FATE OF ALKALI AND TRACE-METALS IN BIOMASS GASIFICATION

The fate of alkali metals (Na, K) and eleven toxic trace elements (Hg, Cd, Be, Se, Sb, As, Pb, Zn, Cr, Co, Ni) in biomass gasification have been extensively investigated in Finland in the past ten years. The fo rmer due to the gas turbine requirements and the latter to comply with environmental regulations. In this paper the results of several exper imental studies to measure Na and K in the vapor phase after the gas c ooler of a simplified (air-blown) Integrated Gasification Combined-Cyc le (IGCC) system are reported. Also, trace element emissions from an I GCC plant using alfalfa as the feedstock are discussed and the concent rations of a few toxic trace metals in the vapor phase in the gasifier product gas are reported. (C) 1998 Elsevier Science Ltd. All rights r eserved.