OLI Simulation Conference 2010

Transcription

1 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

2 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

3 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

4 Example 1: WFGD

5 Example 1: WFGD OLI Example 1: WFGD OLI Representation

6 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

7 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 ½ O 2 SO 4 2- Ca 2+ +SO 2-4 CaSO 4(s)

8 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

9 Example 1: WFGD Model Development Model 1 No REDOX Absorber Section and all other units except Oxidation section

10 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 H 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 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 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

11 Example 1: WFGD Model Development N 2 H 4VAP =N 2 H 4AQ N 2 H 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 OH 1- NH 3VAP =NH 3AQ NH 4 NO 3.(NH 4 ) 2 SO 4AQ =3NH 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 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

12 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)

13 Example 1: WFGD Model Development NO AQ + 0.5O 2AQ =NO 2AQ NO O 2AQ +0.25H 3 O 1+ =NO 2AQ +0.75OH 1- NO H 3 O 1+ =NO 2AQ +0.25O 2AQ +0.75OH 1+ NH O 2AQ =NO 2AQ +0.25OH H 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 OH AQ +1.25O 2AQ 2AQ +0.75OH +0.75H 3 O S O 2AQ +0.5H 3 O 1+ =HSO OH 1- S O 2AQ +3.5OH H3O 1+ =5HSO 1-5 SO 2-3 +O 2AQ +0.5H 3 O 1+ =HSO OH 1- SO O 2AQ +0.5H 3 O 1+ =HSO OH 1- S 2 O O 2AQ +0.5OH H 3 O 1+ =2HSO 1-5 S 2 O O 2AQ +0.5OH H 3 O 1+ =2HSO 1-5 S =5HSO 1-5 O O 2AQ +3.5OH +0.5H 3 O 5 S 2 O O 2AQ +0.5OH H 3 O 1+ =2HSO 1-5.2H 2AQ +.1O 2AQ =.2H 2 O

14 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

15 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

16 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

17 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

18 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

19 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

20 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

21 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

22 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

23 Example 1: WFGD Model Example 1: WFGD Model Development Selective Redox

24 Example 1: WFGD Model Details

25 Example 1: WFGD Model Details: Stream: Flue Gas Temperature 138 o C Pressure 1.2 Atm H2O 50, ppmv CH4 10 ppmv CO2 150,000 ppmv HCl 100 ppmv NO2 500 ppmv O2 30,000 ppmv SO2 800 ppmv N2 Balance

26 Example 1: WFGD Model Details

27 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

28 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

29 Example 1: WFGD Model Details

30 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

31 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.

32 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

33 Example 1: WFGD Model Details

34 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

35 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.

36 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

37 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

38 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

39 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

40 Example 2: Gas Sweetening Enhanced Modeling capabilities Several Column Types Packed Column Sieve Tray Bubble Cap Valve Tray

41 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

42 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

43 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

44 Example 2: Gas Sweetening Standard OLI Columns: Stream Summary 1 Feed Gas Clean Gas % Removal 2 CO2 20, H2S 20, C3H8 10,000 10, C4H10 5,000 5, CH4 925, , C2H6 20, , Total (moles/hr) Flow (ft 3 /hr) concentrations are ppmv 2 based on total feed moles

45 Example 2: Gas Sweetening Standard OLI Columns: Stream Summary 1 CO2-H2S H2O CO2 249,766 DEA Nil H2S 247,206 C3H C4H CH C2H Total (moles/hr) 80.0 Flow (ft 3 /hr) concentrations are ppmv

46 Example 2: Gas Sweetening Standard OLI Columns: Stream Summary Stream Flow 1 Water In 42.4 DEA In Recycled DEA moles/hr

47 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

48 Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary 1 Feed Gas Clean Gas % Removal 2 CO2 20, H2S 20, C3H8 10,000 10, C4H10 5,000 5, CH4 925, , C2H6 20, , Total (moles/hr) Flow (ft 3 /hr) concentrations are ppmv 2 based on total feed moles

49 Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary 1 CO2-H2S H2O CO DEA 24.4 H2S C3H C4H CH C2H Total (moles/hr) 158 Flow (ft 3 /hr) concentrations are ppmv

50 Example 2: Gas Sweetening Mass Transfer OLI Columns: Stream Summary Stream Flow 1 Water In DEA In Recycled DEA moles/hr

51 Example 2: Gas Sweetening Additional Block Reports for Mass Transfer Columns An Example DEA Absorber Column Diameter = m Stage 10 Load Velocity (m/s) Liquid =0.011 Vapor = Flooding Velocity (m/s) Liquid = Vapor = Actual Velocity (m/s) Liquid = Vapor = Liquid Hold-up (m3/m3) = Pressure Drop (atm/m) = Actual Velocities < Flooding Velocities The column should not flood

52 Example 2: Gas Sweetening Comparing the two models: Stream Summary 1 Clean Gas (Standard) d) CO Clean Gas (Mass Trans) H2S C3H8 10,400 10,400 C4H10 5,150 5,130 CH4 964, ,000 C2H6 20,900 20,900 Total (moles/hr) Flow (ft 3 /hr) concentrations are ppmv

53 Example 2: Gas Sweetening Comparing the two models: Stream Summary CO2-H2S (Standard) H2O CO DEA Nil 24.4 H2S C3H C4H CH C2H Total (moles/hr) Flow (ft 3 /hr) CO2-H2S (Mass-Trans)

54 Example 2: Gas Sweetening Comparing the two models: Stream Summary Stream Flow 1 Standard Mass Transfer Water In DEA In Recycled DEA moles/hr

55 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.

56 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.