Presentation on theme: "University of Illinois at Chicago Department of Chemical Engineering"— Presentation transcript:
1 Improved Nitric Acid Production via Cobalt Oxide Catalysis for use in Ammonia-based Fertilizers University of Illinois at ChicagoDepartment of Chemical EngineeringCHE 397 Senior Design IIApril 24, 2012Mentor: Bill KeesomThomas Calabrese (Team Leader)Cory ListnerHakan SomuncuDavid SonnaKelly Zenger
2 Today’s Agenda Recap of Questions from the Previous Meeting Project OverviewDesign BasisBlock Flow DiagramProcess Flow DiagramCatalyst ChoiceEnvironmental Issues ReviewEconomicsProcess Safety ReviewReport
3 Project OverviewThe nitric acid plant will be located in the Bakken Formation of the Williston Basin, located in Northwest North Dakota.Over 1.85 trillion cubic feet natural gas33
4 Project OverviewWellhead gas will be purified by the Gas Purification Team and sent to the Ammonia Team.Ammonia Team will produce ammonia and send it to the Nitric Acid Team.Nitric Acid Team will convert ammonia to nitric acid.Nitric acid will be sent to Ammonium Nitrate Team
7 Ostwald Process Industry Standard for Nitric Acid Production Ammonia OxidationNitrogen Monoxide OxidationAbsorption of Nitrogen Dioxide with WaterPrimary Chemical ReactionsOxidation of Ammonia to Nitrogen Monoxide 4NH3 (g) + 5O2 (g) 4NO (g) + 6H2O (g)Oxidation of Nitrogen Monoxide to Nitrogen Dioxide 2NO (g) + O2 (g) 2NO2 (g)Reaction of Nitrogen Dioxide to Nitric Acid 2NO2 (g) + O2 (g) + 2H2O (l) 4HNO3 (aq)
10 Benefits of Cobalt Oxide Platinum-RhodiumCobalt Oxide (Co3O4)Cost ($/short ton of HNO3 produced)$3 - $4$ $0.75Lifespan3-4 months12 monthsDowntime4 hours to replace gauze at end of lifespanRemove Rhodium Oxide buildup (every 3-4 weeks)NoneConversion Efficiency93% - 96%95% - 98%Operating Parameters24-95 psi, °F0-95 psi, °FUseVery common, industry standardNew, commercial useDrawbacksCost, lifespan, and greater N2O formationNew reactor design, deactivation to CoO
11 Controlling N2O Release Primary Methods-reduce N2O formed during ammonia oxidation70-85% efficiencyAdd an “empty” reaction chamber between the catalyst bed and the first heat exchanger (increase residence time)Modify the catalyst used during the ammonia oxidationSecondary Methods-reduce N2O formed immediately after ammonia oxidation (Selective Catalytic Reduction)Up to 90% efficiencySecondary catalyst is used to promote N2O decomposition by increasing the residence time in the ammonia burner2N2O (g) 2N2 (g) + O2 (g)
12 Controlling N2O Release Tertiary Methods-reduce N2O from or to the tail gas (Non-Selective Catalytic Reduction)80-98+% efficiencyA reagent fuel (e.g. H2 from an ammonia plant purge) is used over a catalyst to produce N2 and waterAlternatively, following SCR the tail gas is mixed with ammonia and reacts over a second catalyst bed to give N2 and waterCatalytic Reduction : burningMolecular sieve: Selectively absorb NO2 and return to absorption towerWet Scrubber: React the NOx through an aqueous solution, turns NOx into solid nitrates or salts12
13 Economics: Materials Materials Material Requirement Base Cost Total Cost [per year]Air10,344 TPD$0.00/ton$0.00Ammonia Vapor571.5 TPD$350/ton$73,009,125Nitric Acid* (SOLD)2,571.2 TPD$220/ton$206,467,360Nitric Acid** (SOLD)717.8 TPD$300/ton$78,599,100Steam (SOLD)1,843 TPD$20/ton$13,451,491Cobalt Oxide Catalyst-$0.50/ton acid$476,454TOTAL+ $225,000,000/year*Sold to Ammonium Nitrate, **Sold to Open Market1313
15 Economics: NPV Payback Period: 7 years Expected Plant Life: 20 years Yearly ProfitItemCostMaterials+$225,032,372Operation & Maintenance-$2,900,000Utilities-$9,535,283TOTALEst. Profit: $213,000,000/yearPayback Period: 7 yearsExpected Plant Life: 20 yearsInterest Rate: 8%Inflation Rate: 3%Installation Time: 3 yearsInstallation Cost: $348 millionNet Present Value after 20 years: $984 millionInternal Rate of Return: 23.98%1515
16 Process Safety ILarge release of process chemicals due to catastrophic failureBe prepared, emergency procedure with LECPPrevention of release & associated problems :Neutralizing materialsInitial construction of componentsRelease valvesBunding, dikesVentilationFireproofingLow release of process chemicalsCaused by operator error, poor maintenanceLarge release: be prepared beforehand with in-depth study of potential hazards, evacuation plansLEPC: Local Emergency Planning Committee:-Write emergency plans to protect the public from chemical accidents;-Establish procedures to warn and, if necessary, evacuate the public in case of an emergency;-Provide citizens and local governments with information about hazardous chemicals and accidental releases of chemicals in their communitiesInitial Construction: Ensure that proper materials and design specification are chosen, quality construction, equipment can handle conditions outside of the normal range of operation,Relief valves to prevent a situation of overpressurization in the first place.Neutralization: for nitric acid, we can either stock a weak base or use third-party materialsOperator error can include leaving a sample point open or a spill during loading and unloading1616
17 Process Safety II Other Safety Precautions Long-term exposure Noise Maintain PEL and STEL as dictated by OSHANoiseGoverned by OSHA, PEL of 90 dBMaintain & lubricate equipment, sound barriers, limiting exposureGeneral protectionInsulate or guard heated surfaces on working floorGood lightingRailings & non-slip surfacesTraining, safety checklistsChemical exNoise: 90 dB Time-Weighted Average, and above a certain threshold, we must implement Hearing Conservation Program for employeesHeated surfaces must be 7 feet from ground in areas if not guarded1717
19 Summary Recap of Questions from the Previous Meeting Project Overview Design BasisBlock Flow DiagramProcess Flow DiagramCatalyst ChoiceEnvironmental Issues ReviewEconomicsProcess Safety ReviewReport
20 ReferencesParkinson, Richard. UOP. Where Does It Go? An Introduction to the Placement of Process EquipmentAvailable and Emerging Technologies for Reducing Greenhouse Gas Emissions from the Nitric Acid Production Industry. U.S. Environmental Protection Agency <http://www.epa.gov/nsr/ghgdocs/nitricacid.pdf>.Best Available Techniques for Pollution Prevention and Control in the European Fertilizer Industry, Production of Nitric Acid. EFMA <http://www.efma.org/PRODUCT-STEWARDSHIP- PROGRAM-10/images/EFMABATNIT.pdf>.
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