Lignin hydrogenolysis with in-situ glycerol aqueous phase reforming

Abstract

Lignin hydrogenolysis was conducted with glycerol aqueous phase reforming (APR) in the in-situ reaction. Given that glycerol, a by-product of the biodiesel process, produces hydrogen and lignin, a lignocellulosic constituent, produces renewable phenolics, a substitution for petroleum-based chemical compounds can be obtained. In order to understand the mechanistic reaction of the glycerol APR reaction and the in-situ reaction, the initial study was conducted with phenol as a substitute for the lignin model compounds. Depending on local hydrogen availability, glycerol APR was found to proceed in parallel to form ethylene glycol or 1,2 propylene glycol. Hydrogenation of phenol was found to scavenge hydrogen produced from APR leading to the suppression of the undesired reactions of glycerol APR. Based on the fundamental study on the reaction mechanism of in-situ hydrogenation and aqueous phase reforming, various lignins and bio-oil have been depolymerized and hydrogenated. Comparative results between various technical lignins and bio-oils will be presented in terms of product distribution and monomeric yield, as well as interesting phenomena during the reaction.