Abstract: This invention relates to a crude oil desulfurization process which comprises hydrodesulfurizing a crude oil feed in a crude desulfurization unit. The desulfurized crude oil is then separated into a light gas oil fraction, a vacuum gas oil fraction and a vacuum residuum fraction. The vacuum gas oil is hydrocracked to form at least one low sulfur fuel product. The light gas oil fraction is hydrotreated. The vacuum gas oil may be hydrocracked in one or more stages. Hydrocracking in the second stage, if present, will convert of at least 20% of the first zone effluent, to create a low sulfur light gas oil fraction. The light gas oil fraction may then be hydrotreated.

Abstract: A method for reforming a lubricating oil which comprises holding stably a container (6) containing a lubricating oil (5) on a stand (4) being insulated to the earth with four high-voltage insulators (3), applying an electrostatic potential of 30 to 50 voltages by the use of an electrostatic charge generating device (7), to thereby charge electrons to the lubricating oil (5). The above charge of electrons converts an unsaturated hydrocarbon (1a) and an aromatic hydrocarbon (2a) in the lubricating oil (5) to a saturated hydrocarbon (1b) or (2b) and a naphthenic hydrocarbon (2c), which reduces the viscosity of the lubricating oil. Accordingly, the use of the lubricating oil (5) in an internal combustion engine lowers the friction resistance therein, which leads to the decrease of the fuel consumption of the engine. The method allows, therefore, the enhancement of fuel economy, in combination with the suppression as much as possible of oxidation of a lubricating oil itself.

Abstract: The invention relates to a process of producing gasoline with a low sulphur content from a feedstock containing sulphur. This process comprises at least one step a1 of selectively hydrogenating the diolefins and acetylenic compounds, at least one separation of the gasoline (step b) obtained at step a1 into at least three fractions, at least one step c1 of treating the heavy gasoline separated at step b on a catalyst enabling the unsaturated sulphur compounds to be at least partially decomposed or hydrogenated and at least one step d to remove the sulphur and nitrogen from at least one intermediate fraction, followed by catalytic reforming.

Abstract: A process to produce base oils through the use of fractionation, solvent extraction, dewaxing, and hydrofinishing

Abstract: A process for producing a diesel fuel stock from bitumen uses steam and a hydroisomerized diesel fraction produced by a gas conversion process, to respectively stimulate the bitumen production and increase the cetane number of a hydrotreated diesel fuel fraction produced by upgrading the bitumen, to form a diesel stock. The diesel stock is used for blending and forming diesel fuel.

Abstract: The present invention relates to a medium-pressure hydrocracking process which uses a fresh hydrogen resource and a hydrosaturation catalyst with reduced metals of group VIB and/or group VIII as the active ingredients to selectively and deeply hydrosaturate jet fuel and/or diesel cuts derived in the medium-pressure hydrocracking process.

Abstract: With this invention, high conversion of heavy gas oils and the production of high quality products is possible in a single high-pressure loop with reaction stages operating at different pressure and conversion levels. The flexibility offered is great and will allow the refiner to avoid decrease in product quality while at the same time minimizing capital cost. Feeds with varying boiling ranges can be introduced at different sections of the process, thereby minimizing the consumption of hydrogen and further reducing capital investment.

Abstract: This invention is directed to a process for hydroprocessing vacuum gas oils and other feeds in order to produce unconverted oil suitable for use as base oil feed for white oils, Group III oils, and BMCI (Bureau of Mines Correlation Index) ethylene plant feed. Ammonia, hydrogen sulfide, and light products are removed from the first stage at high pressure in order to produce a higher quality of unconverted oil that is suitable for Group III base oils.

Abstract: A novel process for forming hydrocarbon waxes from synthesis gas is disclosed. This invention teaches a process whereby a Fischer-Tropsch wax can be formulated such that the wax softness as defined by ASTM Standard Test Method for Needle Penetration of waxes (ASTM D-1321) can be adjusted to within a region most preferred for end use applications while simultaneously removing undesirable impurities, such as oxygenates (e.g., primary alcohols), olefins, and trace levels of aromatics. In a Fischer-Tropsch reactor, Fischer-Tropsch wax is formed from synthesis gas in a catalyzed reaction. The Fischer Tropsch wax is then subjected to a relatively mild hydroprocessing over a hydroisomerization catalyst under conditions such that essentially no boiling point conversion is obtained, but yet chemical conversions (e.g., hydrogenation and mild isomerization) occur yielding a high purity, hydrocarbon wax product of reduced hardness.

Abstract: The invention concerns a method for simultaneously producing very high quality oil bases and high quality middle distillates comprising successive steps of hydroisomerization and catalytic dewaxing. The hydroisomerization is carried out in the presence of a catalyst containing at least a noble metal deposited on an amorphous acid support, the metal dispersion being less than 20%. The support is preferably an amorphous silica-alumina. The catalytic dewaxing is carried out in the presence of a catalyst containing at least a hydro-dehydrogenating element (group VIII) and at least a molecular sieve selected among ZBM-30, EU-2 and EU 11.

Abstract: For desulfurization of a hydrocarbon-containing feedstock, at least one stage for selective hydrogenation of diolefins present in the initial hydrocarbon feedstock, in the presence of a catalyst of group VIII of the period table, and a stage for extraction by a solvent of the resultant hydrogenated fraction under conditions that provide at least two fractions:

Abstract: A process for the conversion of hydrocarbons that are solid or have a high boiling temperature and may be laden with metals, sulfur or sediments, into liquids (gasolines, gas oil, fuels) with the help of a jet of gas properly superheated between 600 and 800° C. The process comprises preheating a feed 5 in a heater 8 to a temperature below the selected temperature of a reactor 10. This feed is injected by injectors 4 into the empty reactor 10 (i.e., without catalyst.) The feed is treated with a jet of gas or superheated steam from superheater 2 to activate the feed. The activated products in the feed are allowed to stabilize at the selected temperature and at a selected pressure in the reactor and are then run through a series of extractors 13 to separate heavy and light hydrocarbons and to demetallize the feed. Useful products appearing in the form of water/hydrocarbon emulsions are generally demulsified in emulsion breaker 16 to form water laden with different impurities.

Abstract: Process to prepare a spindle oil, light machine oil and a medium machine oil base oil grade by (a) performing a separate catalytic dewaxing on a spindle oil fraction, a light machine oil fraction and a medium machine oil fraction as obtained in a vacuum distillation of a bottoms fraction of a fuels hydrocracking process; (b) performing a separate hydrofinishing of the light and medium machine oil fractions obtained in step (a); (c) separating the low boiling compounds from the spindle oil, light machine oil and medium machine oil fractions as obtained in step (a) and (b) and obtaining the spindle oil, light machine oil and medium machine oil base oil grade; (e) wherein the vacuum distillation is performed by alternatingly performing the distillation in two modes wherein the first mode (d1) the bottoms fraction is separated into a gas oil fraction, a spindle oil fraction, a medium machine oil fraction and a first rest fraction boiling between said spindle oil and medium machine oil fraction and in the second m

Abstract: An apparatus for the purification of catalytic cracking gasolines containing dienic and/or acetylenic impurities, and mercaptans, said apparatus comprising at least one selective hydrogenation reactor 3 containing at least one fixed catalyst bed, and having at least one line 1 for introducing a feed, at least one effluent outlet line, and a line supplying hydrogen to the reactor, said reactor being followed by at least one stabilization drum 4 connected to said effluent outlet line, the drum having at least one gas outlet line 5 and at least one stabilized effluent outlet line, and said effluent passing into at least one sweetening reactor 8 comprising at least one effluent inlet line 6 and at least one effluent outlet line, said reactor having close thereto at least one oxidizing agent supply line, said apparatus also comprising at least one drum 9 for degassing the effluent from the sweetening reactor 8, said drum 9 having at least one gas outlet line and at least one outlet line 11 for dedienized, stabiliz

Abstract: A VGO stream is initially hydrocracked in a hydrocracking reaction zone within an integrated hydroconversion process. Effluent from the hydrocracking reaction zone is combined with a light aromatic-containing feed stream, and the blended stream hydrotreated in a hydrotreating reaction zone. Heat exchange occurs between the hydrocracking reaction zone and the hydrotreating reaction zone, permitting the temperature control of the initial hydrocracking zone. The integrated reaction system provides a single hydrogen supply and recirculation system for use in two reaction processes.

Abstract: A process for producing low pour point diesel and lubricating base oil products by bulk dewaxing a C5 plus Fischer-Tropsch syncrude, hydrofinishing the dewaxed intermediate, and recovering 120 degrees C. plus products having improved properties.

Abstract: The present invention concerns an improved procedure for producing basic oils and in particular very high quality oils, i.e. oils possessing a high viscosity index (VI), a low aromatics content, good UV stability and a low pour point, from oil cuts having an initial boiling point higher than 340° C., possibly with simultaneous production of middle distillates (in particular gasoils and kerosene) of very high quality, i.e. having a low aromatics content and a low pour point.

Abstract: A process wherein all of the unsaturates within a cracked naphtha stream are substantially hydrogenated to alkanes and the olefin depleted stream is then subjected to hydrodesulfurization to achieve the desired sulfur levels without the formation of recombinant mercaptans.

Abstract: An integrated process for preparing a lubricating oil base stock includes an isomerization step followed by a solvent dewaxing step. A waxy feed is isomerized to an intermediate pore point, which is at least 6° C. above a target pour point, over a select molecular sieve having specified pore properties. The isomerized oil is then solvent dewaxed to a very low pour point. This process produces a dewaxed lubricating oil base stock which has an exceptionally high viscosity index.

Abstract: A method for hydroprocessing hydrocarbon products, preferably Fischer-Tropsch products, and a reactor useful for performing the method, are disclosed. The reactor includes one or more first catalyst beds comprising a catalyst useful for conducting relatively severe hydroprocessing and one or more second catalyst beds comprising a catalyst useful for conducting relatively mild hydroprocessing. The second catalyst beds are located at a position in the reactor where they can receive the products from the first catalyst bed(s), at least one of each of the first and second catalyst bed(s) comprises a catalyst grading scheme sufficient to remove at least a portion of any particulates from their respective feeds, and the reactor is set up to receive hydrocarbon feeds at a position above or within the first catalyst bed(s) and above or within the second catalyst bed(s).

Abstract: A method for processing a gasoline range hydrocarbon stream wherein a single reactor/distillation tower stream is fractionated into a light fraction and a heavy fraction, the light fraction is hydrodesulfurized, the heavy fraction is optionally hydrocracked and then hydrodesulfurized, and the light and heavy fractions are separately recovered.

Abstract: This invention is directed to middle distillate production (e.g., diesel and kerosene products) by means of a reactor hydroprocessing system using two or more reactors (or a single reactor vessel having two or more stages, each stage containing one or more reaction zones). Hydrocracking is preferably performed in the initial reactor, and hydrotreating (and/or further hydrocracking) is preferably performed in the subsequent reactor vessel or stages within a single vessel. Reaction stages are effectively segregated to avoid recracking of products, to dramatically reduce hydrogen consumption in saturating the bottoms product and to carry out aromatic saturation of middle distillates in a clean low-temperature environment.

Abstract: An integrated distillate hydrocracking process produces one or more fuel products and one or more lube products from a first reaction stage. Heavy fractions from the first stage, which are not recovered as lube products, are cracked to fuels in a second reaction stage. This invention is intended to provide a full range of lube streams, over a wide viscosity range and a wide viscosity index range, from a fuels hydrocracker, in addition to high yields of high quality fuels.

Abstract: A process for producing low pour point diesel and lubricating base oil products by bulk dewaxing a C5 plus Fischer-Tropsch syncrude, hydrofinishing the dewaxed intermediate, and recovering 120 degrees C. plus products having improved properties.

Abstract: A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.

Abstract: A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then separated into fractions of different volatility, and the lowest boiling fraction is contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.

Abstract: A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then separated into at least three fractions of different volatility, and the lowest boiling first fraction is contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide. The intermediate boiling fraction is contacted with a selective hydrotreating catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.

Abstract: A process for the production of naphtha streams from cracked naphthas having sulfur levels which help meet future EPA gasoline sulfur standards (30 ppm range and below).

Abstract: The present invention is directed to a method for hydroprocessing Fischer-Tropsch products. The invention in particular relates to an integrated method for producing liquid fuels from a hydrocarbon stream provided by Fischer-Tropsch synthesis. The method involves separating the Fischer-Tropsch products into a light fraction with normal boiling points below 700° F. and including predominantly C5-20 components and a heavy fraction with normal boiling points above 650° F. and including predominantly C20+ components. The heavy fraction is subjected to hydrocracking conditions, preferably through multiple catalyst beds, to reduce the chain length. The light fraction is used as all or part of a quench fluid between each catalyst bed.

Abstract: The invention relates to a process for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) ebulliated-bed catalytic hydrocracking, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Make-up hydrogen, preferably all make-up hydrogen, is to stage c). Advantageously, the heavier fraction from step (b) is subjected to catalytic cracking. The invention also relates to an installation that can be used for implementing this process.

Abstract: The invention relates to a process and installation for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) mild hydrocracking in a fixed catalyst bed, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment (including desulfurization) of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Advantageously, the heavy fraction is sent into catalytic cracking. The process preferably operates with make-up hydrogen that is brought to stage c), and very advantageously all of the make-up hydrogen of the process in introduced in stage c).

Abstract: The invention relates to a hydrotreating and hydrocracking process for various oils nominally boiling between 600 and 1500° F. to produce diesel oil and lighter materials. The process includes a first hydrogenation reaction in the presence of multiple hydrogenation catalyst beds which is limited to the hydrogenation level needed for the removal of sulfur and nitrogen and for aromatic saturation and to produce an effluent of both hydrocracked oil and uncracked heavy oil. The effluent is then flashed to produce hydrocracked oil vapors and liquid uncracked heavy oil. The hydrocracked oil fraction is further hydrotreated by catalytic distillation in a post-treatment reactor to give the final product quality while the liquid uncracked heavy oil bypasses the post-treatment reactor. The process significantly reduces hydrogen consumption and reduces the overall reactor and catalyst volumes for a given level of performance.

Abstract: An improved heavy oil conversion process is disclosed in which the heavy oil feed is first thermally cracked using visbreaking or hydrovisbreaking technology to produce a product that is lower in molecular weight and boiling point than the feed. The product is then deasphalted using an alkane solvent at a solvent to feed ratio of less than 2 wherein separation of solvent and deasphalted oil from the asphaltenes is achieved through the use of a two-stage membrane separation system in which the second stage is a centrifugal membrane.

Abstract: The invention relates to a hydrocracking and hydrotreating process for hydrocracking feedstock oils such as vacuum gas oil to produce diesel and lighter distillate products. A first hydrogenation process is carried out in a main reactor with the feedstock and hydrogen flowing cocurrently down through a top section containing a layered system of hydrotreating and hydrocracking catalyst. The feedstock is substantially desulfurized and denitrified, the aromatics are at least partially saturated and cracked products are formed. The vapor and liquid are separated in a disengaging zone below the top section and the liquid flows down through a bottom section also containing a layered catalyst system countercurrent to make-up hydrogen flowing up. The vapor removed from the disengaging zone and the liquid bottoms are then further processed in a post treatment catalytic distillation reactor having an upper catalytic distillation section and a lower stripping section which may also contain a catalyst.

Abstract: Production of gasolines with low sulfur contents from a starting gasoline containing sulfur-containing compounds comprising a stage a) for selective hydrogenation of non-aromatic polyunsaturated compounds present in the starting gasoline, a stage b) for increasing the molecular weight of the light sulfur-containing products that are initially present in the gasoline that enters this stage, a stage c) for alkylation of at least a portion of the sulfur-containing compounds present in the product that originates stage b), a stage d) for fractionation of the gasoline that originates from stage c0 into at least two fractions, one fraction virtually lacking in sulfur-containing compounds, whereby the other contains a larger proportion of sulfur-containing compounds (heavy gasoline), a stage e) for catalytic treatment of the heavy gasoline for transformation of sulfur-containing compounds under conditions for the at least partial decomposition of hydrogenation of these sulfur-containing compounds.

Abstract: The invention relates to a process for the production of gasoline with a low sulfur content that comprises at least the following stages:

Abstract: A membrane process for the removal of sulfur species from a naphtha feed, in particular, a FCC light cat naphtha, without a substantial loss of olefin yield is disclosed. The process involves contacting a naphtha feed stream with a membrane having sufficient flux and selectivity to separate a sulfur deficient retentate fraction from a sulfur enriched permeate fraction, preferably, under pervaporation conditions. Sulfur deficient retentate fractions are useful directly into the gasoline pool. Sulfur-enriched permeate fractions are rich in sulfur containing aromatic and nonaromatic hydrocarbons and are further treated with conventional sulfur removal technologies, e.g. hydrotreating, to reduce sulfur content. The process of the invention provides high quality naphtha products having a reduced sulfur content and a high content of olefin compounds.

Abstract: The present invention is directed to a method for hydroprocessing Fischer-Tropsch products. The invention in particular relates to an integrated method for producing liquid fuels from a hydrocarbon stream provided by Fischer-Tropsch synthesis. The method involves separating the Fischer-Tropsch products into a light fraction with normal boiling points below 700° F. and including predominantly C5-20 components and a heavy fraction with normal boiling points above 650° F. and including predominantly C20+ components. The heavy fraction is subjected to hydrocracking conditions, preferably through multiple catalyst beds, to reduce the chain length. The light fraction is used as all or part of a quench fluid between each catalyst bed.

Abstract: A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then separated into fractions of different volatility, and the lowest boiling fraction is contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.

Abstract: A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.

Abstract: A method for concentrating the amount of alkylated mono-aromatics in a lubricating oil feedstock useful as a feedstock for sulfonation. The method comprises extracting a feedstock rich in aromatics with a solvent selected from NMP, phenol and furfural, said feedstock containing sufficient water to provide a raffinate having a target VI between about 86 and 97 under extraction conditions of treat and temperature selected to achieve the target VI. The raffinate is then hydrofmed and solvent dewaxed.

Abstract: A hydrocarbonaceous feed is hydroprocessed in a single vessel containing two reaction stages and a stripping stage. The feed is fed into the first reaction stage to produce a vapor and liquid effluent which are separated, and the liquid stripped. The stripped liquid is passed as feed into the second stage, in which it meets with fresh hydrogen to produce a hydroprocessed liquid product and a hydrogen-rich vapor. The vapor is passed into the first stage, to provide the hydrogen for that stage. The use of a single vessel provides an efficient and economical addition to, or replacement for, a vessel for an existing hydroprocessing facility.

Abstract: A process for producing a lubricating oil basestock having at least 90 wt. % saturates and a VI of at least 105 by selectively hydroconverting a raffinate from a solvent extraction zone in a two step hydroconversion zone followed by a hydrofinishing zone, and a lubricating oil basestock produced by said process.

Abstract: The invention relates to a process for converting cycle oils produced in catalytic cracking reactions into olefinic naphthas. More particularly, the invention relates to a process for hydroprocessing a catalytically cracked light cycle oil, and then re-cracking in an out-board FCC reactor it in order to form a naphthenic blend-stock.

Abstract: The invention relates to a process of producing gasoline with a low sulphur content from a feedstock containing sulphur. This process comprises at least one step a1 of selectively hydrogenating the diolefins and acetylenic compounds, at least one separation of the gasoline (step b) obtained at step a1 into at least three fractions, at least one step c1 of treating the heavy gasoline separated at step b on a catalyst enabling the unsaturated sulphur compounds to be at least partially decomposed or hydrogenated and at least one step d to remove the sulphur and nitrogen from at least one intermediate fraction, followed by catalytic reforming.

Abstract: A process for producing a lubricating oil basestock having at least 90 wt. % saturates and a VI of at least 105 by selectively hydroconverting a raffinate from a solvent extraction zone in a two step hydroconversion zone followed by a hydrofinishing zone, and a lubricating oil basestock produced by said process.

Abstract: This invention is directed to middle distillate production (e.g., diesel and kerosene products) by means of a reactor hydroprocessing system using two or more reactors (or a single reactor vessel having two or more stages, each stage containing one or more reaction zones). Hydrocracking is preferably performed in the initial reactor, and hydrotreating (and/or further hydrocracking) is preferably performed in the subsequent reactor vessel or stages within a single vessel. Reaction stages are effectively segregated to avoid recracking of products, to dramatically reduce hydrogen consumption in saturating the bottoms product and to carry out aromatic saturation of middle distillates in a clean low-temperature environment.

Abstract: The invention is related to a two step process wherein the first step comprises cracking an olefinic naphtha resulting in a cracked product having a diminished total concentration of olefinic species. The second step comprises hydroprocessing at least a portion of the cracked product, especially a naphtha fraction, to provide a hydroprocessed cracked product having a reduced concentration of contaminant species but without a substantial octane reduction.

Abstract: The invention includes a process of making a lubricating oil composition including: a process for making a high VI lubricating oil composition including the steps of (1) contacting a waste plastics feed including mainly polyethylene in a pyrolysis zone at pyrolysis conditions, whereby at least a portion of the waste plastics feed is cracked, thereby forming a pyrolysis zone effluent including 1-olefins and n-paraffins; (2) passing the pyrolysis zone effluent, including a heavy fraction and a middle fraction, the pyrolysis effluent middle fraction including 1-olefins, to a separations zone; where the pyrolysis effluent heavy fraction portion is separated from the pyrolysis effluent middle fraction; (3) passing the pyrolysis effluent middle fraction to a dimerization zone, where at least a portion of the pyrolysis effluent middle fraction is converted to a lube oil range material; and (4) passing at least a portion of the lube oil range material to a catalytic isomerization dewaxing zone, where at least a porti

Abstract: Lubricant oils of low pour point and improved oxidation stability are produced by catalytically dewaxing a lube feedstock over a zeolite dewaxing catalyst such as ZSM-5 in the hydrogen or decationized form. The use of these catalysts enables products of excellent oxidative stability to be obtained and reduces the catalyst aging rate in the first and subsequent dewaxing cycles to values below 5° F./day. The duration of the dewaxing cycles may be extended, particularly in the second and subsequent cycles after hydrogen reactivation.