columns A and B, compares the activity of two TON zeoHte/ umina mixed powder catalysts in which the noble metal has been - 17 -
• Loading additiond Pt or Pd on the dumina component improves the activity of the catdyst to the level of that observed in Column A.
• Feed Hydrocracker Distillate, Feed B t >

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• 1999
  • 1999-02-12 JP JP2000531517A patent/JP2002503753A/ja active Pending
  • 1999-02-12 WO PCT/US1999/002986 patent/WO1999041333A1/en not_active Application Discontinuation
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