Dissertation Thesis Presentation - uiam.skjelemensky/Material/diss_press.pdfDissertation Thesis...
Transcript of Dissertation Thesis Presentation - uiam.skjelemensky/Material/diss_press.pdfDissertation Thesis...
Optimal Control of Membrane Processes inthe Presence of Fouling
Dissertation Thesis Presentation
Ing. Martin Jelemensky
Supervisor: prof. Ing. Miroslav Fikar, DrSc.
Faculty of Chemical and Food TechnologySlovak University of Technology in Bratislava
August 24, 2016
IAM
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 1 / 31
Motivation – Applications
Food Industry Biotechnological Industry
Chemical Industry Pharmaceutical IndustryMartin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 2 / 31
Motivation
product + impurities
¤£$⇒
separation
product
Operation goals:
Cost function: minimization of production costsState constraints: satisfaction of production quality (product purity)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 3 / 31
Motivation – Membrane Fouling
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 4 / 31
Goals of Thesis
Study of optimal operation of membrane processes in the presence ofmembrane fouling.
Characterization of fully analytical optimal operation in the presence ofmembrane fouling.
Implementation and verification of the proposed optimal operation in casestudies and comparison of the results with traditional control approaches.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 5 / 31
Presentation Outline
1 Membrane Process
2 Membrane Fouling
3 Optimal Operation
4 Fouling Estimation
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 6 / 31
Presentation Outline
1 Membrane Process
2 Membrane Fouling
3 Optimal Operation
4 Fouling Estimation
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 7 / 31
Process Description
u(t)
product (c1)
impurity (c2)
q(t, c1, c2)
permeability of membrane – rejection coefficient (R) :absolutely impermeable for product (R1 = 1)perfectly permeable to impurities (R2 = 0)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 8 / 31
Process Control
u(t)
product (c1)
impurity (c2)
q(t, c1, c2)
control variable: α(t) =u(t)
q(t, c1, c2)∈ [0,∞)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 9 / 31
Process Control
u(t)
product (c1)
impurity (c2)
q(t, c1, c2)
concentration mode: α(t) = 0 ⇒ u(t) = 0 and q(t, c1, c2) > 0
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 10 / 31
Process Control
u(t)
product (c1)
impurity (c2)
q(t, c1, c2)
pure dilution mode: α(t) = ∞ ⇒ u(t) > 0 and q(t, c1, c2) = 0
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 11 / 31
Process Control
u(t)
product (c1)
impurity (c2)
q(t, c1, c2)
constant-volume diafiltration: α(t) = 1 ⇒ u(t) = q(t, c1, c2)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 12 / 31
Traditional Control Approach
TD - traditional diafiltrationα(t) ∈ {0, 1}
α(t)
time
0
1
α = 1
α = 0
product
c0
cf
c1,0 c1,f
impurity
c2,0
c2,f
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 13 / 31
Presentation Outline
1 Membrane Process
2 Membrane Fouling
3 Optimal Operation
4 Fouling Estimation
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 14 / 31
Membrane Fouling
CAUSE : deposit of the solutes in/on the membrane pores
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 15 / 31
Standard Fouling Models
Complete blocking model (n = 2) Intermediate blocking model (n = 1)
Internal blocking model (n = 1.5) Cake filtration model (n = 0)
J. Hermia, Constant pressure blocking filtration laws-application to power-law non-Newtonian
fluids, Trans. IchemE, vol. 60, no. 183, 1982.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 16 / 31
Membrane Fouling
Feed Retentate
Permeate
Permeate flow
q(t) = AJ
Membrane fouling approaches
1) Membrane area foulingq(t) = A(t)J
2) Permeate flux foulingq(t) = AJ(t)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 17 / 31
Membrane Fouling
Feed Retentate
Permeate
Permeate flow
q(t, c1, c2,K , n) = AJ(t, c1, c2,K , n)
Fouling modeln = [0, 2)
J(t, c1, c2,K , n) = J0
(
1 + K(2− n)(AJ0)2−n
t)
1
n − 2
n = 2J(t, c1, c2,K) = J0e
−Ktaaaaaaaaaaaaaaaaaaaassa
Flux of unfouled membrane
J0(c1, c2)
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 18 / 31
Presentation Outline
1 Membrane Process
2 Membrane Fouling
3 Optimal Operation
4 Fouling Estimation
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 19 / 31
Optimization Objectives
Minimum Time Minimum Diluant Multi Objective
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 20 / 31
Optimization Objectives
Minimum Time Minimum Diluant Multi Objective
M. Jelemensky, R. Paulen, M. Fikar, and Z. Kovacs. Time-optimal Diafiltration in the Presence
of Membrane Fouling. In Preprints of the 19th IFAC World Congress, Cape Town, South Africa,
pp. 4897–4902, 2014.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 20 / 31
Optimization Objectives
Minimum Time Minimum Diluant Multi Objective
M. Jelemensky, A. Sharma, R. Paulen, and M. Fikar: Multi-Objective Optimization of Batch
Dialfiltration Processes in the Presence of Membrane Fouling. In Proceedings of the 20th
International Conference on Process Control, Slovak Chemical Library, Strbske Pleso, Slovakia,
pp. 84–89, 2015.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 20 / 31
Optimization Objectives
Minimum Time Minimum Diluant Multi Objective
M. Jelemensky, A. Sharma, R. Paulen, and M. Fikar : Time-optimal Operation of Diafiltration
Processes in the Presence of Fouling. In 12th International Symposium on Process Systems
Engineering And 25th European Symposium on Computer Aided Process Engineering, Elsevier
B.V, Copenhagen, Denmark, pp. 1577–1582, 2015.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 20 / 31
Optimization Problem
minα(t)
∫ tf
0
1 dt
s.t. c1 = c21AJ(t, c1, c2,K , n)
c1,0V0(1− α)
c2 = −c1c2AJ(t, c1, c2,K , n)
c1,0V0α
ci(t0) = ci ,0 i = 1, 2
ci(tf) = ci ,f i = 1, 2
α ∈ [0,∞)
Solution :
1) Numerical: various methods of dynamic optimization (CVP, OC)2) Analytical: Pontryagin’s minimum principle
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 21 / 31
Analytical Solution of Optimal Operation
α =
0
α(t, c1, c2,K , n)
∞
c1
c2
S(t, c1, c2,K , n) = 0
Traditional control modes
concentration mode
α = 0
pure dilution mode
α = ∞
Advanced control mode
singular surface
S = S(t, c1, c2,K , n)
singular control
α = α(t, c1, c2,K , n)
M. Jelemensky, A. Sharma, R. Paulen, and M. Fikar : Time-optimal control of diafiltrationprocesses in the presence of membrane fouling. Computers & Chemical Engineering, vol. 91,
pp. 343–351, 2016.Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 22 / 31
Case Study
Separation goal
product + impurities
⇒separation
product
Permeate flux model
J0(c1) = k ln
(
clim
c1
)
Fouling – intermediate fouling model (n = 1)
1
J(t, c1)=
1
J0(c1)+ Kit
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 23 / 31
Results
0 5 10 15 20 25 30 35 40 45
0
1
2
3
4
5
6
C-CVDKi = 0Ki = 0.01Ki = 0.03
product [g/dL]
impurities
[g/dL]
0 5 10 15 20 25 ... 80 85
0
0.2
0.4
0.6
0.8
1
C-CVDKi = 0Ki = 0.01Ki = 0.03
α
time [h]
Ki[h−1] ∆[%]
0 120.01 520.03 260
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 24 / 31
Presentation Outline
1 Membrane Process
2 Membrane Fouling
3 Optimal Operation
4 Fouling Estimation
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 25 / 31
Estimation of Fouling Parameters
complete fouling intermediate fouling
internal fouling cake fouling
M. Jelemensky, M. Klauco, R. Paulen, J. Lauwers, F. Logist, J. Van Impe, M. Fikar :
Time-Optimal Control and Parameter Estimation of Diafiltration Processes in the Presence of
Membrane Fouling. In 11th IFAC Symposium on Dynamics and Control of Process Systems,
including Biosystems, vol. 11, pp.242 – 247, 2016.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 26 / 31
Case Study
Separation goal
c1, 0 = 10mol/m3 c2, 0 = 100mol/m3
c1, f = 100mol/m3 c2, f = 1mol/m3
Model of permeate flux
J0(c1) = k lnclim
c1k , clim = known
On-line estimation of fouling parameters (K , n)
J(t, c1,K , n) = J0(
1 + K(2 − n)(AJ0)2−nt
)
1
n − 2
Measured outputs
y =
(
c1, c2, J,dJ
dt
)T
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 27 / 31
Results – Fouling Parameters Estimation
0 2 4 6 8 10 12
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
estimated (n = 0)estimated (n = 1)estimated (n = 1.5)true value
time [h]
K
0 2 4 6 8 10 12
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
estimated (n = 0)estimated (n = 1)estimated (n = 1.5)true value
time [h]
n
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 28 / 31
Results – Internal Fouling Model (n = 1.5)
0 50 100 150 200 250
0
20
40
60
80
100
ideal caseestimated caseinitial case
c1 [mol/m3]
c2[m
ol/m
3]
0 5 10 15 20
0
0.2
0.4
0.6
0.8
1
1.2
ideal caseestimated caseinitial case
time [h]
α
case tf [h]
ideal 10.39estimated 10.41initial 15.91
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 29 / 31
Conclusions
Optimal control theory was proposed for analysis of time-optimal control ofmembrane processes in the presence of fouling.
Derivation of fully analytical optimal operation in the presence of membranefouling.
Significant savings compared to traditional operation even at lower fouling.
On-line estimation of unknown fouling parameters using Extended Kalmanfilter.
Satisfactory convergence of estimated fouling parameters with minordifferences between ideal and estimated state and control trajectories.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 30 / 31
Publications – Journals
R. Paulen – M. Jelemensky – M. Fikar – Z. Kovacs : Optimal balancing oftemporal and buffer costs for ultrafiltration/diafiltration processes underlimiting flux conditions. Journal of Membrane Science, vol. 444, pp. 87 – 95,2013.
R. Paulen – M. Jelemensky – Z. Kovacs – M. Fikar :Economically optimal batch diafiltration via analytical multi-objective optimalcontrol. Journal of Process Control, vol. 28, pp. 73 – 82, 2015.
M. Jelemensky – R. Paulen – M. Fikar – Z. Kovacs : Time-OptimalOperation of Multi-Component Batch Diafiltration. Computers & ChemicalEngineering, vol. 83, pp. 131 – 138, 2015.
M. Jelemensky – A. Sharma – R. Paulen – M. Fikar : Time-optimal controlof diafiltration processes in the presence of membrane fouling. Computers &Chemical Engineering, vol. 91, pp. 343 – 351, 2016.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 31 / 31
Publications
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 31 / 31
Publications – Journals
R. Paulen – M. Jelemensky – M. Fikar – Z. Kovacs : Optimal balancing oftemporal and buffer costs for ultrafiltration/diafiltration processes underlimiting flux conditions. Journal of Membrane Science, vol. 444, pp. 87 – 95,2013.
R. Paulen – M. Jelemensky – Z. Kovacs – M. Fikar :Economically optimal batch diafiltration via analytical multi-objective optimalcontrol. Journal of Process Control, vol. 28, pp. 73 – 82, 2015.
M. Jelemensky – R. Paulen – M. Fikar – Z. Kovacs : Time-OptimalOperation of Multi-Component Batch Diafiltration. Computers & ChemicalEngineering, vol. 83, pp. 131 – 138, 2015.
M. Jelemensky – A. Sharma – R. Paulen – M. Fikar : Time-optimal controlof diafiltration processes in the presence of membrane fouling. Computers &Chemical Engineering, vol. 91, pp. 343 – 351, 2016.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 31 / 31
Publications – Conferences
M. Jelemensky, R. Paulen, M. Fikar, and Z. Kovacs. Time-optimalDiafiltration in the Presence of Membrane Fouling. In Preprints of the 19th
IFAC World Congress, Cape Town, South Africa, pp. 4897–4902, 2014.M. Jelemensky, A. Sharma, R. Paulen, M. Fikar: Multi-ObjectiveOptimization of Batch Dialfiltration Processes in the Presence of MembraneFouling. Editor(s): M. Fikar and M. Kvasnica, InProceedings of the 20th
International Conference on Process Control, Slovak Chemical Library,Strbske Pleso, Slovakia, pp.84–89, 2015.M. Jelemensky, A. Sharma, R. Paulen, M. Fikar : Time-optimal Operationof Diafiltration Processes in the Presence of Fouling. Editor(s): Krist V.Gernaey and Jakob K. Huusom and Rafiqul Gani, In 12th International
Symposium on Process Systems Engineering And 25th European Symposium
on Computer Aided Process Engineering, Elsevier B.V, Copenhagen,Denmark, pp.15771582, 2015.M. Jelemensky, M. Klauco, R. Paulen, J. Lauwers, F. Logist, J. Van Impe,M. Fikar : Time-Optimal Control and Parameter Estimation of DiafiltrationProcesses in the Presence of Membrane Fouling. In 11th IFAC Symposium on
Dynamics and Control of Process Systems, including Biosystems, vol. 11,pp.242 – 247, 2016.
Martin Jelemensky (FCFT, STU) Optimal Control of Membrane Processes August 24, 2016 31 / 31