Download presentation

Presentation is loading. Please wait.

Published byShaniya Grills Modified over 3 years ago

1
Solubility of K 2 SO 4 in CO 2 Loaded MEA/PZ Solution Jan 10th, 2008 Qing Xu Rochelle group Department of Chemical Engineering University of Texas at Austin

2
Outline Reclaiming process Why reclaiming Reclaiming processes Experiment Conductivity for K 2 SO 4 solution Ranges of the experiments Apparent K sp dependence on T, amine and I Regression Analysis – Electrolyte-NRTL (in Aspen Plus 2006.5) Interaction parameters regression Flash simulation test for regression results Conclusion Future work

3
Why reclaiming ? What to reclaim: SO 2, HCl, NO x SO 4 -2, Cl -, NO 3 - … Organic acids, amine polymers Why reclaiming? To remove heat stable salts and degradation products, which may cause corrosion, foaming, and will affect the capacity of amine solution. Chemical reactions:

4
Reclaiming Processes: Thermal reclaiming with addition of NaOH Na 2 SO 4 (s) MEA degradation products Sodium formate Electrodialysis Ion exchange Sulfate precipitation Fertilizer

5
CO 2 Capture Process High T Low T CaSO 4 CaCO 3

6
Precipitation Reclaiming for Hot Lean Solvent 3×3× Hot Lean Cool Lean CO 2 H2OH2O K 2 SO 4 (s) KOH

7
Solubility of K 2 SO 4 in CO 2 Loaded Amine can Determine: Solvent flow rate for reclaiming. Operating condition to avoid scaling. Energy and equipment cost.

8
Apparatus and Method - 1 Stirrer K 2 SO 4 Conductivity meter Water Bath

9
Apparatus and Method - 2 BottleTop Water Bath Conductivity Meter Water Bath

10
11m MEA, [CO 2 ] t =0.4 mol/mol MEA, 80 o C Conductivity~[K 2 SO 4 ] Start with K 2 SO 4 slurry End, clear solution

11
Ranges of the Experiments T: 25 ℃, 40 ℃, 80 ℃ Amine: 7m MEA, 11m MEA, 4m PZ, 7m MEA/2m PZ, 8m PZ, 10m PZ, etc. CO 2 loading: Loading Extra K + : 0, 0.35m Extra SO 4 = : 0, 0.15m

12
K sp dependence on T, amine concentration, and ionic strength 7m 11m 80C 40C

13
Regression Analysis - K sp K sp of K 2 SO 4 : Property method: elecNRTL in Aspen Plus 2006.5 Based on solubility data of K 2 SO 4 in water by Söhnel, 1985, regress A, B, and C in K sp (T): ParameterValue (SI units)σ A235.02.5 B-13227118 C-36.20.4

14
Originally by Chen et al., for aqueous electrolyte systems. Later extended to mixed solvent electrolyte systems (Mock et al., 1984, 1986). A versatile model for the calculation of activity coefficients. Adjustable ENRTL interaction parameters: Molecule-molecule Molecule-electrolyte Electrolyte-electrolyte Each interaction consists of both the nonrandomness factor and energy parameters . Regression Analysis – Electrolyte NRTL Model

15
Regression Analysis – Interaction parameters Framework Data Regression System in Aspen Plus Electrolyte-NRTL model Chemistry: K sp (T) from previous regression. ｝

16
Existing parameters Electrolyte-NRTL default values in Aspen Plus Hilliard, 2005 (10 C, D & E for MEA-H 2 O-CO 2 system and parameters for pure/binary components) Objective Parameters (C) and (D) related to K + and SO 4 = Solubility data used Water data by Söhnel, 1985; MEA data by Xu, 2006~2007. Method Select parameters with small correlation coefficients. Small residual root mean square error. Small AARD (average absolute relative deviations) in flash simulation test Regression Analysis – Interaction parameters

17
Regression Analysis - Results Component iComponent j CD H2OH2O(K +,MEACOO - ) xx MEA xx (MEA +,SO 4 -2 )H2OH2O xx MEA x (MEA +,SO 4 -2 ) x (K +, SO 4 -2 )MEA xx (K +, HCO 3 - )MEA xx

18
A series of flash simulation Using the regressed interaction parameter set Simulate under each experimental condition Get activity coefficient and mole fraction for each case, calculate K sp and the error from K sp (T). AARD: 45.6% Regression Analysis – Test

19
Dependence of K sp (meas)/K sp (T) on [CO 2 ]

20
Dependence of K sp (meas)/K sp (T) on [MEA]

21
Dependence of K sp (meas)/K sp (T) on T

22
Conclusions K sp dependence on T, equivalent amine concentration, and ionic strength: A parameter set in Electrolyte-NRTL model for the CO 2 -MEA-H 2 O-K + -SO 4 = system was developed. Still need modification. K sp (meas)/K sp (T) is dependent on MEA concentration and CO 2 loading, independent on temperature.

23
Future work Modify the regression; get more accurate C/D/E parameter set for the . Conduct experiments of K 2 SO 4 crystallization Slurry characteristics: settling rates, filterability, drying rates and final moisture contents. Crystal characteristics: composition, form, habit, shape factors, and solid density. Crystallization kinetics: crystal nucleation, growth. Modify Aspen reclaiming process model with regressed parameters, optimize conditions, add crystallization data into the model.

Similar presentations

OK

Karst Chemistry I. Definitions of concentration units Molality m = moles of solute per kilogram of solvent Molarity [x]= moles of solute per kilogram.

Karst Chemistry I. Definitions of concentration units Molality m = moles of solute per kilogram of solvent Molarity [x]= moles of solute per kilogram.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on different types of transport Ppt on marketing strategy of coca cola in india Ppt on duration of a bond Ppt on bombay stock exchange Ppt on quality education fund Download ppt on national festivals of india Present ppt on ipad Flat panel display ppt on tv Ppt on action words for grade 1 Ppt on national education day 2016