Resource Conservation and Waste Minimization for Property Networks

Transcription

1 Resource Conservation and Waste Minimization or Property Networks Vasiliki Kazantzi, Abdulaziz M. Almutlaq and Mahmoud M. El-Halwagi Department o Chemical Engineering Dominic C.Y. Foo and Zainuddin A. Manan Chemical Engineering Pilot Plant (CEPP)

2 Outline Introduction: why property-based design? deinition conditions Approach

3 To develop an algebraic procedure to minimize esh usage and waste discharge through recycle/reuse in a process with property-based constraints. Fresh Process with Property Constraints Waste

4 Traditional recycle/reuse strategies in mass integration have been chemo-centric,i.e. component dependent Many constraints on recycle are governed by properties and not only chemicals Process perormance & product quality tied to properties Environmental perormance is linked to properties (e.g., ph, COD, BOD, color, toxicity, etc.)

5 Need a new design paradigm: based on properties and unctionalities Property Integration Property-based holistic approach to the allocation and manipulation o streams and processing units, which is based on tracking, adusting and matching unctionalities throughout the process

6 Previews Work on Property Integration - Shelley and El-Halwagi (2000) Componentless design and clustering concept - Glasgow et al. (2002), Eden et al. (2003) and El-Halwagi et al. (2004) Cluster-based lever-arm optimization rules - Qin et al. (2004) Algebraic techniques or property integration - Gani and Pistikopoulos (2002) and Eden et al. (2004) Simultaneous process and product design - Kazantzi et al. (2004) Incorporation o process modiications

7 o this Work For property-based direct recycle, can we identiy rigorous targets or: - Minimum esh usage? - Maximum recycle o process resources? - Minimum discharge o waste? s: Derivation o optimality criteria Non-iterative visualization and algebraic approaches A priori targets ahead o detailed design!

8 Statement Given is a process with: - a number o process sources (streams), N s Each source has a given lowrate, F i and a given property p i - a number o process units, N u, which accept streams with a given lowrate, G, and an inlet property p in,that satisies the ollowing constraint: p min < pin in < pmax max Given is also: - a esh resource with known property value, p

9 Representation Sources i i in s.... Fresh F, p F i, p i F Ns, p Ns p Mixtures G p min <pin <pmax G Nu p min Nu <pin Nu <pmax Nu. Sinks N u Waste

10 Property Mixing Rule Ns ψ in x ψ + x ψ i, i, i is the property-mixing operator or mixture entering sink ψ in For a stream i and esh entering sink : i, x i, G G and, x, N s ψ in ψ + i, i, i ψ G where G i, +, i

11 Optimization Formulation min N u subect to :, F i N u i, + i, waste or i, 2,...,N s G, + N s i i, or, 2,..., N u G ψ in N s i i, ψ i +, ψ or, 2,..., N u p min i, 0 p in or i p max or, 2,...,N ψ s min ψ in ψ, 2,..., N max u or, 2,..., N u, 0 or, 2,..., N u

12 Derivation o Conditions Parametric optimization through dynamic programming (Bellman s s Principle),,,Nu R 0 Sink R R - Sink R R N u- Sink N u R N u R R i, [ R, R, KR, K, R ] F, i 2, i, i, N or i, s, 2,..., N s

13 Conditions Example: Fresh has property operator less than process streams ψ ψ Sink Conditions When a esh source is mixed with a process source, the inlet property operator to the sink should be in assigned to its maximum easible value, i.e. ψ ψ Source Prioritization Conditions ψ ψ 2 N max u N u opt. max, N, N R, N F, 0 u u u N u Maximize use o process sources ranked in ascending order o their property operators Use source and sink optimality conditions in graphical representation

14 Graphical Targeting Sink Composite Diagram Load M 3 Sink, max Sink Composite Curve Rank in ascending order o operator ψ M Sink ψ ψ in max,max max G ψ M 2 Sink, max M Sink, max G G 2 G 3 Flowrate

15 Graphical Targeting Load Source Composite Diagram M 3 Source M Source i Fψ i i Rank in ascending order o operator M 2 Source Source Composite Curve M Source F F 2 F 3 Flowrate

16 Property-based Material Recycle Pinch Diagram Load Material Recycle/Reuse Property Pinch Point Sink Composite Source Composite Min. Fresh Fresh Flowrate Min. Waste

17 Implementing Process Modiication Load Fχ Sink Composite Source Composite Property Interception Network Fresh Min. Fresh Fχ Flowrate Min. Waste Discharge

18 Extension to Other Cases Fresh has property operator greater than process streams Load ψ ψ i Material Recycle/Reuse Property Pinch Point Sources plotted in descending order o property-operator Source Composite Fresh Sink Composite Sinks plotted in descending order o minimum property-operator Min. Fresh Usage Flowrate Min. Waste Discharged

19 Load Transormation to Algebraic δ Source Composite Curve δ 2 δ 3 Fresh locus Sink Composite Curve Maximum ineasibility Maximum negative residual Minimum esh target Flowrate F F 2 F 3 G G 2 G 3

20 Property-Load Interval Diagram Interval 2 Load M M 2 Interval Load ( M k ) M M 2 Sources Source Source 2 Source Flow per Interval ( F k ) M ψ ψ s, M 2 ψ ψ s, M 3 ψ ψ s,2 Sink ψ u, max Sinks Sink 2 ψ u,2 max Sink Flow Per Interval ( G k ) M ψ ψ max u, M 2 ψ ψ max u,2 M 3 ψ ψ max u,2 M k- k M k M k Source 3 M k ψ ψ s in interval k Sink 3 M k max ψ ψ u in interval k M n- Source N s n M n M n M n ψ ψ s in interval n Sink N u M n max ψ ψ u in interval n

21 Cascade Diagram δ 0 0 F G F 2 Interval δ Interval 2 δ 2 G 2 δ 0 δ max F G F 2 Interval δ Interval 2 δ 2 Min. Fresh G 2 F k δ k Interval k Gk F k δ k Interval k Gk δ k δ k F n δ n Interval n δ n Gn F n δ n Interval n δ n Gn Min. Waste

22 Absorber Thermal Processing, Solvent Regeneration & makeup T 55 K Case Study Property Mixing Rule To Flare Ogas Absorber Bottoms (to boiler uel) Condensate I (to waste disposal) 4.0 kg/s Metal Regenerated Solvent 2.0 kg/s Organic Additives RVP To Flare Degreaser Fresh Solvent 5.0 kg/s.44 N s i Condensate II (to waste disposal) 3.0 kg/s Metal Finishing x i RVP i Degreased Metal.44 Source Property Values RVP cond. II 2. 5atm RVP cond. I 6. 0atm RVP esh 2. 0atm Sink Constraints 2.0 RVP degreaser ( atm) ( atm) 4. 0 RVP absorber

23 Case Study Reduction o Solvent Consumption by 66% Fχ

24 Case Study Reduction o Solvent Consumption by 00%

25 Absorber Thermal Processing, Solvent Regeneration & makeup T 437 K Case Study To Flare Ogas 2.0 kg/s Absorber Bottoms (to boiler uel) Condensate I 4.0 kg/s Metal Regenerated Solvent Final coniguration ater process modiication Organic Additives To Flare Degreaser 5.0 kg/s Condensate II 3.0 kg/s Metal Finishing Degreased Metal

26 New property-based pinch analysis and visualization technique or maximum integration o process sources and units conditions derived using dynamic programming principles Graphical-based insights or property interception strategies and enhanced reuse Novel, non-iterative and systematic algebraic procedure or identiying rigorous targets in a process with property constraints

27 Future Work Investigate New Approach or Multiple Properties Optimize Process Perormance and Properties Integrate Process and Material Synthesis Combining Process Integration and Optimization Principles with Material Design Strategies