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
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G11/14—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts
  • C10G11/18—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts according to the "fluidised-bed" technique

Definitions

• This invention relates to an improved catalyst, one or more methods for its preparation, and a process for its use in the conversion of carbo-metallic oils to liquid transportation and/or heating fuels. More particularly, the invention is related to a catalyst composition comprising a catalytically active crystalline aluminosilicate zeolite uniformly dispersed within a matrix containing a metal additive as a free metal, its oxides or its salts to immobilize vanadium oxides deposited on the catalyst during the conversion reaction.
• the metal additive for vanadia immobilization may be added during catalyst manufacture, after manufacture by impregnation of virgin catalyst, or at any point in the catalyst cycle for conversion of the oil feed.
• VGO vacuum gas oils
• the catalysts employed in early homogeneous fluid cense beds were of an amorphous siliceous material, prepared synthetically or from naturally occurring materials activated by acid leaching.
• Tremendous strides were made in the 1950's in FCC technology in the areas of metallurgy, processing equipment, regeneration and new more active and more stable amorphous, catalysts.
• increasing demand with respect to quantity of gasoline and increased octane number requirements to satisfy the new high horsepower-high compression engines being promoted by the auto industry put extreme pressure on the petroleum industry to increase FCC capacity and severity of operation.
• the new catalyst developments revolved around the development of various zeolites such as synthetic types X and Y and naturally occurring faujasites; increased thermal-steam (hydrothermal) stability of zeolites through the inclusion of rare earth ions or ammonium ions via ion-exchange techniques; and the development of more attrition resistant matrices for supporting the zeolites.
• These zeolitic catalyst developments gave the petroleum industry the capability of greatly increasing throughput of feedstock with increased conversion and selectivity while employing the same units without expansion and without requiring new unit construction.
• these heavier crude oils also contained more of the heavier fractions and yielded less or a lower volume of the high quality FCC charge stocks which normally boil below about 1025 °F and are usually processed so as to contain total metal levels below 1 ppm, preferably below 0.1 ppm, and Conradson carbon values substantially below 1.0.
• This coke production has been attributed to four different coking mechanisms, namely, contaminant coke from adverse reactions caused by metal deposits, catalytic coke caused by acid site cracking, entrained hydrocarbons resulting from pore structure adsorption and/or poor stripping, and Conradson carbon resulting from pyrolytic distillation of hydrocarbons in the conversion zone.
• contaminant coke from adverse reactions caused by metal deposits catalytic coke caused by acid site cracking
• entrained hydrocarbons resulting from pore structure adsorption and/or poor stripping entrained hydrocarbons resulting from pore structure adsorption and/or poor stripping
• Conradson carbon resulting from pyrolytic distillation of hydrocarbons in the conversion zone There has been postulated two other sources of coke present in reduced crudes in addition to the four present in VGO. They are: (1) adsorbed and absorbed high boiling hydrocarbons which do not vaporize and cannot be removed by normally efficient stripping, and (2) high molecular weight nitrogen containing hydrocarbon compounds
• the coked catalyst is brought back to equilibrium activity by burning off the deactivating coke in a regeneration zone in the presence of air, and the regenerated catalyst is recycled back to the reaction zone.
• the heat generated during regeneration is removed by the catalyst and carried to the reaction zone for vaporization of the feed and to provide heat for the endothermic cracking reaction.
• the temperature in the regenerator is normally limited because of metallurgical limitations and the hydrothermal stability of the catalyst.
• the hydrothermal stability of the zeolite containing catalyst is determined by the temperature and steam partial pressure at which the zeolite begins to rapidly lose its crystalline structure to yield a low activity amorphous material.
• the presence of steam is highly critical and is generated by the burning of adsorbed and absorbed (sorbed) carbonaceous material- which has a significant hydrogen content (hydrogen to carbon atomic ratios generally greater than about 0.5).
• This carbonaceous material is principally the. high boiling sorbed. hydrocarbons with boiling points as high as 1500-1700 °F or above that have a modest hydrogen content and the high boiling nitrogen containing hydrocarbons, as well as related porphyrins and asphaltenes.
• the high molecular weight nitrogen compounds usually boil above 1025°F.
• the porphyrins and asphaltenes also generally boil above 1025 °F. and may contain elements other than carbon and hydrogen. As used in this specification, the term "heavy hydrocarbons" includes all carbon and hydrogen compounds that do not boil below about 1025°F regardless of whether other elements are also present in the compound.
• the heavy metals in the feed are generally present as porphyrins and/or asphaltenes.
• certain of these metals, particularly iron and copper, may be present as the free metal or as inorganic compounds resulting from either corrosion of process equipment or contaminants from other refining processes.
• the Conradson carbon value of the feedstock increases, coke production increases and this increased load will raise the regeneration temperature; thus the unit may be limited as to the amount of feed that can be processed because of its Conradson carbon content.
• Earlier VGO units operated with the regenerator at 1150-1250°F.
• a new development in reduced crude processing namely, Ashland Oil's "Reduced Crude Conversion Process", as described in the pending U.S.
• regenerator temperatures in the range of 1350-1400°F. But even these higher regenerator temperatures place a limit on the Conradson carbon value of the feed at approximately 8, which represents about 12-13 wt. % coke on the catalyst based on the weight of feed. This level is controlling unless considerable water is introduced to further control temperature, which addition is also practiced in Ashland's RCC processes.
• the metal containing fractions of reduced crudes contain NiV-Fe-Cu in the form of porphyrins and asphaltenes. These metal containing hydrocarbons are deposited on the catalyst during processing and are cracked in the riser to deposit the metal or are carried over by the coked catalyst as the metallo-porphyrin or asphaltene and converted to the metal oxide during regeneration.
• the adverse effects of these metals as taught in the literature are to cause non-selective or degradative cracking and dehydrogenation to produce increased amounts of coke and light gases such as hydrogen, methane and ethane. These mechanisms adversely affect selectivity, resulting in poor yields and quality of gasoline and light cycle oil.
• This invention provides an improved catalyst and method for the conversion of petroleum oil feeds containing significant levels of vanadium (at least about 0.1 ppm). More particularly, metal additives are provided on the catalyst to reduce the deactivation of catalyti ⁇ ally active crystalline aluminosilicate zeolites by the vanadium contaminants in oil feeds of all types utilized in FCC and/or RCC operations . The invention is particularly useful in the processing of carbometallic oil feeds in RCC units.
• Some crude oils and some FCC charge stocks from the distillation of crude oils contain significant amounts (greater than 0.1 ppm) of heavy metals such as Ni, V, Fe, Cu, Na. Residual fractions from crude oil distillation have even greater amounts of heavy metals and may also have high Conradson carbon values. According to the present invention, these oils are converted to liquid transportation and distillate heating fuels by contact with a zeolitic catalyst containing a metal additive to immobilize vanadium oxides deposited on the catalyst during the conversion reaction.
• vanadia refers collectively to the oxides of vanadium.
• vanadium is especially detrimental to catalyst life.
• the elevated temperatures encountered in the catalyst regeneration zone cause vanadium pentoxide (V 2 O 5 ) to melt and this liquid vanadia to flow.
• this vanadia enters the zeolite structure leading to neutralization of acid sites and more significantly to irreversible destruction of the crystalline aluminosilicate structure so as to form a less active amorphous material.
• this melting and flowing of vanadia can, at high levels and for catalyst materials with low surface area, also coat the outside of catalyst microspheres with liquid and thereby cause coalescence between catalyst particles which adversely affects its fluidization properties.
• the select metal additives of this invention were chosen so as to form compounds or complexes with vanadia which have melting points above the temperatures encountered in the regeneration zone, thus avoiding zeolite destruction, surface sintering and particle fusion.
• the select additives were also chosen for the purpose of immobilizing vanadia while simultaneously avoiding neutralization of acidic sites. Many additional additives which do affect the melting point of vanadia were eliminated due to their negative effect on catalyst activity. Titania and zirconia not only tie up the vanadia but, in combination with silica, form acidic catalysts with cracking activity in their own right.
• the method of addition of the metal additive can be during catalyst manufacture or at any point in the reduced crude processing cycle. Addition during manufacture may be made either to the catalyst slurry before particle formation or by impregnation after catalyst particle formation, such as after spray drying of the catalyst slurry to form micorspheres. It is to be understood that the catalyst particles can be of any size, depending on the size appropriate to the conversion process in which the catalyst is to be employed. Thus, while a fluidizable size is preferred, the metal additives may be employed with larger particles, such as those for a moving catalyst bed in contact with unvaporized feeds.
• this invention is especially effective in the processing of reduced crudes and other carbo-metallic feeds with high metals, high vanadium to nickel ratios and high Conradson carbon values.
• This RCC feed having high metal and Conradson carbon values is preferably contacted in a riser with a zeolite containing catalyst of relatively high surface area at temperatures above about 950°F. Residence time of the oil in the riser is below 5 seconds, preferably 0.5-2 seconds.
• the preferred catalyst is a spray dried composition in the form of microspherical particles generally in the size range of 10 to 200 microns, preferably 20 to 150 microns and more preferably between 40 and 80 microns, to ensure adequate fluidization properties.
• the RCC feed is introduced at the bottom of the riser and contacts the catalyst at a temperature of 1275-1450°F. to yield a temperature at the exit of the riser in the catalyst disengagement vessel of approximately 950-1100 °F.
• water, steam, naphtha, flue gas, or other vapors or gases may be introduced to aid in vaporization and act as a lift gas to control residence time and provide the other benefits described in Ashland's co-pending PvCC applications.
• Coked catalyst is rapidly separated from the hydrocarbon vapors at the exit of the riser by employing the vented riser concept developed by Ashland Oil, Inc., and described in U.S. Patent Nos. 4,066,533 and 4,070,159 to Myers, et al, which patents are incorporated herein by reference.
• the metal and Conradson carbon compounds are deposited on the catalyst.
• the coked catalyst is deposited as a dense but fluffed bed at the bottom of the disengagement vessel, transferred to a stripper and then to the regeneration zone.
• the coked catalyst is there contacted with an oxygen containing gas to remove the carbonaceous material through combustion to carbon oxides to yield a regenerated catalyst containing less than 0.1 wt. % carbon, preferably less than 0.05 wt. % carbon.
• the regenerated catalyst is then recycled to the bottom of the riser where it again joins high metal and Conradson carbon containing feed to repeat the cycle.
• the vanadium deposited on the catalyst in the riser is converted to vanadium oxides, in particular, vanadium pentoxide.
• the melting point of vanadium pentoxide is much lower than the temperatures encountered in the regeneration zone.
• This application describes a new approach to offsetting the adverse effects of vanadium pentoxide by the incorporation of select free metals, their oxides or their salts into the catalyst matrix during manufacture, either by addition to the undried catalyst composition or by impregnation techniques after spray drying or other particle forming techniques, or during FCC or RCC processing by introducing these additives at select points in the FCC or RCC unit to affect vanadium immobilization through compound, complex, or alloy formation.
• These metal additives serve to immobilize vanadia by creating complexes, compounds or alloys of vanadia having melting points which are higher than the temperatures encountered in the regeneration zone.
• the metal additives for immobilizing vanadia include the following metals, their oxides and salts, and their organometallic compounds: Mg, Ca, Sr, Ba, Sc , Y, La, Ti, Zr, Hf, Nb, Ta, Mn, Fe, In, Tl, Bi, Te, the rare earths, and the Actinide and Lanthanide series of elements.
• These metal additives based on the metal element content may be used in concentration ranges from about 0.5 to 20 percent, more preferably about 1 to 8 percent by weight of virgin catalyst. If added instead during the conversion process, the metal elements may build up to these concentrations on equilibrium catalyst and be maintained at these levels by catalyst replacement.
• the catalytically active promoter in the preferred catalyst composition is a crystalline aluminosilicate zeolite, commonly known as molecular sieves.
• Molecular sieves are initially formed as alkali metal aluminosilicates, which are dehydrated forms of crystalline hydrous siliceous zeolites.
• the alkali form does not have appreciable activity and alkali metal ions are deleterious to cracking processes, the aluminosilicates are ion exchanged to replace sodium with some other ion such as, for example, ammonium ions and/or rare earth metal ions.
• the silica and alumina making up the structure of the zeolite are arranged in a definite crystalline pattern containing a large number of small uniform cavities interconnected by smaller uniform channels or pores.
• the effective size of these pores is usually between about 4 A° and 12 A°.
• the zeolites which can be employed in accordance with this invention include both natural and synthetic zeolites.
• the natural occurring zeolites including gmelinite, clinoptilolite, chabazite, dechiardite, faujasite, heulandite, erionite, analcite, levynite, sodalite, cancrinite, nephelite, lcyurite, scolicite, natrolite, offertite, mesolite, mordenite, brewsterite, ferrierite, and the like.
• Suitable synthetic zeolites include zeolites Y, A, L.
• zeolites contemplates not only aluminosilicates but substances in which the aluminum is replaced by gallium and substances in which the silicon is replaced by germanium and also the so called pillared clays more recently introduced into the art.
• the matrix material for the catalyst of this invention should possess good hydro-thermal stability.
• materials exhibiting relatively stable pore characteristics are alumina, silica-alumina, silica, clays such as kaolin, meta-kaolin, halloysite, anauxite, dickite and/or macrite, and combinations of these materials.
• Other clays, such as montmorillonite, may be added to increase the acidity of the matrix. Clay may be used in natural state or thermally modified.
• Fig. 1 is a schematic diagram of an apparatus for carrying out the process of the invention.
• Fig. 2 is a graph showing the change in catalytic activity with increasing amounts of vanadium on the catalyst.
• Fig. 3 is a graph showing changes in catalytic activity with increasing amounts of nickel on the catalyst.
• Fig. 4 is a graph showing the loss of crystalline aluminosilicate zeolite with increasing amounts of vanadium on the catalyst.
• Fig. 5 is a graph showing the loss of crystalline aluminosilicate zeolite with increasing amounts of nickel on the catalyst.
• Fig. 6. is a table giving catalyst parameters and conversion data relative to the amount of nickel or vanadium on a catalyst of relatively low surface area.
• Fig. 7 is a table giving catalyst parameters and conversion data relative to the amount of nickel or vanadium on a catalyst of relatively high surface area.
• Fig. 8 is a table illustrating the effectiveness of titanium in immobilizing vanadium.
• Fig. 9 is a graph showing the change in catalyst relative activity with decreasing vol.% MAT conversion.
• Fig. 10 is a graph showing the time required to build up metals on a catalyst at varying metals level in feed and a catalyst addition rate of 3% of inventory.
• Fig. 11 is a graph showing the time required to build up metals on a catalyst at varying metals level in feed and a catalyst addition rate of 4% of inventory.
• the metal additives of this invention will form compounds, complexes or alloys with vanadia that have higher melting points than the temperatures encountered in the regeneration zone.
• the preferred minimum atomic ratio of additive metal to vanadium to be maintained on the catalyst is at least 0.5 to 1.0, depending on the number of additive metal atoms in the oxide of the additive metal, e.g., TiO 2 or In 2 O 3 , forming a stable, high melting binary oxide material with vanadium pentoxide (V 2 O 5 ).
• the melting point of the binary oxide material should be generally well above the operating temperatures of the regenerator.
• the metal additive may be added to the process at a preferred minimum rate equivalent to either 50% or 100% of the metal content of the feed, depending on whether a 0.5 or 1.0 minimum ratio is to be maintained.
• This latter approach was employed to identify and confirm suitable metal additives which can form binary mixtures with vanadium pentoxide so as to yield a solid material that has a melting point of at least about 1,600°F, preferably at least about 1,700°F, more preferably 1,800oF or higher, at the preferred ratio.
• This high melting point product ensures that vanadia will not melt, flow and enter the zeolite cage structure to cause destruction of the zeolite's crystalline sieve structure as previously described.
• the additive metals of this invention include those elements from the Periodic chart of elements shown in Table A.
• the melting points of Table A are based on a 1:1 mole ratio of the metal additive oxide in its stable valence state under regenerator conditions to vanadium pentoxide.
• Group IIIA In, TI >1800 Group VA Bi, As, Sb >1600
• This invention also recognizes that mixtures of these additive metals with vanadia may occur to form high melting ternary, quaternary, or higher component reaction mixtures, such as vanadium titanium zirc ⁇ nate (VO-TiO 2 -Zr O 2 ).
• binary, ternary and/or quaternary reaction mixtures can occur with metals not covered in the Groups above.
• Group IIA metals and certain other metals that are not specified in Table A are capable of tying up vanadia in high melting immobile materials, those metals may result in excessive neutralization of acidic sites on the catalyst and generally should not be used in the method of the present invention.
• the preferred metal additives are compounds of titanium, zirconium, manganese, indium, lanthanum, or a mixture of the compounds of these metals. Where the additive is introduced directly into the conversion process, that is into the riser, into the regenerator or into any intermediate components, the metal additives are preferably organo-metallic compounds of these metals soluble in the hydrocarbon feed or in a hydrocarbon solvent miscible with the feed.
• Examples of preferred organo-metallic compounds are tetraisopropyltitanate, Ti (C 3 H 7 O) 4 , available as TYZOR from the DuPont Compnay; methylcyclopentadienyl manganese tricarbonyl (MMT), Mn (CO) 3 C 6 H 7 ; and zirconium isopropoxide, Zr (C 3 H 7 O) 4 ; Indium 2,4 pentanedionate - In (C 5 H 7 O 2 ) 3 ; Tantalum ethoxide - Ta (C 2 H 5 O) 5 ; and zirconium 2,4-pentanedionate - Zr (C 5 H 7 O 2 ) 4 .
• organo-metallics are only a partial example of the various types available and others would include alcoholates, esters, phenolates, naphthenates, carboxylates, dienyl sandwich compounds, and the like.
• the invention there fore is not limited-to the examples given.
• Other preferred process additives include titanium tetrachloride and manganese acetate, both of which are relatively inexpensive.
• the organo-metallic additives are preferably introduced directly into the hydrocarbon conversion zone, preferably near the bottom of the riser, so that the metal additive will be deposited on the catalyst along with the heavy metals in the feed.
• the additive metal of the invention reaches the regenerator, its oxide is formed, either by decomposition of the additive directly to the metal oxide or by decomposition of the additive to the free metal which is then oxidized under the regenerator conditions.
• This provides an intimate mixture of metal additive and heavy metals and is believed to be one of the most effective means for tying up vanadium pentoxide as soon as it is formed in the regeneration.
• the metal additive is introduced into the riser by mixing it with, the feed in an amount sufficient to give an atomic ratio between the metal in the additive and the vanadium in the feed of at least 0.25, preferably in the range of 0.5 to 3.0, more preferably in the range of .75 to 1.5, and most preferably 100 to 200 percent of the preferred minimum ratios previously defined.
• the metal additives are preferably water soluble inorganic salts of these metals, such as acetate, halide, nitrate, sulfate, sulfite and/or carbonate. These additive compounds are soluble in the catalyst slurry or in a water impregnating solution. If the metal additive is not added to the catalyst before or during particle formation, then it can be added by impregnation techniques to the dried catalyst particles, which are preferably spray dried microspheres.
• Impregnation after drying may be advantageous in some cases where sites of additive metal are likely to be impaired by catalyst matrix material which might partially cover additive metal sites introduced before spray drying or before some other particle solidification process.
• Inorganic metal additives may also be introduced into the conversion pro cess along with water containing streams, such as used to cool the regenerator or to lift, fluidize or strip catalyst.
• a preferred matrix material is a semi-synthetic combination of clay and silica-alumina as described in U.S. Patent 3,034,994.
• the clay is mostly a kaolinite and is combined with a synthetic silica-alumina hydrogel or hydrosol.
• This synthetic component forms preferably about 15 to 75 percent, more preferably about 20 to 25 percent, of the formed catalyst by weight.
• the proportion of clay is such that the catalyst preferably contains after forming, about 10 to 75 percent, more preferably about 30 to 50 percent, clay by weight.
• the most preferred composition of the matrix contains approximately twice as much clay as synthetically derived silica-alumina.
• the synthetically derived silica-alumina should contain 55 to 95 percent by weight of silica (SiO 2 ), preferably 65 to 85 percent, most preferably about 75 percent. Catalysts wherein the gel matrix consists entirely of silica gel or alumina gel are also included.
• a silica hydrogel is prepared by adding sulfuric acid with vigorous agitation and controlled temperature, time and concentration conditions to a sodium silicate solution.
• Aluminum sulfate in water is then added to the silica hydrogel with vigorous agitation to fill the gel pores with the aluminum salt solution.
• An ammonium solution is then added to the gel with vigorous agitation to precipitate the aluminum as hydrous alumina which combines with silica at the surface of the silica hydrogel pores.
• the hydrous gel is then processed, for instance, by separating a part of the water on vacuum filters and then drying, or more preferably, by spray drying the hydrous gel to produce microspheres.
• the dried product is then washed to remove sodium and sulfate ions, either with water or a very weak acid solution.
• the resulting product is then dried to a low moisture content, usually less than 25 percent by weight, e.g., 10 percent to 20 percent by weight, to provide the finished catalyst product.
• the silica-alumina hydrogel slurry may be filtered and washed in gel form to affect purification of the gel by the removal of dissolved salts. This may enhance the formation of a continuous phase in the spray dried microspherical particles. If the slurry is prefiltered and washed and it is desired to spray dry the filter cake, the latter may be reslurried with enough water to produce a pumpable mixture for spray drying. The spray dried product may then be washed again and given a final drying in the manner previously described.
• the zeolite materials utilized in the preferred embodiments of this invention are synthetic faujasites which possess silica to alumina ratios in the range from about 2.5 to 7.0, preferably 3.0 to 6.0 and most preferably 4.5 to 6.0.
• Synthetic faujasites are widely known crystalline aluminosilicate zeolites and common examples of synthetic faujasites are the X and Y types commercially available from the Davison Division of W.R. Grace and Company and the Linde Division of Union Carbide Corporation.
• the ultrastable hydrogen exchanged zeolites, such as Z-14XS and A-14US from Davison are also particularly suitable.
• other preferred types of zeolitic materials are mordenite and erionite.
• the preferred synthetic faujasite is zeolite Y which may be prepared as described in U.S. Patent No. 3,130,007 and U.S. Patent No. 4,010,116, which patents are incorporated herein by refer ence.
• the aluminosilicates of this latter patent have high silica (SiO 2 ) to alumina (Al 2 O,) molar ratios, preferably above 4, to give high thermal stability.
• a reaction composition is produced from a mixture of sodium silicate, sodium hydroxide, and sodium chloride formulated to contain 5.27 mole percent SiO 2 , 3.5 mole percent Na 2 O, 1.7 mole percent chloride and the balance water. 12.6 parts of this solution are mixed with 1 part by weight of calcined kaolin clay. The reaction mixture is held at about 60°F to 75°F for a period of about four days. After this low temperature digestion step, the mixture is heated with live steam to about 190°F until crystallization of the material is complete, for example, about 72 hours.
• the crystalline material - is filtered and washed to give a silicated clay zeolite having a silica to alumina ratio of about 4.3 and containing about 13.5 percent by weight of Na 2 O on a volatile free basis. Variation of the components and of the times and temperatures, as is usual in commercial operations, will produce zeolite having silica to alumina mole ratios varying from about 4 to about 5. Mole ratios above 5 may be obtained by increasing the amount of SiO 2 in the reaction mixture. The sodium form of the zeolite is then exchanged with polyvalent cations to reduce the Na 2 O content to less than about 1.0 percent by weight, and preferably less than 0.1 percent by weight.
• the amount of zeolitic material dispersed in the matrix based on the final fired product should be at least about 10 weight percent, preferably in the range of about 20 to 50 weight percent, most preferably about 20 to 40 weight percent.
• Crystalline aluminosilicate zeolites exhibit acidic sites on both interior and exterior surfaces with the largest proportion to total surface area and cracking sites being internal to the particles within the crystalline micropores. These zeolites are usually crystallized as regularly shaped, discrete particles of approximately 0.1 to 10 microns in size and, accordingly, this is the size range normally provided by commercial catalyst suppliers. To increase exterior (portal) surface area, the particle size of the zeolites for the present invention should preferably be in the lower portion of this size range.
• the preferred zeolites are thermally stabilized with hydrogen and/or rare earth ions and are steam stable to about 1,650°F.
• the metal additive may be incorporated directly into the matrix material.
• the metal additive can be added in the form of a water soluble compound such as the nitrate, halide, sulfate, carbonate, or the like, and/or as an oxide or hydrous gel, such as titania or zirconia gel. Other active gelatinous precipitates or other gel like materials may also be used.
• This mixture may be spray dried to yield the finished catalyst as a microspherical particle of 10 to 200 microns in size with the active metal additive deposited within the matrix and/or on the outer surface of the catalyst particle.
• concentration of vanadium on spent catalyst can be as high as 4 wt% of particle weight
• concentration of additive metal is preferably in the range of 1 to 8 wt% as the metal element. More preferably, there is sufficient metal additive to maintain at least the preferred atomic ratio of additive metal to vanadium at all times.
• the zeolites and/or the metal additive can be suitably dispersed in the matrix materials for use as cracking catalysts by methods well-known in the art, such as those disclosed, for example, in U.S. Patent Nos.
• the composition is preferably slurried and spray dried to form catalyst microspheres .
• the particle size of the spray dried matrix is generally in the range of about 10 to 200 microns, preferably 20 to 150 microns, more preferably 40 to 80 microns.
• the finished catalyst should contain from 5 to 50% by weight zeolite, preferably rare earth or ammonia exchanged sieve of either or both the X and Y variety and preferably about 15 to 45% by weight, most preferably 20 to 40% by weight.
• rare earth exchanged sieve may be calcined and further exchanged with rare earth or ammonia to create an exceptionally stable sieve.
• a silica sol component is prepared by mixing sodium silicate with water and rapidly mixing with acid to provide a sol which comprises from about 0.5 to 0.6% by weight Na 2 O and sufficient acid to provide a pH of between about 0.5 to 3.3 and preferably of between 1.0 and 3.0.
• the sol is prepared by combining commercially available 40° Baume 3.25 Na 2 O.SiO 2 solution with sulfuric acid solution having a concentration of 9 to 361 by weight H 2 SO 4 .
• the sol may be combined with from about 15 to 45% by weight total solids and the remainder water.
• the metal additive may be added to this sol and/or to the zeolite slurry component below.
• a basic zeolite slurry component is then made up by mixing the desired quantities of zeolite in the sodium form with a sufficient quantity of sodium silicate solution (typically 40° Baume) and water to give a product having the desired pH.
• Clay may be added to the basic zeolite slurry component if desired.
• the pH of the zeolite slurry component is maintained above about 10 and preferably at between 10.5 and 14.
• the slurry component will contain from about 10 to 17% by weight sodium silicate, from about 10 to 17% by weight zeolite and optionally from about 15 to 40% by weight clay and the balance water.
• the total solids content of the zeolite containing basic slurry ranges from about 33 to 46% by weight.
• the two streams are mixed instantaneously and homogeneously in amounts such from about 1.5 to 7.5 parts by weight of the above defined sol component is mixed with each part by weight of the zeolite slurry component.
• the mixture is immediately atomized, i.e., sprayed, into a heated gaseous atmosphere, such as air and/or steam having a temperature of 25° to 300oF, using a commercially available spray drier, such as a Model V Production Minor unit made by Niro Atomizer, Inc. of Columbia, Maryland, U.S.A.
• a water slurry of the spray formed microspherical particles has a pH of about 3.0 to 10.0.
• the air atomizer used should feed the two components into the nozzle at pressures of about 90 to 150 psi and maintain the air in the nozzle at about 80 to 90 psi, preferably about 81-83 psi.
• the metal additive may also be fed separately to the nozzle via a separate line operated at pressures of about 90 to 150 psi.
• vanadyl naphthenate 345 grams is added to 1800 ml of a hydrocarbon solution (1000 ml toluene - 800 ml cyclohexane) and heated to 60°C with stirring to solubilize the vanadyl naphthenate.
• a reduced crude conversion catalyst containing 40% zeolite in a silica bound matrix
• the vanadyl naphthenate solution is added slowly with vibration to cover the catalyst. The pressure is increased to ambient conditions to thoroughly fill the catalyst pores.
• the vanadium impregnated catalyst is dried at 300°F for three hours and a portion calcined at 900°F for 7 hours. This yielded a catalyst containing 0.52 wt% vanadium.
• the catalyst was then regenerated (organic moieties burned off) as a shallow bed in a furnace at 900°F for 6 hours.
• the regenerated catalyst was then steamed at 1,450°F for 5 hours according to the procedure outlined in this invention. This procedure yielded a catalyst containing 0.53 wt% V and 0.53 wt% Ti in a 1/1 weight ratio.
• the select catalysts of this invention include solids of high catalytic activity such as zeolites in a matrix of clays, kaolin, silica, alumina, smectites and other 2-layered lamellar silicates, silica-alumina, and the like.
• the surface area of these catalysts are preferably above 100 m 2 /g and they have a pore volume preferably in excess of 0.2 cc/g and a micro-activity (MAT) value in volume percent conversion as measured by ASTM Test Method No. D-3908-80 of at least 60, and preferably in the range of 65 to 90.
• a catalyst having a relatively high level of cracking activity providing high levels of conversion and selectivity at low residence times.
• the conversion capabilities of the catalyst may be expressed in terms of the conversion produced during actual operation of the process and/or in terms of conversion produced in standard catalyst activity tests.
• a catalyst which, in the course of extended operation under prevailing process conditions, is sufficient active for sustaining a level of conversion of at least about 50% and more preferably at least about 60%.
• conversion is expressed in liquid volume percent based on fresh feed.
• the preferred catalyst may be defined as one which, in its virgin or equilibrium state, exhibits a specified activity expressed as a percentage in terms of MAT (micro-activity test) conversion.
• the foregoing percentage is the volume percentage of standard feedstock which a catalyst under evaluation will convert to 430°F end point gasoline, lighter products and coke at 900°F, 16 WHSV (weight hourly space velocity calculated on a moisture free basis using clean catalyst which has been dried at 1100°F, weighed and then conditioned for a period of at least 8 hours at about 25°C and 50% relative humidity, until about one hour or less prior to contacting the feed), and 3 C/O (catalyst to oil weight ratio) by ASTM D-32 MAT test D-3907-80, using an appropriate standard feedstock, e.g., a sweet light primary gas oil, such as that used by Davison Division of W. R. Grace and defined as follows: PI Gravity at 60° F, degrees 31.0
• the gasoline end point and boiling temperature-volume percent relationships of the products produced in the MAT conversion test may for example be determined by simulated distillation techniques, for example by modification of the gas chromatographic "Sim-D" technique of ASTM D-2887-73.
• the results of such simulations are in reasonable agreement with the results obtained by subjecting larger samples of material to standard laboratory distillation techniques. Conversion is calculated by subtracting from 100 the volume percent (based on fresh feed) of those products heavier than gasoline which remain in the recovered product.
• relative activity is a ratio obtained by dividing the weight of a standard or reference catalyst which is or would be required to produce a given level of conversion, by the weight of an operating catalyst (whether proposed or actually used) which is or would be required to produce the same level of conversion in the same or equivalent feedstock under the same or equivalent conditions.
• Said ratio of catalyst weights may be expressed as a numerical ratio, but preferably is converted to a percentage basis.
• the standard catalyst is preferably chosen from among catalysts useful for conducting the present invention, such as for example, zeolite fluid cracking catalysts, and is chosen for its ability to produce a predetermined level of conversion in a standard feed under the conditions of temperature, WHSV, catalyst to oil ratio and other conditions set forth in the preceding description of the MAT conversion test and in ASTM D-32 MAT test D-3907-80. Conversion is the volume percentage of feedstock that is converted to 430°F end point gasoline, lighter products and coke. For standard feed, one may employ the above-mentioned light primary gas oil, or equivalent.
• a "standard catalyst curve" a chart or graph of conversion (as above defined) vs. reciprocal WHSV for the standard catalyst and feedstock.
• a sufficient number of runs is made under ASTM D-3907-80 conditions (as modified above) using standard feedstock at varying levels of WHSV to prepare an accurate "curve" of conversion vs. WHSV for the standard feedstock.
• This curve should traverse all or substantially all of the various levels of conversion including the range of conversion within which it is expected that the operating catalyst will be tested. From this curve, one may establish a standard WHSV corresponding to that level of conversion which has been chosen to represent 100% relative activity in the standard catalyst.
• the aforementioned reciprocal WHSV and level of conversion are, respectively, 0.0625 and 75%.
• a MAT conversion vs. relative activity curve was developed utilizing a standard catalyst of 75 vol.% conversion to represent 100% relative activity.
• One such curve is shown in Fig. 9.
• a relative activity of 0.5 or 50% means that it would take twice the amount of the operating catalyst to give the same conversion as the standard catalyst, i.e., the production catalyst is 50% as active as the reference catalyst.
• the catalyst may be introduced into the process in its virgin form or, as previously indicated, in other than its virgin form; e.g., one may use equilibrium catalyst withdrawn from another unit, such as catalyst that has been employed in the cracking of a dif ferent feed.
• equilibrium catalyst withdrawn from another unit such as catalyst that has been employed in the cracking of a dif ferent feed.
• the preferred catalysts may be described on the basis of their activity "as introduced” into the process of the present invention, or on the basis of their "as withdrawn” or equilibrium activity in the process of the present invention, or on both of these bases.
• a preferred activity level of virgin and non-virgin catalyst "as introduced" into the process of the present invention is at least about 60% by MAT conversion and preferably at least about 20%, more preferably at least about 40% and still more preferably at least about 60% in terms of relative activity.
• An acceptable "as withdrawn” or equilibrium activity level of catalyst which has been used in the process of the present invention is at least about 20% or more, but about 40% or more and preferably about 60% or more is preferred on a relative activity basis, and an activity level of 60% or more on a MAT conversion basis is also contemplated. More preferably, it is desired to employ a catalyst which will, under the conditions of use in the unit, establish an equilibrium activity at or above the indicated level.
• the catalyst activities are determined with catalyst having less than 0.01 coke, e.g., regenerated catalyst.
• feedstocks contemplated for use with the invention include whole crude oils; light fractions of crude oils such as light gas oils, heavy gas oils, and vacuum gas oils; and heavy fractions of crude oils such as topped crude, reduced crude, vacuum fractionator bottoms, other fractions containing heavy residua, coal-derived oils, shale oils, waxes, untreated or deasphalted residua, and blends of such fractions with gas oils and the like.
• a high vanadium feed for FCC processing is one having more than 0.1 ppm vanadium, preferably 1.0 to 5.0 ppm where a relatively small amount of reduced crude (5-25%) is mixed with VGO to provide an FCC feedstock.
• a high vanadium feed for RCC processing is one having more than 1.0 ppm vanadium, preferably more than about 5.0 ppm.
• the preferred weight ratio of vanadium to. nickel in feed without additive nickel is in the range of from about 1:3 to 5:1, more preferably greater than about 1:1.
• the vanadia immobilization catalysts and/or methods described in this specification are preferably employed in combination with the processes and apparatuses for carbo-metallic oil conversion described in co-pending U.S. applications Serial Nos. 94,091; 94,092; 94,216; 94,217; and 94,227; each of said co-pending applications having been filed on November 14, 1979, and being expressly incorporated herein by reference.
• the preferred feeds capable of being cracked by these methods and apparatuses are comprised of 100% or less of 650°F+ material of which at least 5 wt%, preferably at least 10 wt% , does not boil below about 1,025°F.
• high molecular weight and/or “heavy” hydrocarbons refer to those hydrocarbon fractions having a normal boiling point of at least 1,025°F and include non-boiling hydrocarbons, i.e., those materials which may not boil under any conditions.
• the feedstocks for which the invention is particularly useful will have a heavy metal content of at least about 5 ppm of nickel equivalents, a vanadium content of at least 2.0 ppm, and a Conradson residue of at least about 2.0. The greater the heavy metal content and the greater the proportion of vanadium in that heavy metal content, the more advantageous the metal additives and processes of this invention becomes.
• a particularly preferred feedstock for treatment by the process of the invention includes a reduced crude comprising 70% or more of a 650°F+ material having a fraction greater than 20% hoilirig above about 1,025°F at atmospheric pressure, a metals content of greater than 5.5 ppm nickel equivalents of which at least 5 ppm is vanadium, a vanadium to nickel atomic ratio of at least 1.0, and a Conradson carbon residue greater than 4.0.
• This feed may also have a hydrogen to carbon ratio of less than about 1.8 and coke precursors in an amount sufficient to yield about 4 to 14% coke by weight based on fresh feed.
• the feed is preferably pretreated to remove sodium to a level less than 1 ppm.
• Sodium vanadates have low melting points and may also flow and destroy the crystalline zeolites in the same manner as vanadium pentoxide. Although it is desirable to maintain low sodium levels in the feed in order to minimize neutralization of acid sites, as well as to avoid sodium vanadates on the catalyst, the metal additives of the present invention are also effective in forming compounds, alloys, or complexes with sodium vanadates so as to prevent these compounds from destroying the zeolite.
• such metals may accumulate on an FCC catalyst to levels in the range of 100 to 10,000 ppm total metals, preferably 500-5,000 ppm, of which 5 to 100%, preferably 20 to 80%, is vanadium.
• Such metals may accumulate on RCC catalysts to levels in the range of from about 3,000 to about 70,000 ppm of total metals, preferably 10,000 to 30,000 ppm, of which 5 to 100%, preferably 20 to 80% is vanadium.
• the feed may contain nickel in controlled amounts so that the oxide of nickel may help tie up vanadium pentoxide in a high melting complex, compound or alloy.
• the invention therefore contemplates controlling the amounts of nickel in the feed by introducing nickel additives or feedstocks with high nickel to vanadium ratios so that the compounds of this metal, either alone or in combination with other additives, comprise the metal additive of the invention.
• a nickel containing catalyst may also be made by first using virgin catalyst, with or without another metal additive, in a conversion process employing a feedstock with a high nickel to vanadium ratio; and then using the resulting equilibrium catalyst as make-up catalyst in the process of the present invention.
• the atomic ratio of nickel to vanadium on the catalyst should be greater than 1.0, preferably at least about 1.5.
• the cracking reaction according to the methods disclosed in the above co-pending applications is sufficiently severe to convert 50 to 90 percent of the carbon-metallic oil feed to gasoline per pass and produce coke in amounts of 4 to 14 percent by weight based on weight of fresh feed.
• This coke is laid down on the catalyst in amounts in the range of about 0.3 to 3 percent by weight of catalyst, depending upon the catalyst to oil ratio (weight of catalyst to weight of feedstock) in the riser.
• the feed with or without pretreatment, is introduced as shown in Fig. 1 into the bottom of the riser along with a suspension of hot cracking catalyst prepared in accordance with this invention.
• Steam, naphtha, water, flue gas and/or some other diluent is preferably introduced into the riser along with the feed.
• These diluents may be from a fresh source or may be recycled from a process stream in the refinery. Where recycle diluent streams are used, they may diluent specified includes the amount of water used. Extra diluent would further increase the vapor velocity and further lower the feed partial pressure in the riser.
• the feed As the feed travels up the riser, it is catalytically cracked to form basically five products known in the industry as dry gas, wet gas, cat naphtha, light cycle oil, heavy cycle oil and/or slurry oil.
• the catalyst particles are ballistically separated from product vapors as previously described.
• the catalyst which then contains the coke formed in the riser is sent to the regenerator to burn off the coke and the separated product vapors are sent to a fractionator for further separation and treatment to provide the five basic products indicated.
• the invention may be utilized in FCC processes.
• Preferred riser conditions for an FCC process employing the invention are summarized in Table C-1.
• Th preferred conditions for the riser conversion reaction of Ashland' s RCC processes are summarized in Table C-2.
• the abbreviations used have the following meansings: "Temp.” for temperature, “Dil.” for diluent, “pp” for partial pressure, “wgt” for weight, “V” for vapor, “Res.” for residence, “C/O” for catalyst to oil ratio, “Cat.” for catalyst, “bbl” for barrel, "MAT” for micro-activity by the MAT test using a standard Davison feedstock, "Vel.” for velocity, “cge” for charge, "d” for density and “Reg.” for regeneratede
• the regenerating gas may be any gas which can provide oxygen to convert carbon to carbon oxides. Air is highly suitable for this purpose in view of its ready availability. The amount of air required per pound of coke for combustion depends upon the desired carbon dioxide to carbon monoxide ratio in the effluent gases and upon the amount of other combustible materials present in the coke, such as hydrogen, sulfur, nitrogen and other elements capable of forming gaseous oxides at regenerator conditions.
• the regenerator is operated at temperatures in the range of about 1,000 to 1,600°F, preferably 1,275 to 1,450°F, to achieve adequate combustion while keeping catalyst temperatures below those at which significant catalyst degradation can occur. In order to control these temperatures, it is necessary to control the rate of burning which in turn can be controlled at least in part by the relative amounts of oxidizing gas and carbon introduced into the regeneration zone per unit time.
• the rate of introducing carbon into the regenerator may be controlled by regulating the rate of flow of coked catalyst through valve 40 in conduit.39, the rate of removal of regenerated catalyst by regulating valve 41 in conduit 16, and the rate of introducing oxidizing gas by the speed of operation of blowers (not shown) supplying air to the conduit 14.
• These parameters may be regulated such that the ratio of carbon dioxide to carbon monoxide in the effluent gases is equal to or less than about 4.0, preferably about 1.5 or less.
• water either as liquid or steam, may be added to the regenerator to help control temperatures and to influence the carbon dioxide to carbon monoxide ratio.
• the regenerator combustion reaction is carried out so that the amount of carbon remaining on regenerated catalyst is less than about 0.25, preferably less than about 0.05 percent and most preferably less than about 0.01 percent on a substantially moisture-free weight basis.
• the residual carbon level is ascertained by conventional techniques which include drying the catalyst at 1,100°F for about four hours before actually measuring the carbon content so that the carbon level obtained is on a moisture-free basis.
• the metal additive When the metal additive is introduced as an aqueous or hydrocarbon solution or as a volatile compound during the processing cycle, it may be added at any point of catalyst travel in the processing apparatus. With reference to Fig. 1, this would include, but not be limited to, addition of the metal additive solution at the riser wye 17, along the riser length 4, to the dense bed 9 in the reactor vessel 5, to the strippers 10 and 15, to regenerator air inlet 14, to regenerator dense bed 12, and/or to regenerated catalyst standpipe 16.
• the catalyst of this invention with or without the metal additive is charged to an FCC unit of the type outlined in Fig. 1 or to a Reduced Crude Conversion (RCC) unit of the type disclosed in Ashland's said RCC applications.
• Catalyst particle circulation and operating parameters are brought up to process conditions by methods well-known to those skilled in the art.
• the equilibrium catalyst at a temperature of 1,100-1, 500°F contacts the oil feed at riser wye 17.
• the feed can contain steam and/or flue gas injected at point 2 or water and/or naphtha injected at point 3 to aid in feed vaporization, catalyst fluidization and controlling contact time in riser 4.
• the catalyst and vaporous hydrocarbons travel up riser 4 at a contact time of 0.1-5 seconds, preferably 0.5-3 seconds.
• the catalyst and vaporous hydrocarbons are separated in vented riser outlet 6 at a final reaction temperature of 900-1,100°F.
• the vaporous hydrocarbons are transferred to a multistage cyclone 7 where any entrained catalyst fines are separated and the hydrocarbon vapors are sent to a fractionator (not shown) via transfer line 8.
• the coked catalyst is then transferred to stripper 10 for removal of entrained hydrocarbon vapors and then to regenerator vessel 11 to form a dense fluidized bed 12.
• An oxygen containing gas such as air is admitted to the bottom of dense bed 12 in vessel 11 to combust the coke to carbon oxides.
• the resulting flue gas is processed through cyclones 22 and exits from regenerator vessel 11 via line 23.
• the regenerated catalyst is transferred to stripper 15 to remove any entrained combustion gases and then transferred to riser wye 17 via line 16 to repeat the cycle.
• Addition-withdrawal points 18 and 19 can be utilized to add virgin catalysts containing one or more metal additives of the invention.
• the metal additive as an aqueous solution or as an organo-metallic compound in aqueous or hydrocarbon solvents can be added at points 18 and 19, as well as at addition points 2 and 3 on feed line 1, addition point 20 in riser 4 and addition point 21 near .the bottom of vessel 5.
• the addition of the metal additive is not limited to these locations, but can be introduced at any point in the oil-catalyst processing cycle.
• TPT is diluted with heavy gas oil (HGO) to form a solution of 1 part TPT to 1 part HGO.
• HGO heavy gas oil
• This solution is added to riser feed line 1 in an amount sufficient to yield 1 part titanium by weight to 1 part vanadium in the feed.
• the feed is a reduced crude processed at 600,000 lb. per day with a vanadium content of 200 ppm. Based on the vanadium content and the molecular weight of the TPT, this equates to adding 420 lbs. of TPT per day to 600,000 lbs. of reduced crude feed per day.
• MMT methylcy ⁇ lopentadienyl manganese tricarbonyl
• the rate of metals build up on the circulating catalyst is a function of metals in the feed, the catalyst circulating inventory, the catalyst addition and withdrawal rates (equal), and the catalyst to oil ratio.
• Figs. 10 and 11 give the rate of metal buildup on a circulating catalyst at constant inventory, constant catalyst addition and withdrawal rate and varying metals content in the feed.
• the required concentrations of the metal additives of this invention on the catalyst can be calculated so as to yield the preferred atomic ratio of metal additive to vanadium.
• the unit has 9,000 lbs. of catalyst inventory, a catalyst addition rate of 1.35 Ib./bbl. of feed per day, and a feed rate of 200 bbl./day.
• Curve 1 in Fig. 10 would be utilized to show total vanadium after 150 days of continuous operation with 70 ppm vanadium in the feed.
• the vanadium level on the catalyst would equilibrate at about 17,000 ppm and then remains constant with time.
• the catalst would be prepared such that it would contain at least 8,500 ppm titanium to ensure at least a 0.5 atomic ratio of titanium to vanadium was maintained at equilibrium conditions. Similar calculations can be performed for lower and higher equilibrium vanadium values using the other curves or multiples of those curves (120 ppm metals on catalyst would equilibrate at about 30,000 ppm under the conditions of Fig. 10).
• the rate of vanadium buildup on the catalyst and the equilibrium or steady state level of vanadium on the catalyst is a function of vanadium content of the feed and especially the catalyst addition and withdrawal rates which are equal at equilibrium conditions.
• Table E presents a typical case for a 40,000 bbl./day unit in which the vanadium content of the feed is varied from 1 ppm (FCC operations with VGO containing 5-20% of a heavy hydrocarbon fraction) up to 25-400 ppm (RCC operations).
• the catalyst addition rate can be varied to yield equilibrated vanadium values of from 5,000 to 30,000 ppm.
• vanadium as vanadium pentoxide on the catalyst, causes irreversible zeolite destruction and especially manifests this phenomena at the higher vanadium levels.
• the zeolite content can be reduced by at least 50%, and at 10,000 ppm, complete destruction of the zeolite crystalline structure is apparent.
• the additive of this invention one can now operate in the upper ranges of vanadium levels (20,000-30,000 ppm) without the vanadium destroying the zeolite and causing particle coalescence.
• Table F presents the economic advantage of introducing the additive of this invention into the riser as an aqueous or hydrocarbon solution.
• Table F shows the economic differential (savings in $/day) that can be realized by utilizing the additives of this invention and operating at the 20,000 ppm level versus the 10,000 ppm level of vanadium. These savings can be higher by a factor of about two (2) if one considers operation at the 5,000 ppm level versus the 20,000 ppm level of vanadium.
• a cheaper additive titanium tetrachloride instead of TPT
• TPT costs $12/lb. of titanium content
• titanium tetrachloride costs only $1.50/lb. of titanium content.
• Catalyst Addition Rates required to hold vanadium at given levels on a cacalyst for feeds with varying levels of vanadium content are required to hold vanadium at given levels on a cacalyst for feeds with varying levels of vanadium content.
• Catalyst cost is assumed to be $1/lb. See Table E to obtain catalyst addition rate to maintain catalyst at 10,000 p ⁇ n level and 20,000 ppm level;
• the regenerator vessel as illustrated in Fig. 1 is a simple one zone-dense bed type.
• the regenerator section is not limited to this example but can consist of two or more zones in stacked or side by side relation and with internal and/or external circulation transfer lines from zone to zone.
• Such multistage regenerators are described in more detail in Ashland's above RCC applications.
• calcining, impregnation and steaming a test sequence designated as calcining, impregnation and steaming (CIS) .
• the test measures the effects of nickel and vanadium deposition on fluid cracking catalysts under severe conditions of hydrothermal treatment.
• fresh catalyst is calcined at 1200°F for 3 hours in a shallow bed, 100 gms of the dried material is then vacuum impregnated with 0.25, 0.5, 1.0 and 2.0 wt% of added nickel or vanadium. Either aqueous solutions of the sodium sulfate or pentane solutions of metal organic complex are employed.
• PURPOSE This method outlines the deactivation procedure for impregnated and oxidized catalyst by hydrothermal treatment before the catalytic cracking activity is determined in the Micro-Activity Test (MAT).
• Deactivated catalyst is analyzed for the following parameters:
• CPF Carbon Producing Factor
• HPF Hydrogen Producing Factor
• the clay free of vanadia does not form any crust or clumps or fused particles at temperatures encountered in the regenerator section of the process described in this invention.
• vanadia concentrations of 1,000-5,000 ppm clumping was observed but the crusts binding particles could be readily broken into free flowing, crusty particles.
• vanadia concentrations above 5,000 ppm the clay begins to clump and bind badly and does not flow at all even with moderate impact.
• CRUCIBLE DIFFUSION TEST An extension of the clumping test is the use of a ceramic-alumina crucible to determine whether vanadia reacts with a given metal additive. If vanadia does not react with the metal additive or only a small amount of compound formation occurs, then the vanadia diffuses through and over the porous alumina walls and deposi-ts as a yellowish to orange deposit on the outside wall of the crucible. On the other hand, when compound formation occurs, there are little or no vanadia deposits formed on the outside of the crucible wall. Two series of tests were performed. In the first series shown in Table Y, a 1:1 mixture by weight of vanadium pentoxide and the metal additive was placed in the crucible and heated to 1500°F in air for 12 hours. Compoun formation or vanadia diffusion was as noted in Table Y.
• FIG. 8 An example of the effectiveness of the metals of this invention to immobilize vanadium and reduce its destructiveness towards the crystallinity of the zeolite structure is shown in Fig. 8.
• a standard FCC catalyst was steamed with and without vanadia, as shown in Runs 1 and 2. The presence of vanadium reduces the zeolite content from an intensity of 9.4 down to 3.1.
• Runs 3 and 4 illustrate the effectiveness of titania and the preference for the titania to be present as the vanadia is being deposited on the catalyst in the riser and before regeneration.
• the titanium and vanadium are deposited as organo-metallics, oxidized to remove the hydrocarbon portion of the organo metallic compounds and to oxidize the elements to their corresponding oxides of highest valence.
• titanium vanadate which, is a high melting solid as shown in Table A.
• the invention is useful in catalytic conversion of both. FCC and RCC feeds as descrihLed above.
• the present invention is particularly useful in the catalytic cracking of high boiling carbo-metallic feedstocks to lower boiling hydrocarbon fractions in the liquid fuel range. Examples of these oils are reduced crudes and other crude oils or crude oil fractions containing residua as above defined.
• the catalytic cracking process is preferably conducted in the riser reactor of the vented type, other types of risers and other types of reactors with either upward or downward flow may be employed.
• the cracking operation may be conducted with a moving bed of catalyst which, moves in countercurrent relation to liquid (unvaporized feedstock under suitable contact conditions of pressure, temperature and weight hourly space velocity.
• the feedstock maybe passed through alternating fixed beds of catalyst with cycling cracking and regeneration.
• the catalyst and processes of the invention may be employed in various others types of hydrocarbon conversion operations, such as dehydrocyclization, hydrocracking, hydroforming of naphthene hydrocarbons and the like, polymerization of olefins, depolymerization of polymers, alkylation, dealkylation, dispr ⁇ portionation, reforming of naphthas, isomerization of paraffins and the like, aromatization of paraffins and the like, hydrogenation, dehydrogenation, various types of hydrofining operation in which one or more characteristics of the feedstock are improved by treatment with hydrogen in the presence of a catalyst, and like types of other contacting and/or conversion processes.
• hydrocarbon conversion operations such as dehydrocyclization, hydrocracking, hydroforming of naphthene hydrocarbons and the like, polymerization of olefins, depolymerization of polymers, alkylation, dealkylation, dispr ⁇ portionation, reforming of naphthas, isomerization of paraffins and the

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• 1981
  • 1981-03-19 WO PCT/US1981/000356 patent/WO1982003225A1/en unknown
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