Abstract:
In this work, the catalytic high-pressure steam gasification of coal was carried out in a fixed bed reactor. In order to increase the gas product, the tars were decomposed by using iron oxide catalyst. The lignite coal was obtained from Mae Ta district, Lumpang province. The parameters of interest were pressure, percentage of steam and oxygen addition. The gasification process was studied at temperature of 800 oC, 14.67 concentration of steam and 80 ml/min of carrier gas (N2, Air). The gas product compositions were analyzed by using gas chromatography. From the experiments, it was found that carbon conversion into gas increased with increasing pressure from 1 to 3 bar meanwhile the conversion decreased when the pressure was higher than 3 bar. When using iron oxide catalyst, the results show that hydrogen and carbon dioxide was increased. The addition of air to the reaction results in higher carbon conversion. In addition, the iron oxide was found to perform as an effective catalyst for water-gas shift reaction and tar cracking. The latter was confirmed by analysis results, obtained by GC-MS, of liquid product, indicating reduction of high-molecular weight hydrocarbons in the product.