Interaction of the reaction intermediates in co-reforming of acetic acid and ethanol impacts coke properties

Abstract

Abstract Bio-oil is a mixture of organics and its steam reforming for production of hydrogen has attracted extensive attention. During steam reforming, the reaction intermediates derived from the varied organics in bio-oil might interact with each other, impacting composition/properties of the products. In this study, steam reforming of single or mixture of acetic acid and ethanol, the representatives of carboxylic acid and alcohol, were conducted with Ni/KIT-6 as the catalyst, aiming to probe the potential interaction of the reaction intermediates on the reforming reaction. The results showed that the interactions of the derivatives from acetic acid and ethanol did exist, enhancing conversion of reactants, formation of gaseous by-products and affecting coke properties. The co-reforming of ethanol and acetic acid generates more reaction intermediates bearing hydroxyl group that are difficult to be gasified and also forms more coke, leading to more significant catalyst deactivation. The coke formed from the co-reforming is not only prone to oxidation, but also showed distinct morphologies. Carbon nanotubes with coarse surface and hillocks was the main form of coke from steam reforming of ethanol or acetic acid, while coke from the co-reforming was mainly in the form of carbon nanofiber decorated with the hangnail-like substance or rope-like structures with no cavity and micrometers of length.