OLI Simulation Conference 2010 Advances in OLI Simulation: Examples Wet Flue Gas Desulfurization and Amine Gas Sweetening Think Simulation! Harnessing the power of the OLI Engine James Berthold OLI Systems, Inc November 2010 Marriott Hotel - Whippany, New Jersey
Outline What s new since we last met (in 2007)? Multiple models in ESP Selective Redox Enhanced Mass-Transfer kinetics in ESP Columns Billet and Schultes Examples Wet Flue Gas Desulfurization Multiple Models Selective Redox Amine Gas Sweetening Enhanced Mass-Transfer Kinetics
Example 1: Wet Flue Gas Desulfurization Forced Air Oxidation: Limestone Method Most Commonly used WFGD used in the world Heavily used in the United States Most completely studied air purification process in the world
Example 1: WFGD
Example 1: WFGD OLI Example 1: WFGD OLI Representation
Example 1: WFGD Model Development The WFGD unit is broken down into two sections Absorber Section Flue Gas is absorbed by a falling spay of slurry Oxidation Section Forced air oxidizes sulfite to sulfate
Example 1: WFGD Model Development Basic Chemistry for the process SO 2(vap) SO 2(aq) SO 2(aq) + H 2 O H 2 SO 3(aq) H 2 SO 3(aq) H + + HSO 3 1-2H + +SO 3 2- ( q) CaCO 3(s) Ca 2+ + CO 3 2- SO 3 2- + ½ O 2 SO 4 2- Ca 2+ +SO 2-4 CaSO 4(s)
Example 1: WFGD Model Development Issues with the model! Oxidation from S(+4) to S(+6) should occur only in the forced oxidation section Nitrogen redox needs to have the thermodynamic pathway to N 2 eliminated No oxidation should occur elsewhere in the model Requires two OLI Chemistry Models No REDOX for all units except the oxidation section Selective Redox for the oxidation section
Example 1: WFGD Model Development Model 1 No REDOX Absorber Section and all other units except Oxidation section
Example 1: WFGD Model Development (CONH 2 ) 2 NH (aq) +NH 3(aq) =2UREA (aq) (CONH 2 ) 2 NH (vap) +=(CONH 2 ) 2 NH (aq) CaCO 3(aq) =Ca 2+ +CO 2-3 CaCO 3(s) = Ca 2+ +CO 2-3 CaOH 1- =Ca 2+ +OH 1- CaSO 4.2H 2 O (s) =Ca 2+ +SO 2-4 +2H 2 O CaSO 4(AQ) =Ca 2+ +SO 2-4 CaSO 4(s) =Ca 2+ +SO 2-4 CH 4(VAP) =CH 4(AQ) CO 2(AQ) +2H 2 O=H 3 O 1+ +HCO 1-3 CO 2(VAP) =CO 2(AQ) 2H 2 O= H 3 O 1+ + OH 1- H 2 O (VAP) =H 2 O H 2 S (AQ) +H 2 O=H 3 O 1+ +HS 1- H 2 SO 4(AQ) +H 2 O=H 3 O 1+ +HSO 1-4 H 2 SO 4(VAP) =H 2 SO 4(AQ) H 2 S (VAP) =H 2 S (AQ) H 2(VAP) =H 2(AQ_ HCl (AQ) +H 2 O=H 3 O 1+ +Cl 1- HCl (VAP) =HCl (AQ) HCO 1-3 +H 2 O=H 3 O 1+ +CO 2-3 NH 2 OH (VAP) =NH 2 OH (aq) NH 2 OH 1+ 2 +H 2 O=NH 2 OH (AQ) +H 3 O 1+ (HNCO) 3(AQ) +3NH 3(AQ_ =3UREA (AQ) (HNCO) 3(VAP) =(HNCO) 3(AQ) HNCO (AQ) +NH 3(AQ) =UREA (AQ) HNCO (VAP) =HNCO (AQ) HNO 2(AQ) +H 2 O=H 3 O 1+ +NO 1-2 HNO 2(VAP) =HNO 2(AQ) HNO 3(AQ) +H 2 O=H 3 O 1+ +NO 1-3 HNO 3 (SO 3 ) 2(aq) =HNO 3(AQ) +2SO 3(AQ) HNO 3VAP =HNO 3AQ HS 1- +H 2 O=H3O 1+ +S 2- HSO 1- +H O=H 1+ +SO 2-3 2 3 O 3 HSO 1-4 +H 2 O=H 3 O 1+ +SO 2-4 MgCO 3AQ =Mg 2+ +CO 2-3 MgOH 1+ =Mg 2+ +OH 1- MgSO 4AQ =Mg 2+ +SO 2-4
Example 1: WFGD Model Development N 2 H 4VAP =N 2 H 4AQ N 2 H 1+ 5 +H 2 O=H 3 O 1+ +N 2 H 4AQ N 2 O 5AQ +H 2 O=2HNO 3AQ N 2 O 5VAP =N 2 O 5AQ N 2 O VAP =N 2 O AQ N 2VAP =N 2AQ NH 2 CO 1-2 +H2O=NH 3AQ +HCO 1-3 NH 3AQ +H 2 O=NH 1+ 4 +OH 1- NH 3VAP =NH 3AQ NH 4 NO 3.(NH 4 ) 2 SO 4AQ =3NH 1+ 4 +NO 1-3 +SO 2-4 NO 2VAP =NO 2AQ NO VAP =NO AQ O 2VAP =O 2AQ OCN 1- +NH 1+ 4 =UREA AQ 2S 2-2 +H 2 O=S 2-3 +HS 1- +OH 1-5S 2-2- 2 O 32 +6H 3 O 1+ =2S 5 O 62 +9H 2 O 3S 2-3 +H 2 O=2S 2-4 +HS 1- +OH 1-4S 2-4 +H 2 O=3S 2-5 +HS 1- +OH 1- SO 2AQ +2H 2 O=H 3 O 1+ +HSO 1+ 3 SO 2VAP =SO 2AQ SO 3AQ +H 2 O=H 2 SO 4AQ SO 3VAP =SO 3AQ UREA AQ +H 2 O=2NH 3AQ +CO 2AQ UREA VAP =UREA AQ
Example 1: WFGD Model Development Model 2 Selective REDOX For Oxidation Section Only Contains all the species of Model 1 Does not have the pathway to N(0)
Example 1: WFGD Model Development NO AQ + 0.5O 2AQ =NO 2AQ NO 1-2 +0.25O 2AQ +0.25H 3 O 1+ =NO 2AQ +0.75OH 1- NO 1-3 +0.25H 3 O 1+ =NO 2AQ +0.25O 2AQ +0.75OH 1+ NH 1+ 4 +1.75O 2AQ =NO 2AQ +0.25OH 1- +1.25H 3 O 1+ N 2 O AQ +1.5O 2AQ =2NO 2AQ N 2 H 4AQ +3O 2AQ =2NO 2AQ +OH 1- +H 3 O 1+ NH =NO 11 1+ 2 OH AQ +1.25O 2AQ 2AQ +0.75OH +0.75H 3 O S 2- +2.5O 2AQ +0.5H 3 O 1+ =HSO 1-5 +0.5OH 1- S 2-5 +10.5O 2AQ +3.5OH 1- +0.5H3O 1+ =5HSO 1-5 SO 2-3 +O 2AQ +0.5H 3 O 1+ =HSO 1-5 +0.5OH 1- SO 2-4 +0.5O 2AQ +0.5H 3 O 1+ =HSO 1-5 +0.5OH 1- S 2 O 2-8 +0.5O 2AQ +0.5OH 1- +0.5H 3 O 1+ =2HSO 1-5 S 2 O 2-6 +1.5O 2AQ +0.5OH 1- +0.5H 3 O 1+ =2HSO 1-5 S 2-1- 1+ =5HSO 1-5 O 6 +7.5O 2AQ +3.5OH +0.5H 3 O 5 S 2 O 2-4 +2.5O 2AQ +0.5OH 1- +0.5H 3 O 1+ =2HSO 1-5.2H 2AQ +.1O 2AQ =.2H 2 O
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox
Example 1: WFGD Model Details
Example 1: WFGD Model Details: Stream: Flue Gas Temperature 138 o C Pressure 1.2 Atm H2O 50,000000 ppmv CH4 10 ppmv CO2 150,000 ppmv HCl 100 ppmv NO2 500 ppmv O2 30,000 ppmv SO2 800 ppmv N2 Balance
Example 1: WFGD Model Details
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure Total Flow O2 N2 Stream: Forced Air 25 o C 1.0 Atm 8.7 ft 3 /hr 0.21 mole fraction 0.79 mole fraction
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure Total Flow CaCO3 H2O Stream: Slurry 25 o C 1.0 Atm 2.0 gal/hr 30 % weight 70 % weight
Example 1: WFGD Model Details
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure Total Flow Stream: To Reheater 47.8 o C 1.0 Atm 1010 ft 3 /hr
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure Total Flow Stream: To Stack 43.3 o C 0.8 Atm 1245 ft 3 /hr Reheater Temperature is 47 C. This is above the dew point, no reheating required.
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure H2O CH4 CO2 HCl NO2 O2 SO2 N2 Stream: Plume 43.3 o C 0.8 Atm 109,000 ppmv 9.3 ppmv 140,000 ppmv nil ppmv 560 ppmv 29,000 ppmv 45 ppmv Balance
Example 1: WFGD Model Details
Example 1: WFGD Model Details: Feed Conditions Temperature Pressure Total Flow CaCO3 CaSO4.2H2O Stream: Landfill 35.6 o C 10At 1.0 Atm 17.9 lb/hr 6.0 lb/hr 0.30 lb.hr
Example 1: Conclusions & Future work It would seem that Flue Gas Desulfurization can be modeled. A third model should be added to limit the amount of calcium carbonate that is formed.
Example 2: Gas Sweetening This example will illustrate several things: Alkanolamine gas-sweetening using new parameters in MSE Mass-Transfer using OLI s enhanced capabilities
Example 2: Gas Sweetening What is Mass-Transfer in OLI? Liquid In Vapor out T L T i T V X i X j i Y j i Y j Liquid Out Vapor In X j is the bulk liquid composition Y i is the bulk liquid composition X i j is the liquid interface composition Y ji is the liquid interface composition Tv is the bulk vapor temperature T L is the bulk liquid temperature T i is the interface temperature
Example 2: Gas Sweetening Tmole j A* MV * j Y j Y i j Tmole j HEAT A* ML * j A* MV * X i j X T V T j i A = transfer area MV i = Vapor Component mass transfer coefficient ML i = Liquid component mass transfer coefficient HV = Vapor Heat transfer coefficient HL = Liquid Heat transfer Coefficient Tmole j = moles/hr of component j transferred Heat = heat transfer across interface HEAT A* ML* T i T L
Example 2: Gas Sweetening Existing Modeling capabilities Liquid Mass Transfer Coefficients Vapor Mass Transfer Coefficients Liquid heat transfer coefficients Vapor heat transfer coefficients Transfer Area Component mass transfer coefficients
Example 2: Gas Sweetening Enhanced Modeling capabilities Several Column Types Packed Column Sieve Tray Bubble Cap Valve Tray
Example 2: Gas Sweetening Packed Columns Stage Height Column Diameter Packing Type (Billet and Schultes) Examples: Pall Rings, Rashig Rings, Berl Saddle Packing Material Metal, Plastic, Ceramic Packing Size Packing Parameters
Example 2: Gas Sweetening Sieve Tray Column Diameter Weir Height Froth Height Clear Liquid Height Bubble Cap Column diameter Valve Tray Column diameters W i H i ht Weir Height Liquid Film Segments
Example 2: Gas Sweetening Scrubbing of an acid gas with Diethanolamine Recycled DEA Clean Gas Flash Vapor CO2-H2S Feed Gas Rich Amine Flash Liquid DEA Regenerator DEA Mix DEA Absorber Flash Drum Recycle Recycle 1 Water Water Make-Up Water In Water Mix Water Control DEA In DEA DEA Make-Up DEA Control
Example 2: Gas Sweetening Standard OLI Columns: Stream Summary 1 Feed Gas Clean Gas % Removal 2 CO2 20,000 0.095 100 H2S 20,000 0.00009 100 C3H8 10,000 10,400 0.37 C4H10 5,000 5,150 1.6 CH4 925,000 964,000 0.43 C2H6 20,000000 20,900 033 0.33 Total (moles/hr) 1000 955.8 Flow (ft 3 /hr) 42 41 1 concentrations are ppmv 2 based on total feed moles
Example 2: Gas Sweetening Standard OLI Columns: Stream Summary 1 CO2-H2S H2O 499779 CO2 249,766 DEA Nil H2S 247,206 C3H8 26.8 C4H10 212.4 CH4 2968.4 C2H6 41.1 Total (moles/hr) 80.0 Flow (ft 3 /hr) 68.8 1 concentrations are ppmv
Example 2: Gas Sweetening Standard OLI Columns: Stream Summary Stream Flow 1 Water In 42.4 DEA In 000 0.00 Recycled DEA 623.6 1 moles/hr
Example 2: Gas Sweetening Mass-Transfer Columns DEA Absorber and DEA Regenerator Columns are set to the same type Packed Column Pall Rings, g, 50 mm Stage Height = 1 mm Column Diameter to be calculated Liquid Film segments = 1
Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary 1 Feed Gas Clean Gas % Removal 2 CO2 20,000 0.055 100 H2S 20,000 0.00074 100 C3H8 10,000 10,400 0.38 C4H10 5,000 5,130 1.85 CH4 925,000 964,000 0.42 C2H6 20,000000 20,900 033 0.33 Total (moles/hr) 1000 955.8 Flow (ft 3 /hr) 42 42 1 concentrations are ppmv 2 based on total feed moles
Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary 1 CO2-H2S H2O 745306 CO2 126890 DEA 24.4 H2S 126941 C3H8 15.9 C4H10 146.0 CH4 1652 C2H6 23.6 Total (moles/hr) 158 Flow (ft 3 /hr) 114 1 concentrations are ppmv
Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary Stream Flow 1 Water In 123.0 DEA In 0.004004 Recycled DEA 638.5 1 moles/hr
Example 2: Gas Sweetening Additional Block Reports for Mass Transfer Columns An Example DEA Absorber Column Diameter = 0.046 m Stage 10 Load Velocity (m/s) Liquid =0.011 Vapor = 0.648 Flooding Velocity (m/s) Liquid = 0.022 Vapor = 1.243 Actual Velocity (m/s) Liquid = 0.004 Vapor = 0.196 Liquid Hold-up (m3/m3) = 0.175 Pressure Drop (atm/m) = 0.005 Actual Velocities < Flooding Velocities The column should not flood
Example 2: Gas Sweetening Comparing the two models: Stream Summary 1 Clean Gas (Standard) d) CO2 0.095 0.055 Clean Gas (Mass Trans) H2S 0.00009 0.00074 C3H8 10,400 10,400 C4H10 5,150 5,130 CH4 964,000 964,000 C2H6 20,900 20,900 Total (moles/hr) 955.8 955.8 Flow (ft 3 /hr) 41 42 1 concentrations are ppmv
Example 2: Gas Sweetening Comparing the two models: Stream Summary CO2-H2S (Standard) H2O 499778 745306 CO2 249766 126890 DEA Nil 24.4 H2S 247206 126941 C3H8 26.7 15.9 C4H10 212.5 146.0 CH4 2968.4 1652 C2H6 41.1 23.6 Total (moles/hr) 80 158 Flow (ft 3 /hr) 68.8 114 CO2-H2S (Mass-Trans)
Example 2: Gas Sweetening Comparing the two models: Stream Summary Stream Flow 1 Standard Mass Transfer Water In 42.4 123.0 DEA In 0.00 0.004 Recycled DEA 623.66 638.5 1 moles/hr
Example 2: Gas Sweetening Conclusions OLI now has more formal mass-transfer capabilities The Packed Column has essentially the same performance as the standard column but used more reagent as expected.
Conclusions The ability of multiple models in ESP allows for different phenomena to be modeled in the same flow sheet. Potentially allows for simulating reaction kinetics without actually having kinetic data. Mass-transfer simulations can now approximate actual design specifications. More development in this area is underway.