The potential environmental gains from recycling waste plastics: Simulation of transferring recycling and recovery technologies to Shenyang, China

With the increasing attention on developing a low-carbon economy, it is necessary to seek appropriate ways on reducing greenhouse gas (GHG) emissions through innovative municipal solid waste management (MSWM), such as urban symbiosis. However, quantitative assessments on the environmental benefits of urban symbiosis, especially in developing countries, are limited because only a limited number of planned synergistic activities have been successful and it is difficult to acquire detailed inventory data from private companies. This paper modifies and applies a two-step simulation system and used it to assess the potential environmental benefits, including the reduction of GHG emissions and saving of fossil fuels, by employing various Japanese plastics recycling/energy-recovery technologies in Shenyang, China. The results showed that among various recycling/energy-recovery technologies, the mechanical waste plastics recycling technology, which produces concrete formwork boards (NF boards), has the greatest potential in terms of reducing GHG emissions (1.66 kg CO2e/kg plastics), whereas the technology for the production of refuse plastic fuel (RPF) has the greatest potential on saving fossil fuel consumption (0.77 kgce/kg-plastics). Additional benefits can be gained by applying combined technologies that cascade the utilization of waste plastics. Moreover, the development of clean energy in conjunction with the promotion of new waste plastics recycling programs could contribute to additional reductions in GHG emissions and fossil fuel consumption.

Research highlights
► Urban symbiosis creates compatibility of industrial development and waste management.
► Mechanical technology leads to more CO2 emission reduction.
► Energy recovery technology leads to more fossil fuel saving.
► Clean energy makes recycling technologies cleaner.
► Demand management is crucial for realizing potential environmental gains of recycling.