Development program for MHD power generation: coal devolatilization. Final report, Volume VI, July 1, 1975--September 30, 1976. [Exhaust gas from MHD generator used to pyrolyze coal for production of clean fuel gas of CO and H2]

Technical Report · Fri Apr 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/5330395· OSTI ID:5330395

Ubhayakar, S. K.; Gannon, R.; Stickler, D.

One of the many MHD power cycles which look attractive for producing electric power from coal is the Chemical Regeneration Cycle. In this cycle, pulverized coal is injected into and entrained in the hot exhaust of an MHD power genertor. A large percentage (approximately 70%) of the entrained coal devolatilizes under the rapid heating conditions, and the devolatilized fraction reacts endothermically with the steam and carbon dioxide in the exhaust to produce a fuel gas rich in carbon monoxide and hydrogen. In order to understand the various physico-chemical processes occurring in such a gasifier, an experimental and analytical study was conducted. In this study, pulverized bituminous coal was injected and entrained in hot combustion gases flowing in a constant cross-section gasifier. In this report, data on the weight loss through rapid pyrolysis, on the temperature of the heterogeneous medium, and on the composition of the overall products are presented, and are correlated with an analytical model incorporating two competitive first-order Arrhenius reactions. All data pertain to tests conducted at a pressure of one atm. Heating rates up to 10/sup 5/ /sup 0/K/s and volatile product yields up to 70% of the original dry, ash-free coal were observed. Analysis of the data suggests that a significant fraction of these products crack to soot and hydrogen, and that the cracking fraction increases with the coal fraction in the input gases. Refinements in the chemical regeneration cycle analysis using the experimental data are indicated. The results of exploratory experiments to measure the amount of seed that reacts with the ash/slag during rapid devolatilization are presented. The coal devolatilization reactor was modified to study the devolatilization and burnout of the coal particles in hot oxidizing atmospheres. Design parameters on coal injection nozzles, and other experimental data are presented.

• Research Organization: Avco-Everett Research Lab., Inc., Everett, MA (USA)
• OSTI ID: 5330395
• Report Number(s): FE-2015-20
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
08 HYDROGEN
080107 -- Hydrogen-- Production-- Coal Gasification
090121 -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
30 DIRECT ENERGY CONVERSION
300101 -- MHD Generators-- Design & Development
BITUMINOUS COAL
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COAL
COAL GASIFICATION
CRACKING
DECOMPOSITION
DIRECT ENERGY CONVERTERS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GASES
GASIFICATION
HYDROGEN PRODUCTION
MATHEMATICAL MODELS
MHD GENERATORS
NOZZLES
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
SYNTHESIS
VOLATILE MATTER
WASTE HEAT UTILIZATION
WASTE PRODUCT UTILIZATION
YIELDS