Life cycle assessment of pyrolysis, gasification and incineration waste-to-energy technologies: Theoretical analysis and case study of commercial plants

Jun Dong; Yuanjun Tang; Ange Nzihou; Yong Chi; Elsa Weiss-Hortala; Mingjiang Ni

doi:10.1016/j.scitotenv.2018.01.151

Life cycle assessment of pyrolysis, gasification and incineration waste-to-energy technologies: Theoretical analysis and case study of commercial plants

Sci Total Environ. 2018 Jun 1:626:744-753. doi: 10.1016/j.scitotenv.2018.01.151. Epub 2018 Feb 19.

Authors

Jun Dong¹, Yuanjun Tang², Ange Nzihou³, Yong Chi⁴, Elsa Weiss-Hortala³, Mingjiang Ni⁴

Affiliations

¹ Centre RAPSODEE, Ecole des Mines Albi, Campus Jarlard, 81013 Albi Cedex, France; State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China. Electronic address: zd_dongjun@zju.edu.cn.
² Centre RAPSODEE, Ecole des Mines Albi, Campus Jarlard, 81013 Albi Cedex, France; State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China.
³ Centre RAPSODEE, Ecole des Mines Albi, Campus Jarlard, 81013 Albi Cedex, France.
⁴ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China.

PMID: 29396338
DOI: 10.1016/j.scitotenv.2018.01.151

Abstract

Municipal solid waste (MSW) pyrolysis and gasification are in development, stimulated by a more sustainable waste-to-energy (WtE) option. Since comprehensive comparisons of the existing WtE technologies are fairly rare, this study aims to conduct a life cycle assessment (LCA) using two sets of data: theoretical analysis, and case studies of large-scale commercial plants. Seven systems involving thermal conversion (pyrolysis, gasification, incineration) and energy utilization (steam cycle, gas turbine/combined cycle, internal combustion engine) are modeled. Theoretical analysis results show that pyrolysis and gasification, in particular coupled with a gas turbine/combined cycle, have the potential to lessen the environmental loadings. The benefits derive from an improved energy efficiency leading to less fossil-based energy consumption, and the reduced process emissions by syngas combustion. Comparison among the four operating plants (incineration, pyrolysis, gasification, gasification-melting) confirms a preferable performance of the gasification plant attributed to syngas cleaning. The modern incineration is superior over pyrolysis and gasification-melting at present, due to the effectiveness of modern flue gas cleaning, use of combined heat and power (CHP) cycle, and ash recycling. The sensitivity analysis highlights a crucial role of the plant efficiency and pyrolysis char land utilization. The study indicates that the heterogeneity of MSW and syngas purification technologies are the most relevant impediments for the current pyrolysis/gasification-based WtE. Potential development should incorporate into all process aspects to boost the energy efficiency, improve incoming waste quality, and achieve efficient residues management.

Keywords: Environmental sustainability; Improvement and impediments; Large-scale commercial plants; Life cycle assessment; Non-toxic and toxic impacts; Waste-to-energy technology.