The amount of residual lignin in birch wood after a hot water extraction in a batch reactor was investigated as a function of extraction temperature and time. A kinetic model fitting the experimental data was then developed to explain delignification of wood during a hot water treatment. Results showed that delignification kinetics involves simultaneous degradation and condensation reactions, w...

Pretreatment of miscanthus is essential for efficient enzymatic production of cellulosic ethanol. This study reports a possible pretreatment method for miscanthus using aqueous ethylenediamine (EDA) for 30 min at 180 °C with or without ammonia. The mass ratio of miscanthus to EDA was varied from 1:3, 1:1, and 1:0.5, keeping the mass ratio of miscanthus to liquid (EDA + Water) constant at 1:8. T...

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...

Cocoa pod husks are a type of biomass that is still poorly explored. This work was carried out as part the optimization delignification process for this residue with potassium hydroxide, to maximize reducing sugars content. Screening potentially influencing factors showed solvent ratio and temperature had greatest effect on process. Optimization these using composite central plan revealed quadr...

Abstract Background Hydrogen peroxide–acetic acid (HPAA) is widely used in pretreatment of lignocellulose because it has a good capability selective delignification. However, high concentration (more than 60%) HPAA increases the cost and risk explosion. In this work, alkaline post-incubation was employed to decrease loading improve saccharification poplar. Results Pretreatment with 100% removed...

BACKGROUND Effective enzymatic hydrolysis of lignocellulosic biomass benefits from lignin removal, relocation, and/or modification during hydrothermal pretreatment. Phase transition, depolymerization/repolymerization, and solubility effects may all influence these lignin changes. To better understand how lignin is altered, Populus trichocarpa x P. deltoides wood samples and cellulolytic enzyme ...

Alkaline solutions of hydrogen peroxide partially delignify wheat straw and other lignocellulosic materials, leaving a cellulosic residue that is highly susceptible to enzymatic digestion by cellulase. The delignification reaction is strongly dependent upon the pH of the reaction mixture, with an optimum at pH 11.5-11.6, pKa for the dissociation H(2)O(2) right harpoon over left harpoon H(+) + H...

While many pretreatments attempt to improve the enzymatic digestibility of biomass by removing lignin, this study shows that improving the surface area accessible to cellulase is a more important factor for achieving a high sugar yield. Here we compared the pretreatment of switchgrass by two methods, cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) and soaking ...

Previous work has shown that Trametes (Coriolus) versicolor bleaches kraft pulp brownstock with the concomitant release of methanol. In this work, the fungus is shown to produce both laccase and manganese peroxidase (MnP) but not lignin peroxidase during pulp bleaching. MnP production was enhanced by the presence of pulp and/or Mn(II) ions. The maximum level of secreted MnP was coincident with ...

a study was carried out on totally chlorine-free (tcf) bleachability of dimethyl formamide (dmf) treated bagasse pulps exposed to cz-3 and fp 90031-sp strains of white-rot fungus ceriporiopsis subvermispora. this process involved an oxygen and peroxide stage bleaching sequence. the effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...