Drying and passivating wet coals and lignite

Patent · Tue Feb 10 04:00:00 EST 1981

OSTI ID:6350065

Comolli, A G

This invention discloses a staged process for drying wet carbonaceous materials such as sub-bituminous coal or lignite containing at least about 10 weight percent moisture, usually 15-50 weight percent moisture, by first heating the wet material under low partial pressure of moisture to permit the controlled rapid escape of surface moisture down to a critical moisture content of 8-12 weight percent. In a second step, the material is further heated at lower differential vapor pressure to provide for further moisture evolution at a slower controlled rate. This staged drying procedure permits wicking up of hydrocarbons contained in the coal to seal the surface of the dried coal product sufficient to prevent appreciable reabsorption of moisture and consequent heating and spontaneous ignition.

• Assignee: Hydrocarbon Research Inc
• Patent Number(s): US 4249909
• OSTI ID: 6350065
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010402* -- Coal
Lignite
& Peat-- Purification & Upgrading
013000 -- Coal
Lignite
& Peat-- Transport
Handling
& Storage
BROWN COAL
CARBONACEOUS MATERIALS
COAL
DRYING
ENERGY SOURCES
FOSSIL FUELS
FUELS
HEATING
LIGNITE
MATERIALS
PHYSICAL PROPERTIES
SUBBITUMINOUS COAL
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE