Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, Canada P7E 5E1.
Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, Canada P7E 5E1.
J Environ Manage. 2014 Apr 1;136:62-7. doi: 10.1016/j.jenvman.2014.01.032. Epub 2014 Feb 22.
Hemicelluloses and lignin present in the spent liquor (SL) of neutral sulfite semichemical (NSSC) pulping process can potentially be converted into value-added products such as furfural, hydroxymethylfurfural, levulinic acid, phenols and adhesives. However, the direct conversion of hemicelluloses and lignin of SL into value-added products is uneconomical due to the dilute nature of the SL. To have a feasible downstream process for utilizing lignocelluloses of SL, the lignocelluloses should initially be separated from the SL. In this study, an adsorption process (via applying activated carbon) was considered for isolating the dissolved lignin and hemicelluloses from the SL of an NSSC pulping process. Under the optimal conditions of pH, SL/AC weight ratio, time and temperature of 5.7, 30, 360 min and 30 °C, the maximum lignin and hemicellulose adsorptions were 0.33 and 0.25 g/g on AC. The chemical oxygen demand (COD) and turbidity of the SL were decreased by 11% and 39%, respectively, as a result of lignocellulose adsorption on AC. Also, the incineration behavior of the SL-treated AC was studied with a thermo-gravimetric analysis (TGA).
中性亚硫酸盐半化学（NSSC）制浆过程中废液（SL）中的半纤维素和木质素可以转化为附加值产品，如糠醛、羟甲基糠醛、乙酰丙酸、酚类和粘合剂。然而，由于 SL 的稀释性质，直接将 SL 中的半纤维素和木质素转化为附加值产品是不经济的。为了使 SL 的木质纤维素具有可行的下游利用工艺，木质纤维素应首先从 SL 中分离出来。在这项研究中，考虑了一种吸附工艺（通过使用活性炭）来从 NSSC 制浆过程的 SL 中分离溶解的木质素和半纤维素。在 pH 值、SL/AC 重量比、时间和温度分别为 5.7、30、360 min 和 30°C 的最佳条件下，活性炭对木质素和半纤维素的最大吸附量分别为 0.33 和 0.25 g/g。木质纤维素在活性炭上的吸附使 SL 的化学需氧量（COD）和浊度分别降低了 11%和 39%。此外，还通过热重分析（TGA）研究了 SL 处理后的活性炭的燃烧行为。
