title: Two-stage high temperature sludge gasification using the waste heat from hot blast furnace slags.
abstract: Nowadays, disposal of sewage sludge from wastewater treatment plants and recovery of waste heat from steel industry, become two important environmental issues and to integrate these two problems, a two-stage high temperature sludge gasification approach was investigated using the waste heat in hot slags herein. The whole process was divided into two stages, i.e., the low temperature sludge pyrolysis at ⩽ 900°C in argon agent and the high temperature char gasification at ⩾ 900°C in CO2 agent, during which the heat required was supplied by hot slags in different temperature ranges. Both the thermodynamic and kinetic mechanisms were identified and it was indicated that an Avrami-Erofeev model could best interpret the stage of char gasification. Furthermore, a schematic concept of this strategy was portrayed, based on which the potential CO yield and CO2 emission reduction achieved in China could be ∼1.92∗10(9)m(3) and 1.93∗10(6)t, respectively.
authors.affiliation: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Yongqi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China; Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871, PR China. Electronic address: zuotaizhang@pku.edu.cn.
authors.forename: Zuotai
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China; Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Xidong
authors.initials: X
authors.lastname: Wang
mesh_terms: D002681:China; D005740:Gases; D006358:Hot Temperature; D008962:Models, Theoretical; D012722:Sewage; D013232:Steel; D018505:Waste Management / Q000379:methods*
chemical_list: D005740:Gases; D012722:Sewage; D013232:Steel
keywords: Heat recovery; Hot slag; Kinetic mechanism; Syngas release thermodynamic; Two-stage sludge gasification