草浆黑液磷酸酸析最佳条件和肥料特性的研究

Optimal Conditions of Lignin Precipitation from Straw Pulping Black Liquor by Using Phosphoric Acid

应用磷酸溶液对麦草浆黑液进行木素酸析沉淀反应,对不同pH值下的酸析木素进行了紫外光谱和红外光谱分析,并对沉淀出的酸析木素进行成分分析。实验结果表明,磷酸对麦草浆黑液酸析沉淀的最佳工艺条件为:pH值3,温度60℃,在此工艺条件下酸析木素得率为87%。紫外光谱与红外光谱分析表明,pH值降低有利于酸析木素得率的提高。酸析木素成分分析表明,酸析木素中游离腐植酸较高,是很好的肥料载体。

A process using phosphoric acid to precipitate lignin from straw pulping black liquor was investigated, the conditions were opti- mized, as pH = 3, T = 60℃, the yield of the precipitated lignin was 87%. The precipitated lignins at different pH were analyzed by infrared spectrum and ultraviolet spectral. The components of acid-precipitated lignin at pH = 3 was analyzed, the result indicated that the precipita-ted lignin has the characteristic of fertilizer.