Textural Properties and Catalytic Applications of ZSM-5 Monolith Foam for Methanol Conversion Yun-Jo Lee Æ Ye-Won Kim Æ Ki-Won Jun Æ Nagabhatla Viswanadham Æ Jong Wook Bae Æ Hyung-Sang Park Received: 12 November 2008 / Accepted: 1 December 2008 / Published online: 9 January 2009 Ó Springer Science+Business Media, LLC 2009 Abstract ZSM-5 monolith foam (ZMF) samples with various framework Si/Al ratios have been successfully synthesized by polyurethane foam (PUF) template method and evaluated for their catalytic performance towards methanol to propylene (MTP) reaction. The samples were tested for their textural properties using SEM, XRD, BET surface area, pore volume and NH 3 -TPD techniques revealing the formation of ZMF exhibiting about 100– 300 lm range macro pores created by packed assembly of 5 lm size orthorhombic shaped ZSM-5 crystals. The ZMF samples exhibited effective activity in methanol to olefin conversion, with superior product selectivities at optimum Si/Al ratio of 250. Further, the ZMF catalyst with high macro porosity exhibited superior catalytic activity com- pared to its pelletized form, especially at higher feed flow rates, that signifies the importance of macro porous struc- ture of ZMF in facilitating the enhanced mass transport for the labile diffusion of light olefins. Reaction temperature also played a vital role in determining product selectivity. At 500 °C, the catalysts exhibited the highest light olefin (C 2 = –C 4 = ) selectivity and above this temperature, forma- tion of C 5 ? is prevailed at the cost of C 2 = –C 4 = revealing the accelerated occurrence of oligomerization reactions at these conditions. At optimized catalytic properties and reaction conditions, the catalyst exhibited as high as 75% selectivity to C 2 –C 4 olefins, with propylene as major component (*44%). Keywords Zeolite foam  Monolith  Macroporous ZSM-5  MTP  Methanol  Propylene 1 Introduction Conversion of methanol to light olefins especially propyl- ene is gaining importance due to the significant applications of propylene in the production of various petrochemicals and provides an alternative source to tra- ditional resources such as natural gas, coal and biomass, for the production of gasoline. Zeolites, by virtue of their acidity and selective cracking, have been employed for the MTO reaction [1–6]. The product is generally a mixture of C 2 –C 4 olefins. The well-known Lurgi process operates for the production of propylene from methanol, where gaso- line, LPG and fuel gas appear as byproducts that limit the maximization of propylene yields in once-through opera- tion. Hydro process of UOP/Norsk operates for the selective production of ethylene followed by propylene from methanol on a SAPO based catalyst [2, 3]. But achieving high selectivity of propylene is still challenging. The classical representation for the reaction pathways of methanol conversion consist of several consecutive reac- tion steps initialized by the dehydration of methanol to dimethyl ether (DME) followed by its further dehydration to form light olefins, which are highly reactive to form several hydrocarbon end products such as paraffins, olig- omers, aromatics and even the coke precursors responsible for the catalyst deactivation [4]. The key step in effective Y.-J. Lee (&)  Y.-W. Kim  K.-W. Jun (&)  N. Viswanadham  J. W. Bae Alternative Chemicals/Fuel Research Center, Korea Research Institute of Chemical Technology (KRICT), P.O. Box 107, Daejeon 305-343, Republic of Korea e-mail: yjlee@krict.re.kr K.-W. Jun e-mail: kwjun@krict.re.kr Y.-W. Kim  H.-S. Park Department of Chemical and Biomolecular Engineering, Sogang University, C.P.O. Box 1142, Seoul 100-611, Republic of Korea 123 Catal Lett (2009) 129:408–415 DOI 10.1007/s10562-008-9811-z