Compare systems, not labels.
Technology labels are poor substitutes for comparable evidence. GCCEI compares complete thermal systems rather than idealised reactor chemistry.
Common feedstock
The same or materially equivalent feedstock must be used where technology performance is compared. Clean dry plastic cannot fairly represent one technology while wet mixed municipal waste represents another.
Common boundaries
Comparison should align equipment, facility, waste/resource, product-use and lifecycle boundaries and identify the counterfactual.
Operating conditions
Scale, throughput, temperature, residence time, preprocessing, operating hours, startup, shutdown and upset conditions can change performance.
Pollution control
Combustion control, filtration, acid-gas treatment, gas capture, wastewater and residue systems belong inside the technology boundary.
Products and residues
Useful output, contamination, upgrading, actual end use, displacement and final fate must be considered alongside residual streams.
Compliance and consequence
Regulatory compliance is important evidence. It does not necessarily answer every environmental or public-health question, just as detection of a hazardous emission does not by itself demonstrate population harm.
The useful question is: which complete system performs better for this material, place, operating condition and realistic alternative?