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
  • C10G45/66—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 with moving solid particles

Definitions

• This invention relates to a process for the production of middle distillate fuels from waxy hydrocarbons.
• it relates to a process for the production of distillate fuels, notably kerosene, diesel fuels, jet fuels, lube base stocks and high quality blending components useful for the production of such fuels, via the hydroisomerization of waxy hydrocarbon feeds.
• distillate fuels from waxy hydrocarbon feeds via catalytic hydrocracking or hydroisomerization, or by both catalytic hydrocracking and hydroisomerization reactions.
• a waxy product made by the reaction of a synthesis gas over a Group VI or VIII metal catalyst is mildly hydroisomerized and/or mildly hydrocracked over a suitable catalyst to produce some distillate fuel, or refinery feedstock useful for conversion to a distillate fuel.
• middle distillate fuels made from wary products generally possess notoriously poor cold flow properties. This makes it difficult or even impossible to use such products in many environments since low freeze points are required to maintain fluidity, or flowability of the fuel at low temperatures.
• the heavier 500°F+ fraction is directly hydrocracked over a fixed bed of catalyst to produce a 320-700°F fraction which is useful as a diesel or jet fuel, or as a blending component of a diesel or jet fuel.
• this process demonstrates the feasibility of producing distillates with improved cold flow properties from waxy hydrocarbons there remains a desire, inter alia , to provide further improvements in hydroisomerization processes; both as relates to process improvements, and to improvements in product quality.
• the present invention accordingly, relates to a hydroisomerization process, or further improved hydroisomerization process, for producing distillates with good cold flow properties in good yield from C 5 + paraffinic, or waxy hydrocarbon feeds, contacted and reacted, with added hydrogen, over a small particle size hydroisomerization catalyst dispersed, or slurried, in a paraffinic or waxy liquid hydrocarbon medium.
• the hydroisomerization reaction is conducted at conditions which produce C 5 - 700°F distillate products including jet fuel, diesel fuel, lubes and high quality blending components for the production of these materials.
• the hydroisomerization reaction is conducted at controlled temperatures ranging from about 400°F to about 850°F, preferably from about 500°F to about 700°F, at pressures ranging generally from about 100 pounds per square inch gauge (psig) to about 1500 psig, preferably from about 300 psig to about 1000 psig.
• the reaction is generally conducted at hydrogen treat gas rates ranging from about 1000 SCFB to about 10,000 SCFB, preferably from about 2000 SCFB to about 5000 SCFB.
• Space velocities range generally from about 0.5 LHSV to about 20 LHSV, preferably from about 2 LHSV to about 10 LHSV.
• the hydroisomerization catalyst is contained in the slurry in concentration greater than about 10 percent, preferably greater than about 25 percent, based on the total weight of the slurry, and the particles are of small average particle diameter, ranging generally from about 30 microns to about 150 microns, preferably from about 40 microns to about 60 microns average diameter.
• the catalyst is bifunctional, containing a active metal hydrogenation component or components, and a support component.
• the active metal component is preferably a Group IB, Group VIB, and/or Group VIII metal, or metals, of the Periodic Table Of The Elements (Sargent-Welch Scientific Company Copyright 1968) in amount sufficient to be catalytically active for hydroisomerization in the slurry within which the catalyst is dispersed.
• metal concentrations range from about 0.05 percent to about 20 percent, based on the total weight of the catalyst (wt.%), preferably from about 0.1 wt. percent to about 10 wt. percent.
• Exemplary of such metals are such non-noble Group VIII metals as nickel and cobalt, or mixtures of these metals with each other or with other metals, such as copper, a Group IB metal, or molybdenum, a Group VIB metal. Palladium is exemplary of a suitable Group VIII noble metal.
• the metal, or metals is incorporated with the support component of the catalyst by known methods, e.g., by impregnation of the support with a solution of a suitable salt or acid of the metal, or metals, drying and calcination.
• the catalyst support is constituted of metal oxide, or metal oxides, components at least one component of which is a acidic oxide active in producing olefin cracking and hydroisomerization reactions.
• exemplary oxides include silica, silica-alumina, clays, e.g., pillared clays, magnesia, titania, zirconia, halides, e.g., chlorided alumina, and the like.
• the catalyst support is preferably constituted of silica and alumina, a particularly preferred support being constituted of up to about 35 wt.% silica, preferably from about 2 wt.% to about 35 wt.% silica, and having the following pore-structural characteristics: Pore Radius, ⁇ Pore Volume 0-300 >0.03 ml/g 100-75,000 ⁇ 0.35 ml/g 0-30 ⁇ 25% of the volume of the pores with 0-300 ⁇ radius 100-300 ⁇ 40% of the volume of the pores with 0-300 ⁇ radius
• a suitable acid or base is added and the pH is set within a range of about 6.0 to 11.0.
• Precipitation and aging are carried out, with heating, by adding an acid or base under reflux to prevent evaporation of the treating liquid and change of pH.
• the remainder of the support producing process is the same as those commonly employed, including filtering, drying and calcination of the support material.
• the support may also contain small amounts, e.g., 1-30 wt.%, of materials such as magnesia, titania, zirconia, hafnia, or the like.
• the support materials generally have a surface area ranging from about 180-400 m 2 /g, preferably 230-375 m 2 /g, a pore volume generally of about 0.3 to 1.0 ml/g, preferably about 0.5 to 0.95 ml/g, bulk density of generally about 0.5-1.0 g/ml, and a side crushing strength of about 0.8 to 3.5 kg/mm.
• the feed materials that are isomerized with the catalyst of this invention are waxy feeds, i.e., C 5 +, preferably boiling above about 350°F (117°C) preferably above about 550°F (288°C) and may be obtained either from a Fischer-Tropsch process which produces substantially normal paraffins, or it may be obtained from slack waxes.
• Slack waxes are the byproducts of dewaxing operations where a diluent such as propane or a ketone (e.g., methylethyl ketone, methyl isobutyl ketone) or other diluent is employed to promote wax crystal growth, the wax being removed from the lubricating oil base stock by filtration or other suitable means.
• the slack waxes are generally paraffinic in nature, boil above about 600°F (316°C), preferably in the rage of 600°F (316°C) to about 1050°F (566°C), and may contain from about 1 to about 35 wt% oil. Waxes with low oil contents, e.g., 5-20 wt.% are preferred; however, waxy distillates or raffinates containing 5-45% wax may also be used as feeds.
• Slack waxes are usually freed of polynuclear aromatics and hetero-atom compounds by techniques known in the art; e.g., mild hydrotreating as described in U.S. Patent No. 4,900,707, which also reduces sulfur and nitrogen levels preferably to less than 5 ppm and less than 2 ppm, respectively. Fischer-Tropsch waxes are preferred feed materials, having negligible amounts of aromatics, sulfur and nitrogen compounds.
• total conversion of the 700°F+ feed to produce a 700°F- product is maintained at a level ranging from about 30 percent to about 90 percent, preferably from about 50 percent to about 80 percent on a once-through, or fresh feed basis.
• the slurry hydroisomerization reaction is conducted in one or a plurality of reactors connected in series, generally from about 1 to about 5 reactors; but preferably the reaction is conducted in a single reactor.
• the waxy hydrocarbon feed e.g., a C 5 + Fischer-Tropsch wax, preferably one boiling above about 350°F (177°C), more preferably above about 550°F (288°C)
• the waxy hydrocarbon feed is fed, with hydrogen, into the reactor, a first reactor of the series, into a slurry of the catalyst at hydroisomerization reaction conditions to hydroisomerize and convert a portion of the waxy feed to 700°F- products which include jet fuel, diesel fuel, lubes and high quality blending components.
• the hydroisomerized and partially hydrocracked wax, after passage through filters located at the top of the reactor is removed as a product, or preferably, is split in a pipe still into, e.g., 700°F- and 700°F+ fractions, the 700°F- fraction is removed as product, and all or a part of the 700°F+ fraction is recycled or pumped back into the reactor for further conversion to 700°F-products.
• Gas and light liquids from the top of the reactor are passed to a high pressure separator ad split into byproduct fractions. Flashing and recovery of the primary products are readily accomplished in the slurry reactor, or series of reactors, which is characterized by short liquid and vapor residence times.
• the 700°F+ recycle or pump around feature reduces the amount of 700°F+ and unreacted heavy liquids as occurs in once-through operations.
• a small secondary fixed bed reactor, or slurry upgrader can be staged with the larger single slurry reactor, or staged as a last reactor of a series of larger slurry hydroisomerization reactors, to convert the heavy liquids to lighter boiling products.
• the slurry upgrader reactor is preferably operated at temperatures ranging from about 450°F to about 750°F, preferably at pressures ranging from about 250 psig to about 1200 psig, and preferably at residence times ranging from about 0.05 hour to about 2 hours.
• Preferred catalysts contain cobalt-molybdenum, palladium, or nickel-copper dispersed on acidic supports.
• Suitable supports include both amorphous and crystalline inorganic oxides. Examples of supports comprise silica, alumina, clays, e.g., pillared clays, magnesia, titania, zirconia, halides, e.g., chlorided alumina, and mixtures thereof.
• a bifunctional hydroisomerization catalyst comprised of 0.50 wt.% palladium on an acidic silica-alumina support containing 25 wt.% Al 2 O 3 was tested for activity as a hydroconversion catalyst using, as a representative test, the preparation of iso -C 16 H 34 from n -C 16 H 34 (i.e., hexadecane).
• the test procedure was as follows:
• Table 1A shows the conversion at three different pressures.
• Example 1 The catalyst described in Example 1 was further evaluated, this time at various temperatures and residence times using the same procedure as described in Example 1.
• Table 2A shows the conversion and selectivity for the catalyst at a loading of 10 wt.% based on hexadecane feed at a pressure of 250 psig hydrogen and temperatures ranging from 650-700°F.
• Table 2B shows similar data under identical conditions with the exception of the temperature and the time. In this case, the temperature was held constant 700°F and the time varied over a range from 5-120 minutes.
• the weight percent conversion to C 16 it will be observed, increases with increasing temperature, while the weight percent selectivity to C 16 isoparaffins decreases with increasing temperature. As the residence time is increased the amount of C 16 conversion is increased, and the C 16 isoparaffins selectivity is decreased. The conversion/selectivity relationship is not changed.
• a bifunctional catalyst was prepared using a pillared interlayer clay (PILC) as the acidic support with palladium (0.50 wt.%) as the dehydrogenation source. Pillared clays are microporous materials formed by intercalating inorganic polyoxocations between clay layers.
• PILC pillared interlayer clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zirconium pillared bentonite clay
• Zr-PILC zi
• the catalyst was then dried at 120°C for two days and calcined at 400°C for two hours.
• the resulting Zr-PILC had a layer repeat distance 21 ⁇ and a BET surface area of 350 m 2 /gram.
• Palladium (0.50 wt.%) was added by incipient wetness using an aqueous solution of palladium amine nitrate (Aldrich).
• Example 1 the catalyst was tested for activity as a hydroconversion catalyst using, as a representative test, the preparation of iso -C 16 from n -C 16 (i.e., hexadecane). The test procedure was identical to Example 1.
• Table 3 shows the conversions and selectivity for the Pd/Zr-PILC catalyst at a loading of 10 wt.% based on hexadecane feed at a pressure of 250 psig hydrogen and temperatures ranging from 500-575°F.
• a catalyst prepared in accordance U.S. Patent No. 5,187,138 containing 4% SiO2, 3% Co, 0.5% Ni, and 12% Mo supported on a silica alumina support initially containing 10% bulk silica was tested for activity and selectivity in conversion of a 500°F+ Fischer Tropsch wax at several processing conditions.
• the catalyst was evaluated in a fixed bed reactor as 1/20" quadrilobe extrudates using a 200 cc catalyst charge.
• Table 4A summarizes results of these studies.
• the hydroisomerization process of this invention can be practiced over a wide variety of hydrodynamic regimes, particularly those characterized as bubbling flow, turbulent flow and churn turbulent flow slurry operations.
• the process is particularly adapted to achieve effective use of reactor volume over a variety of processing conditions.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Crystallography & Structural Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Catalysts (AREA)

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• 1996
  • 1996-06-13 CA CA 2179093 patent/CA2179093A1/en not_active Abandoned
  • 1996-06-19 MY MYPI9602470 patent/MY115196A/en unknown
  • 1996-07-04 DE DE1996604978 patent/DE69604978T2/de not_active Expired - Lifetime
  • 1996-07-04 EP EP19960110796 patent/EP0753563B1/de not_active Expired - Lifetime
  • 1996-07-10 JP JP19982196A patent/JP3860863B2/ja not_active Expired - Fee Related
  • 1996-07-12 NO NO962940A patent/NO962940L/no unknown
  • 1996-07-12 AU AU60511/96A patent/AU702829B2/en not_active Ceased
  • 1996-07-13 SG SG1996010245A patent/SG67953A1/en unknown

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