[O5A.1] Ethanol pervaporation through high-silica MFI zeolite membrane T. Leppäjärvi*, I. Malinen, J. Tanskanen University of Oulu, Finland

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1 Introducton [OA.] Ethanol ervaoraton through hgh-slca MFI zeolte membrane. Leäjärv I. Malnen. anskanen Unversty o Oulu Fnland he exact transort and searaton mechansms n ervaoraton are not ully understood (Bettens et al. ). he sorton-duson s the most acceted to descrbe ervaoraton through norganc membranes. he ocus o most ervaoraton s s on adsorton and duson through the membrane even though the suort can contrbute to the overall mass transer resstance notceably. he urose n ths study s to comare derent mass transer s n ervaoraton o ure ethanol through a thn (. µm) suorted hghslca MFI zeolte membrane. Methods Steady-state ervaoraton lux was measured at temerature range o 6 ⁰C. Drvng orce chemcal otental gradent over the membrane s tycally descrbed wth ugactes. In a sem-emrcal the lux can be exressed as Q( E )ex R ( ) () Q ( ) s ermeance at erence temerature ermeance and and are eed and ermeate ugactes. E s actvaton energy o Maxwell-Stean ormulatons that take nto account ntracrystallne duson and adsorton have been used n descrbng searaton usng mcroorous membranes (Katejn et al. ; de Brujn et al. 7). Adsorton o ethanol on hgh slca MFI zeolte rom Nayak and Moat (989) can be ed wth Langmur sotherm and the temerature deendency o adsorton can be descrbed by urated vaor ressure (Leäjärv et al. ): q q b + b θ () θ s coverage q and dmensonless adsorton arameter. q are adsorton and uraton loadngs and b s

2 In one-comonent ervaoraton system lux (mol m - s - ) s gven by ρq Ð l z + b ln + b () ρ s zeolte densty and l s membrane thckness. deend only on temerature as (era-tus et al. 6) Ð s MS dusvty assumed to z Ðz Ð( E )ex R d () d E s actvaton energy o duson. Models o two derent levels based on Eqs. () (Models ) and () (Models ) are aled. In Models and the ermeate ugacty s rom exerments and n Models and the ermeate-sde ugacty s determned rom correctng the ugacty derence over the suort. he ugacty at the zeolte-suort nterace s determned by ng the transort n suort wth Knudsen duson and vscous low (de Brujn et al. ). Results he arameters determned by MALAB or Models and the average ercentage devaton n n j ex red ex () red are resented n able. Correlaton o redcted luxes ( ) and exermental luxes ( ) are resented n Fg. ex

3 able. Model arameters. a) [kg m - h - ] exerments b) [kg m - h - ] exerments 6 6 7

4 c) [kg m - h - ] exerments d) [kg m - h - ] exerments Fg. Correlaton between a) b) c) d) and exerments. Lnes are gudance or the eye. Dscusson Evaluaton o the results ndcates that all the s ntroduced can descrbe the ervaoraton o ethanol relatvely well and the derences between the s are mnor. Smlcty avors esecally the use o Model. In Models and based on Eq. () the adsorton and duson arameters are more undamental than n Models and. Consderng that the adsorton data and zeolte densty or Models and are taken rom the lterature the t o those s s very good. Detaled ng oers a good nsght nto the mass transer mechansms. ure comonent ng creates a bass or ng also transort o mult-comonent mxtures. Reerences Bettens B. Dekeyzer S. Van der Bruggen B. Degrève. Vandecasteele C.. ransort o ure comonents n ervaoraton through a mcroorous slca membrane. ournal o hyscal Chemstry B 9 6-.

5 de Brujn F. Gross. Olujć Ž ansens. Katejn F. 7. On the drvng orce o methanol ervaoraton through a mcroorous methylated slca membrane. Industral & Engneerng Chemstry Research de Brujn F.. Sun L. Olujć Ž. ansens.. Katejn F.. Inluence o the suort layer on the lux lmtaton n ervaoraton. ournal o Membrane Scence -6. Katejn F. Mouljn.A. Krshna R.. he generalzed Maxwell-Stean or duson n zeoltes: sorbate molecules wth derent uraton loadngs. Chemcal Engneerng Scence 9-9. Leäjärv. Malnen I. Kangas. anskanen.. Utlzaton o temeraturedeendency n lng adsorton on zeoltes. Chemcal Engneerng Scence Nayak V.S. Moat.B Sorton and duson o alcohols n heterooly oxometalates and ZSM- zeolte. ournal o hyscal Chemstry era-tus M. Llorens. ejero. Cunll F. 6. Descrton o the ervaoraton dehydraton erormance o A-tye zeolte membranes: A ng aroach based on the Maxwell-Stean theory. Catalyss oday Keywords: ervaoraton Modellng Zeolte membrane