Effects of eucalyptus leaves blending on combustion characteristics of an Indian reject coal

ABSTRACT

Presents work aims at the results obtained from experimental studies on utilization of eucalyptus leaves (ECL) to enhance the burning performance of a coal cleaning plant reject well known as reject coal (RC). Different parameters of combustion like; temperature of ignition (T_i), peak temperature (T_p), temperature of burnout (T_b), peak combustion rate (DTG_max), index of ignition (D_i), index of burnout (D_f), index of combustion performance (S), and index of rate intensity (H_f) were obtained from TGA-DTG experiments to optimize the blending ratio of ECL and RC. Experimental results showed that there is improvement in combustion performance of RC when 20% by mass of ECL is blend with 80% by mass of RC and reducing T_i from 449℃ to 429℃, T_p from 511℃ to 509℃, and T_f from 567℃ to 552℃. Addition of higher quantities of ECL up to 90% mass, reduces T_i, T_p, T_b further down to 234℃, 476℃ and 508℃ respectively and increases DTG_max from 3.64 to 4.73 wt%/minute. Considering the various parameters of combustion, maximum of 20% mass of ECL having 78% volatile matter, 6985 kcal/kg GCV are recommended to blend with 80% by mass of RC having 11% volatile matter and 3105 kcal/kg GCV for thermal utilities. Experimental results confirmed that, ECL can be burned with coal to reduce the overall coal consumption, thus decreases the carbon footprint of coal fired utilities.

KEYWORDS:

• Eucalyptus leaves
• reject coal
• co-combustion
• TGA-DTG
• combustion indices
• activation energy

Additional information

Notes on contributors

Subhajit Aich

Subhajit Aich obtained his B. Tech. in Mechanical Engineering and M.Tech. in Fuel Engineering. Currently he is pursuing his PhD at Indian Institute of Technology (Indian School of Mines) Dhanbad, India in the area of co combustion of coal and Biomass blends.

Barun Kumar Nandi

Barun Kumar Nandi is currently working as Assistant Professor at the Department of Fuel and Mineral Engineering, Indian Institute of Technology (Indian School of Mines) Dhanbad, India.

Sumantra Bhattacharya

Sumantra Bhattacharya is currently working as Professor at the Department of Fuel and Mineral Engineering, Indian Institute of Technology (Indian School of Mines) Dhanbad, India.