皇竹草碱法蒸煮黑液特性研究

Characteristics of Alkali Cooking Black Liquors of Hybrid Giant Napier

研究了皇竹草KPAQ与SodaAQ法制浆黑液的物理性质、化学成分和污染负荷;探讨了两种黑液在碱回收处理中关键特性行为。研究表明,两种黑液分别含SiO21.15、1.21g/L,粘度分别为9.61、7.32mPa·s,SiO2占总固形物含量分别为0.67%、0.92%,低于芦苇,在非木造纸原料中较低;浓缩过程中粘度升高速率大于木材、稍低于芦苇、明显低于稻草麦草;两种黑液氧弹发热量分别为14.89、15.39kJ/g;两种黑液的CODCr分别为1.60、1.98kg/kg浆,BOD5分别为0.32、0.38kg/kg浆,SS分别为0.01、0.01kg/kg浆;在黑液酸化过程pH值7.5时,SiO2析出率最高分别为82%、85%,低于其他非木造纸原料。

The physical characteristics, pollution loads, and chemical components of KP-AQ and Soda-AQ black liquors of Hybrid Giant Napier (HGN, a new non-wood papermaking raw material in China) under optimum cooking conditions were studied.The key characteristics and behaviors of HGN black liquors in conventional chemical recovery were discussed. It was found that the SiO_2 contents were 1.15 and 1.21g/L, viscosities were 9.61 and 7.32mPa·s for the two kinds of black liquor which had 10.9 and 8.4°Be in 20℃ respectively, their SiO_2 contents accounted for 0.67% and 0.92% of total solid content and were much lower than that of reed black liquor. Their viscosities increased faster than the black liquor of wood, but slower than the black liquor of reed and much slower than the black liquors of rice and wheat straw when the black liquors were concentrated. The heat values of these two kinds of black liquor were 14.89 kJ/g and 15.39 kJ/g. COD_(Cr) were 1.60 and 1.98 kg/kg pulp, BOD_5 0.32 and 0.38 kg/kg pulp, SS 0.01 and 0.01kg/kg pulp respectively. The max precipitation yields of silica during acidification were 82% and 85% at pH 7.5.It was also demonstrated that HGN black liquors are easier to process than that of other non-wood materials, and the traditional alkali-recovery system is feasible for processing the HGN black lignin from economical and technical.