Combustion Characteristics of Dried Sewage Sludge and Control of

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Energy & Fuels 2005, 19, 2298-2303

Combustion Characteristics of Dried Sewage Sludge and Control of Trace-Metal Emission Hong Yao and Ichiro Naruse* Department of Ecological Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580, Japan Received April 14, 2005. Revised Manuscript Received June 26, 2005

While the volume of sludge is increasing, it is difficult to find new final disposal sites, especially in Japan. The incineration of sewage sludge is a suitable way to decrease the volume. However, one of the principal problems is the elevated content of trace metals in sewage sludge. These trace metals can escape post-combustion cleanup as a gaseous phase or enrichment in fine particles. In this paper, the combustion tests of dried sewage sludge are performed using a 2-mtall, 40-mm-inner-diameter electrically heated drop tube furnace. Experimental procedures involve (i) the combustion characteristics of dried sewage sludge and (ii) baseline runs of sludge alone and several runs with the kaolin addition as a sorbent at 1073, 1148, and 1223 K. The sample is collected by an aerosol size fractionation system that is composed of a water-cooled rapid N2 quenching probe and a low-pressure impactor. The results show that the ignition temperature of dried sewage sludge is