Abstract
In this study a multi-scale simulation of the propane aromatization process is presented. The recent interest in this technology derives from the development of new conversion routes of third generation biomass. Advanced processes for the production of drop-in biofuels from vegetable (e.g. algal) oils are based on hydrogenation reactions, which lead to the production of green diesel, and selective cracking reactions that maximise the production of bio-jet fuels C10-C15 fractions. These catalytic processes involve the cracking of triglycerides, saturation of double bonds, heteroatoms rejection (especially deoxygenation) and isomerization. Moreover, while glycerol is the low added value co-product for oils transesterification (Bianchi et al., 2009), propane represents more than 30 % of the final product in the hydrotreatment of the lipid fraction. Propane can be upgraded by catalytically convert it to aromatics, which are additives for jet- fuels and bulk feedstock for the chemical industry. The low selectivity towards aromatics strongly reduces the efficiency of the overall process, caused by a large production of cracking gases. In general, zeolites with MFI pore structure are used due to their high resistance to deactivation (Pirola et al., 2010) with metal components, such as gallium, added to enhance the dehydrogenation function. Kinetic studies of propane aromatization over H-ZSM-5 at 500 °C and atmospheric pressure in a wide range of conversions are reported in the literature (Nguyen et al., 2006). Based on these and similar results (Bhan et al., 2005), a general kinetic model for propane aromatization has been developed. In this work the revised kinetic model is presented and embedded in the multi-scale simulation of a propane aromatization process, performed with the commercial code Invensys PRO/II. Several technologies have been designed to directly convert LPG into aromatics (BTX). In this study the Cyclar process (Giannetto et al., 1994) developed by UOP and BP was selected.
