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Title: Fluidized bed selective pyrolysis of coal

Abstract

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.

Inventors:
; ;
Publication Date:
OSTI Identifier:
7279618
Patent Number(s):
US 5171406; A
Application Number:
PPN: US 7-599322
Assignee:
Western Research Inst., Laramie, WY (United States) PTO; EDB-94-086167
DOE Contract Number:
AC21-87MC24268
Resource Type:
Patent
Resource Relation:
Patent File Date: 17 Oct 1990
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; CHARS; SYNTHESIS; COAL; PYROLYSIS; COAL GAS; COAL LIQUIDS; CHEMICAL REACTORS; PROCESS CONTROL; TEMPERATURE CONTROL; CARBONACEOUS MATERIALS; CHEMICAL REACTIONS; CONTROL; DECOMPOSITION; ENERGY SOURCES; FLUIDS; FOSSIL FUELS; FUELS; GASES; LIQUIDS; MATERIALS; PYROLYSIS PRODUCTS; THERMOCHEMICAL PROCESSES; 010409* - Coal, Lignite, & Peat- Pyrolysis & Carbonization- (1987-)

Citation Formats

Shang, J.Y., Cha, C.Y., and Merriam, N.W. Fluidized bed selective pyrolysis of coal. United States: N. p., 1992. Web.
Shang, J.Y., Cha, C.Y., & Merriam, N.W. Fluidized bed selective pyrolysis of coal. United States.
Shang, J.Y., Cha, C.Y., and Merriam, N.W. 1992. "Fluidized bed selective pyrolysis of coal". United States. doi:.
@article{osti_7279618,
title = {Fluidized bed selective pyrolysis of coal},
author = {Shang, J.Y. and Cha, C.Y. and Merriam, N.W.},
abstractNote = {The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1992,
month =
}
  • The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products aremore » recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.« less
  • Method and apparatus are claimed for pyrolyzing agglomerative coals. The method comprises introducing a fluidized bed of hot char particles into a pyrolysis chamber or reactor, and injecting upwardly into the chamber a high velocity jet of agglomerative coal particles in a carrier gas, the fluidized hot char particles surrounding the high velocity coal jet and heating the coal particles to yield gaseous products and char. The hot char particles in the fluidized state and disposed around the coal jet are entrained in the upwardly expanding coal jet and mixed with the coal particles, so that by the time themore » coal particles contact the pyrolysis chamber wall, such coal particles being heated by the char have passed through the tacky state and are no longer tacky and do not adhere to the chamber wall. The gaseous product and char formed during pyrolysis are rapidly removed from the pyrolysis chamber, and such char can be separated, e.g. in a cyclone, reheated and introduced into the fluidized bed of char particles as a fresh source of heat. The hot char particles from the fluidized bed which are entrained in the coal jet are removed from the pyrolysis chamber with the gaseous product, without any appreciable recirculation or mixing of such entrained char particles back into the fluidized char within the pyrolysis chamber.« less
  • A description is given of a process for the pyrolysis of coal comprising, (A) countercurrently contacting coal subdivided to a particle size fluidizable in gas in the form of a relatively cool, upwardly mving fluidized mass in a first vertically-oriented preheating zone with an inert relatively hot first particulate heat carrier thereby transferring sensible heat from the heat carrier to the subdivided coal and heating said coal to an elevated temperature not above the boiling point of water, said coal being fluidized in gas in a manner to create a dilute-phase fluidized mass in said first preheating zone and saidmore » particulate heat carrier being introduced in the upper portion of the preheating zone and having a particle size and density such that it falls through the dilute-phase fluidized mass at a substantially uniform rate and collects in the lower portion of the vertical preheating zone as a relatively cool first particulate heat carrier; (B) recovering the bulk of said subdivided coal at elevated temperature in the upper portion of said preheating zone and passing said recovered coal to a second preheating zone; (C) recovering said relatively cool first particulate heat carrier in the lower portion of said preheating zone, and passing said recovered heat carrier to a heat recovery zone; (D) introducing said subdivided coal at elevated temperature into a second verticaly-oriented preheat zone as a dense phase, flidized mass in gas, and countercurrently contacting said fluidized mass with a second inert particulate heat carrier heated to a temperature above the boiling point of water to transfer sensible heat from the heat carrier to the coal and remove any water in the coal, said second particulate heat carrier being introduced in the upper portion of the second preheat zone.« less
  • A process and equipment are described for the pyrolysis of solid carbonaceous materials such as oil shale and coal. A carrier gas is introduced to the base of an upward flowing fast fluidized bed. Simultaneously, there is introduced to the base of the bed a particulate source of heat which contacts and pyrolyzes the carbonaceous material. The particulate source of heat is sufficient to raise the carbonaceous material to a pyrolysis temperature of at least 600/sup 0/F. The pyrolysis of the carbonaceous material yields a particulate carbon containing solid residue and a pyrolytic vapor containing hydrocarbons. The fluidized bed ismore » contained in a vertically diposed open duct. The gaseous mixture is separated from the entrained solids mixture, and the hydrocarbons are recovered from the gaseous mixture. The separated entrained solids mixture is cycled back to the pyrolysis reactor. Pyrolysis occurs at temperatures of 600/sup 0/ to 2,000/sup 0/F. Short reaction times and low temperatures in the fast fluidized bed enhance formation of middle distillate hydrocarbons. (34 claims)« less