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

多羟基醇（PHA）制浆是为了分离稀化和改进切割生产的低质量软木的组分，并建立一种新的木材自备溶剂制浆工艺。丙二醇（PG）作为常压制浆溶剂优于乙二醇（EG）。以含硫酸PG为催化剂对杉木、落叶松和雪松进行PHA制浆，与EG相比，废渣少，木质素残留量极低，制浆效果满意。PG纸浆经亚氯酸钠一次处理后，易于漂白至Kappa值约为1，亮度约为80%。得到的杉木漂白浆的切屑率为44.7%，α-纤维素含量和结晶度很高，强度性能与硫酸盐浆相当。因此，PHA制浆在软木、硬木和非木材的制浆中具有广阔的应用前景。从杉木和桦木PHA制浆废液中分离木质素并进行冷冻干燥。用丙酮、二氧六环和吡啶等传统木质素水溶液溶解后，再进行热熔处理，得到两种木质素的收率均接近定量。碳的含量均高于相应的乙酸木质素和原木质素。桦木和杉木木质素的质量平均分子量分别为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.