Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
178 words
A process for producing a pitch for using as a raw material for producing carbon fibers, comprising the steps of: subjecting a petroleum heavy residual oil comprising a fraction having a boiling point of 300° C. or more to hydrogenation treatment in the presence of a catalyst under a condition comprising a temperature of 370° to 450° C., a pressure of 70 to 210 Kgf/cm 2 , a liquid space velocity of 0.4 to 2.0 Hr -1 and a ratio of hydrogen/oil of 700 to 1,700 Nm 3 /Kl, removing a fraction having a boiling point of 500° C. or less by reduced pressure distillation, subjecting the resulting reduced pressure distillation residual oil to solvent extraction treatment using a saturated hydrocarbon compound having 3 to 7 carbon atoms as a solvent under a condition comprising a ratio of solvent to oil of 3:1 to 15:1, a temperature of 50° to 230° C. and a pressure of 5 to 50 Kgf/cm 2 , and carrying out thermal modification of the extracted material by heating at 390° to 430° C.
Claim 2
Dependent Claim
178 words
A process for producing a pitch for using as a raw material for producing carbon fibers, comprising the steps of: subjecting a petroleum heavy residual oil comprising a fraction having a boiling point of 300° C. or more to hydrogenation treatment in the presence of a catalyst under a condition comprising a temperature of 370° to 450° C., a pressure of 70 to 210 Kgf/cm 2 , a liquid space velocity of 0.4 to 2.0 Hr -1 and a ratio of hydrogen/oil of 700 to 1,700 Nm 3 /Kl, removing a fraction having a boiling point of 500° C. or less by reduced pressure distillation, subjecting the resulting reduced pressure distillation residual oil to solvent extraction treatment using a saturated hydrocarbon compound having 3 to 7 carbon atoms as a solvent under a condition comprising a ratio of solvent to oil of 3:1 to 15:1, a temperature of 50° to 230° C. and a pressure of 5 to 50 Kgf/cm 2 , and carrying out thermal modification of the extracted material by heating at 390° to 430° C.
Claim 3
Dependent Claim
196 words
A process for producing a pitch as a raw material for producing carbon fibers, which comprises the steps of: hydrogenating a petroleum heavy residual oil comprising a fraction having a boiling point of 300° C. in the presence of a hydrogenation catalyst at 370° to 450° C., a pressure of 70 to 210 Kgf/cm 2 , a liquid space velocity of 0.4 to 2.0 Hr -1 and a hydrogen/oil ratio of 700 to 1,700 Nm 3 /Kl; removing a fraction having a boiling point of about 450° C. or less reduced pressure distillation; subjecting the resulting reduced pressure distillation residual oil to solvent extraction using one or more saturated hydrocarbon compound solvents having 3 to 7 carbon atoms at a solvent to oil ratio of 3:1 to 15:1, a temperature of 50° to 230° and a pressure of 5 to 50 Kgf/cm 2 to obtain an extract having a sulfur content of 2.5 wt% or less, a vanadium content of 15 ppm or less, a nickel content of 7 ppm or less, and an asphaltene content of 0.05 wt% or less; and thermally modifying the resulting extraction component at a temperature of 390° to 430° C.
Claim 4
Dependent Claim
196 words
A process for producing a pitch as a raw material for producing carbon fibers, which comprises the steps of: hydrogenating a petroleum heavy residual oil comprising a fraction having a boiling point of 300° C. in the presence of a hydrogenation catalyst at 370° to 450° C., a pressure of 70 to 210 Kgf/cm 2 , a liquid space velocity of 0.4 to 2.0 Hr -1 and a hydrogen/oil ratio of 700 to 1,700 Nm 3 /Kl; removing a fraction having a boiling point of about 450° C. or less reduced pressure distillation; subjecting the resulting reduced pressure distillation residual oil to solvent extraction using one or more saturated hydrocarbon compound solvents having 3 to 7 carbon atoms at a solvent to oil ratio of 3:1 to 15:1, a temperature of 50° to 230° and a pressure of 5 to 50 Kgf/cm 2 to obtain an extract having a sulfur content of 2.5 wt% or less, a vanadium content of 15 ppm or less, a nickel content of 7 ppm or less, and an asphaltene content of 0.05 wt% or less; and thermally modifying the resulting extraction component at a temperature of 390° to 430° C.