portuguese national inventory report on greenhouse gases, 1990

Industrial ProcessesAmmonia is formed after reaction of hydrogen with nitrogen from air. In the start of year 1990there was another unit operating in Portugal, but has stopped activity already in the beginning ofthat year. The conversion of feedstock to hydrogen results in the liberation of the associatedcarbon as ultimate CO 2 which is vented to atmosphere. Although actually some part of CO 2liberated from VRF, during ammonia production, is in fact used in urea production, it is notimmediately emitted to atmosphere. However, because liberation to atmosphere is eventuallyachieved after the application of urea in agricultural soils as amendment, and also becausesome other sources of CO 2 may be used in urea manufacturing, the option was not to deducethis CO 2 fixation in feedstock.Other pollutants result from the process, either from escape of ammonia (NH 3 ) or either fromrelease of products from feedstock: CO and NMVOC.4.3.2.1.2 MethodologyCarbon dioxide emissions were estimated from feedstock consumption using the followingformulation:Emi CO2(y) = 44/12 * Feedstock (y) * C Feed(y) * 10 -5whereEmi CO2(y) - Emission of carbon dioxide (kton/yr);FeedStock (y) - Annual consumption of feedstock (ton/yr)C Feed(y) - Carbon content of feedstock (%).4.3.2.1.3 Emission FactorsDue to confidentiality constraints it is not possible to publish emission factors.4.3.2.1.4 Activity DataBecause there was only one industrial plant in operation in the period 1990-2009, it is notpossible to present any absolute information concerning activity data for this source activity,neither ammonia production nor feedstock and methanol consumption. The overall trend in theamount of ammonia produced in the period may be however depicted in the figure below, fromwhere it is evident the significant inter-annual changes in the period 1991-1996. In 2009 theonly facility that produced ammonia in Portugal has stopped and the production was relocatedto India.Portuguese National Inventory Report 2013MAMAOT4-21