Alkylation of benzene with ethanol was analysed using unmodified as well as modified shape selective HZSM-5 (Si/Al = 31) zeolite catalysts. The reaction was carried out in a continuous fixed bed flow reactor in the temperature range of 300-500°C at atmospheric pressure to investigate the activity of various catalysts for the selectivity and yield of ethylbenzene (the desired product). The alkylation of benzene with ethanol (2:1 by volume) produces ethyl benzene as primary product and others like diethylbenzene, triethylbenzene and xylene mixtures as secondary products. The modification of HZSM-5 was done by impregnation using boron and magnesium. The modification caused changes in the surface area, acidity and pore volume of zeolite sample. The physiochemical properties of catalysts were characterised by XRD, TEM, BET, TGA, FTIR, NH 3 -TPD and SEM. The feed and products were analysed by gas chromatography. The conversion of benzene was found to be better in bi metallic (B and Mg) modified HZSM-5 followed by unmodified HZSM-5. The modified catalysts gave better selectivity (72.8 %) and yield (38.1 %) of ethylbenzene.

According to International Zeolite Association (2014), until now, there are 218 zeolite framework type codes that have been discovered. Worldwide consumption of zeolites (natural and synthetic) is estimated to be about 5 million tons per year. The annual market for synthetic zeolites and molecular sieves was developed vastly to 1,800,000 ton worldwide in 2008. 3 Alkylation of benzene is a vital reaction in the petrochemical industry. Benzene alkylation technologies offer improvements in octane number and gasoline volume. Ethylbenzene, diethylbenzene, toluene, and xylenes are important raw materials for many intermediates of commodity petrochemicals and valuable fine chemicals. Ethylbenzene (EB), which is one of the most important products used as the chemical intermediate, is the main feedstock for the synthesis of styrene which is then polymerized into polystyrene, a common plastic material. 4 Ethylbenzene is also used in the chemical industry in the manufacture of acetophenone, cellulose acetate, diethylbenzene (DEB), ethyl anthraquinone, ethylbenzene sulfonic acids, propylene oxide, and α-methylbenzyl alcohol. 5 Additionally it is used as a solvent, a constituent of asphalt and of naphtha, and in fuels. Ethylbenzene and xylene mixtures are used in the paint industry and in the production of pesticides in agriculture. 5

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