Targeted Substituted-Phenol Production by Strategic Hydrogenolysis of Sugar-Cane Lignin

In this work, a waste-derived lignin with abundant uncondensed linkages, using accessible solvents (acetone/water mixture) and low-cost catalysts showed successful depolymerization for the production of target molecules 4-ethylphenol, 4-propyl-2,6-dimethoxyphenol 4-propyl-2-methoxyphenol. Lignin samples were obtained from sugar-cane bagasse residue by an organosolv process. Four alumina-based (Pt/Al2O3, Rh/Al2O3, Ni/Al2O3 Fe/Al2O3) used to depolymerize sugar cane (SCL) in acetone/water mixture 50/50 v/v at 573 K 20 barg hydrogen. This strategic depolymerisation-hydrogenolysis process resulted molecular weight SCL being reduced half while polydispersity also decreased. Catalysts significantly improved product yield compared thermolysis. Specific metals directed distribution yield, Rh/Al2O3 gave highest overall (13%), but selectivity given (~32% 4-ethylphenol). Mechanistic routes proposed either fragments or main polymer. evidence carbon laydown that was specific rather than catalyst. These results control over could be achievable appropriate combination catalyst, solvent mixture.