Emissions black carbon emissions (kg). Emissions, PM emissions,, (kg). [1A1b] Petroleum refining and [1A1c] Solid fuel manufacturing and other energy industries The estimation of black carbon emissions was made considering that it is emitted as part of the solid fraction of PM₂ particulate material, therefore its contribution was estimated from a percentage of these particles. Consequently, the first step was to calculate the emission of these particles for each of the fuels, using the emission factors shown in Table 2.