Roughly two-thirds of its CO2 is released by limestone chemistry (calcination), not fuel — so even a zero-carbon-fuel kiln still emits. Deep cuts need less clinker per tonne (SCMs) or carbon capture.
From our guide: Decarbonizing Cement — full context, charts and sources there.
Boilers, kilns, heat exchangers, valves and steam lines lose energy continuously. Inzonex makes patented (UK GB2508992.1) removable modular insulation — snap-fastened covers engineered per temperature tier, not generic off-the-shelf jackets: