US4591424A
Expired / Lapsed
US
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Method of preparing carbonaceous pitch
Assignee: Fuji Standard Research Inc
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Filing: 1984-05-17
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Granted: 1986-05-27
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Expires: 2004-05-17
Abstract
Abstract A method of preparing an carbonaceous pitch, including the steps of: subjecting a raw material oil to thermal cracking conditions while removing cracked, light hydrocarbon components to obtain a pitch product containing at least 5 weight % of mesophase and not more than 10 weight % of light hydrocarbon components with a boiling point at 60 mmHg of 300 DEG C. or less and having a softening point of between 160 DEG and 220 DEG C., the raw material oil being composed mainly of a residual oil which has a boiling point of 350 DEG C. or more and which is derived from a naphthene base petroleum crude; and removing the mesophase from the pitch product to obtain a substantially mesophase-free carbonaceous pitch.
Inventors
- 👤 Shimpei Gomi
- 👤 Tomio Arai
- 👤 Fumio Mogi
- 👤 Takao Nakagawa
- 👤 Kunio Miura
- 👤 Sugio Otani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:51
CPC Classifications
C; C10; C10C; C10C3/00; D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
187 words
A method of preparing an optically isotropic carbonaceous pitch which is convertible inot optically anisotropic pitch when subjected to shear forces, said method comprising the steps of: providing a raw material oil comprising at least 45% of a residual oil having a boiling point of 350° C. or more and obtained from fractionation of a naphthene base petroleum crude, said napbtbene base petroleum crude having a characterization factor K of between 11.0 and 11.5, said factor K defined as: ##EQU2## wherein T B is the molar average bioling point in Rankine (° F.+460) and S is the specific gravity at 60° F. of the distillate; thermally cracking said raw material oil in a reaction zone to remove light hydrocarbon components and to obtain a pitch product containing 5-40 weight % of mesophase and not more than 10 weight % of light hydrocarbon components with a bioling point at 60 mmHg (absolute) of 300° C. or less and having a softening point of between 160° and 220° C.; and removing the mesophase from said pitch product to obtain a substantially mesophase-free carbonaceous pitch as said optically isotropic pitch.
Claim 2
Independent Claim
187 words
A method of preparing an optically isotropic carbonaceous pitch which is convertible inot optically anisotropic pitch when subjected to shear forces, said method comprising the steps of: providing a raw material oil comprising at least 45% of a residual oil having a boiling point of 350° C. or more and obtained from fractionation of a naphthene base petroleum crude, said napbtbene base petroleum crude having a characterization factor K of between 11.0 and 11.5, said factor K defined as: ##EQU2## wherein T B is the molar average bioling point in Rankine (° F.+460) and S is the specific gravity at 60° F. of the distillate; thermally cracking said raw material oil in a reaction zone to remove light hydrocarbon components and to obtain a pitch product containing 5-40 weight % of mesophase and not more than 10 weight % of light hydrocarbon components with a bioling point at 60 mmHg (absolute) of 300° C. or less and having a softening point of between 160° and 220° C.; and removing the mesophase from said pitch product to obtain a substantially mesophase-free carbonaceous pitch as said optically isotropic pitch.
Claim 3
Dependent Claim
36 words
A method as claimed in claim 1, wherein said thermal cracking is performed while maintaining the reaction zone under a reduced pressure so that the cracker light hydrocarbon components are continuously removed from said reaction zone.
Claim 4
Dependent Claim
37 words
A method ad claimed in claim 1, wherein said thermal cracking is performed while continuously feeding a gaseous heat transfer medium so that the cracked light hydrocarbon components are continuously removed by stripping from said reaction zone.
Claim 5
Dependent Claim
27 words
A method in accordance with claim 3 wherein said heat-transfer medium is a substantially oxygen-free, non-oxidative gas which supplies the heat necessary for effecting said thermal cracking.
Claim 6
Independent Claim
28 words
A method in accordance with clalm 4 wherein said heat transfer medium is selected from the group consisiting of steam, hydrocarbons, perfect combustion waste gas, nitrogen and hydrogen.
Claim 7
Independent Claim
28 words
A method in accordance with clalm 4 wherein said heat transfer medium is selected from the group consisiting of steam, hydrocarbons, perfect combustion waste gas, nitrogen and hydrogen.
Claim 8
Dependent Claim
24 words
A method in accordance with claim 1 wherein said thermal cracking is conducted at a pressure of between 5 to 500 mm Hg (absolute.)
Claim 9
Dependent Claim
27 words
A method in accordance with claim 1 wherein said thermal cracking is conducted at a partial pressure of hydrocarbon vapor of between 5 and 500 mm Hg.
Claim 10
Dependent Claim
19 words
A method as claimed in claim 1, wherein said removing step is effected by filtration at an elevated temperature.
Claim 11
Dependent Claim
65 words
A method as claimed in claim 1, wherein the thermal cracking is conducted so that said mesophase-free pitch contains polycyclic, polycondensed ring aromatic hydrocarbons having naphthenic rings and aliphatic side chains and has a greater number of hydrogen atoms bonded to non-aromatic carbon atoms located at β or more remote positions the number of hydrogen atoms bonded to non-aromatic carbon atoms located at α positions.
Claim 12
Dependent Claim
27 words
A method in accordance with claim 1 wherein said pitch product contains 10-25% weight mesophase and no more than 5 weight % of said light hydrocarbon components.
Claim 13
Dependent Claim
16 words
The method of claim 1 wherein said thermal cracking is conducted at 350° to 500° C.
Claim 14
Dependent Claim
16 words
The method of claim 1 wherein said thermal cracking is conducted at 400° to 440° C.
Claim 15
Dependent Claim
32 words
The method of claim 1 wherein said mesophase formed by thermal cracking is in the form of botryoidal aggregates between 25 and 150 μm homogeneously dispersed in the matrix of isotropic pitch.
Claim 16
Dependent Claim
20 words
A process in accordance with claim 1 wherein said separation is by filtration, sedimentation, centrifugation or high gradient magnetic separation.
Claim 17
Dependent Claim
13 words
A process in accordance with claim 1 wherein said separation is by filtration.
Claim 18
Dependent Claim
32 words
A process in accordance with claim 1 wherein said residual oil contains metal impurities and wherein the major portion of the metal impurities is removed with the mesophase from the pitch product.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |