EFFECT OF ULTRAFINE IRON AND MINERAL MATTER OIL CONVERSION OF NITROGEN AND CARBON DURING PYROLYSIS AND GASIFICATION OF COAL

A subbituminous coal was used to determine the distribution of N-2, NH3, and HCN during slow rate heating pyrolysis in He and gasification in 10% CO2 + He balance. During pyrolysis, the N-2 the major product followed by NH3 and HCN. During gasification, the N-2 fields were significantly enhanced and those of NH3 and HCN decreased: Partial demineralization of coal resulted in a decrease in carbon and nitrogen conversion. This effect was also evident by comparing the nitrogen and carbon conversions of chars prepared at 500 degrees C from the fresh and demineralized coals. The addition of ultrafine Fe to coal increased conversion of carbon and nitrogen to N-2 during gasification but had little effect during pyrolysis. Thus, during the former more than 80% of the coal nitrogen was released as N-2. Also, in the presence of Fe the temperature of N-2 release was decreased by about 100 degrees C both during pyrolysis and gasification. During gasification of chars prepared at 1000 degrees C, the conversion of the coal nitrogen to Na was much lower than that of carbon.