title: Pyrolysis of Dried Wastewater Biosolids Can Be Energy Positive.
abstract: Pyrolysis is a thermal process that converts biosolids into biochar (a soil amendment), py-oil and py-gas, which can be energy sources. The objectives of this research were to determine the product yield of dried biosolids during pyrolysis and the energy requirements of pyrolysis. Bench-scale experiments revealed that temperature increases up to 500 °C substantially decreased the fraction of biochar and increased the fraction of py-oil. Py-gas yield increased above 500 °C. The energy required for pyrolysis was approximately 5-fold less than the energy required to dry biosolids (depending on biosolids moisture content), indicating that, if a utility already uses energy to dry biosolids, then pyrolysis does not require a substantial amount of energy. However, if a utility produces wet biosolids, then implementing pyrolysis may be costly because of the energy required to dry the biosolids. The energy content of py-gas and py-oil was always greater than the energy required for pyrolysis.
authors.affiliation: Department of Civil, Construction and Environmental Engineering, Marquette University, 1515 W Wisconsin Ave, Milwaukee, Wisconsin, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McNamara
authors.forename: Jon D
authors.initials: JD
authors.lastname: Koch
authors.forename: Zhongzhe
authors.initials: Z
authors.lastname: Liu
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Zitomer
mesh_terms: D002606:Charcoal / Q000032:analysis*; D006358:Hot Temperature; D062065:Wastewater / Q000737:chemistry*
chemical_list: D002606:Charcoal; D062065:Wastewater; C540010:biochar