C · 3
Calorific value (gross and net, GAR / NAR)
The energy released by the complete combustion of a unit mass of fuel, in kcal/kg or MJ/kg. Gross calorific value (GCV) includes the latent heat of the water vapour formed; net calorific value (NCV) excludes it and is closer to the energy a boiler can actually use. For coal the figure also depends on its basis: GAR (gross as received, including total moisture), ADB (air-dried) or NAR (net as received). Indonesian coal is mostly priced on GAR, European and South African coal (API2, API4) on NAR 6,000, so offers must be converted to the same basis before comparison.
Carbon footprint (product carbon footprint and Scopes 1-2-3) PCF
The total greenhouse-gas emissions caused by a product over its life cycle – usually from raw-material extraction to the factory gate (“cradle-to-gate”) – expressed in kg CO₂e and calculated under ISO 14067 and the GHG Protocol. At company level, Scope 1 covers direct emissions, Scope 2 purchased energy and Scope 3 the supply chain; most of a manufacturer’s Scope 3 comes from the raw materials it buys. That is why CBAM, CSRD reporting and brand targets now drive buyers to ask raw-material suppliers for verified product carbon footprints (PCF) and EPDs.
Coal quality parameters (moisture, ash, volatile matter, sulphur, HGI)
Besides calorific value, the value of thermal coal is set by total moisture (TM), ash, volatile matter (VM), fixed carbon, total sulphur (TS), the Hardgrove grindability index (HGI) and ash fusion temperature. High ash and moisture raise transport and burning costs; sulphur affects flue-gas treatment and emission limits; HGI determines mill capacity. For coking coal, CSR, CRI and fluidity also matter. Contracts give “typical” and “rejection” limits plus price-adjustment formulas for deviations in each parameter.