Analysis of the effect of temperature and reaction time on yields, compositions and oil quality in catalytic and non-catalytic lignin solvolysis in a formic acid/water media using experimental design

Mild thermolytic solvolysis of technical lignins in polar organic solvents to a crude lignin oil

“…% after 4 h. We observed that the lignin concentration in the resulting crude lignin oil (CLO) increased slightly from 5.5 to 7.5 wt. %, when the reaction time was increased from 0.5 h to 4 h. Noncatalytic lignin solvolysis at moderate temperatures in the 200-250 °C range in the absence of stabilizing agents has been studied before 37,38. Reaction time is an important parameter determining the yield and quality of fractionated lignins because of repolymerization reactions of intermediates.…”

One-step alcoholysis of lignin into small-molecular aromatics: Influence of temperature, solvent, and catalyst

“…Although temperature imposes a remarkable influence on distribution of the liquid products, the obtained aromatics are alkylated arenes and mono-phenols with one hydroxyl group and no methoxy groups, and contain no oligomers at 450 or 500 °C, different from the reported lignin depolymerization [23,24,29,41]. The reactant suspension mode holds some advantages.…”

“…For the catalyst influence, the obtained arenes and mono-phenols are alkylated, and phenols only possess one hydroxyl group and have no methoxy groups like guaiacols by using the Pt/C catalyst [43] or Pt/alumina catalyst [33]. There are not oligomers [41]. The Cu-C catalyst has the optimal catalytic activity and selectivity in methanol, whereas the Fe-SiC catalyst possesses the optimal catalytic deoxygenation in ethanol.…”

Effective Depolymerization of Sodium Lignosulfonate over SO42−/TiO2 Catalyst

“…As the reaction time prolongs, lignin conversion gradually tends to balance (i.e., the rate of depolymerization is equal to that of condensation). However, when the reaction time exceeds 1h, the condensation between lignin intermediates will gradually dominate the remaining liquefaction reaction (i.e., the rate of condensation will be higher than that of depolymerization), which will greatly promote the re-polymerization reaction of liquefied products (i.e., reactive lignin intermediates with small-molecular weight) [26]. On the other hand, the solid products with large-molecular weight obtained after liquefaction reaction will be adsorbed on the surface of catalyst to block the active acid sites, which decreases the catalytic activity of solid super catalyst to some extent [27].…”