Nagaland coals: suitability as an energy source

Northeast Indian coals have immense potential for energy, power and other value added products. In comparison to the country’s total deposit, the reserve though less, deserves attention owing to different physico-chemical characteristics and non-availability of good quality coal in the country. The state of Nagaland forms a part of the northern extension of the Arakan-Yoma range which has undergone orogenic upheavals during the Cretaceous and Tertiary period. The state has a good deposit of high sulfur coals, lying unexploited industrially so far. In the present investigation, a systematic study on Nagaland coals has been done to explore their suitability as a source of energy. Coal samples from different coalfields have been analyzed for proximate, ultimate, TGA, composition of ash, and petrographic constituents. The swelling and caking indices have been determined. The fouling and slagging indices of these coals have also been reported. The Nagaland coals have high sulfur content similar to those of the other tertiary coals and low ash fusion temperature range, for which they are not suitable for the power generation with the conventional combustion systems, however could be suitable for combustion with FBC techniques, which operate at lower temperature (≤ 850°C) with in-situ desulphurization mechanism. These coals also show characteristics of non-caking and swelling in general.