Ash analyses of bio-coal briquettes produced using blended binder

Area of Science:

• Materials Science
• Energy Science
• Environmental Science

Background:

• Fuel ash behavior significantly impacts thermal efficiency.
• Limited research exists on the ash composition of bio-coal briquettes derived from lean coal and torrefied biomass.
• Understanding ash properties is crucial for optimizing biomass-coal fuel utilization.

Purpose of the Study:

• To analyze the ash composition and fusion characteristics of bio-coal briquettes made from lean grade coal and torrefied woody biomass.
• To investigate the influence of varying biomass ratios and binder types (coal tar pitch and molasses) on ash properties.
• To characterize the mineral phases and oxides present in the bio-coal ash.

Main Methods:

• Bio-coal briquettes were produced using different ratios of coal and torrefied biomass with blended binders.
• Ash samples were prepared by muffle furnace ashing at 850°C for 3 hours.
• Mineral phases were identified using X-ray Diffraction (XRD), and mineral oxides were quantified using X-ray Fluorescence Spectrometry (XRF).
• Ash fusion temperatures were determined using an AFT700 Furnace.

Main Results:

• XRD analysis showed quartz as the predominant mineral phase in both raw coal and bio-coal briquettes.
• Major detected oxides were SiO2 (57-58%), Al2O3 (19-21%), and Fe2O3 (8-9%).
• The final ash fusion temperatures ranged from 1300°C to 1350°C.
• Ash compositions were classified as detrital minerals.

Conclusions:

• The addition of torrefied biomass (up to 25%) and blended binders (up to 15%) had a negligible effect on the ash composition and fusion behavior of the resulting bio-coal briquettes.
• The characterized ashes are primarily composed of detrital minerals, with quartz being the dominant phase.
• The findings suggest that these bio-coal briquettes possess stable ash characteristics suitable for thermal applications.