DEVEPOLPMENT OF NOVEL PHAPULPING PROCESS BY ORGANIC SOLVENTS SELF-SUPPLIED FROM BIOMASS

采用多元醇（PHA）制浆技术，对间伐和改良切削产生的劣质针叶材进行组分分离，建立木材自供溶剂制浆新工艺。丙二醇（PG）作为普阿常压制浆的溶剂上级乙二醇（EG）。用PG含硫酸作催化剂，对杉木、落叶松和雪松进行PHA制浆，与EG相比，所得浆的弃浆率低，残余木质素含量低，PG浆经烧碱一次漂白，卡伯值约为1，白度可达80%。杉木漂白浆的木片得率为44.7%，α-纤维素含量和结晶度都很高，强度性能与硫酸盐浆相当。从杉木和桦木PHA法制浆废液中分离并冷冻干燥木质素。这两种木质素都以几乎定量的产率获得，用常规的水性木质素溶剂如丙酮、二氧六环和吡啶溶解，并进一步热熔融。每种木质素的碳含量均高于相应的乙酸木质素和原木质素。桦木和冷杉木片木质素的重均分子量较低，分别为670-710和720-830，低于相应的乳酸木质素和MWLs。

Polyhydric alcohol (PHA) pulping was developed to separate components of low-quality softwoods that are produced by thinning and improvement cutting as well as to establish a new pulping process with solvent self-supplied from wood. Proplylene glycol (PG) was superior to ethylene glycol (EG) as solvent for PUA pulping at atmosphereic pressure. PHA pulping of fir, larch and cedar with PG containing sulfuric acid as a catalyst gave satisfactory pulps with few rejects and a very low level of residual lignin as compared with that with EG.PG pulps were readily bleached to approximately Kappa number 1 and 80% brightness by one treatment with sodium chlorite. The bleached pulp of fir was obtained in a yield of 44.7% of chips, had very high α-cellulose content and crystallinity, and had thesimilar strength properties to those for kraft pulp. Therefore, PHA pulping apperas to be promising for pulping of softwood, hardwood and nonwood.Lignins were isolated and freezing-dried from spent liquors in PHA pulping of fir and birch. Both the lignins were obtained in almost quantitative yields, dissolved with conventional aqueous lignin-solvents such as acetone, dioxane and pyridine, and further hot-melted. Each content of carbon was higher than those for corresponding acetic acid lignin and protolignin. Lignins of birch and fir chips had lower weight average-molecular weight of 670-710 and 720-830 than those for corresponding actic acid lignins and MWLs.