Use of surfactants in fine coal dewatering: Volume 1

Technical Report · Thu May 01 04:00:00 EDT 1986

OSTI ID:6688568

Gala, H B; Venkatadri, R; Chiang, S H

The moisture in coal prior to its utilization is undesirable. The removal of moisture from fine coal (less than 500 microns in size) by filtration and thermal drying contributes heavily to the cost of the clean coal. As an alternative to thermal drying, the use of surfactants in vacuum filtration was investigated. The effect of cationic (dodecyl pyridinium chloride, Arosurf MG 83A), anionic (Aerosol-OT) and non-ionic (Triton X-114 and Triton X-100) surfactants on the filtration and dewatering characteristics of -32 mesh Pittsburgh Seam-Bruceton Mine coal was investigated by conducting adsorption, dynamic and equilibrium experiments at various surfactant concentrations. The surfactant concentration was monitored by measuring the surface tension of the aqueous solution. The adsorption isotherm of the surfactants exhibited three different region characteristic of a bilayer formation. A model for the adsorption isotherm, incorporating the orientation of the surfactant molecules at the surface of the coal particles was proposed, based on which the surface area of the coal was found to be 1000 to 2500 m/sup 2//kg. The observed complex behavior of the moisture content versus the surfactant concentration curve was also consistent with the proposed model. An improvement in the dewatering characteristics was observed whenever the surfactant adsorption made the coal surface hydrophobic. The Darcy's equations for the flow of two phases through a porous medium predicted th dewatering curves for the filter cakes formed with thee surfactant solution coal slurry reasonably well. The relative permeability of the filtrate through the filter cake was calculated using the capillary pressure desaturation data obtained from the equilibrium experiments. 75 refs., 39 figs., 14 tabs.

• Research Organization: Pittsburgh Univ., PA (USA). Dept. of Chemical and Petroleum Engineering
• DOE Contract Number: AC22-81PC42302
• OSTI ID: 6688568
• Report Number(s): DOE/PC/42302-T5; ON: DE87006831
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010300* -- Coal
Lignite
& Peat-- Preparation-- (1987-)
ADSORPTION
ADSORPTION ISOTHERMS
CARBONACEOUS MATERIALS
COAL
COAL FINES
COAL PREPARATION
DATA
DISPERSIONS
ENERGY SOURCES
EXPERIMENTAL DATA
FILTRATION
FOSSIL FUELS
FUELS
INFORMATION
ISOTHERMS
MATERIALS
MATHEMATICAL MODELS
MIXTURES
MOISTURE
NUMERICAL DATA
PERMEABILITY
REMOVAL
RESEARCH PROGRAMS
SEPARATION PROCESSES
SLURRIES
SORPTION
SURFACE AREA
SURFACE PROPERTIES
SURFACTANTS
SUSPENSIONS
WATER REMOVAL