Dividing Wall Column Technology Recent Developments and Challenges

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1 ividing Wall olumn Technology Recent evelopments and hallenges Žarko Olujić elft University of Technology (retired, guest associate) elft, the Netherlands Thomas Rietfort Helmut Jansen Julius Montz GmbH Hilden, Germany Igor ejanović The Univeristy of Zagreb Faculty of hemical Engineering and Technology Zagreb, roatia EFE WP FLUI SEPRTIONS nnual Meeting, May, 2016, openhagen, enmark

2 Towards a Sustainable istillation olumn (Using less energy and material and doing less damage to the environment.) Minimization of energy requirement by thermal coupling Thermodynamic efficiency of a sequence of two or more (n) conventional distillation columns as required for obtaining (n-1) pure products can be maximized by utilizing full thermal coupling. Where appropriate, full thermal coupling can be implemented in single shell. Such a configuration is generally known as ividing Wall olumn (W). Liquid and vapor split additional degrees of freedom, i.e. design variables onventional two-column sequence Thermally coupled column ividing Wall olumn (W) Each with a number of alternatives

3 W pplications Range Equipment size: olumn diameters: 0.5 m 6.5 m, olumn heights: up to 100 m Laboratory/pilot scale diameters: m Operating pressure: to 10 bar Nature of application: ll kind of distillation applications/chemicals. Purity requirements: From typical solvent recovery to ultra purity (in ppb range) specifications Extractive distillation, Reactive distillation,... Low energy requirement enefits: (Vapor throughput minimized, and repeated evaporation and/or condensation eliminated) Reduced OPEX/PEX (~ 30 %) & footprint (plot area) Shorter residence time Higher yields, Less maintenance,.. In revamps, energy saving enables capacity increase! 25

4 ividing Wall olumn Number of industrial applications/milestones olumns in operation: > 250 (> 1/3 at SF SE), ~ 90% are packed Ws TU conducted large scale air (tracer)/water (dye) tests prior first industrial application at SF Other manufacturers/licensors: (a guess) Sulzer: 45 Koch-Glitsch: 30 UOP: 10 KR: 5 UHE: 5 ir Products: 5 Linde: 5 Sumitomo (Japan): 5 S. Korean: 5 Indian:? hinese: 10 Milestones: 1 st packed W in operation (SF), st packed W with non-welded partition wall (SF), st revamp into a W (UHE), st tray W (SSOL), st four-product W (SF), st multipurpose W (Lonza), 2010 ourtesy of MONTZ

5 W Technology New milestone First multipurpose W at Lonza in Visp, Switzerland Three periodic operations carried out in a W: (i) (ii) batch distillation column side product column (iii) onventional twocolumn sequence Source: Staak,., Grutzner, T., Schwegler,., Roederer,., hem. Eng. Process.: Process Intensification 75 (2014)

6 Novel Field of W pplication ryogenic ir istillation Source, with permission of ir Products: M. Kalbasi, ir Products, 2015 International Forum on Mass Transfer and Se[paration Engineering, November 16-18, Tianjin, hina

7 ividing Wall olumn onstraints and concerns One operating pressure Higher T from top to bottom,, Higher pressure drop Temperature penalty Taller column T across the partition wall,, Vapor split ratio control Lack of detailed design know-how Existing patents restrictions

8 ividing Wall olumn onstraints, an example NGL fractionation in (F)LNG plants 1()/2()/3&4()/5+() separation sequence Most promising W involving arrangement (11 options evaluated) 34 bar 17 bar 7 bar. s well known, benefits of thermal coupling fade away with increasing boiling point range of the feed. In given cryogenic application example, the total energy requirement was significantly reduced (17%), but at the expense of an increased amount of much costlier refrigeration ( temperature penalty, i.e. an increased OPEX). Important consideration: energy quality - quantity. Source: I. Halvorsen, I. ejanović, K.. Marak, Ž. Olujić, S.Skogestad, hem. Eng. Technol. 39 (2016) in print.

9 ividing Wall olumn Ongoing challenges esign, construction, and operation of a fully thermally coupled 4-product Ws enefits increase largely, but at the cost of increased complexities in design, construction, and operation. To exploit full potential of a 4-p W, a complex, multi partition internal arrangement required (single partition designs in operation). etails matter, and during preliminary evaluations feasibility studies, dimensioning needs to be carried out with sufficient rigor to allow proper evaluation and choices among feasible alternative options. The know-how available in public domain is sufficient in this respect, for packed Ws.

10 Starting Point: 4-p Kaibel W ( 2-4 configuration) Proven in practice Proposed by G. Kaibel 1987,,, Single partition wall Theoretical savings: larger than experienced with 3-p Ws (> 30% ) Not a full Petlyuk arrangement, i.e. less efficient, but practical First application: 2002 at SF

11 Full Scale 4-p W ( configuration) 4-p Petlyuk arrangement accommodated within one shell , N R,, N N3.2 R L1 N 3.1,,, N1.1 N2.2, N3.3 R L2 R L3 N 2.1 N3.2 N 1.1 N 2.2 N 3.3 S ,,, N1.2 N N3.4 R V1 R V2 N 1.2 N 2.3 N 3.4 N 2.4 N 3.5 S 2,, N2.4 N3.5 R V3 N 3.6, 3.3 N3.6 V/ W with three partition walls, i.e, three vapor and three liquid splits (Not attempted yet in practice!)

12 4-p W esign Method evelopment The collaborating institutions/people (2009 on) I. Halvorsen, SINTEF (Norway) S. Skogestad, NTNU (Norway) I. ejanović, Univ. of Zagreb (roatia) Identification and evaluation of feasible configurations (V-min diagram method) Process control considerations* etailed simulation and estimation of stage and reflux requirements Ž. Olujić, TU elft (Netherlands) H. Jansen, J. Montz (Germany). Kaibel (Presently with SF SE) T. Rietfort hoice of equipment and dimensioning of packed Ws *SINTEF and NTNU process dynamics and control studies concerning four-product Ws: wivedi, Strandberg, Halvorsen, Skogestad, Steady state and dynamic operation of four-product dividing-wall (Kaibel) columns: Experimental verification, Ind. Eng. hem. Res. 51 (2012) wivedi, Strandberg, Halvorsen, Preisig, Skogestad, ctive vapor split control for dividing-wall columns, Ind. Eng. hem. Res. 51 (2012) wivedi, Halvorsen, Skogestad, ontrol structure selection for four-product Petlyuk column, hem. Eng. Process. 67 (2013)

13 ESIGN SE: 15 component feed 4 products ased on actual aromatics plant data Identification and evaluation of feasible configurations (V-min diagram method) ( stand-alone Matlab program or implemented in a commercial software package) ase case configuration 2 (5-6) 7.4 t/h etailed estimation of stage and reflux requirements (Utilizing tools available in commercial simulation packages, initial guesses output of Vmin diagram method) Feed 31.7 t/h 1 3 S1 (R) 3.9 t/h S2 (toluene) 8.0 t/h 4-p packed W dimensioning (n Excel soubroutine) Total annualized cost estimation (n Excel soubroutine) (heavies) 12.4 t/h Product specs: 5-6 fraction < 1.3 mass % benzene R > 67 mass % benzene Toluene purity > 97 mass %

14 Four-product W lternative configurations for aromatics separation base case F F F F Single partition 1 x (V/V) & (L/L) 3 x (V/V) & (L/L) 2 x (V/V) & 3 x (L/L) M u l t i p l e p a r t i t i o n s (thermodinamically equivalent) 2 x (V/V) & (L/L) 3 x (V/V) & 2 x (L/L) etails on preliminary rigorous simulation, dimensioning and cost estimation of these configurations can be found in: ejanović, Matijašević, Halvorsen, Skogestad, Jansen, Kaibel, Olujić, hem.eng.res.es., 89 (2011) Olujić, ejanović, Kaibel, Jansen, hem. Eng. Technol., 35 (2012) Halvorsen, ejanović, Skogestad, Olujić, hem. Eng. Res. es., 91 (2013),

15 V min diagram method ifferences in peak heights give operational/design flexibility V/F V/F V/F V/F /F /F /F /F, 2.1,,, 1 2.x, 2.2 V con >> V > Vmin V = Vmin onfiguration W W W W V/F (-) Saving (%) Halvorsen, Skogestad: Ind. Eng. hem. Res. 42 (2003) ; Halvorsen, Skogestad, J. Nat. Gas. Sci. Eng. 3 (2011) Halvorsen, ejanović, Skogestad, Olujić, hem. Eng. Res. es. 91 (2013) ejanović, Halvorsen, Skogstad, Jansen, Olujić, hem. Eng. Process. 84 (2014) 71 81

16 4-p ( ) W Pressure drop balancing in partitioned part P 5 P 6 F 2.1b 3.1a For p5=p6: p I + p H = p Y 2.1b 3.1a P 4 X p H + p G = p G b p G + p F = p X H P 3 Y b Fine-tuning by adjusting free area of collectors Range: 5 30% b P 2 I P If insufficient: additional flow resistance needs to be introduced, where appropriate to generate missing Δp!

17 Hydraulic esign in EXEL Solver Interactively, by adjusting free area of liquid collectors p1 2,5 2,5 p2 J h 1,500 0, a Y I h 0,550 0,950 0, b H Pressure drop estimation: Packed column internals Rix, Olujić, hem. Eng. Process. 47 (2008) Structured packings: elft Model (all working equations can be found in:) ejanović et al., Ind. Eng. hem. Res. 50 (2011) Relevant numbers for four alternative arrangements: p ς ς ct ld int = nccς ϕ cc cc nctς ct + ϕ = 1.2 [ ( 1 ϕ)] ct ( ) ς = 1.5 5ϕ cc nld ς + ϕ [ 1.5 ϕ( 2. ϕ) ] = Olujić, ejanović, Kaibel, Jansen, hem. Eng. Technol. 50 (2012) ejanović, Halvorsen, Skogestad, Jansen, Olujić, hem. Eng. Process. 84 (2014) ld ld F 2 2 G h 0,700 0,600 0, a X G h 1,300 0, a F 2, ab ollectors (n example from preliminary calculations) Position 2.1a 2.1b 3.1a b a 3.4b M L kg/h ρ L kg/m V L kg/h 42,3 36,6 7,0 2,5 35,2 63,6 23,6 81,0 81,4 89,7 u Le m 3 /m 2 h 16,7 14,5 11,3 3,5 14,4 29,4 24,1 25,8 25,9 28,6 Type - T T T T T T T ϕ cc/ctc/distr - 0,30 0,30 0,06 0,30 0,17 0,07 0,30 0,25 0,25 0,25 F G Pa 0.5 1,40 1,27 1,50 1,38 1,27 1,39 1,56 1,53 1,55 1,73 dp mbar 0,28 0,29 12,09 0,28 1,08 8,83 0,45 0,65 0,66 0,83 Total M dp 15,76 mbar Pressure drop paths dp ϕ cc/ctc/distr i 0,76 oundary values ii 0,00 Lower 0,05 iii 0,00 Upper 0,30 Similar computational Excel tables for all packed beds and liquid distributors.

18 W Technology Summary Limitations, concerns, issues, etc. 1 Increasing, when a 4-p W is considered! 2.1a 2 One operating pressure Larger Δp and ΔT over the column, -> expensive cooling and/or heating!? 3 2.1b Larger column height, -> large h/d ratio!? Fraction of wall zone area much larger -> a serious concern for packed columns! Non-circular cross section areas in partitioned sections -> internal liquid (mal)distribution patterns may be different! Large ΔT across the partition wall -> thermal insulation (packed columns-high purities!) Very high purities (ppm & ppb): -> leak-free non-welded wall!? Revamp (retrofit) -> time available for this may become a limiting factor! ontrol of vapor split by design -> control devices!

19 ividing Wall olumn Vapor split control concerns and challenges vapor split is arranged by design, and can to a lesser extent be controled by manipulation of liquid split (limited range!) ctive control of vapor split needed to enable full operational flexibility of a W. vailability of such devices would stimulate design and building multipartition Ws for four and more products (OPEX and PEX savings in range of 50% and more!). Two designs of a vapor-splitter described in hinese patents. Prototypes tested extensively in air/water and cold mass transfer tests. Not yet fully develped to be implemented in industrial practice.

20 4-p W: as retrofit option ircumventing multiple vapor split problem! T cond = 44 p top = 1.7 bar F a p bott = 2.5 bar 3.6b 3.4 Jansen, ejanović, Kaibel, Olujić hem. Engineering (ugust 2014) T reb =

21 oncluding Remarks W is a genuinely sustainable distillation column (minimum energy, capital and plot-area)! Four-product Ws -> higher gains (± 50 %)! Single-partition W proven; multi-partition maximizes energy efficiency/savings New designs or retrofit (single shell revamps not an option, two shells in series yes!) Two-partition, two vapor splits ( ) W, a feasible configuration to start with, either as new design, or a retrofit! rranging and control of multiple vapor splits, a serious concern/challenge! Status of W technology in general. Manufacturers know how to make it, and some daring on industrial side is required! H. Schoenmakers (former SF) : The choice of a dividing wall column for a separation task is a question of readiness for decision making, it is not really a risk, neither for construction nor for operation GO FOR IT, where appropriate!!!

22 THNK YOU for your interest and kind attention! ourtesy of J. Montz