Effect of MgO dispersion on catalytic conversion of ethanol into butanol

Bio-ethanol is currently used as a fuel additive although issues as water solubility,corrosivity and low calorific value limit the fraction that can be introduced. These limitations can be overcome substituting ethanol for butanol. Bio-butanol can be produced by ABE fermentation of the biomass and the fraction of ethanol produced in this process can be upgraded to butanol via catalytic routes (Sun and Wang,2014). The main process to increase the carbon number of alcohols is the Guerbet reaction (Ndou et al.,2003). Preliminary results of catalytic tests highlighted the main role of basic sites in the butanol formation (Cimino et al.,2018) identifying metal-promoted MgO as the most performing catalyst. The role of metal, in addition to provide dehydrogenation activity, was to increase the surface area of MgO. In order to investigate the effect of MgO dispersion, excluding that more closely related to that of the metal, magnesium oxide was dispersed on two different types of activated carbons and results compared to unsupported MgO. This support was selected due to both its high surface area and porosity and to the low interaction with MgO not significantly modifying the nature of the basic oxide (Zhou et al.2018).