Successive vapour phase Guerbet condensation of ethanol and 1-butanol over Mg-Al oxide catalysts in a flow reactor

[Display omitted] •Guerbet condensation of 1-butanol to 2-ethyl-1-hexanol over solid catalysts in a flow is performed for the first time.•Experimental opportunities for production of 2-ethyl-1-hexanol from ethanol over Mg-Al oxide catalysts are shown.•Guerbet alcohol selectivity/yield strongly depends on acid/base capacity ratio determined by a Mg/Al ratio of the catalyst. The successive vapour phase condensation of ethanol and 1-butanol (via Guerbet reaction) in a flow reactor under atmospheric pressure was studied over catalytic Mg-Al oxide compositions. Wherein the vapour phase condensation of 1-butanol to 2-ethyl-1-hexanol in flow has been investigated for the first time. The acid/base capacity ratio, which is determined by the Mg/Al ratio, is an important characteristic for the activity and selectivity of Mg-Al oxide catalysts in the abovementioned processes. The carbon chain length of the reacting alcohols, an arrangement of surface active sites and other steric factors also have an impact on Guerbet condensation in the vapour phase. High productivity of Mg-Al oxide system to the Guerbet alcohols: 1-butanol – 25 g/(Lcat·h), 2-ethyl-1-hexanol – 19 g/(Lcat·h), has been achieved. The results have shown a prospect of successive conversion realization: 1) ethanol → 1-butanol; 2) 1-butanol → 2-ethyl-1-hexanol for the production of 2-ethyl-1-hexanol from ethanol.