水素化によるパルプ製造

抄録

The hydrogenolysis pulping is proposed as a new process which is pollution free, energy saving and possible to separate biomass into hemicellulose and lignin that may be used for various fermentation process or as feedstock for chemical conversions.
Birch (Betula platyphylla var. japonica) chips were hydrogenolized in an autoclave with NaOHaq., phenol and cresols-water as solvents, on catalysts Cu₂O and reduced Ni, at reaction temperature 160180°C, in 13 hr. under the hydrogen pressure 1865 kg/cm².
Satisfactory results were obtained with the solvent of cresols-water and the catalyst Cu₂O even under the reaction pressure 18 kg/cm². The screened pulp yields are 5063%, and the strength properties of pulp sheet are almost equivalent to those of kraft pulp except tear factor. Their folding endurance is especially high.
The reaction mixture was separated into two phases, water and cresol layers. In the former, the hemicellulose sugars were dissolved, and the dominant one was xylose which amounted to over 60% of them. The latter dissolved lignin with relatively low molecular weight. These two wood components obtained separately would be usable by further processing.
The energy used for pulping may be largely saved, because the hydrogenolysis reaction is exothermic. Further, in this process the solvent, cresols can be supplied from the hydrogenolysis products of the lignin.