Improvement of n-butanol Guerbet condensation: a reaction integration of n-butanol Guerbet condensation and 1,1-dibutoxybutane hydrolysis

Abstract

n-Butanol Guerbet condensation is a green route to 2-ethylhexanol (2EHO). The by-product water not only hinders the reaction progress and reduces the selectivity to 2EHO, but also causes catalyst deactivation. Therefore, simultaneous consumption of water is an effective way to improve n-butanol Guerbet condensation reaction performance. For this purpose, herein, 1,1-dibutoxybutane hydrolysis was incorporated to eliminate the adverse effect of water. Firstly, n-butanol Guerbet condensation and the reaction integration of n-butanol Guerbet condensation with 1,1-dibutoxybutane hydrolysis were thermodynamically analyzed. The results showed that the reaction integration is beneficial to the progress of n-butanol Guerbet condensation and the formation of 2EHO. Then, the appropriate reaction conditions for the reaction integration were determined by a single-factor experiment; the selectivity to 2EHO reached 73.3% at an n-butanol conversion of 70.5%. Finally, through the kinetic analysis of the two reaction systems, it is confirmed that the 1,1-dibutoxybutane hydrolysis reaction can reduce the activation energy of both the n-butanol dehydrogenation step and n-butanal aldol condensation step, effectively promoting the n-butanol Guerbet condensation reaction.