Behavior of trace metals in simulated gasification conditions
- Univ. of North Dakota, Grand Forks, ND (United States)
The fate of trace metals is being investigated in two emerging coal gasification electric power-generating systems: integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC). Some of the trace metals in coal are considered air toxics when released into the atmosphere and can also cause the degradation of fuel cell efficiency as a result of contamination. The fate of trace metals during coal conversion in GCC and IGFC systems is closely tied to how the trace metals are associated in the coal and gasification conditions. Bench- and pilot-scale gasification experiments were performed using Illinois No. 6 coal to determine the partitioning of mercury, selenium, arsenic, nickel, cadmium, lead, and chromium into gas, liquid, and solid phases as a function of gasification conditions and coal composition. Entrained ash was collected from the small-scale reactor using a multicyclone and impinger sampling train. Coal analysis revealed arsenic, mercury, nickel, lead, and selenium to be primarily associated with pyrite. Chromium was associated primarily with clay minerals, and cadmium appeared to have mostly an organic association. The partitioning during gasification indicated that chromium, lead, and nickel were enriched in the small ash particulate fraction (less than 1.5 {mu}m), while arsenic, selenium, and mercury were depleted in the particulate and more enriched in the vapor-phase fraction (collected in the impingers). Oxygen contents were varied to represent both combustion and gasification systems. Most of the work was conducted at lower oxygen-to-carbon ratios. Lower oxygen-to-carbon ratios resulted in more reducing environments in the gasification system, which appeared to drive more mercury to the vapor phase. Under constant oxygen-to-carbon ratios, mercury, selenium, and cadmium showed increasing volatility with increasing reaction zone temperature.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Reaction Engineering International, Salt Lake City, UT (United States)
- OSTI ID:
- 83344
- Report Number(s):
- EPRI-TR-104982; CONF-9408200-; TRN: 95:005151-0037
- Resource Relation:
- Conference: 4. EPRI conference on the effect of coal quality on power plants, Charleston, SC (United States), 17-19 Aug 1994; Other Information: PBD: Mar 1995; Related Information: Is Part Of Effects of coal quality on power plants: Fourth International Conference. Proceedings; Harding, N.S. [ed.] [Reaction Engineering International, Salt Lake City, UT (United States)]; Mehta, A.K. [ed.] [Electric Power Research Inst., Palo Alto, CA (United States)]; PB: 776 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Trace element emissions
Trace metal transformations in gasification