Global emissions of hydrogen chloride and chloromethane from coal combustion, incineration and industrial activities: Reactive Chlorine Emissions Inventory

Much if not all of the chlorine present in fossil fuels is released into th e atmosphere as hydrogen chloride (HCl) and chloromethane (CH3Cl, methyl ch loride). The chlorine content of oil-based fuels is so low that these sourc es can be neglected, but coal combustion provides significant releases. On the basis of national statistics for the quantity and quality of coal burne d during 1990 in power and heat generation, industrial conversion and resid ential and commercial heating, coupled with information on the chlorine con tents of coals, a global inventory of national HCl emissions from this sour ce has been constructed. This was combined with an estimate of the national emissions of HCl from waste combustion (both large-scale incineration and trash burning) which was based on an estimate of the global quantity releas ed from this source expressed per head of population. Account was taken of reduced emissions where flue gases were processed, for example to remove su lphur dioxide. The HCl emitted in 1990, comprising 4.6 +/- 4.3 Tg Cl from f ossil fuel and 2 +/- 1.9 Tg Cl from waste burning, was spatially distribute d using available information on point sources such as power generation uti lities and population density by default. Also associated with these combus tion sources are chloromethane emissions, calculated to be 0.075 +/- 0.07 T g as Cl (equivalent) from fossil fuels and 0.032 +/- 0.023 Tg Cl (equivalen t) from waste combustion. These were distributed spatially exactly as the H Cl emissions, and a further 0.007 Tg Cl in chloromethane from industrial pr ocess activity was distributed by point sources.