Investigation of the effects of Sub-bituminous coal with new formulated coal additives using 150 kw combustion test rig

Abstract

Purpose: Ash deposition from coal combustion has been one of the main operational problems for power plant generation industry. A severe ash deposition in the boiler has led to unschedule outage of the unit. Therefore, there is an urgent need to gain a sound understanding of coal ash deposition behaviour and its relation to the boiler operating conditions. In this study a new formula and improved product of customised coal additive has been developed namely from Dolomite and Kaolin. Methodology: The characteristic of coal additive and combustion testing has been carried out using TNBR lab and 150kw solid fuel combustion test rig in order to study the effectiveness of the coal additive in reducing slagging and fouling by blending at 3, 5 and 10% ratio with three types of sub-bituminous coal namely CAD (Coal A), CFKP (Coal B) and CAH (Coal C). Results: The results show significant reduction of Fe2O3 content in ash samples, increase in the hemisphere temperature of ash melting point and reduction of Na2O content in ash composition, which leads to reduction in its fouling propensity. The formulation of Kaolin active compound is found to give the best results that reduces slagging and fouling propensity. The Kaolin formulation at 10% premixed with Coal B shows the best coal additive in reducing slagging propensity at 82.1% and at 10% premixed with Coal C coal shows the best coal additive in reducing fouling propensity at 96.4% Applications/Originality/Value: In this study a new formula and improved product of customised coal additive has been developed namely from Dolomite (D+ additive) and Kaolin (K+ additive). The new properties of coal additive formulation have been analysed in TNBR combustion and fuel laboratory. The combustion testing of the new formulated coal additives is carried out in using TNBR combustion test-rig facility (CTF).