Paper details

Title:

The Effect of Sewage Sludge Blending on the Properties of Precipitator Ash Generated in a Coal or Biomass Fired Boiler

Author(s):

Tóth, P., Szemmelveisz, K., Palotás, Á.B.

Document(s):

Abstract:

In Hungary, roughly 1,5 million tons of sewage sludge is produced each year. This yearly quantity shows a steady increase since year 2000, which is not expected to change in the near future. Due to stricter and stricter environmental regulations, trends in the European Union (EU) show that the share of sewage sludge combustion among other disposal methods, such as dumping or agricultural use is increasing each year, therefore, as an alternative of utilization, co­combustion can be an option for large scale power plants firing coal or wood as base fuel. A fact based on literature data, the co­combustion of sewage sludge is known to be economically feasible in most cases with very slight changes to the combustion technology needed, however in the operation of electrostatic precipitators (ESPs), problems may arise due to the increased amount of ash generated and also by the changes in ash properties and composition. From an environmental point of view, the enrichment of certain toxic heavy metals in precipitator ash (PA) may cause further hindrances. In the summer of 2008 and the spring of 2009, as pioneer projects in Hungary, experimental sludge­wood and sludge­coal co­combustion sessions were carried out in a co­generating power plant operating with fluidized bed and pulverized coal fired boilers. The aim of this study is to provide a general picture on the effect of sewage sludge blending to the ESP ashes originating from wood chips or coal fired boilers. The operational parameters of ESPs during co­combustion were investigated along with the changes in the concentrations of main and some trace components of the generated precipitator ash. Examination methods included X­ray diffractometry (XRD) and atomic absorption spectrometry (AAS).

Keywords:

boiler, chemical composition, coal, sewage sludge, co-combustion, wood chips

Topic:

Thermochemical conversion - Combustion and co-combustion

Subtopic:

Combustion and co-combustion for large utility and industrial scale applications

Event:

18th European Biomass Conference and Exhibition

Session:

VP2.4.8

Pages:

1139 - 1144

ISBN-13:

978-88-89407-56-1

ISBN-10:

88-89407-56-5

Paper DOI:

10.5071/18thEUBCE2010-VP2.4.8

Price:

FREE