Hydrogen-donor coal liquefaction process

Claim 2

A hydrogen-donor liquefaction process for converting coal or similar carbonaceous solids into lower molecular weight liquid hydrocarbons which comprises: (a) contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen at a temperature in the range between about 775° F. and about 950° F. in a liquefaction zone operated such that the temperature remains substantially constant throughout said zone and wherein said carbonaceous solids are converted into lower molecular weight liquid hydrocarbons to form a liquefaction effluent, said hydrogen-donor solvent having a donatable hydrogen concentration higher than the thermodynamic equilibrium concentration at the temperature in said liquefaction zone when said solvent enters said zone; (b) maintaining a higher concentration of catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics in said liquefaction zone near said outlet of said zone than near said inlet of said zone; and (c) recovering liquid hydrocarbonaceous products from said liquefaction effluent.

Claim 3

A process as defined by claim 1 wherein said higher concentration is maintained by introducing catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics into said liquefaction zone near said outlet.

Claim 4

A process as defined by claim 1 including the step of withdrawing mineral constituents of said carbonaceous solids from said liquefaction zone near said inlet of said zone.

Claim 5

A process as defined by claim 1 wherein said higher concentration is maintained by introducing a manufactured hydrogenation catalyst into said liquefaction zone downstream of the midpoint of said zone.

Claim 6

A process as defined by claim 1 wherein said carbonaceous solids include mineral constitutents that are active in promoting the hydrogenation of aromatics to form hydroaromatics and said high concentration is maintained by withdrawing mineral constituents from said solids at a point upstream of the midpoint of said liquefaction zone and reintroducing said mineral constituents into said liquefaction zone at a point downstream of the midpoint of said liquefaction zone.

Claim 7

A process as defined by claim 1 wherein said higher concentration is maintained by introducing an iron-containing mineral that is active in promoting the hydrogenation of aromatics to form hydroaromatics into said liquefaction zone at a point where the donatable hydrogen concentration of said solvent in said zone is below the thermodynamic equilibrium concentration at the temperature in said zone.

Claim 8

A process as defined by claim 1 wherein said higher concentration is maintained in said liquefaction zone by introducing liquefaction bottoms produced from a coal containing mineral constituents that are active in promoting the hydrogenation of aromatics to form hydroarmoatics into said liquefaction zone at the point where the donatable hydrogen concentration is below the thermodynamic equilibrium concentration at the temperature in said liquefaction zone.

Claim 9

A process as defined by claim 1 wherein said higher concentration in said liquefaction zone is maintained by introducing mineral matter produced from a coal containing mineral constituents that are active in promoting the hydrogenation of aromatics to form hydroaromatics into said zone at a point where the concentration of donatable hydrogen is below the thermodynamic equilibrium concentration at the temperature in said zone.

Claim 10

A process as defined by claim 1 wherein said liquefaction zone comprises a series of liquefaction reactors all of which are operated at substantially the same temperature.

Claim 11

A process as defined by claim 8 wherein said mineral matter is derived from a coal which is different from the feed solids to said liquefaction zone.

Claim 12

A process as defined by claim 8 wherein said mineral matter is derived by the gasification of coke produced from liquefaction bottoms.

Claim 13

A process as defined by claim 8 wherein said mineral matter is contained in pyrolysis bottoms produced by the pyrolysis of liquefaction bottoms.

Claim 14

A hydrogen-donor liquefaction process for converting coal or similar carbonaceous solids into lower molecular weight liquid hydrocarbons which comprises: (a) contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen at a temperature in a range between about 775° F. and about 950° F. in a liquefaction zone operated such that the temperature remains substantially constant throughout said zone and wherein said carbonaceous solids are converted into lower molecular weight liquid hydrocarbons to form a liquefaction effluent; (b) maintaining a higher concentration of catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics in the portion of said liquefaction zone where the donatable hydrogen concentration of the said solvent is below the thermodynamic equilibrium concentration at the temperature in said zone, thereby maintaining a relatively high concentration of donatable hydrogen throughout said liquefaction zone by the in situ hydrogenation of said solvent to convert the aromatics in said portion of said liquefaction zone into hydroaromatics; (c) separating said liquefaction effluent into a vaporous fraction and a liquid fraction; (d) recovering a substantially solids free liquid hydrocarbon stream containing hydrogen-donor solvent constituents from said liquid fraction; (e) hydrogenating said liquid hydrocarbon stream in a catalytic solvent hydrogenation zone at a temperature below the temperature in said liquefaction zone to produce a hydrogenated effluent containing hydrogen-donor constituents; (f) recovering a liquid fraction containing said hydrogen-donor solvent constituents from said hydrogenated effluent; and (g) recycling at least a portion of said liquid fraction recovered in step (f) as hydrogen-donor solvent to said liquefaction zone.

Claim 15

A hydrogen-donor liquefaction process for converting coal or similar carbonaceous solids into lower molecular weight liquid hydrocarbons which comprises: (a) contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen at a temperature in a range between about 775° F. and about 950° F. in a liquefaction zone operated such that the temperature remains substantially constant throughout said zone and wherein said carbonaceous solids are converted into lower molecular weight liquid hydrocarbons to form a liquefaction effluent; (b) maintaining a higher concentration of catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics in the portion of said liquefaction zone where the donatable hydrogen concentration of the said solvent is below the thermodynamic equilibrium concentration at the temperature in said zone, thereby maintaining a relatively high concentration of donatable hydrogen throughout said liquefaction zone by the in situ hydrogenation of said solvent to convert the aromatics in said portion of said liquefaction zone into hydroaromatics; (c) separating said liquefaction effluent into a vaporous fraction and a liquid fraction; (d) recovering a substantially solids free liquid hydrocarbon stream containing hydrogen-donor solvent constituents from said liquid fraction; (e) hydrogenating said liquid hydrocarbon stream in a catalytic solvent hydrogenation zone at a temperature below the temperature in said liquefaction zone to produce a hydrogenated effluent containing hydrogen-donor constituents; (f) recovering a liquid fraction containing said hydrogen-donor solvent constituents from said hydrogenated effluent; and (g) recycling at least a portion of said liquid fraction recovered in step (f) as hydrogen-donor solvent to said liquefaction zone.

Claim 16

A process as defined by claim 13 wherein said liquefaction zone is maintained at a substantially constant temperature in the range between about 800° F. and about 900° F. and said catalytic solvent hydrogenation zone is maintained at the temperature in the range between about 675° F. and about 750° F.

Claim 17

A process as defined by claim 13 wherein said higher concentration is maintained by introducing catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics into said liquefaction zone at a point where the donatable hydrogen concentration of said solvent in said zone is below the thermodynamic equilibrium concentration at the temperature in said zone.

Claim 18

A hydrogen-donor liquefaction process for converting coal or similar carbonaceous solids into lower molecular weight liquid hydrocarbons which comprises: (a) contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen at a temperature in the range between about 775° F. and about 950° F. in a liquefaction zone operated such that the temperature remains substantially constant throughout said zone and wherein said carbonaceous solids are converted into lower molecular weight liquid hydrocarbons to form a liquefaction effluent, said hydrogen-donor solvent having a donatable hydrogen concentration higher than the thermodynamic equilibrium concentration at the temperature in said liquefaction zone when said solvent enters said zone; (b) maintaining a higher concentration of catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics in the portion of said liquefaction zone where the donatable hydrogen concentration of the said solvent is below the thermodynamic equilibrium concentration at the temperature in said zone, thereby maintaining a relatively high concentration of donatable hydrogen throughout said liquefaction zone by the in situ hydrogenation of said solvent to convert the aromatics in said portion of said liquefaction zone into hydroaromatics; and (c) recovering liquid hydrocarbonaceous products from said liquefaction effluent.

Claim 19

A hydrogen-donor liquefaction process for converting coal or similar carbonaceous solids into lower molecular weight liquid hydrocarbons which comprises: (a) contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen at a temperature in the range between about 775° F. and about 950° F. in a liquefaction zone operated such that the temperature remains substantially constant throughout said zone and wherein said carbonaceous solids are converted into lower molecular weight liquid hydrocarbons to form a liquefaction effluent, said hydrogen-donor solvent having a donatable hydrogen concentration higher than the thermodynamic equilibrium concentration at the temperature in said liquefaction zone when said solvent enters said zone; (b) maintaining a higher concentration of catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics in the portion of said liquefaction zone where the donatable hydrogen concentration of the said solvent is below the thermodynamic equilibrium concentration at the temperature in said zone, thereby maintaining a relatively high concentration of donatable hydrogen throughout said liquefaction zone by the in situ hydrogenation of said solvent to convert the aromatics in said portion of said liquefaction zone into hydroaromatics; and (c) recovering liquid hydrocarbonaceous products from said liquefaction effluent.

Claim 20

A process as defined by claim 16 wherein said higher concentration is maintained by introducing catalytic material that is active in promoting the hydrogenation of aromatics to form hydroaromatics into said liquefaction zone at a point where the donatable hydrogen concentration of said solvent in said zone is below the thermodynamic equilibrium concentration at the temperature in said zone.