Electrical conductivity of coal and coal char

✍ Scribed by Alfred G. Duba

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 350 KB
• Volume: 56
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(77)90074-6

✦ Synopsis

The electrical conductivity of coal, at either 1 kHz or d.c., was measured at 24°C on samples recovered from pyrolysis experiments aimed at modelling conditions during in situ gasification of coal. From an initial value of low3 S/m (when the coal is saturated with formation water), the conductivity decreases to 10V8 S/m when the coal is heated to 110°C in vacuum. This low value, presumably due to dehydration of the coal, prevails for samples heated as high as 500°C in dry argon. Samples of char recovered after pyrolysis to 800°C or more have a conductivity of lo* S/m. Capitalizing on the large contrast between the conductivities of coal and char produced during gasification, electrical probing may be a sensitive tool for monitoring 'burn-front' progress during in situ coal gasification.