New Albany shale flash pyrolysis under hot-recycled-solid conditions: Chemistry and kinetics, II
The authors are continuing a study of recycle retorting of eastern and western oil shales using burnt shale as the solid heat carrier. Stripping of adsorbed oil from solid surfaces rather than the primary pyrolysis of kerogen apparently controls the release rate of the last 10--20% of hydrocarbons. Thus, the desorption rate defines the time necessary for oil recovery from a retort and sets the minimum hold-time in the pyrolyzer. A fluidized-bed oil shale retort resembles a fluidized-bed cat cracker in this respect. Recycled burnt shale cokes oil and reduces yield. The kerogen H/C ratio sets an upper limit on yield improvements unless external hydrogen donors are introduced. Steam can react with iron compounds to add to the H-donor pool. Increased oil yield when New Albany Shale pyrolyzes under hot-recycled-solid, steam-fluidization conditions has been confirmed and compared with steam retorting of acid-leached Colorado oil shale. In addition, with retorted, but unburnt, Devonian shale present at a recycle ratio of 3, the authors obtain 50% more oil-plus-gas than with burnt shale present. Procedures to make burnt shale more like unburnt shale can realize some increase in oil yield at high recycle ratios. Reduction with H{sub 2} and carbon deposition are possibilities that the authors have tested in the laboratory and can test in the pilot retort. Also, eastern spent shale burned at a high temperature (775 C, for example) cokes less oil than does spent shale burned at a low temperature (475 C). Changes in surface area with burn temperature contribute to this effect. 15 refs., 8 figs., 4 tabs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- Sponsoring Organization:
- DOE/FE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6306677
- Report Number(s):
- UCRL-JC-105169; CONF-901181-3; ON: DE91006708
- Resource Relation:
- Conference: Eastern oil shale symposium: oil shale, tar sands, heavy oil, Lexington, KY (USA), 6-8 Nov 1990
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OIL SHALES
RETORTING
SPENT SHALES
COMBUSTION
BLACK SHALES
CARBON
CHEMICAL ANALYSIS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
COKING
COLORADO
DEPOSITION
DESIGN
DESORPTION
DEVOLATILIZATION
DEVONIAN PERIOD
FISCHER ASSAY
FLASH HEATING
FLUIDIZED BEDS
GREEN RIVER FORMATION
HEAT TRANSFER
HYDROGEN TRANSFER
KENTUCKY
KEROGEN
OIL YIELDS
POROSITY
PYROLYSIS
RECYCLING
RESEARCH PROGRAMS
RETORTS
STEAM
SURFACE AREA
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CARBONIZATION
CHATTANOOGA FORMATION
CHEMICAL REACTIONS
CHEMICAL REACTORS
DECOMPOSITION
DISTILLATION EQUIPMENT
ELEMENTS
ENERGY SOURCES
ENERGY TRANSFER
EQUIPMENT
FEDERAL REGION IV
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC FORMATIONS
HEATING
KINETICS
MATERIALS
NONMETALS
NORTH AMERICA
ORGANIC MATTER
OXIDATION
PALEOZOIC ERA
REACTION KINETICS
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
USA
YIELDS
040402* - Oil Shales & Tar Sands- Surface Methods
044000 - Oil Shales & Tar Sands- Combustion- (1990-)