Climate change mitigation potential of kitchen waste utilization in China for combined heat and power production

Weiguo Liu; Dan Zhang; Jiajing Tian; Feiyan Yu; Yuanming Xie; Shengkui Cheng; Qiang Li; Weizhong Li; Changhui Peng; Yan Yan

doi:10.1016/j.scitotenv.2023.164165

Climate change mitigation potential of kitchen waste utilization in China for combined heat and power production

Sci Total Environ. 2023 Aug 25:888:164165. doi: 10.1016/j.scitotenv.2023.164165. Epub 2023 May 15.

Authors

Weiguo Liu¹, Dan Zhang², Jiajing Tian³, Feiyan Yu³, Yuanming Xie³, Shengkui Cheng², Qiang Li⁴, Weizhong Li³, Changhui Peng⁵, Yan Yan⁴

Affiliations

¹ College of Forestry, Northwest A&F University, Yangling 712100, China; Qinling National Forest Ecosystem Research Station, Yangling, Shaanxi 712100, China. Electronic address: liuweiguo110@nwafu.edu.cn.
² Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing, China.
³ College of Forestry, Northwest A&F University, Yangling 712100, China.
⁴ College of Forestry, Northwest A&F University, Yangling 712100, China; Qinling National Forest Ecosystem Research Station, Yangling, Shaanxi 712100, China.
⁵ College of Forestry, Northwest A&F University, Yangling 712100, China; Qinling National Forest Ecosystem Research Station, Yangling, Shaanxi 712100, China; Department of Biology Sciences, Institute of Environment Sciences, University of Quebec at Montreal, C.P. 8888, Succ. Centre-Ville, Montreal H3C3P8, Canada.

PMID: 37196958
DOI: 10.1016/j.scitotenv.2023.164165

Abstract

Given the concerns about climate change, energy sustainability, and public health, the reuse of kitchen wastes (KW) is attracting increasing interest. In China, the municipal solid waste sorting scheme has increased the available KW. To assess the available KW and the climate change mitigation potential of KW utilization for bioenergy in China, three scenarios (base, conservative, and ambitious) were defined. A new framework was implemented to assess the climate change impacts of bioenergy. The annual available KW ranged from 11.450 million dry tons (in metric) under the conservative scenario to 22.898 million dry tons in the ambitious scenario, and had the potential to produce 12.37 × 10⁶-24.74 × 10⁶ MWh heat and 9.62 × 10⁶-19.24 × 10⁶ MWh power. The total potential climate change impacts of KW for combined heat and power were 3.339-6.717 million tons CO₂ eq in China. The highest eight provinces and municipalities contributed over half of the national total. Among the three components of the new framework, fossil fuel-derived greenhouse gas emissions and biogenic CO₂ emissions were positive. The difference in carbon sequestration was negative and ensured a lower integrated life-cycle climate change impacts than that of natural gas-derived combined heat and power. The mitigation effects of using KW as a substitute for natural gas and synthetic fertilizers were 2.477-8.080 million tons CO₂ eq. These outcomes can inform relevant policymaking and benchmark climate change mitigation in China. The conceptual framework of this study can also be adapted for applications in other countries or regions worldwide.

Keywords: Anaerobic digestion; Biogenic CO(2) emission; Climate change impact; Combined heat and power; Kitchen waste; Mitigation.