Thesis Archive
Evaluation of Iron Oxide from Scrap Metal as Oxygen Carrier in Chemical-Looping Combustion of Philippine Coal (2012)
Abe, Jemelyn
Baes, Norman Vincent
Panglinawan, Joanne
Abstract:
-This research study evaluated iron oxide derived from scrap metal in combustion of two types of Philippine coal, Semirara and Malangas coal in thermo-gravimetric analyser (TGA). The coal samples as well as the scrap metal was ground and sieved to Tyler equivalent 150 mesh. The coal-metal oxide mixture was analysed using the TGA under two different environments for the reduction part, N2 and CO2, and air for the oxidation part. The scrap metal that was characterized with high concentration of 98.61% Fe2O3 was oxidized up to 27.76% by exposing to air for 3 hours at 900°C in N2 atmosphere and 21.2% at 700°C for 3 hours in CO2 atmosphere. The weight ratios(coal/Fe2O3) per run were varied into three: 1/17.14, 1/18.00 and 1/18.86 for Semirara Coal and 1/25.24 and 1/26.5 for Malangas Coal. Three hold temperatures were used in each cycle, 700°C, 800°C and 900°C. The results showed that in N2 atmosphere, the sample weight loss that was obtained from the TGA profile includes only the primary gasification and combustion of the primary gasification products. However, in CO2 atmosphere, the chemical-looping combustion of Semirara coal resulted in the gasification of coal in the sample as the derivative curve exhibited three peaks corresponding to the drying stage, primary gasification stage and the secondary gasification stage where most of the syngas are produced with reduction of iron oxide. The effect of hold temperature in chemical-looping combustion in N2 atmosphere both for Semirara and Malangas Coal was not evident in the TGA profiles since gasification occurred below the hold temperatures. The effect of weight ratio was also not evident since the weight ratio increments were low so as to observe an evident effect on variation of weight ratio. In CLC in CO2 atmosphere, successful runs were conducted only at 800 °C where three peaks of weight loss were observed. The effect of weight ratio was seen at this temperature where 1/17.14, 1/18.00 and 1/18.86 resulted in weight loss of 5.04%, 5.64% and 4.33%, respectively.
Adviser:
Nathaniel Dugos
Susan Roces