SO2 REDUCTION USING MERIT PILA COAL BLENDING TECHNIQUE IN FLUIDISED BED COMBUSTION

Abstract

Coal has advontages over other sources of fuels due to vast world reserves, estimated to the five folds that of gas and oil put together. From economies of scale, coal-fired power generation is the cheapest. contributing to 40% of world energy power generation. However, burning coal creates environmental effects although modern cleanup technologies are able to reduce the impact. However. clean-up facilities will cause high capital and operational costs besides creating an additional impact due to discharge of processing wastes including treatment of discharged water. Research into new technologies depending on sizes and its technological complication requires high financial investment, Therefore coal blending technique needs to be investigated simply because it requires little modifications with small investment to the existing plants
It is the objective of this research to optimize local coal consumption by paring with other
types of imported coals as blending partners. The main focus of the research is to observe in
detail the reaction of blending local coal so as to obtain the optimum ratio for the blended coal to improve combustion performance. Secondly, to obtain a responsive reaction of coal blending in combustion to reduce SO2 emission, Merit Pila coal as a local coal is blended with other types of imported coals such as Blair Athol. Tanito Harum. Ulan and Datong at 10% step ratio for each.blend,
In the coal combustion test, a fluidized bed test-rig of 0.123m was successfully designed.
fabricated and commissioned by local experts and fabricated using local materials. One of the special components of the test rig is the distribution plate with tapped distribution nozzles to promote good distribution of air to form well equal bubbles and at the same time to avoid the fluidized bed material re-entering into the air distribution tube
From coal blending combustion tests in th e fluidized bed test-rig. the SO emission profiling is quite similar to that shown by the sulphur contents analysis. If a linear equation is taken from 100:0 ratio to 0:100. it can be seen that the SO2 profile will cut the line at around 50:50 with the first half curving upward and the second half curving downward The profiling behavior is related to the chemical reaction between sulphur and the mineral content of blended coals. For SO2 analysis, the emission can be correlated with other parameters. as in the derived equation  where linear relationship can be achieved. The linear equation is determined by the difference of reaction from sulphur to SO2 and sulphur in ash. By estimating the sulphur content in the ash several simulations can be carried out until the calculated SO2 of the coal reaches the actual values of measured SO2 analysis. Thus. the emission of SO2 could be reduced substantially using local coal blending techniques, The coal blending combustion test has shown that 70%-80'% of imported coal blended with Merit Pila coal will achieve 20%-30'% reduction of S02. The finding will give more options for cheaper and simple techniques to reduce the emission of SO2 from coal fired power stations compared to traditional methods such as commonly Flue Gas Desulphurisation FGD which would require a quater of the plant total cost.