Presentation on theme: "Ammonium Nitrate and UAN"— Presentation transcript:
1 Ammonium Nitrate and UAN ChE 397 – Team 7Ammonium Nitrate and UANMentorAdam Kanyuh (UOP)MembersTim Brown (Team Leader)Mahalet Sebhatu (Scribe)Gabriel SalamancaRami Saigh
2 IntroductionThis plant focuses on the production of Ammonia-Based fertilizers.The plant will be located in the Williston, North DakotaOur focus is on the production of Ammonium Nitrate (A.N.) and Urea-Ammonium Nitrate (UAN-32)These products are valuable in the fertilizer industry due to their high levels of nitrogen.
4 Design Basis Ammonium Nitrate Production Based on a total output of TPD ( TPD) of NH4NO3, dry weightFeed streams:423.9 TPD (460.8 TPD) NH3 dry weightTPD ( TPD) HNO3 dry weightAt 63% HNO3 by weight: TPD ( TPD)Output streams920.5 TPD ( TPD) NH4NO3 dry weightSplit between granular and solution streams, amounts are to be determinedTPD ( TPD) NH4NO3 dry weightSent to UAN processAssumptions:100% yieldFull separation of product from wasteRed figures based on 92% operation timeThe process is extremely exothermic, producing heat in excess of it’s own required processes resulting in available heat for other processes. If the ammonium nitrate reaches 240 degree Celsius, it has the potential to blow up.Utilities required: Steam, Electricity, Water
5 Design Basis Environmental Review: Ammonium nitrate: Processes releasing most of emissions are the neutralizers (nitric acid, ammonia, and particulates) depending on which reactant is present in excess, but mostly ammonia.Ammonia emission range from g/kg to 3.14 g/kg.According to EPA, particulate emission from ammonium nitrate solutions based on an average neutralizer capacity of 131,500 metric tons/year. :Emission pointMaximum ground level concentration (μg/m3)Neutralizer539Evaporator/concentrator190Cooler16
6 Competing Processes I Nitrophosphate Process (a.k.a. Odda process) Involves acidifying phosphate rock with nitric acid to produce calcium nitrate crystals, which later react with NH3 to produce ammonium nitrate.Process uses many raw materials that aren’t supplied, so it is economically unsound to run in the plant as currently designed.This process has an addition of Carbon and Calcium, which would be excessive to remove and extra equipment. Ca3(PO4)2 + 6 HNO H2O → 2 H3PO4 + 3 Ca(NO3) H2OCa(NO3)2 + 2 NH3 + CO2 + H2O → 2 NH4NO3 + CaCO3
7 Competing Processes II Carnit ProcessTwo reactors are required for this processA titanium reactor for the acidic solutionA low carbon stainless steal reactor for the alkaline solution.Process involves boilers and a falling film evaporator made from low carbon stainless steelUnreacted nitric acid recycles to the reactor to react with additional ammonia.Extra steps are required to produce granular ammonium nitrate. 
8 Competing Processes III Stengel processEnergy EfficientRelatively few pieces of equipmentRecovers much of the exothermic energy and has the potential to use it in another process.NH3(g) + HNO3 (aq) NH4NO3 (aq) 99% yieldThis is the most viable option, both feed streams can be easily provided and doesn’t produce excessive waste.
9 Process Selection [Odda] Process uses many reactants that aren’t supplied, so it is economically unsound to run in the plant as currently designed.This process has an addition of Carbon and Calcium, which would be excessive to remove and extra equipment. [Carnit]Process requires extra equipmentProcess is more complicated97.5% yield[Stengel]Process uses reactants efficientlyGood energy recover in terms of recycled steamLow emissions99% Yield
11 Design Basis Urea-Ammonium Nitrate (UAN-32) Based on Product steam of TPD (2590.9)Feed Streams:TPD ( TPD) NH4NO3 dry weight831.3 TPD (903.6 TPD) CO(NH2)2 dry weight687.6 TPD (747.4 TPD) H2OMay be mixed in with the two previous feedsProduct streamTPD (2590.9) UAN-32 (solution)UAN-32 is defined to have 32% nitrogen by weightAssumptionsWell-MixedNo Waste StreamsPerfect pH balanceDry feed steamsRed figures based on 92% operation timeUtilities – Water, Electricity
12 Design Basis Environmental Review: UAN: Handling and Storage: UAN solution is not explosive; however, it decomposes to noxious, poisonous gases when exposed to high temperature.No gaseous emissions or waste arise during the non-pressure mixing of the aqueous based components if the best available technology is employed.pH values and temperatures must be monitored continuously.The ammonium/nitric acid levels are generally too small to cause a major hazard. Handling and Storage:Avoid using zinc or copper alloys in contact with UAN solution due to corrosion. Use corrosion inhibitors to prevent corrosion. 
14 ConclusionWe will use the Stengel process to manufacture A.N. on a total basis of TPD.Also include the manufacture of UAN on a basis of TPD by a mixing processAll information presented today is a portion of our Report Outline.Design BasisIntroductionEnviromental concerns and standardsProcess DescriptionBlock Flow DiagramsFlow Sheet, material and energy balances, hand calculations, and rough economics will be covered on the next presentation.