Sewage sludge is the residue produced by the domestic or industrial wastewaters treatment plants. According to the principles of sustainability, several restrictions have been imposed on the conventional methods currently adopted for its disposal. In order to select alternative routes, this work investigated gasification to assess its suitability for the disposal and valorization of sewage sludge. In the present study, dehydrated sewage sludge gasification was performed with air in a pilot scale fixed bed updraft gasifier operating at atmospheric pressure at a continuous feed rate of 3.5 kg/h. In order to assess the technical feasibility of the process, several tests were carried out to evaluate the influence of the main operative parameters on the syngas quality and gasification efficiency. Experimental tests were conducted by blending dehydrated sewage sludge pellets with wood pellets to obtain a feed composition ranging between 0 and 100% (sludge wt/total feed wt) in order to compare the process performances when the gasifier is fed by conventional woody biomass, a blend of sewage sludge and wood pellets, or sewage sludge pellets. The results show that dehydrated sewage sludge can be gasified or co-gasified with wood pellets by producing a fuel gas with a calorific value of 3-5 MJ/Nm3. Henceforth, gasification can be considered a promising alternative solution for the disposal and valorization of sewage sludge.
Sewage sludge gasification in a pilot scale plant
PUCCINI, MONICA;SEGGIANI, MAURIZIA;VITOLO, SANDRA
2010-01-01
Abstract
Sewage sludge is the residue produced by the domestic or industrial wastewaters treatment plants. According to the principles of sustainability, several restrictions have been imposed on the conventional methods currently adopted for its disposal. In order to select alternative routes, this work investigated gasification to assess its suitability for the disposal and valorization of sewage sludge. In the present study, dehydrated sewage sludge gasification was performed with air in a pilot scale fixed bed updraft gasifier operating at atmospheric pressure at a continuous feed rate of 3.5 kg/h. In order to assess the technical feasibility of the process, several tests were carried out to evaluate the influence of the main operative parameters on the syngas quality and gasification efficiency. Experimental tests were conducted by blending dehydrated sewage sludge pellets with wood pellets to obtain a feed composition ranging between 0 and 100% (sludge wt/total feed wt) in order to compare the process performances when the gasifier is fed by conventional woody biomass, a blend of sewage sludge and wood pellets, or sewage sludge pellets. The results show that dehydrated sewage sludge can be gasified or co-gasified with wood pellets by producing a fuel gas with a calorific value of 3-5 MJ/Nm3. Henceforth, gasification can be considered a promising alternative solution for the disposal and valorization of sewage sludge.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
