Mobil Oil Corporation

Grant G Karsner

Nai Y Chen

Stephen S Wong

Rene B LaPierre

Tai-Sheng Chou

Clinton R Kennedy

Richard J Quann

Melcon G Melconian

William J Tracy, Iii

Mark P Bartilucci

Byung C Choi

Thomas F Degnan

Dominick N Mazzone

Donald Milstein

Solomon M Jacob

Lawrence J Altman

Madhava Malladi

Fred S Zrinscak, Sr

Robert T Hanlon

Chang-Kuei Lee

Solomon W Jacob

J Jay Grove

Nitrogenous compounds especially bases such as ammonia vapor are used to control the operation of a hydrocracker or catalytic dewaxer. Catalyst activity and selectivity may be controlled by addition of the base to the feed, for example, to control the balance between isomerization and hydrocracking in an operation using a zeolite beta catalyst. Runaway conditions may be controlled by the addition of nitrogenous compounds to regulate the temperature profile within the reactor.

Method for controlling hydrocracking and isomerization dewaxing operations

Petroleum wax feeds are converted to high viscosity index lubricants by a two-step hydrocracking-hydroisomerization process in which the wax feed which exhibits branchingis initially subjected to hydrocracking under mild conditions with a conversion to non-lube range products of no more than about 30 weight percent of the feed. The hydrocracking is carried out at a hydrogen pressure of at least 1000 psig (7000 kPa) using an amorphous catalyst which preferentially removes the aromatic components present in the initial feed. The hydrocracked effluent is then subjected to hydroisomerization in a second step using a low acidity zeolite beta catalyst which effects a preferential isomerization on the paraffin components to less waxy, high VI isoparaffins. The second stage may be operated at high pressure by cascading the first stage product into the second stage or at a lower pressure, typically from 200 to 1000 psig. The second stage catalyst is preferably a noble metal containing zeolite beta catalyst which contains boron as a framework component of the zeolite to give a low alpha value, typically below 10 while maintaining an isomerizaiton selectiveity of no less than 48%. The second stage is carried out at relatively low temperature, typically from 600&deg; to 650&deg; F. with a 650&deg; F.&plus; conversion in the range of 10 to 20 weight percent of the second stage feed but with high selectivity for isomerization of the paraffins. A final dewaxing step to target pour point may be used with relatively low loss, typically no more than 15 weight percent, during this dewaxing. The final products typically have VI values in excess of 140 and usually in the range of 143 to 147 and are characterized by exceptional stability.

Production of high viscosity index lubricants

Method for controlling hydrocracking and isomerization dewaxing

Nitrogenous compounds especially bases such as amines are used to control the operation of a hydrocracker. Catalyst activity and selectivity may be controlled by addition of the base to the feed, for example, to control the balance between isomerization and conversion in an operation using a zeolite beta catalyst. Runaway conditions may be controlled by the addition of nitrogenous compounds and if they are added at intermediate points along the length of the reactor, the temperature profile within the reactor can be effectively regulated.

Method for controlling hydrocracking operations

Petroleum refinery waste stream sludges are recycled by segregating the sludges according to their oil content. Sludges of high oil content are developed and then injected into a delayed coking unit during the coking phase so that they are converted to coke and liquid coking products. High water content sludges are used to quench the coke during the quench phase of the coking cycle, with minimal increases in coke volatile matter. The process increases the capacity of the delayed coking unit to process and recycle refinery waste sludges and produce a coke of lower volatile content.

Recycle of oily refinery wastes

A process for deasphalting a heavy hydrocarbon feed and catalytically cracking same is disclosed. Relatively low efficiency deasphalting is used to remove at least a majority of the metals in the feed, but to leave at least 10% of the asphaltenes and at least 10% of the solvent. This demetallized material is catalytically cracked. Preferably, the solvent used in deasphalting is derived from, and recycled from the catalytic cracking unit fractionator. Preferably a majority of the solvent recovery from the deasphalting step occurs in the catalytic cracking fractionator.

Low efficiency deasphalting and catalytic cracking

A method for assaying incompatible sediment in a blended heavy fuel oil is provided. The method is based on measuring total light absorption at 1600 nanometers wavelength, for example, of two or more samples blended to different viscosities, at least one such sample being at specification viscosity. The method may be used to control visbreaker severity so as to reduce the large ERT safety margin commonly used by refiners.

Method for control of visbreaker severity

A solvent extract obtained from a conventional hydrocarbon oil solvent extraction process, e.g., one employing furfural as the extraction solvent, is cooled to a temperature providing, following a secondary decantation of the cooled extract, a pseudo raffinate containing most of the non-aromatics and a pseudo extract possessing a hydro-aromatic content of H.sub.alpha hydrogen of at least 20 percent of the total hydrogen content. The pseudo extract is ideally suited as a hydrogen-donor for a variety of refinery operations such as visbreaking. The pseudo raffinate is suitable as a co-feed for such catalytic cracking operations as fluidized catalytic cracking (FCC) and thermofor catalytic cracking (TCC) and can be recycled to the extraction unit to produce more lube oil.

Upgrading solvent extracts by double decantation and use of pseudo

Petroleum refinery waste stream sludges are recycled by segregating the sludges according to their oil content. Sludges of high oil content are injected into a delayed coking unit during the coking phase so that they are converted to coke and liquid coking products. High water content sludges are used to quench the coke during the quench phase of the coking cycle, with minimal increases in coke volatile matter. The process increases the capacity of the delayed coking unit to process and recycle refinery waste sludges and produce a coke of lower volatile content.

Delayed coking process in which improved liquid yield is achieved by varying the rate at which the heavy feedstock is fed to the coke drum. Tandem operation of two active coking drums is disclosed which permits feedrate variation without change of load on furnace.

Delayed coking process

Hydrocarbon-containing liquid waste sludges from refinery waste streams can be disposed of by blending with the feedstock being passed to a fluid catalytic cracking unit. Preferably, the sludge is premixed with a hydrocarbon, such as a light oil, prior to mixing with the feed.

Liquid sludge disposal process

Metal-contaminated oils, including mildly hydrotreated residual oils, are catalytically cracked in the absence of added hydrogen in a fluid catalytic cracking process wherein the regenerated catalyst has less than about 0.05 wt. % residual carbon. By conducting regeneration of the catalyst to that level at 1300.degree. to 1400.degree. F. (preferably at about 1350.degree. F.) with excess air, additional benefits are realized in that metal deposited on the catalyst by cracking of residual stocks is thereby passivated.

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Voorhees Township, NJ, United States of America

Grant G Karsner