title: Integrated carbon dioxide/sludge gasification using waste heat from hot slags: syngas production and sulfur dioxide fixation.
abstract: The integrated CO2/sludge gasification using the waste heat in hot slags, was explored with the aim of syngas production, waste heat recovery and sewage sludge disposal. The results demonstrated that hot slags presented multiple roles on sludge gasification, i.e., not only a good heat carrier (500-950 °C) but also an effective desulfurizer (800-900 °C). The total gas yields increased from 0.022 kg/kgsludge at 500 °C to 0.422 kg/kgsludge at 900 °C; meanwhile, the SO2 concentration at 900 °C remarkably reduced from 164 ppm to 114 ppm by blast furnace slags (BFS) and 93 ppm by steel slags (SS), respectively. A three-stage reaction was clarified including volatile release, char transformation and fixed carbon using Gaussian fittings and the kinetic model was analyzed. Accordingly, a decline process using the integrated method was designed and the optimum slag/sludge ratio was deduced. These deciphered results appealed potential ways of reasonable disposal of sewage sludge and efficient recovery of waste heat from hot slags.
authors: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
authors: Yongqi
authors: Y
authors: Sun
authors: 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: Zuotai
authors: Z
authors: Zhang
authors: Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
authors: Lili
authors: L
authors: Liu
authors: 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: Xidong
authors: X
authors: Wang
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000737:chemistry*; D006358:Hot Temperature; D007221:Industry; D007700:Kinetics; D008962:Models, Theoretical; D012722:Sewage / Q000737:chemistry*; D013232:Steel / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*
chemical_list: D012722:Sewage; D013458:Sulfur Dioxide; D013232:Steel; D002245:Carbon Dioxide
keywords: Hot slag; SO(2) fixation; Sludge gasification; Syngas production; Waste heat recovery