Abstract

Sludge from municipal wastewater treatment plants and organic fines from mechanical sorting of municipal solid waste (MSW) are two common widespread waste streams that are becoming increasingly difficult to utilise. Changing perceptions of risk in food production has limited the appeal of sludge use on agricultural land, and outlets via landfilling are diminishing rapidly. These factors have led to interest in thermal conversion technologies whose aim is to recover energy and nutrients from waste while reducing health and environmental risks associated with material re-use. Pyrolysis yields three output products: solid char, liquid oils and gas. Their relative distribution depends on process parameters which can be somewhat optimised depending on the end use of product. The potential of pyrolysis for the conversion of wastewater sludge (SS) and organic fines of MSW (OF) to a combustion gas and a carbon-rich char has been investigated. Pyrolysis of SS and OF was done using a laboratory fixed-bed reactor. Herein, the physical characterisation of the reactor is described, and results on pyrolysis yields are presented. Feedstock and chars have been characterised using standard laboratory methods, and the composition of pyrolysis gases was analysed using micro gas chromatography. Product distribution (char/liquid/gas) from the pyrolysis of sewage sludge and composted MSW fines at 700 degrees C for 10min were 45/26/29 and 53/14/33%, respectively. The combustible fractions of pyrolysis gases range from 36 to 54% for SS feedstock and 62 to 72% from OF. The corresponding lower heating value range of sampled gases were 11.8-19.1 and 18.2-21.0MJm(-3), respectively.

Keywords

Waste valorisation; Pyrolysis; Sewage sludge; Municipal solid waste; Syngas; Biochar

Published in

Environmental Science and Pollution Research
2018, Volume: 25, number: 36, pages: 35874-35882

SLU Authors

• Agar, David

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    
  • University of Limerick

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all
End hunger, achieve food security and improved nutrition and promote sustainable agriculture


UKÄ Subject classification

Chemical Process Engineering


Publication identifier

DOI: https://doi.org/10.1007/s11356-018-1463-y

Permanent link to this page (URI)

https://res.slu.se/id/publ/96606