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Presented to: Training & ISO Department Presented by: Kashif Yasin

Punjab University

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Continued Brief Overview of Urea FormationSynthesis Decomposition Recovery Finishing

Comparison of UTIC & SNAMPROGETTIPowerpoint Templates Page 4

UREA

Urea is a white crystalline solid containing 46% nitrogen and is used as a fertilizer widely. It is available in the form of prills and granules It provides required nitrogen to the plant for its growth Commercial manufacture of urea started in 1932 in Germany.Powerpoint Templates Page 5

Once Through Process Once through process is simplest and less expensive Even though the process is simplest, it is least flexible It must be used in conjunction with the coproduction of some other materials, e.g. ammonium sulfate

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Partial Recycle Process In this case partial ammonia is recycled to the urea reactor The remaining ammonia is to be used for some other material Lesser ammonia is available for co-production (15%less)

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Total Recycle Process In this process all the unconverted ammonia and carbon dioxide mixture is recycled to urea reactor No co-production is necessary This is the most flexible process

It is most expensive in investment & operating costsPowerpoint Templates Page 8

Brief Overview of Urea Formation Types of Urea production processBy Wohler reaction(never tried for industrial use) NH3 + HCNO NH4OCN NH4OCN NH2CONH2

By Hydrolysis of Calcium Cyanamid CaCN2 + 3H2O NH2CONH2 + Ca (OH)2Powerpoint Templates Page 9

Two Steps Chemical Reactiona) Carbamate Formation

CO2

+

2NH3

NH2COONH4

b) Dehydration

NH2COONH4c) Overall

NH2CONH2 + H2O

CO2

+

2NH3

NH2CONH2 + H2O

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All Urea Processes have 4 steps1) Urea SynthesisCO2 + 2NH3 NH2CONH2 + H2O

2) Product Separation(Decomposition)NH2-COO-NH4 2NH3 + CO2Page 11

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3) Non reacted gases utilization(Recovery) Off gases used in heat recovery Formation of Carbamate Sent back to urea Reactor

4) Finishing Prilling Bagging & ShippingPowerpoint Templates Page 12

Vendors of Total Recycle Processes Ivo Mavrovic UTIC Heat Recycle Process Mitsui Toatsu Total Recycle(Now Toyo Aces Process)

Stamicarbon Stripping Process

Snamprogetti Stripping Process

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Comparison of UTIC & Snamprogetti

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Parameters studied to compare UTIC & SNAMPROGETTI? Reaction Parameters Reactor Performance Decomposition Energy ConsumptionPowerpoint Templates Page 15

Reaction Parameters Pressure

Temperature NH3/CO2 Ratio H2O/CO2 Ratio Powerpoint Templates

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Reaction ParametersUTIC P=3200psigSNAMPROGETTI P=2275 psig

T=380FNH3/CO2=4.5:1 H2O/CO2=0.8

T=370FNH3/CO2=3.6:1 H2O/CO2=0.7Page 17

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Reactor PerformanceReactor performance is measured by the Conversion of CO2 in reactorUTIC SNAMPROGETTI

74% 65%Powerpoint Templates Page 18

DecompositionIt is the main point of difference between UTIC & SNAMPROGETTI

UTICHP Decomposition LP Decomposition

SNAMPROGETTIHP Stripping MP Decomposition LP Decomposition

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UTIC DecompositionHP Decomposition (280-320psig) LP Decomposition (20-30psig) Degasser & Vacuum Concentrator (20 inHg)

CO2 is used as a stripping agent High steam consumptionPowerpoint Templates Page 20

SNAMPROGETTI DecompositionHP Stripper (2130psig) MP Decomposer (270psig) LP Decomposer (70psig) Vacuum Concentrator (0.35-0.03 kg/cm2)

NH3 is used as self stripping agent Less steam consumptionPowerpoint Templates Page 21

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Energy ConsumptionEnergy consumption in Snamprogetti is less than UTIC

REASONSUTICMore Steam Consumption No arbamate Ejector No HP Stripper Electricity Motors

SNAMPROGETTILess Steam Consumption Carbamate Ejector HP Stripper Steam Turbines

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REASONS HP Stripper pressure is 2130psig Less pressure is required in reactor in Snamprogetti than Utic Steam turbines are used in Snamprogetti Steam consumption is large in UticPowerpoint Templates Page 24

ComparisonVendors Pressure Temperature NH3/CO2 Ratio Reactor Efficiency NH3 Consumption/ton urea UTIC 3200 psig 380F 4.5 74% 0.58 ton SNAMPROGETTI 2275 psig 370F 3.6 65% 0.566 ton

CO2 Consumption/ton ureaSteam Consumption/ton urea Power Consumption/ton

0.75 ton1.2 ton 148 KWh

0.735 ton0.9 ton 120 KWh

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