Activated carbon polyurethane membrane for a model fuel desulfurization by pervaporation R.A. Amaral n , A.C. Habert, C.P Borges Chemical Engineering Program—COPPE, Federal University of Rio de Janeiro, UFRJ, P.O. Box 68502, 21941-972 Rio de Janeiro, RJ, Brazil article info Article history: Received 23 July 2014 Accepted 21 September 2014 Available online 1 October 2014 Keywords: Model fuel desulfurization Activated carbon polyurethane membrane Pervaporation abstract Flat sheet membrane of polyurethane filled with activated carbon (ACPU) was prepared for sulfur compounds removal from a model fuel by pervaporation process. To evaluate the pervaporation performance a binary mixture containing 1500 mg kg 1 of 2-methyl thiophene in iso-octane was tested. This sulfur compound was selected because it is difficult to be removed by the conventional hydrodesulfurization process. Enrichment factor as high as 20 and normalized permeate flux of 1.52 kg mmm 2 h 1 demonstrated the very good potential of this composite membrane and the presence of activated carbon in the polymer matrix remained the membrane performance even at higher temperatures. & 2014 Elsevier B.V. All rights reserved. 1. Introduction The removal of sulfur in fuels has been worldwide, an impor- tant issue in the refining industry. Regulations are increasingly pointing out the need of much lower sulfur content in fuels. For instance, about 70% of the gasoline pool in Brazil is naphtha derived from the fluid catalytic cracking (FCC) process without any additional treatment. In general, high sulfur content (average 1000 mg kg 1 ) can be found in this stream, which directly con- tributes to SO 2 emission and corrosion of equipment and pipelines. Pervaporation is a membrane separation process (MSP) that can be applied for desulfurization of liquid hydrocarbon streams. When compared to conventional process of naphtha hydrodesulfurization, pervaporation enables to remove organosulfur compounds with much lower loss of octane rating. Furthermore, it operates at mild conditions and conveniently does not require the use of hydrogen and catalysts, leading therefore to lower operating costs. The desulfurization efficiency of pervaporation is related to the membrane affinity to sulfur compounds. Polydimethylsiloxane (PDMS), polyimide, polyethyleneglicol (PEG) and polyurea/ureth- ane polymers are the most successful materials reported in literature. However, the main problem is the high swelling degree in contact with the liquid phase, which may reduce the membrane selectivity. The strategies to prevent this problem include the polymer crosslinking, use of polymer blends and mixed matrix membranes (MMMs) [1]. The MMMs are defined as the synergistic combination of organic polymers with inorganic nanofillers. Silica nanoparticles have been successfully introduced into PDMS membranes to improve the pervaporation performance for desulfurization of thiophene/n-octane mixture [2]. The high adsorp- tive capacity of mesoporous silica in desulfurization has also been proven by other authors [3]. In other study, ethyl cellulose/fullerene hybrid membranes were prepared and investigated for sulfur com- pounds removal from synthetic gasoline mixture [4]. The authors reported that the interaction between hybrid membrane and thiophene improved by addition of fullerene in the membrane matrix. Liu et al. [5] produced facilitated transport membranes by incorporating Ag þ /TiO 2 microspheres into PDMS matrix. The com- posite membrane was evaluated for desulfurization of synthetic gasoline mixture by pervaporation. The permeated flux and the enrichment factor were simultaneously enhanced with increasing Ag þ /TiO 2 weight fraction in the membrane.The authors discussed the results considering changes in the polymer packing density due to interaction with the inorganic particle, as well as occurrence of specific reversible chemical reaction between Ag þ and thiophene. Similar results were obtained by using Ag þ /SiO 2 microspheres blended with PDMS [6]. Sulfur removal was also studied using mixed matrix mem- branes (MMMs) from polyimide and different zeolites [7]. The adsorption and desorption behavior of MMMs with various func- tional zeolites was related to binding forces between the particles and sulfur compounds. For NaY zeolites adsorption of sulfur com- pounds occurs in the pore channels by van der Waals forces, leading to low adsorption selectivity and, consequently, low desulfurization performance. On the other hand, AgY and CeY Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/matlet Materials Letters http://dx.doi.org/10.1016/j.matlet.2014.09.072 0167-577X/& 2014 Elsevier B.V. All rights reserved. n Corresponding author. Tel.: þ55 21 39388351; fax: þ55 21 39388300. E-mail address: ramaral@peq.coppe.ufrj.br (R.A. Amaral). Materials Letters 137 (2014) 468–470