Obtaining hydrocarbons from ethanol over iron-modified ZSM-5 zeolites Na ´dia Regina Camargo Fernandes Machado a, * , Valmir Calsavara a , Nelson Guilherme Castelli Astrath b , Ce ´lia Kimie Matsuda b , Andrea Paesano Junior b , Mauro Luciano Baesso b a Departamento de Engenharia Quı ´mica, Universidade Estadual de Maringa ´, Av. Colombo, 5790, CEP 87020-900 Maringa ´, Parana ´, Brazil b Departamento de Fı ´sica, Universidade Estadual de Maringa ´, Av. Colombo, 5790, CEP 87020-900 Maringa ´, Parana ´, Brazil Received 26 November 2004; received in revised form 28 March 2005; accepted 8 May 2005 Available online 9 June 2005 Abstract The search for new energy sources has impulsed hydrocarbon production from methanol and ethanol over ZSM-5 zeolites. Iron incorporation by different methods has led to a variety of chemical applications. Thus, hydrocarbon production from ethanol was studied over a ZSM-5 zeolite modified by ion exchange and impregnation with iron. XRD, FTIR, TPR, nitrogen adsorption, Mo ¨ssbauer and photoacoustic spectroscopies were used for the samples characterization. The highest yield of liquid hydrocarbons was obtained with the low iron-exchanged zeolite, especially co-feeding hydrogen. The calcination procedure led to a migration of the iron species, probably forming iron oxide particles. q 2005 Elsevier Ltd. All rights reserved. Keywords: Fe/ZSM-5; Ethanol; Hydrocarbons 1. Introduction ZSM-5 zeolite was developed by the time of the 1970s oil crisis, aiming the production of synthetic gasoline from methanol. Because of the great demand for hydrocarbons, ethanol transformation over this zeolite was found to be promising [1,2]. Ethanol is particularly attractive in Brazil since it can be obtained from renewable biomass (sugarcane). Modification of ZSM-5 zeolite with iron by different ways has led to several applications, such as benzene oxidation to phenol [3], N 2 O reduction [4], ethane aromatization [5] and the transformation of methanol [6] and ethanol [7] into hydrocarbons. Besides, iron catalysts have been historically used for hydrocarbons production from syngas by the Fischer–Tropsch process [8]. According to Kucherov and Shelef [9], iron-containing zeolites may show at least four different kinds of Fe 3C cations: isolated cations, small clusters, Fe 2 O 3 microcrystals and Fe 3 O 4 microcrystals. The proportion of isolated cations depends on the calcination procedure applied to the samples. In this way, the combination of the shape selectivity and acidity properties of the pentasil zeolites with the activity of the different iron species may influence the product distribution and catalyst stability in the ethanol conversion, as verified for the methanol [6] and syngas [10] conversion into hydrocarbons. In this work hydrocarbons production from ethanol was studied over iron-modified ZSM-5 zeolites, before and after calcination. 2. Experimental The starting material was a ZSM-5 zeolite supplied by CENPES/PETROBRAS, with 0.26% Na 2 O and a SiO 2 / Al 2 O 3 molar ratio of 41.2. In order to lower the Na 2 O content to less than 0.02% this zeolite underwent two consecutive exchanges with ammonium chloride solution (1 N) in pH 4.5 and 10% solids content, under stirring at 348 K for 2 h. After filtration, rinsing and drying at 373 K, the material was calcined at 773 K for 6 h, with a heating rate of 2 K/min and isothermal steps of 1h at 393 and 473 K, in oxidative atmosphere, generating zeolite ZP1TC. This zeolite was then submitted to the maximum Fuel 84 (2005) 2064–2070 www.fuelfirst.com 0016-2361/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2005.05.001 * Corresponding author. Tel.: C55 4432614747; fax: C55 4432633440. E-mail address: nadia@deq.uem.br (N.R.C.F. Machado).