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.