Simultaneous catalytic dehydration of methanol and ethanol: How ZSM-5 acidity addresses conversion and products distribution

The sustainable chemistry based on acid-catalysed alcohol conversion reaction is a promising route to contribute to the de-fossilization strategies completion. In this concern, C1 and C2 alcohols are both well recognised sources for the production of ethers and olefins from sustainable sources in acid catalysed dehydration reaction pathway. Most of the literature is devoted to the investigation of pure alcohols conversion, whilst the simultaneous dehydration of alcohol in mixture can broad the product panel (contributing to the enlargement of bio-alcohols based chemistry) also elucidating the role of acidity (type and distribution) on the reaction mechanism. This paper is the first contribution analysing the role of acid sites (amount and distribution) on the simultaneous methanol/ethanol dehydration using ZSM-5 zeolites. ZSM-5 materials with different aluminium content were synthesised and used in catalytic test. The obtained results showed how Lewis acid sites are less important when dealing with ethanol (also in mixture with methanol) and how the different methylated- ethylated species formation can affect the product composition and the coke amount and composition.