Coal cleaning employing quaternary salts: Annual report, March 1, 1986-February 28, 1987
Present New Source Performance Standards and the prospect of new acid rain legislation at the federal level require that methods be developed to remove substantial portions of sulfur from Illinois Basin coals. This report describes an innovative approach to coal desulfurization. In this approach, quaternary ammonium salts are employed as catalysts to swell coal. The process is designed to address three basic problems which exist in Illinois Basin coals. First, the pyrite in these coals is at a high level and is very finely dispersed. Therefore, the pyrite particles cannot be liberated by conventional coal cleaning techniques. Second, the porosity of these coals is routinely high but is closed to many reactants because of the lack of feeder and transitional pore structure. Third, the high organic sulfur levels require that some sort of chemical desulfurization occur before most Illinois coals meet NSPS standards. The swelling of coals by quaternary salt results in the liberation of the smallest pyrite and inertinite particles of the coal. Furthermore, cracks occur in the coal particle after swelling. These cracks are associated with the larger size pyrite material embedded in -60 mesh ground coal. Only small amounts of quaternary salt are exchanged on the coal. In some cases, a small amount of exchange results in pore enlargement. Under other conditions, chemical desulfurization of organic sulfur is observed. Relationships between the conditions of exchange, mineral and inertinite liberation, pore enlargement, and coal desulfurization are discussed. The results suggest that: (1) quaternary salts may be used to interrupt oxidation degradation of the coal; (2) coals might be liquified employing specific quaternary salt treatments; and (3) under specific conditions, organic sulfur may be attacked selectively. 3 refs., 22 figs., 30 tabs.
- Research Organization:
- Southern Illinois Univ., Carbondale (USA). Coal Extraction and Utilization Research Center
- DOE Contract Number:
- FC22-86PC91272
- OSTI ID:
- 6340756
- Report Number(s):
- DOE/PC/91272-T11; ON: DE87010424
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Coal cleaning employing quaternary salts. Annual report, July 1, 1984-June 30, 1985. [Tetrabutyl ammonium hydroxide; tetramethyl ammonium hydroxide]
Size classification of Illinois Basin coals for desulfurization by froth flotation. Final report, July 1, 1984-June 30, 1985
Related Subjects
COAL
COMMINUTION
DESULFURIZATION
SWELLING
COAL PREPARATION
FEASIBILITY STUDIES
ACID RAIN
ILLINOIS
LEGISLATION
ORGANIC SULFUR COMPOUNDS
OXIDATION
PYRITE
QUATERNARY COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
SULFUR CONTENT
USA
AMINES
AMMONIUM COMPOUNDS
ATMOSPHERIC PRECIPITATIONS
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
ENERGY SOURCES
FEDERAL REGION V
FOSSIL FUELS
FUELS
IRON COMPOUNDS
IRON SULFIDES
MATERIALS
MINERALS
NORTH AMERICA
ORGANIC COMPOUNDS
RAIN
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
010300* - Coal
Lignite
& Peat- Preparation- (1987-)
010402 - Coal
Lignite
& Peat- Purification & Upgrading