Texaco Inc.

Scott M Sayles

Roy E Pratt

Richard P Scott, Deceased

MIchael P Bellinger

William B Livingston

Kerry W Bowers

Leonce F Castagnos, Jr

Charles H Schrader

Gerald V Nelson

Govanon Nongbri

Edward W Dillingham

In a two stage catalytic cracking process a heavy cycle gas oil fraction (HCGO) nominal boiling range 600.degree. F. to 1050.degree. F., API gravity of -10.degree. to +10.degree. and 65 to 95 vol % aromatics is recycled to extinction between an ebullated bed hydrocracking zone and fluidized catalytic cracking zone to yield a liquid fuel and lighter boiling range fraction as the light fraction from each zone. The catalyst in the fluidized catalytic cracking zone is maintained at a micro activity 68 to 72 while cracking a virgin gas oil to HCGO. HCGO is then mixed with vacuum residuum and hydrocracked in an ebullated bed reactor. The mid range fraction is recycled to the fluidized catalytic cracking zone. The 1000.degree. F..sup.+ fraction is blended with a fuel oil.

Two catalyst stage hydrocarbon cracking process

A method has been discovered for controlling catalytic reactor bed temperature in an ebullated bed process. A sour, aromatic feedstock is mixed with a conventional ebullated bed residual oil feedstock in a controlled ratio. The aromatic feedstock is catalytically cracked and thereby releases heat. The flow rate of the aromatic feedstock is controlled to maintain the reactor bed at a selected catalytic reaction temperature. Both feedstocks are upgraded to a fuel boiling range fraction and the fired heater is eliminated for the conventional feedstock and optionally for the hydrogen-containing gas feed stream as well.

Temperature control in an ebullated bed reactor

In an ebullated bed process, it has been found that in switching from one sediment yielding feedstock to a second sediment yielding feedstock that the transient sediment concentration is 5 to 8 times the steady state concentration. Such transients have caused unit shutdowns with lost production time. A method has been found which avoids these high transient sediment concentrations. Second feedstock is added incrementally (1 vol % to 2 vol % of the final rate) over the period of a week or more and sediment in the product analyzed. After full second feedstock rate is achieved, first feedstock is reduced incrementally with sediment analysis. Higher unit utilization is achieved with the corresponding increased yearly production.

Method for controlling sedimentation in an ebullated bed process

In an ebullated bed process, a residual hydrocarbon oil and a hydrogen containing gas is passed upwardly through an ebullated bed of catalyst in a hydrocracking zone at a temperature in the range of 650.degree. F. to 950.degree. F. and pressure of 1000 psia to 5000 psia. FCCU catalyst fines are added to the ebullated bed in an amount of 15 wt % to 21 wt % of total catalyst comprising hydrocracking catalyst and fines. A hydrocracked oil is recovered characterized by having a reduced sediment content.

Suppressing sediment formation in an ebullated bed process

In an ebullated bed process it has been found that a hydroclone effectively removes gas from recycled liquid used to ebullate the catalyst bed. When a 5 psi or greater inlet head and 5 psi pressure drop from the hydrocyclone inlet to the liquid outlet is maintained, essentially all gas is removed form the recycled liquid. Stabilized recycle pump operation is experienced and steady state achieved thereby.

Gas-liquid separation in an ebullated bed process

Apparatus for catalytic cracking of a selected portion of a hydrocarbon feedstock comprising a riser reactor and a catalyst regenerator, a regenerated catalyst cooler, and an absorber. Regenerated catalyst from the catalyst regenerator is conducted through the catalyst cooler into the absorber where it adsorbs hydrocarbon cracking feedstock and then returned to the riser reactor. A duct carries part of the hot regenerated catalyst from the catalyst regenerator directly to the riser reactor to supply heat for cracking the hydrocarbon feedstock.

Fluid catalytic cracking apparatus

An improved method for fluidized catalytic cracking of a selected portion of a paraffinic hydrocarbon feedstock in which a paraffinic chargestock for a fluid catalytic cracking unit is processed for the separation of at least a part of its paraffinic components from non-paraffins by means of a zeolite composition which acts both as a molecular sieve and a cracking catalyst. The paraffins-containing fraction adsorbed on the molecular sieve is subjected to catalytic cracking in a riser-type fluid catalytic cracking reaction zone at a temperature in the range of 650.degree. to 700.degree. C. under subatmospheric pressure conditions for the production of light olefins.

Fluid catalytic cracking method

A separator apparatus has been invented which rapidly disengages catalyst from product vapor in the reactor discharge stream of a fluid catalytic cracking (FCC) apparatus. The separator apparatus comprises a flow diverter which comprises a frustum in which are spiral channels which induce a spin on the impacting stream and are sufficiently deep to contain a layer of catalyst. A position member is attached to the frustum base and apertures in the position member allow the flow of vapor to a bore and on to cyclone separators where final catalyst-vapor separation is made. Catalyst does not pass through the apertures and remains within a cylindrical separation chamber in flow communication with a dip leg which directs the catalyst to a stripper vessel in the fluid catalytic cracking apparatus. The separator apparatus is a solution to the vibration problem experienced in the use of rough-cut cyclones.

FCCU Catalyst-high velocity vapor separator

A two-stage cascade flow fluid catalytic cracking process capable of converting high molecular weight hydrocarbons containing catalyst poisons into products of lower molecular weight with high activity cracking catalyst susceptible to catalyst poisons, the cascade flow process resulting in higher yields of desired motor fuel fractions than those obtainable with conventional riser flow fluid catalytic cracking processes. Catalyst poisons, e.g. nitrogen compounds, sulfur compounds, heavy metal compounds and high Conradson Carbon Residues, are removed from the heavy hydrocarbon charge stocks by first contacting the charge stock containing catalyst poisons with a low activity catalyst comprising used catalyst from the process under fluid catalytic cracking reaction conditions effective for the conversion of a minor portion of the heavy feed hydrocarbons to hydrocarbons of lower molecular weight, recovering gas oils from the products of said first fluid catalytic cracking reactor and subjecting the gas oils to more severe cracking conditions in the presence of high activity cracking catalyst, e.g. a molecular sieve catalyst.

Two stage catalytic cracking process

A process for conversion of paraffinic base petroleum cracking stocks to high octane motor fuels and petrochemical feedstocks in which paraffinic components are separated from the cracking stock to yield a deparaffined fraction which is hydrotreated and catalytically cracked and a paraffin fraction which is separately catalytically cracked whereby improved yields of normally gaseous olefins and normally liquid products including high octane motor fuel components are obtained.

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Baton Rouge, LA, United States of America

Scott M Sayles