A new environmentally friendly technology for wood pulp delignification, based on the use of polyoxometalates (POMs) and oxygen, is being developed. Polyoxometalate solutions that selectively oxidize lignin under anaerobic conditions can be reoxidized by oxygen and also catalyze the aerobic mineralization ofthe lignin fragments to CO2 and H2O, making possible the closed-mill manufacture of pape...

Valorization of agri-food residues to produce bio-based platform chemicals will enhance the transition bio-economy era. To this end, a sustainable process has been developed for overall valorization grape stalks (GS) according circular approach, starting from lignin fraction further deal with cellulose-rich residue. This non-conventional protocol fully adheres green chemistry principles, exploi...

Abstract Corncob waste is not managed properly has the potential to environmental pollution. The purpose of this reasearch utilize corncob as a biomass into bioethanol. Process making bioethanol carried out in 4 steps, namely delignification, hydrolysis, fermentation, distillation. substrate were prepared mechanically become size powder 40 mesh. Delignification by fungi Dekkera Bruxellensis was...

The screened Eucalyptus camendulensis chips were cooked in the laboratory at various alkalinities (14, 16, 18 and 20 per cent) and sulphidity (20, 30 and 40 per cent). Due to the variation in chemical charge, the pulp yield was found to be different. The average pulp yield was 50.6 per cent after washing and the final yield was obtained 40 per cent, which followed the normal kraft yield trend. ...

Oxygen delignification can be considered to be the most important part of TCF and ECF bleaching sequences because it allows for cleaner production of pulp. During the process, oxygen gets one electron from lignin in the alkaline condition to form some active oxygen species (AOS), including a superoxide anion radical (O2-•), which is crucial for lignin degradation without damage of carbohydrates...

The electronic structures of three lignin model compounds were computed by means of semi-empirical (PM3) and density functional methods (B3LYP), both in vacuo and in solution. The computed values of proton affinities, electron affinities and O-H bond dissociation energies for 4-methylphenol, 2-methoxy-4methylphenol and 2,6-dimethoxy-4-methylphenol were compared with those of the oxygen-derived ...

The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer graf...

The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction...