United States Patent
US Patent 4578175: Combined process for coal pyrolysis and char…
US 4578175 · granted 1986-03-25
Abstract
Finely divided coal is reacted in a combination of processes comprising flash pyrolysis and fluidized bed gasification of char from the pyrolysis. A portion of the char which is heated by the steam-oxygen gasification provides the heat for the pyrolysis step, which can be controlled to emphasize production of such materials as light olefins and BTX pyrolyzing at lower pressure and more severe temperature, or to emphasize production of a tar, suitable for processing as a synthetic crude oil, by pyrolyzing at higher pressure and less severe temperature. In either instance the fluidized bed gasification produces a useful synthesis gas.
| Patent Number | 4578175 |
|---|---|
| Title | Combined process for coal pyrolysis and char gasification |
| Filed | 1984-04-02 |
| Granted | 1986-03-25 |
| Inventor(s) | Gorin; Everett |
| Assignee | Conoco Inc. |
| Number of Claims | 53 |
Abstract
Finely divided coal is reacted in a combination of processes comprising flash pyrolysis and fluidized bed gasification of char from the pyrolysis. A portion of the char which is heated by the steam-oxygen gasification provides the heat for the pyrolysis step, which can be controlled to emphasize production of such materials as light olefins and BTX pyrolyzing at lower pressure and more severe temperature, or to emphasize production of a tar, suitable for processing as a synthetic crude oil, by pyrolyzing at higher pressure and less severe temperature. In either instance the fluidized bed gasification produces a useful synthesis gas.
Claim 1
The method of converting coal to gaseous and liquid products which consisting essentially of: (a) admixing finely divided coal into a hydrogencontaining recycle gas stream, (b) providing a vertically elongated pyrolysis zone, (c) introducing the coal-containing recycle gas stream of step (a) into a lower region of said pyrolysis zone, (d) introducing a finely divided particulate heated char into a lower region of said pyrolysis zone, (e) passing the resulting mixture of heated char, finely divided coal, and recycle gas upwardly through said pyrolysis zone at a temperature between about 500.degree. and about 950.degree. C. and a pressure between about 3 and about 33atmospheres absolute, (f) removing from an upper region of said pyrolysis zone a raw vapor stream comprising tar and lighter hydrocarbons, (g) separating condensible liquid products from said raw vapor stream of step (f) to produce a gas stream, (h) returning at least a portion of said gas stream from step (g) to comprise said recycle gas of step (a), (i) removing from an upper region of said pyrolysis zone a stream of finely divided hot solids comprising char and ash, (j) providing a vertically elongated fluidized bed ga
Claims
53 totalThe method of converting coal to gaseous and liquid products which consisting essentially of: (a) admixing finely divided coal into a hydrogencontaining recycle gas stream, (b) providing a vertically elongated pyrolysis zone, (c) introducing the coal-containing recycle gas stream of step (a) into a lower region of said pyrolysis zone, (d) introducing a finely divided particulate heated char into a lower region of said pyrolysis zone, (e) passing the resulting mixture of heated char, finely divided coal, and recycle gas upwardly through said pyrolysis zone at a temperature between about 500.degree. and about 950.degree. C. and a pressure between about 3 and about 33atmospheres absolute, (f) removing from an upper region of said pyrolysis zone a raw vapor stream comprising tar and lighter hydrocarbons, (g) separating condensible liquid products from said raw vapor stream of step (f) to produce a gas stream, (h) returning at least a portion of said gas stream from step (g) to comprise said recycle gas of step (a), (i) removing from an upper region of said pyrolysis zone a stream of finely divided hot solids comprising char and ash, (j) providing a vertically elongated fluidized bed ga