40 CFR §98.72

1. (a)CO2 process emissions from steam reforming of a hydrocarbon or the gasification of solid and liquid raw material, reported for each ammonia manufacturing unit following the requirements of this subpart.
2. (b)CO2, CH4, and N2O emissions from each stationary fuel combustion unit. You must report these emissions under subpart C of this part (General Stationary Fuel Combustion Sources), by following the requirements of subpart C, except that for ammonia manufacturing processes subpart C does not apply to any CO2 resulting from combustion of the waste recycle stream (commonly referred to as the purge gas stream).
3. (c)CO2 emissions collected and transferred off site under subpart PP of this part (Suppliers of CO2), following the requirements of subpart PP.