Control of trace elements in gasification: A measurement methodology to validate thermodynamic predictions
- British Coal, Cheltenham (United Kingdom). Coal Technology Development Div.
Many heavy metals and other elements with known toxicological and/or ecological effects at high concentrations are present in coal in trace quantities. These trace elements are mobilized by the processes of combustion or gasification. Higher gas cleaning temperatures and the co-utilization of fuels such as sewage sludge may increase the partitioning of the trace elements to the gas phase. As part of the program being carried out by British Coal and its collaborators to develop components of the Air Blown Gasification Cycle (ABGC), the partitioning of trace elements in the gasifier with hot gas cleanup is being investigated. Thermodynamic predictions of trace element behavior over the temperature range 400 to 1000 C in a typical fuel gas composition produced by a UK coal have been made. The predicted volatility of the elements indicates that Zn, Cu, Mo, Sn, Pb and Mn may condense between the gasifier outlet and the final stage of gas cleaning, depending on the gas cleaning temperature; Hg, Se, As and Cd are likely to remain in the vapor state and therefore will enter the gas combustion system. A novel trace element vapor sampler has been used to determine the levels of As, B, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni,m Pb, Sb, Se, Sn, V and Zn in the hot filtered gas from the CTDD 2MW{sub t} Fluidized Bed Gasifier Pilot Plant at Stoke Orchard. Tests to study the effect of feedstock variations (coal/sewage sludge/sorbent) and filter temperature have been carried out. The initial results indicate that background contamination has been controlled sufficiently to allow the levels of trace elements in the fuel gas to be measured. Thermodynamic and fundamental studies to support the interpretation of the data are continuing at Imperial College, London under the EU JOULE III program.
- OSTI ID:
- 357909
- Report Number(s):
- CONF-9705116-; ISBN 0-7918-1557-9; TRN: IM9932%%254
- Resource Relation:
- Conference: 14. international conference on fluidized bed combustion, Vancouver (Canada), 11-16 May 1997; Other Information: PBD: 1997; Related Information: Is Part Of Proceedings of the 14. international conference on fluidized bed combustion: Volume 2; Preto, F.D.S. [ed.] [Canada Centre for Mineral and Energy Technology, Ottawa, Ontario (Canada). Energy Technology Centre]; PB: 647 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of hot gas filtration for air blown gasification plant
Environmental assessment of the HYGAS Process. Monthly progress report, April 1--April 30, 1977