Sorbent compositions for coal contain nitrogenous components that reduce
the level of mercury and/or sulfur emitted into the atmosphere upon
combustion. The sorbent compositions are added directly to the fuel
before combustion; directly into the fireball during combustion; are
added to the fuel before combustion and into the flue gas post combustion
zone; or are added completely into the flue gas post combustion zone,
preferably where the flue gas temperature is at least 500.degree. C. The
sorbent compositions comprise a source of nitrate ions, a source of
nitrite ions, or a combination of nitrate and nitrite sources. The
sorbents are added as solids or as solutions in water. In various
embodiments, the sorbent compositions further comprise a source of
halogen such as bromide.