Sains Malaysiana 42(4)(2013):
515–520
Separation
of Hydridocarbonyltris(triphenylphosphine) Rhodium (I) Catalyst
Using Solvent Resistant Nanofiltration Membrane
(Pemisahan Pemangkin Rodium (I) Hidridokarboniltris(trifenilfosfin) Menggunakan Membran Nanoturasan Tahan Pelarut)
Nur S. A. Razak & Hilmi Mukhtar
Chemical
Engineering Department, Universiti Teknologi PETRONAS
Bandar
Seri Iskandar, 31750 Tronoh,
Malaysia
Maizatul S. Shaharun*
& Mohd F. Taha
Fundamental
and Applied Sciences Department, Universiti Teknologi PETRONAS
Bandar
Seri Iskandar, 31750 Tronoh,
Malaysia
Diserahkan: 24 Jun 2011 / Diterima:
8 Mac 2012
ABSTRACT
An investigation was conducted into the nanofiltration of rhodium tris(triphenyl-phosphine) [HRh(CO)(PPh3)3]
catalyst used in the hydroformylation of olefins. The
large size of the catalyst (>400 Da) – relative to other components of
the reaction provides the opportunity for a membrane separation based on
retention of the catalyst species while permeating the solvent. The compatibility
of the solvent-polyimide membrane (STARMEMTM 122
and STARMEMTM 240) combinations was
assessed in terms of the membrane stability in solvent plus non-zero solvent
flux at 2.0 MPa. The morphology of the membrane was
studied by field emission scanning electron microscopy (FESEM).
The solvent flux and membrane rejection of HRh(CO)(PPh3)3 was
then determined for the catalyst-solvent-membrane combination in a dead-end
pressure cell. Good HRh(CO)(PPh3)3 rejection
(>0.93) coupled with good solvent fluxes (>72 L/m2 h1 at 2.0 MPa)
were obtained in one of the systems tested. The effect of pressure and catalyst
concentration on the solvent flux and catalyst rejection was conducted.
Increasing pressure substantially improved both solvent flux and catalyst
rejection, while increasing catalyst concentration was found to be beneficial
in terms of substantial increases in catalyst rejection without significantly
affecting the solvent flux.
Keywords: Catalyst recycle; hydroformylation;
membrane separation; solvent resistant nanofiltration
ABSTRAK
Penyelidikan telah dijalankan ke atas teknik nanoturasan kepada pemangkin rodium tris(trifenilfosfin) [HRh(CO)(PPh3)3]
yang digunakan dalam proses penghidroformilan olefin. Saiz pemangkin yang besar (>400 Da) – berbanding dengan komponen lain dalam tindak balas memberi ruang kepada penggunaan membran yang berasaskan kepada penggunaan spesies pemangkin di samping peresapan pelarut. Keserasian pelarut-membran poliimida (STARMEMTM122 dan STARMEMTM240) telah dinilai daripada segi kestabilan membran di dalam pelarut, berserta nilai fluks pelarut bukan sifar pada 2.0 MPa. Peresapan fluks dan pengekalan pemangkin HRh(CO)(PPh3)3 menggunakan membran polyimide, telah dikaji untuk melihat kombinasi pemangkin-pelarut-membran di dalam sel tekanan tinggi. Pengekalan pemangkin [HRh(CO)(PPh3)3]
yang baik (>0.93) di samping peresapan fluks pelarut yang baik (>72 L/m2 h1) diperoleh daripada salah satu sistem yang dikaji. Kesan daripada tekanan dan kepekatan pemangkin terhadap fluks pelarut dan pengekalan pemangkin telah dijalankan. Peningkatan tekanan yang ketara dapat menambah baik peresapan fluks pelarut dan juga pemangkin. Manakala peningkatan kepekatan pemangkin dapat meningkatkan pengekalan pemangkin tanpa mempengaruhi peresapan fluks pelarut.
Kata kunci: Hidroformilasi; kitar semula pemangkin; nanoturasan tahan pelarut; pemisahan menggunakan membran
RUJUKAN
Behr, A., Henze, G., Obst, D. & Turkowski, B. 2005. Selection process of new solvents in
temperature-dependent multi-component solvent systems and its application in isomerising hydroformylation. Green Chem. 7: 645-649.
Cornils, B. & Herrmann, W.A. 2002. Applied Homogeneous Catalysis
with Organometallic Compounds. 2nd edition. New York, USA:
Wiley-VCH.
Garton, R.D., Ritchie, J.T. & Caers, R.E. 2003. Hydroformylation process improvement in catalyst recovery. PCT International Applications, WO 2003/082789 A2: 20.
Luthra, S.S., Yang, X., Freitas dos Santos, L.M., White, L.S. & Livingston, A.G. 2002. Homogeneous
phase transfer catalyst recovery and re-use using solvent resistant membranes. J. Membr. Sci. 201: 65-75.
Machado,
D.R., Hasson, D. & Semiat,
R. 1999. Effect of solvent properties on permeate flow
through nanofiltration membranes. Part I.
Investigation of parameters affecting solvent flux. J. Membr. Sci. 163: 93-102.
Scarpello, J.T., Nair, D., Freitas dos santos, L.M., White,
L.S. & Livingston, A.G. 2002. The separation of
homogeneous organometallic catalysts using solvent resistant nanofiltration. J. Membr. Sci. 203: 71-85.
Shaharun, M.S., Dutta,
B.K., Mukhtar, H. & Maitra,
S. 2009. Hydroformylation of 1-octene using rhodium–phosphite catalyst in a thermomorphic solvent system. Chem.
Eng. Sci. 65: 273-281.
Yang, X.J., Livingston, A.G. & Freitas dos Santos, L. 2001. Experimental
observations of nanofiltration with organic solvents. J. Membr. Sci. 190: 45-55.
Whu, J.A., Baltzis,
B.C. & Sirkir, K.K. 2000. Nanofiltration studies of larger
organic microsolutes in methanol solutions. J. Membr. Sci. 170: 159-172.
*Pengarang untuk surat-menyurat; e-mail: maizats@petronas.com.my
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