title: Ex-situ catalytic pyrolysis of wastewater sewage sludge - A micro-pyrolysis study.
abstract: Concerns over increasing amounts of sewage sludge and unsustainability of current disposal methods have led to development of alternative routes for sludge management. The large amount of organics in sewage sludge makes it potential feedstock for energy or fuel production via thermochemical pathways. In this study, ex-situ catalytic pyrolysis using HZSM-5 catalyst was explored for the production of olefinic and aromatic hydrocarbons and nutrient-rich char from sewage sludge. The optimal pyrolysis and catalysis temperatures were found to be 500°C and 600°C, respectively. Carbon yields of hydrocarbons from sewage sludge were higher than for lignocellulose; yield differences were attributed to the high extractives content in the sludge. Full recovery of most inorganic elements were found in the char, which suggests that catalyst deactivation maybe alleviated through ex-situ catalytic pyrolysis. Most of the nitrogen was retained in the char while 31.80% was released as ammonia, which suggests a potential for nitrogen recycling.
authors.affiliation: Bioeconomy Institute, Iowa State University, Ames, IA 50011, USA. Electronic address: kaigew@gmail.com.
authors.forename: Kaige
authors.initials: K
authors.lastname: Wang
authors.affiliation: Bioeconomy Institute, Iowa State University, Ames, IA 50011, USA; Key Laboratory for Biomass Clean Energy of Anhui Province, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Key Laboratory for Biomass Clean Energy of Anhui Province, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Xifeng
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Brewer
authors.affiliation: Bioeconomy Institute, Iowa State University, Ames, IA 50011, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Brown
mesh_terms: D002384:Catalysis; D006358:Hot Temperature; D055616:Microtechnology / Q000379:methods*; D009584:Nitrogen; D012722:Sewage / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D009584:Nitrogen; D012722:Sewage; D062065:Wastewater
keywords: Biochar; Catalytic pyrolysis; Sewage sludge; Waste management