Sustainability-based economic and ecological evaluation of a rural biogas-linked agro-ecosystem Jing Dai a , Bin Chen a,b,n , Tasawar Hayat b,c , Ahmed Alsaedi b , Bashir Ahmad b a State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China b NAAM Group, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia c Department of Mathematics, Quaid-i-Azam University 45320, Islamabad, Pakistan article info Article history: Received 10 August 2012 Received in revised form 3 August 2014 Accepted 15 August 2014 Keywords: Life cycle analysis Climate change Biogas project Exergy Rural energy Carbon emission abstract Biogas-linked agro-ecosystems provide economic and environmental benefits by using resources in a multipurpose manner. They utilize an energy consumption pattern that has prominent advantages in relieving energy shortages and reducing environmental pollution. To better understand the effects of these multiple aspects, it is important to study how much of the energy flow is extracted and available through the biogas-linked agro-ecosystem using an economic input–output evaluation or ecological and social influence assessments. It is also equally important to understand the conversion efficiency during the life cycle of biogas production, and how humans influence the whole process of the biogas-linked agro-ecosystem. This paper attempts to establish a life cycle-based accounting model of a household biogas system using different economic and ecological metrics for multiple objective considerations, to provide a powerful and comprehensive perspective to illustrate sustainability problems. In this study we use a typical household biogas system in Gongcheng Autonomous County (Guangxi Province, China) as a case study to reveal an effective route and strategy to relieve energy shortage, reduce environmental pollution, and improve human productivity. In this way, we can construct an exemplary example of how to realize sustainable development in a rural area with positive objective conditions. & 2014 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 348 2. Methodology ....................................................................................................... 349 2.1. Method...................................................................................................... 349 2.1.1. Extended exergy accounting .............................................................................. 349 2.1.2. Life cycle analysis....................................................................................... 349 2.2. System boundary .............................................................................................. 349 2.3. Data source .................................................................................................. 349 3. Results ............................................................................................................ 349 3.1. Cost accounting and substitution benefit ........................................................................... 349 3.2. Ecological benefit .............................................................................................. 350 3.3. Direct and indirect social amelioration............................................................................. 350 3.3.1. Direct carbon trading value ............................................................................... 350 3.3.2. Indirect social improvements ............................................................................. 350 3.4. EEA analysis .................................................................................................. 352 4. Conclusions and discussions ........................................................................................... 353 Acknowledgements ...................................................................................................... 354 References ............................................................................................................. 354 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews http://dx.doi.org/10.1016/j.rser.2014.08.043 1364-0321/& 2014 Elsevier Ltd. All rights reserved. n Corresponding author. Postal address: 19 Xinjiekouwai Street, Beijing 100875, China. Tel./fax: þ86 10 58807368. E-mail address: chenb@bnu.edu.cn (B. Chen). Renewable and Sustainable Energy Reviews 41 (2015) 347–355