The distribution of trace elements to the output streams in a coal and waste gasification scheme for clean energy production have been investigated on a pilot scale gasifier. A 2 MW, air-blown fluidized bed gasifier operated at nominal bed conditions of 960 degreesC and 13 bar has been used for these investigations. The effects of feedstock variations (coal/sewage sludge/sorbent) and hot gas filter temperatures of 580 to 450 degreesC were studied. Feedstock sampling and deposition within the plant were found to be significant contributions to mass balance closures outside the expected range. The total trace element emission in the fuel gas from co-gasification of sewage sludge with coal was not significantly increased, and remained within potential legislative limits. No Zn was present in the fuel gas, despite the high levels of this element in the sewage sludge, but there was evidence of an increase in Sn emissions under certain conditions. Hg and Se were only detected in the fuel gas, while Cd and Pb were concentrated in the fine dust removed by the hot gas filter. A reduction in hot gas filter temperature to 350 degreesC was shown to substantially reduce Pb emissions in the fuel gas. B was retained in the solid streams when sulfur sorbents were used.