Environment–Energy–Economy Analysis and Related Technical Transition Strategies for Spent Activated Carbon Regeneration in China

Spent activated carbon (AC) regeneration attracts growing interests due to the increased waste amounts and limited AC resources. Herein, environment–energy–economy performances of four spent AC regeneration technologies demonstrated in China were compared with conventional incineration via life cycle assessment (LCA), energy-efficiency analysis (EEA), and environmental life-cycle costing. Their energy efficiencies are lower than 42%, which should be improved. Tradeoffs between environmental and economic performances found such as tunnel kiln regeneration technology were handled by integrating both performances with emission monetization model by internalizing environmental externalities as economic metric. Results indicated that microwave and rotary-kiln regeneration are preferred and break even in 2 years even with externalities. Potential pollution migration (in air–water–human medium) analysis illustrates that technical-sustainable transition from spent AC incineration to regeneration may relieve GHG emissions but add human risks due to dioxins and heavy metal emitted. Regeneration rate and energy use are sensitive to environmental and economic result.