Degradation of solvolysis lignin using Lewis acid catalysts

TLDR: In this paper, Alcell-derived lignin was depolymerized in a batch reactor using the Lewis acid catalysts NiCl2 and FeCl3, achieving 30% and 26% from Ni and Fe, respectively, at reaction conditions of 305°C and 1 h reaction time.

Abstract: Alcell-derived lignin was depolymerized in a batch reactor using the Lewis acid catalysts NiCl2 and FeCl3. The objective was to investigate the use of Lewis acids in the production of useful liquid products directly from solvolysis lignin. The effects of reaction temperature, time and catalyst were studied on the conversion of this lignin to gas, solid and liquid products. Also, selected monomeric compounds in the ether solubles were monitored in terms of the variation in their yields with different reaction conditions. The highest conversions, 30% and 26% from Ni and Fe, respectively, were both attained at the reaction conditions of 305°C and 1 h reaction time. The Ni produced a somewhat higher yield of ether solubles, reflecting its slightly higher performance. Under the reaction conditions studied, both catalysts apparently favour condensation reactions leading to the formation of insoluble reactor residue from solvolysis lignin. Low quantities of monomeric compounds were produced, with phenols dominating over ketones and aldehydes for both catalysts. De la lignine obtenue par le procede Alcell a ete depolymerisee dans un reacteur discontinu a l'aide de catalyseurs acides de Lewis NiCl2 et FeCl2. L'objectif etait d'etudier l'utilisation des acides de Lewis dans la production de produits liquides utiles directement a partir de la lignine de solvolyse. On a etudie les effets de la temperature de reaction, du temps de reaction et du catalyseur sur la conversion de cette lignine en produits gazeux, solides et liquides. En outre, on a suivi la variation du rendement de composes monomeres selectionnes dans les solubles ethers dans differentes conditions de reaction. Les plus fortes conversions, soient 30% et 26% du Ni et du Fe respectivement, etaient dans les deux cas reliees aux conditions de reaction, soient une temperature de 305°C et un temps de reaction de 1 heure. Le Ni produit un rendement de solubles ethers un peu plus eleve, refletant sa performance sensiblement meilleure. Dans les conditions de reaction etudiees, les deux catalyseurs favorisent des reactions de condensation, ce qui mene a la formation de residus de reacteur insolubles a partir de la lignine de solvolyse. De faibles quantites de composes monomeres ont ete produites, les phenols dominant les cetones et aldehydes pour les deux catalyseurs.