Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 33 NITRIC ACID3.1 General informationNitric acid is one of the most important and quantitatively one of the top ten industrialchemicals. Production levelled off in the 1990s because of the increased use of the downstreamproduct urea. In 2003, 16.6 million tonnes HNO 3 were produced in Europe [102, EFMA, 2000].In the EU-25, Switzerland and Norway about 100 European nitric acid plants are in operation in2006. The capacity ranges from 150 – 2500 tonnes/day [154, TWG on LVIC-AAF, 2006].4000Production of nitric acid in ktonnes35003000250020001500100050001997 2003AustriaBelgiumCanadaCroatiaCzech RepublicDenmarkFinlandFranceGermanyGreeceHungaryIrelandItalyLithuaniaNorwayRomaniaSpainSwedenSwitzerlandUnited KingdomFigure 3.1: HNO 3 production levels in some European countries in 1997 and 2003[117, UNFCCC, 2006]Most of the nitric acid produced is used for inorganic fertilisers; it is mostly neutralised withammonia to form ammonium nitrate [15, Ullmanns, 2001]. Other uses for nitric acid are in themanufacture of AN explosives, and chemicals, such as caprolactam, adipic acid, dinitro tolueneor nitrobenzene. A weak acid (relating to the greater part of the production of nitric acid) or astrong acid can be produced, depending on the application required: weak acid (50 – 65 % w/w)is suitable for use in the production of fertilisers, but stronger acid (up to 99 % w/w) is requiredfor many organic reactions. Concentrated nitric acid can be manufactured directly andindirectly. The direct process is quite different from the process to produce weak nitric acid; theindirect process uses weak nitric acid as one of the starting materials.The other plant type operates with a dual pressure process in order to increase the efficiency.Older dual plants operate with low pressure/medium pressure, while more modern dual plantsoperate with medium pressure/high pressure.Generation of the greenhouse gas N 2 O as a by-productOxidation of ammonia generates NO, with N 2 O as a by-product. Increases in combustionpressure from 1 to 5 bar in the last decades has slightly increased the N 2 O emission level.According to [107, Kongshaug, 1998], the average European plant emits 6 kg of N 2 O per tonneof HNO 3 corresponding to about 2 tonnes CO 2 -eq. per tonne of 100 % HNO 3 .Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers 95