Combustion of Dried Sewage Sludge in a Fluidized-Bed Reactor

Abstract

Fluidized-bed combustors are capable of destroying effectively a variety of organic wastes such as sewage sludge. Because of its very high content of water, mechanically dewatered sewage sludge cannot be incinerated on its own. Peculiar characteristics of dried sewage sludge include its very high proportion of volatile matter and its high contents of the fuel-bound nitrogen and ash. The experimental apparatus consisted of three fundamental parts: an electrically heated reactor, 0.98-m height and 0.0936-m diameter; a facility for the continuous withdrawal and analysis of gas samples, and a feeder of solids. Predried sewage sludge particles were injected near the base of a shallow, air-fluidized, bubbling bed of ceramsite under different operating conditions. The study comprised an experimental program of steady-state tests for providing a full picture concerning the influence of the main operating variables (i.e., bed temperature, freeboard temperature, and excess air) on the most significant gaseous emissions (i.e., CO, NO x , and N 2 O). Further, this work also explores the significant influence of the freeboard (i.e., the region above a dense, bubbling bed) on the overall combustor performance. Of concern are also elements such as As, Cd, Hg, Cr, Ni, P, Pb, and Zn and their partitioning between the bottom (bed) ash and the fly (cyclone) ash.

Recovering wastes from the paper industry: Development of ceramic materials

“…The chlorine content in the sludge samples was less than 0.1%, and this element was not detected in the samples of paper waste. These data agree with those obtained in studies such as Hartman et al (2005) and Colomer et al (2010), in which the percentages for this kind of residue range from 0.05 to 0.2% in weight. The residues comply with the NPR-CENT/TS 15359EN standard and are therefore appropriate for use in incineration.…”

“…Adding this waste to the maximum percentage studied (10% in weight) would provide 7% of the fuel needed in manufacturing traditional brick[28][29][30][31][32]. This waste would yield 1.92% sulphur, which Intensity (a.u.XRD pattern, a) clay; b) sludge paper wastewater; c) paper waste.…”

Hydrothermal carbonization of stabilized sludge and meat and bone meal

“…of all water is very low. According to the results of the research works of Hartman et al (2003 and2005) from the Institute of Chemical Process Fundamentals of the Academy of Sciences of the Czech Republic, which dealt with chemical and fuel characteristics of anaerobically stabilized sewage sludge and its ash, the LHV of dry digested stabilized sludge is 10-11 MJ/kg and it corresponds to the LHV of energy brown coal. The reason for increased LHV at the hydrothermal treatment is a large reduction in all water and oxygen in the sample.…”

CFD based combustion model for sewage sludge gasification in a fluidized bed

“…In addition, sewage sludge is similar to the other organic solid wastes such as plant biomass. Therefore, in recent years, many researchers have become interested in utilizing sewage sludge as a renewable energy resource to generate hydrogen (H 2 ) and/or syngas (H 2 + CO), and/or fuel gases (H 2 + CO + C m H n ) through pyrolysis technology [1][2][3][4][5].…”