Process

Claim 2

The process of claim 1 wherein the normally liquid hydrocarbon distillate is a petroleum distillate boiling above about 300* F. to about 900* F. and having a nitrogen content of over about 200 p.p.m.

Claim 3

The process of claim 1 wherein the normally liquid effluent from the hydrogenation reaction passed to the hydrocracking reaction has a nitrogen content of less than about 10 p.p.m.

Claim 4

The process of claim 1 wherein the acidic support of the hydrocracking catalyst contains crystalline aluminosilicate.

Claim 5

The process of claim 1 wherein a portion of the hydrogen-containing gas from the hydrocracking zone is recycled to the hydrocracking zone and the nitrogen content of the gas is reduced before charging to the hydrocracking zone.

Claim 6

The process of claim 6 wherein the nitrogen content of the gas is reduced by absorption of ammonia through contact with a molecular sieve.

Claim 7

The process of claim 6 wherein fresh hydrogen makeup and hydrogen-containing recycle gas from the hydrocracking zone are supplied to the hydrocracking zone with a minimum hydrogen partial pressure of about 250 and a maximum total pressure of about 800 p.s.i.g. and the ratio of hydrogen to hydrocarbon in the hydrocracking reaction is about 6,000 to 30,000 standard cubic feet per barrel of normally liquid hydrocarbon feed, and the hydrocarbon space velocity in the hydrocracking zone is about 1.5 to 3 times that in the hydrogenation zone.

Claim 8

The process of claim 7 wherein the ammonia absorber additionally removes hydrogen sulfide.

Claim 9

The process of claim 1 wherein the hydrogenator effluent is distilled and resulting bottoms are recycled to the hydrogenation zone.

Claim 10

The process of claim 1 wherein the mole ratio of hydrogen to hydrocarbon in the hydrocracking zone is at least about 1.5 times that in the hydrogenation zone.

Claim 11

A process for the production of hydrocarbons boiling in the gasoline range which comprises subjecting a normally liquid hydrocarbon distillate boiling above the gasoline range and in the range of about 300* to 900* F. and having a nitrogen content of at least about 100 p.p.m., to a hydrogenation reaction under denitrogenation conditions including a pressure of at least about 1,000 p.s.i.g. and a reaction temperature of about 550*-900* F. in the presence of a catalyst having denitrogenation activity, and molecular hydrogen to produce a normally liquid effluent having a nitrogen content of less than about 10 p.p.m. and a hydrogen- and ammonia-containing gas, removing ammonia from and recycling such hydrogen-containing gas to the hydrogenation zone, subjecting normally liquid effluent reduced in nitrogen content from said hydrogenation reaction together with hydrogen in an amount of at least about 1.5 times the mole ratio of hydrogen to hydrocarbon in the hydrogenation zone, including at least a major portion of the fresh, high purity hydrogen makeup used in the hydrogenation-hydrocracking system, to a catalytic hydrocracking reaction in the presence of a catalyst comprising a platinum group metal on a crystalline aluminosilicate-containing acidic support and under hydrocracking conditions including a temperature of about 500* F. to 850* F. and a pressure of up to about 800 p.s.i.g. to provide hydrocarbon effluent containing gAsoline and a hydrogen-containing gas, recycling portions of the hydrogen-containing gas from the hydrocracking zone to each of the hydrogenation zone and the hydrocracking zone, and removing nitrogen from the gas being recycled to the hydrocracking zone, said fresh hydrogen makeup, the nitrogen removal from the hydrogen-containing gas from the hydrocracking zone recycled to such zone, and any hydrocarbons recycled from the hydrocracking reaction liquid effluent to the hydrocracking zone being controlled to maintain the nitrogen content of the effluent from the hydrocracking zone at less than about 10 p.p.m., with the proviso that the hydrocarbon space velocity in the hydrocracking zone is about 1.5 to 3 times that in the hydrogenation zone.

Claim 12

The process of claim 12 in which the hydrogenation zone reaction conditions include temperatures of about 600* to 850* F. and pressures of about 1,000 to 2,000 p.s.i.g., and the hydrocracking zone reaction conditions include temperatures of about 550* to 750* F. and pressures of about 400 to 800 p.s.i.g.

Claim 13

The process of claim 13 in which all of the makeup hydrogen is added to the hydrocracking zone.

Claim 14

The process of claim 14 wherein the hydrogenator effluent is distilled and resulting bottoms are recycled to the hydrogenation zone.

Claim 15

The process of claim 15 in which a heavy portion of the hydrocracking zone liquid effluent is recycled to the hydrogenation zone for further reduction of the nitrogen content of such effluent portion.

Claim 16

The process of claim 1 in which the hydrocracking portion of the process is carried out by a plurality of reactors suitable for pressures up to about 800 pounds with no inner coolers in such reactors and with needed cooling provided by coolers in the flow system between such hydrocracking reactors.