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Prilled Urea- A Cost Effective Way to Feed the World. Sule Alabi Jonathan Arana Elizabeth Moscoso Oleg Yazvin Mentor: Dan Rusinak – Middough. Team Echo. Table of Contents. Purpose BFD Overview of Urea Plant Process Description Sinks & Loads Sizing and Costing Conclusion Q & A .
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Prilled Urea- A Cost Effective Way to Feed the World Sule Alabi Jonathan Arana Elizabeth Moscoso Oleg Yazvin Mentor: Dan Rusinak – Middough Team Echo
Table of Contents • Purpose • BFD Overview of Urea Plant • Process Description • Sinks & Loads • Sizing and Costing • Conclusion • Q & A
Williston Nitrogen Partners • Purpose: • Convert shale gas into a nitrogen-based fertilizer • Plant Location: • Williston Basin • Reason for Location: • Bakken Shale Gas Formation
Urea- Solution & Prill • Urea has a high nitrogen content (47%) • Liquid Urea (72.0wt%) - Urea Ammonium Nitrate (UAN 32) • Prilled Urea (99.8wt%)- Controlled release fertilizer • Overall Reaction: • Overall Exothermic: -120 BTU/mol
BFD of Urea & Prill Plant Output NH3 Purge & Urea SolutionTo Amm. Nitrate & UAN Plants Urea Production Plant CO2 & NH3 Recycled Gas Inlet NH3 & CO2from NH3 Plant Waste Water Treatment Plant Condensate Water with NH3, CO2 & Impurities Cooling Water from CHP Plant Urea Solution (72%) Air Out Prilling Tower Evaporator Unit Prilled Urea (99.8%)Product Solid Urea (99.8%) Air In
BFD of Urea & Prill Plant Output NH3 Purge & Urea SolutionTo Amm. Nitrate & UAN Plants Urea Production Plant CO2 & NH3 Recycled Gas Inlet NH3 & CO2from NH3 Plant Waste Water Treatment Plant Condensate Water with NH3, CO2 & Impurities Cooling Water from CHP Plant Urea Solution (72%) Air Out Prilling Tower Evaporator Unit Prilled Urea (99.8%)Product Solid Urea (99.8%) Air In
Urea Production Plant • Converts reactants into urea • NH3 and CO2 from Nitrate Plant • Produces 72 wt% Urea solution • Main Components of Plant • Reactor • Stripper • Decomposer • Scrubber • Absorber • Overall Reaction:
Urea Production Plant – Sinks & Loads Load Sink Energy Saver
Urea Production Plant- Aspen • Mass Balance • No Convergence • Recycle streams • Attempted Solution • Increased number of iterations- no change • Cut recycle streams- Mass Balance Converged • Energy Balance • No Values Given • No Ammonium Carbamate properties within Aspen data libraries • Attempted Solutions • Free energy of formation • Heat of formation • Heat of dissolution in water • Pending Solutions • Heat Capacity • Component with similar properties
BFD of Urea & Prill Plant Output NH3 Purge & Urea SolutionTo Amm. Nitrate & UAN Plants Urea Production Plant CO2 & NH3 Recycled Gas Inlet NH3 & CO2from NH3 Plant Waste Water Treatment Plant Condensate Water with NH3, CO2 & Impurities Cooling Water from CHP Plant Urea Solution (72%) Air Out Prilling Tower Evaporator Unit Prilled Urea (99.8%)Product Solid Urea (99.8%) Air In
Evaporation Section • Multiple-Effect Evaporation under Vacuum • Incoming Urea Solution: • 72% Urea, 28% Water • Two evaporators required • 1st Evaporator: • 72% to 94.6% Urea • 2nd Evaporator: • 94.6% to 99.8% Urea
Evaporator Process • Temp and Pressure are the main operating parameters
Importance of Vacuum Pressure • Minimization of Biuret (Poison) • Lowering of Boiling Point for next evaporation stage • Consequently, reduces steam load
Evaporator- Sinks & Loads Load Sink Energy Saver
BFD of Urea & Prill Plant Output NH3 Purge & Urea SolutionTo Amm. Nitrate & UAN Plants Urea Production Plant CO2 & NH3 Recycled Gas Inlet NH3 & CO2from NH3 Plant Waste Water Treatment Plant Condensate Water with NH3, CO2 & Impurities Cooling Water from CHP Plant Urea Solution (72%) Air Out Prilling Tower Evaporator Unit Prilled Urea (99.8%)Product Solid Urea (99.8%) Air In
Prill Section • Converts Urea Melt into Prill • Main Components • Prill Tower • Screen • Cyclone • Bag House • Heater • Dehumidifier
Prill Sinks & Loads Load Sink Energy Saver
Prill Section Cost and Sizing • Research yielded a previously done mathematical simulation of prilling tower • From simulation data, airflow and size for our prilling tower were obtained • Cost for prilling tower will be approximated by a similar capacity storage tank • Cyclone and bag house sizing in progress due to potential redesign of prilling tower
Potential Redesign of Prilling Tower • Standard Oil Patent Filed in 1978 • Uses co-current airstream and fluidized bed • Benefits: • Less dust emissions • Smaller tower required
BFD of Urea & Prill Plant Output NH3 Purge & Urea SolutionTo Amm. Nitrate & UAN Plants Urea Production Plant CO2 & NH3 Recycled Gas Inlet NH3 & CO2from NH3 Plant Waste Water Treatment Plant Condensate Water with NH3, CO2 & Impurities Cooling Water from CHP Plant Urea Solution (72%) Air Out Prilling Tower Evaporator Unit Prilled Urea (99.8%)Product Solid Urea (99.8%) Air In
Waste Water Treatment Plant • For every ton of urea produced 0.3 tons of waste water is produced • Co-Current thermal hydrolysis of urea with steam • Main Components: • 1stDesorber • Hydrolyzer • 2ndDesorber • 2 HX • Overall Reaction: Reverse of Urea Plant Overall Endothermic: +58 BTU/mol
Waste Water Treatment Plant • Waste Water Content: • 2- 9 wt% Ammonia • 0.8- 6 wt% CO2 • 0.3-1.5 wt% Urea • Simple discharge is a waste of resources and environmentally harmful • Ammonia is hazardous, toxic, and volatile • Urea promotes algae growth and hydrolyses slowly • EPA Emission Requirements: 10 ppm
WWTP Sinks & Loads Load Load Load Load Sink Sink Energy Saver
WWTP Equipment Costs • Total Project Capital Cost 2.25 Million • Total Operating Cost 1.2 Million • Total Utilities Cost $42,000/yr
Conclusion • Total Plant Cost: $400 Million • Produce 793 TPD of Prilled Product • Produce 836 TPD of Urea melt for UAN Plant • Numerous Instances of Efficient Energy Usages. • Aspen Simulation: Great Start
Thank you • Questions?