Abstract: Spent or inactive alumina-supported catalysts removed from a catalytic hydrotreating process and having carbonaceous and metallic deposits thereon are reactivated. After a solvent wash to remove process oils, the spent catalyst is contacted with steam at a temperature of 1000.degree. to about 1250.degree. F. for a period of about 2 to about 5 hours to form a reactivated catalyst suitable for reuse in a catalytic hydrotreating process. Optionally, the steam-treated catalyst can be regenerated by contact with an oxygen-containing gas at a temperature of about 700.degree. to about 900.degree. F. to remove carbon deposits from the catalyst, or, alternatively, the steam-treated catalyst can be acid-leached to remove undesired metals and then contacted with an oxygen-containing gas at an elevated temperature to remove carbon deposits.

Abstract: Hydrodesulfurization of a cracked naphtha is effected in the presence of, as catalyst, a non-noble metal of Group VIII and a metal of Group VI-B on an alumina support containing a hydrotalcite-like composition. The process of the instant invention gives high levels of hydrodesulfurization compared to prior art magnesia-containing catalysts and lower levels of olefin saturation, and less octane reduction in the desulfurized gasoline.

Abstract: A naphtha or a middle distillate hydrocarbon is dehydroaromatized by hydrotreating in the presence of a catalyst containing non-noble Group VIII metal and Group VI-B metal on carbon.

Abstract: Hydrodesulfurization of cracked naphtha, with minimum attendant hydrogenation of olefins, is effected over a sulfided carbon support catalyst bearing (i) a non-noble Group VIII metal, (ii) a Group VI-B metal, and (iii) a metal of Group IA, II A, III B, or the lanthanide Group of rare earths.

Abstract: Naphtha is selectively hydrodesulfurized using spent resid upgrading catalyst to remove sulfur while minimizing loss in octane level due to olefin saturation.

Abstract: A method for preparing catalysts suitable for hydroprocessing and hydrocracking of naphthas and gas oils is provided. Catalysts consist of an aerogel support comprising one or more transition metal oxide polymers, prepared by the super-critical fluid extraction of alkoxide alcogels, together with one or several promoting metals in oxide or sulfide form. A process for hydroprocessing hydrocarbons using the catalyst of this invention is also provided.

Abstract: Diesel fuels are decolorized by hydrotreatment under mild conditions. The feedstock is normally severely hydrotreated to convert organosulfur or organonitrogen and the effluent passed to a smaller downstream hydrotreating zone at a lower temperature but sufficient to lighten the color of a finished product hydrocarbon.

Abstract: Heavy oils may be hydrotreated in the presence of a porous alumina support bearing metals of Group VIII and VI-B and optionally phosphorus, the catalyst having a Total Surface Area of 165-230 m.sup.2 /g, a Total Pore Volume of 0.5-0.8 cc.g, and a Pore Diameter Distribution whereby less than about 5% of the Total Pore Volume is present as primary micropores of diameter less than 80.ANG., and secondary micropores of diameter of .+-.20.ANG. of a Pore Mode of 100-135.ANG. are present in amount of at least about 65% of the micropore volume having pores with diameter less than 250.ANG., and 22-29% of the Total Pore Volume is present as macropores of diameter >250.ANG.. The process of the instant invention is particularly effective in achieving desired levels of hydrodemetallation, hydrodesulfurization, and hydrocracking of asphaltenes in the fraction of hydrotreated/hydrocracked petroleum resid product having a boiling point greater than 1000.degree. F.

Abstract: A method of selectively hydrodenitrogenating various raw hydrocarbon oils such as various petroleum feedstocks, coal liquids, shale oils and sand oils, which method comprises passing the raw hydrocarbon oil along with hydrogen (H.sub.2) over sulfided carbon supported Fe--Mo catalysts, whereby the raw hydrocarbon oil is hydrodenitrogenated with a selectivity significantly higher than that is possible with conventional alumina supported hydrotreating catalysts.

Abstract: A process for producing a desulfurized gasoline boiling range product of relatively high octane number from a sulfur containing feed boiling in the naphtha boiling range by converting the feed in a single stage over a catalyst which comprises a) a substantially acidic porous refractory solid having an intermediate effective pore size and the topology of a zeolitic behaving material, which, in the aluminosilicate form, has a Constraint Index of about 1 to 12, e.g., MCM-22, b) a Group VI metal, e.g., Mo, c) a Group VIII metal, e.g., Co, and d) a suitable refractory support, e.g., Al.sub.2 O.sub.3, under hydrotreating conditions to produce a product comprising a normally liquid fraction boiling in substantially the same boiling range as the feed, but which has a lower sulfur content than the feed and which has an octane number substantially no less than the feed.

Abstract: There is disclosed a process for hydrogenating treatment of a heavy hydrocarbon oil comprising the successive steps of (1) hydrogenating-demetalizing treatment, (2) hydrocracking treatment and (3) hydrodesulfurizing-hydrodenitrifying treatment in the presence of respective catalysts which process comprises employing in the hydrodesulfurizing-hydrodenitrifying treatment, a catalyst having a pore size distribution restricted to a specific range as measured by nitrogen release method. According to the above-mentioned process, a product oil with a low sulfur content can be obtained in high cracking efficiency from a heavy hydrocarbon oil without equipment trouble due to sludge formation.

Abstract: Heavy oil is hydrotreated by processing with hydrogen in the presence of a catalyst composition comprising an activated carbon component having a specified range of pore volume distribution and average pore diameter, a molybdenum or tungsten component and a cobalt or nickel component to reduce the content of nickel and vanadium therein and to achieve demetallation and conversion of the carbon residue for producing a lighter oil.

Abstract: A method of catalytically hydroconverting a hydrocarbon feed stream containing a substantial quantity of components boiling above about 1000.degree. F. to convert a substantial portion thereof to components boiling below 1000.degree. F. is disclosed. More particularly, aromatic heavy oil additive, such as Heavy Cycle Gas Oil, is added to a heavy hydrocarbon feed stream and the stream is contacted with a solid catalyst and an oil-miscible metal naphthenate. The method disclosed herein advantageously substantially eliminates plugging of the hydroconversion reactor and minimizes the amount of insolubles in the total liquid product.

Abstract: A process for treating heavy oil by contacting the oil with hydrogen in a reactor containing an activated carbon catalyst having a specified range of Alpha value, and average pore diameter, and pore distribution, to reduce the content of nickel and vanadium in the feedstock and to achieve conversion of the carbon residue for producing a lighter oil. Demetallation capacity of the carbon catalyst is enhanced by the addition of a carbon-reactive oxidant, e.g., steam, under conditions sufficient to form additional carbon surface.

Abstract: Hydrodesulfurization of a cracked naphtha is effected in the presence of a transition alumina support bearing a Group VIII non-noble metal oxide and a Group VI-B metal oxide, the atom ratio of Group VIII metal to Group VI-B metal being 1-8. The process of the instant invention gives high levels of hydrodesulfurization compared to prior art magnesia-containing catalysts and lower levels of olefin saturation, and less octane reduction in the desulfurized gasoline.

Abstract: A waste molybdenum-containing stream recovered from the work-up of a reaction mixture wherein propylene has reacted with t-butyl hydroperoxide to form propylene oxide (in the presence of a complex of ethylene glycol and a molybdenum compound) is passed as an oil-miscible/soluble molybdenum-containing catalyst to a reaction wherein heavy hydrocarbon is hydroconverted to lower boiling products in the presence of heterogeneous catalyst.

Abstract: A process and catalyst are provided for the hydrogenation of a hydrocarbon feedstock consisting essentially of hydrocarbon boiling between about 150.degree. F. and 700.degree. F. at atmospheric pressure. The process comprises reacting the feedstock with hydrogen at hydrogenation conditions in the presence of a catalyst comprising hydrogenation metals and a support comprising beta zeolite. The hydrogenation metals comprise from about 0.1 percent by weight to about 2.0 percent by weight each of palladium and platinum measured as a percentage of the catalyst. The beta zeolite comprises from about 1 ppm by weight to about 3.0 percent by weight sodium calculated as a percentage of said beta zeolite.

Abstract: Hydrodesulfurization of a cracked naphtha is effected in the presence of, as catalyst, an alkali metal, a metal of Group VIII, and a metal of Group VI-B on an alumina support containing a hydrotalcite-like composition.

Abstract: A catalyst useful for hydroprocessing a hydrocarbon-containing oil contains at least one hydrogenation component on an amorphous, porous refractory oxide support containing between 2 and 8 weight percent of silica. The catalyst is prepared by impregnating support particles having a narrow pore size distribution and a median pore diameter greater than about 120 angstroms with a solution containing precursors of the hydrogenation components, followed by drying and calcining. The catalyst is useful for promoting a number of hydrocarbon hydroprocessing reactions, particularly simultaneous hydrogenative desulfurization, demetallization and denitrogenation of residuum-containing oils.

Abstract: A process for the production of a low-sulfur diesel gas oil having a sulfur content of 0.05% by weight or lower and having a Saybolt color number of -10 or higher, from a petroleum distillate having a sulfur content of 0.1 to 2.0% by weight and having an inferior color and inferior oxidation stability comprises contacting the petroleum distillate with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 350.degree. to 450.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the first step to thereby produce materials having a sulfur content of 0.05% by weight or lower, and contacting further the materials issued from the first step with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 200.degree. to 300.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the second step to thereby produce the finished low-sulfur diesel gas oil.

Abstract: An aromatic saturation process is catalyzed under relatively low pressure conditions in the presence of a halide-containing compound. Additive fluoride-containing compounds can be injected into the feedstock just prior to contact of the feedstock with either a fluoride or nonfluoride-containing catalyst. Also, a catalyst utilized in the invention contains Group VIB and/or Group VIII hydrogenation metals, phosphorus and fluoride supported on an amorphous, porous refractory oxide and has a narrow pore size distribution.

Abstract: Naphtha is selectively hydrodesulfurized using deactivated hydrotreating catalyst to remove sulfur while minimizing loss in octane level due to olefin saturation.

Abstract: A process, catalyst, and method of making a catalyst are provided for the selective hydrotreating of a selective hydrotreating feedstock comprising reacting the feedstock with hydrogen at hydrotreating conditions in the presence of a catalyst comprising a hydrogenation component and a support component. The hydrogenation component comprises a Group VIB metal component and a Group VIII metal component wherein the Group VIB metal component is present in an amount ranging from about 4 wt % to about 20 wt % and the Group VIII metal component is present in an amount ranging from about 0.5 wt % to about 10 wt %, both calculated as oxides and based on the total catalyst weight. The support component comprises from about 0.5 wt % to about 50 wt % of a magnesium component and from about 0.02 wt % to about 10 wt % of an alkali metal component, both calculated as oxides and based on the total catalyst weight.

Abstract: The present invention relates to a process for removing hetero-atoms from a hydrocarbonaceous feedstock using novel catalysts comprised of highly dispersed molybdenum sulfide promoted with a noble metal such that the noble metal is in an oxidation state greater than 0 and coordinated to S. The noble metal is selected from Pt, Pd, Rh, and Ir. It is preferred that the catalysts of be prepared from a precursor composition selected from platinum ethoxyethyl xanthate or platinum dithiocarbamate. Additionally, the catalyst may include a promotor sulfide such as nickel sulfide, cobalt sulfide or iron sulfide, etc. or mixtures thereof.

Abstract: A process is described for producing a catalyst composition for hydrodesulfurization of hydrocarbon oil, which comprises:drying and calcining a carrier comprising alumina or an alumina-containing material impregnated with a solution mixture of(A) at least one of an alkoxide, a chelate compound, or a glycoxide of molybdenum or chromium;(B) at least one of an alkoxide, a chelate compound, or a glycoxide of cobalt or nickel; andan organic solvent capable of dissolving (A) and (B).Also described is a process for hydrodesulfurizing hydrocarbon oil using the same catalyst composition.

Abstract: This invention relates to a hydrorefining catalyst containing ruthenium sulphide and cobalt and/or nickel sulphide on a refractory oxides support. These catalysts are only very slightly inhibited by polyaromatic compounds or hydrogen sulphide.

Abstract: In a hydrotreating process, a hydrocarbon feedstock having a boiling of at least about 460.degree. F. is contacted with a catalyst having at least one member selected from the group consisting of a carbide of a Group VIB metal and a nitride of a Group VIB metal under hydrotreating conditions.

Abstract: A hydrotreating process using a sulfided catalyst composition comprised of at least one Group VIII metal and at least one Group VI metal on an inorganic oxide support, which sulfided catalyst is derived from a catalyst precursor comprised of salts and/or complexes of a Group VIII metal(s) with a Group VI metal heteropolyacid on an inorganic oxide support material, wherein the concentration of Group VIII metal ranges from about 2 to 20 wt. %, and the concentration of Group VI metal ranges from 5 to 50 wt. %, which percents are on support and which catalyst composition is substantially free of free water.

Abstract: The hydroprocessing of heavy oils is improved by the use of a high activity slurry catalyst prepared by sulfiding an aqueous Group VIB metal compound with a gas containing hydrogen sulfide to a dosage greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal. After introducing the slurry catalyst into the heavy oil, and subjecting the mixture to elevated temperatures and partial pressures of hydrogen, the mixture is treated in a fixed or ebullated bed of hydrodesulfurization/hydrodemetalation catalyst under hydroprocessing conditions.

Abstract: The present invention relates to a hydroprocessing process that employs a catalyst that has been regenerated by subjecting the catalyst to an initial partial decoking step, followed by impregnation with a Group IIA metal-containing component and then subjected to a final decoking step.

Abstract: A process for removing heteroatoms from a hydrocarbonaceous feedstock using a catalyst composition comprised of: about 0.005 to 5.0 wt. % noble metal, about 0.5 to 5 wt. % of at least one Group VIII metal, and about 3 to 18 wt. % of a Group VI metal, and a refractory support, wherein the noble metal is incorporated into the refractory support by use of a precursor represented by ML.sub.2 when the noble metal is Pt or Pd, and ML.sub.3, when the noble metal is Rh or Ir, where M is the noble metal and L is a ligand selected from the dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates, thioxanthates, and further wherein L has organo groups having a sufficient number of carbon atoms to render the noble metal complex soluble in oil.

Abstract: A process and catalyust are provided for hydrogenation of a hydrocarbon feedstock consisting essentially of material boiling between about 150.degree. F. and about 700.degree. F. which comprises reacting the feedstock with hydrogen at hydrogenation conditions in the presence of a catalyst comprising from about 0.1% to about 2.0% by weight each of palladium and platinum and a support comprising mordenite. The process of the present invention provides substantially improved dearomatization performance, increased desulfurization and denitrogenation, increased distillate product cetane number, increased distllate volume expansion, and utilizes a more durable catalyst.

Abstract: Middle distillate petroleum streams are hydrotreated to produce a low sulfur and low aromatic product in a process employing three reaction zones in series. Hydrogen flows between the reaction zones countercurrent to the hydrocarbons. Hydrogen sulfide is removed from effluent of the first two reaction zones by hydrogen stripping. The second and third reaction zones employ a sulfur-sensitive noble metal hydrogenation catalyst. Operating pressure increases and temperature decreases from the first to third reaction zones.

Abstract: This invention relates to a novel synthetic crystalline molecular sieve composition, MCM-37, which may contain framework +3 valence element, e.g. aluminum, and +5 valence element, e.g. phosphorus or with an addition +4 valence element, e.g. silicon, and to use thereof as a support and in catalytic conversion of organic compounds. The crystalline composition of this invention can easily be converted to catalytically active material.

Abstract: The present invention relates to a spent hydroprocessing catalyst regeneration process wherein the catalyst is subjected to an initial partial decoking step, followed by the addition of at least one rare earth metal, and then subjected to a final decoking step.

Abstract: The present invention relates to a process for increasing the desulfurization activity of a catalyst prepared by incorporating an element selected from the group consisting of nickel, cobalt and mixtures thereof, and a heavy metal selected from the group consisting of molybdenum, tungsten and mixtures thereof, into an alumina hydrogel, wherein said catalyst is sulfided with the gaseous sulfur compound at a temperature of at least about 900.degree. F. at least one hour.

Abstract: A process is disclosed for removing sulfur from a naphtha feedstream comprising contacting a naphtha feed with a platinum on alumina sulfur conversion catalyst under mild reforming conditions so that thiophenic and other organic sulfur compounds are converted to hydrogen sulfide without any significant cracking of the naphtha feed. Thereafter, the naphtha feed stream is contacted with a sulfur sorbent that has a metal component selected from Group I-A or Group II-A of the Periodic Table supported on a refractory inorganic oxide support, to remove hydrogen sulfide from the naphtha feed.

Abstract: A catalyst composition useful in the hydroprocessing of a sulfur- and metal-containing hydrocarbon feedstock comprises 1.0-5.0 weight percent of an oxide of nickel or cobalt and 10.0-25.0 weight percent of an oxide of molybdenum, all supported on a porous alumina support in such a manner that the molybdenum gradient of the catalyst has a value of less than 6.0 and 15-30% of the nickel or cobalt contained in the catalyst is in an acid extractable form. The catalyst is further characterized by having a total surface area of 150-210 m.sup.2 /g, a total more volume of 0.50-0.75 cc/g, and a pore size distribution such that pores having diameters of less than 100A constitute less than 25.0%, pores having diameters of 100-160A constitute 70.0-85.0% and pores having diameters of greater than 250A constitutes 1.0-15.0% of the total pore volume of the catalyst.

Abstract: A novel noble metal containing high SiO.sub.2 /Al.sub.2 O.sub.3 ratio large pore zeolite catalyst is used for the direct reforming and desulfurization of olefinic gasolines derived from catalytic cracking processes. The aromatic gasoline obtained from this process has a higher octane rating and is lower in sulfur than the FCC gasoline fraction feed.

Abstract: Supported carbon-coated catalyst material and a method for producing and using same in catalytic reaction processes, preferably in ebullated or fluidized catalyst beds. The catalyst materials are prepared by depositing a porous carbon layer on a support material of a selected metal oxide or compound to produce 5-40 wt. % carbon thereon, then preferentially treating the carbon based layer by partial oxidation, pyrolysis or reduction to enhance and activate the carbon layer on the catalyst. Promoter materials can also be advantageously added either to the support material or to the carbon layer in 0.5-10 wt. % to provide an improved composite carbon-coated catalyst having total pore volume of 0.3-1.0 cc/gm, substantially increased surface area of 80-600 M.sup.2 /gm, low surface acidity, particle strength of 1.8-5 lb/mm with reduced particle attrition losses and improved catalyst performance characteristics.

Abstract: Heavy oils containing metal contaminants are hydrodesulfurized in a reactor containing a series of fixed beds of catalyst. The catalyst particles become caked together during the hydrodesulfurization process, possibly due to formation of metal sulfides and carbonaceous deposits, and the caked catalyst is removed by a hydro drilling method. The hydro drilling is preferably commenced by drilling a central opening through the catalyst beds. The catalyst particles and chunks are cut from the bed and removed from the reactor vessel through catalyst dump openings at the bottom of the vessel. Preferably, the dump openings are maintained open by hydro lancing as the cutting of catalysts in the upper part of the vessel loosens the catalyst so that the catalyst will drop down the central opening and thus out through the catalyst dump openings at the bottom of the reactor vessel.

Abstract: A combined process for hydrotreating and isomerizing a C.sub.4 -C.sub.7 feedstock is simplified and made more efficient by the use of a common hydrogen source and low hydrogen to hydrocarbon ratio in both the hydrotreating and isomerization steps of the invention. The method supplies hydrogen to a combined hydrotreatment and isomerization process for the isomerization of a feed stream comprising C.sub.4 -C.sub.7 hydrocarbons. The hydrocarbon feed stream contains sulfur and oxygen contaminants and is combined with a hydrogen-containing stream in an amount that produces a maximum hydrogen to hydrocarbon ratio of 0.9 stdm.sup.3 m.sup.3 (50 SCFB). The hydrotreater feed is contacted in a hydrotreater reactor with a catalyst comprising a Group VIB metal and a Group VIII metal on an alumina support.

Abstract: The instant invention comprises an improved hydrorefining process which comprises contacting hydrocarbonaceous oil feed and hydrogen with a catalyst comprising a hydrogenation component selected from the group consisting of Group VIB metal component, Group VIII non-noble metal component and mixtures thereof, optionally comprising a phosphorous-containing component or compound, and an alumina-containing support, at hydrorefining conditions, wherein the improvement comprises heating the catalyst in substantially non-sulfided form at initial start-up from a temperature below about 450.degree. F. to hydrorefining temperature at an average rate of less than 30.degree. F. per hour in the presence of hydrogen and a start-up hydrocarbonaceous oil feed having a sulfur content in the form of organosulfides of greater than 0.5 moles (basis elemental sulfur) per kilogram of start-up feed.

Abstract: The instant invention comprises an improved hydrorefining process which comprises contacting hydrocarbonaceous oil feed and hydrogen with a catalyst comprising a hydrogenation component selected from the group consisting of Group VIB metal component, Group VIII non-noble metal component and mixtures thereof, optionally comprising a phosphorous-containing component or compound, and an alumina-containing support, at hydrorefining conditions, wherein the improvement comprises heating the catalyst at initial start-up from a temperature below about 450.degree. F. to hydrorefining temperature at an average rate of less than 30.degree. F. per hour in the presence of hydrogen and said oil feed.

Abstract: The present invention relates to a process for increasing the desulfurization activity of a catalyst prepared by incorporating an element selected from the group consisting of nickel, cobalt and mixtures thereof, and a heavy metal selected from the group consisting of molybdenum, tungsten and mixtures thereof, into an alumina hydrogel, wherein said catalyst is sulfided with the gaseous sulfur compound at a temperature of at least about 900.degree. F. for at least one hour.

Abstract: Disclosed is a process for hydrotreating a hydrocarbonaceous feed wherein the feed is contacted in a mixed catalyst bed at a temperature of about 200.degree. C. to 450.degree. C., in the presence of hydrogne, which catalyst bed is comprised of: (a0 one or more catalysts comprised of at least one metal selected from Group VIB and at lease one metal selected from Group VIII of the Periodic Table of the Elements, on an inorganic oxide support material; and (b) one or more catlayst represented by MM'.sub.a S.sub.x where M is Cr or one or more divalent promoter metals selected from Mn, Fe, Co, Ni, Cu and Zn; M' is one or both of MO and W; x is 0.5 to 9, and a=1 when Cr is not one of metals represented by M, and 0.5.ltoreq.a.ltoreq.3 when Cr is one of the metals represented by M.

Abstract: Hydrotreating at relatively low pressure and elevated temperature followed by a selective distillation results in lighter fractions substantially free of sulfur and nitrogen. Over half of the total liquid product is suitable for sweet hydroprocessing over a noble metal catalyst.

Abstract: Catalytic materials are modified by adding one or more electropositive and/or electronegative elements thereto in amounts sufficient to adjust the resultant geometric mean electronegativity to a value within a desired or predetermined range. The invention is particularly suited to the preparation of hydrocarbon hydroprocessing catalysts, particularly with respect to hydrodesulfurization catalysts comprising a support material containing a porous refractory oxide. With such catalysts, not only is the geometric mean electronegativity adjusted to a desired value, but if the electropositive or electronegative element added to the catalyst has pore growth promotion properties, the average pore size of the resultant catalyst is increased while its surface area, and usually also its total pore volume, is decreased.

Abstract: A method for hydrocracking a heavy fraction oil which comprises cracking a heavy fraction oil in the coexistence of a catalyst and a hydrogen donating solvent such as tetralin while adding a hydrogen-containing gas to the cracking reactor thereby inhibiting the formation of carbonaceous substances and precursors thereof and then hydrogenating the reaction products in the presence of a solid catalyst while adding a hydrogen-containing gas to the hydrogenating reactor thereby to convert the toluene-insoluble carbonaceous substances and precursors thereof to toluene-soluble ones, thus causing no clogging in an apparatus used.

Abstract: An improved method of presulfiding a hydrotreating catalyst which minimizes sulfur stripping upon start-up of a hydrotreating reactor utilizing such a catalyst. The method comprises the steps of contacting a hydrotreating catalyst with elemental sulfur at a temperature below the melting point of sulfur, thereby forming a sulfur-catalyst mixture, and heating the sulfur-catalyst mixture to a temperature above the melting point of sulfur. Preferably, the sulfur-catalyst mixture is first mixed with a high boiling oil or a hydrocarbon solvent to form a prewet mixture prior to heating at a temperature above the melting point of sulfur.