污泥的正己烷亚/超临界萃取及其产物特征

n-Hexane Subcritical/Supercritical Extraction of Sludge and Its Product Characteristics

对污泥的正己烷亚/超临界萃取特征进行了研究,发现萃取过程中污泥中的有机质发生裂解和脱O、N、S等杂原子的反应,同时伴随污泥颗粒表面水分的有效分离。同时,分析了产物的分布情况及产物的特征,结果表明：采用正己烷亚/超临界萃取可有效提取污泥中的有机质,正己烷萃取物的产率可达19.5%~24.2%（daf）,其O含量较低,N和S含量较高,不适宜直接作为液体燃料燃烧利用,可进一步加氢精制处理后使用;水相产物所含的有机物主要由醇类和羧酸类组成,可作为萃取残渣水热液化的溶剂被循环利用;萃取残渣的有机质中四氢呋喃可溶物总质量分数高达74.1%~84.9%（daf）,可用作水热液化制备生物油的原料。

The n-hexane subcritical/supercritical extraction process of sludge was investigated.During the process,the organic matters were cracked,O,N and S in sludge were removed by reactions,and water on the sludge particle surface was efficiently separated.Simultaneously,the product distribution and characterization of extractives were analyzed.The results showed that the organic matters in sludge could be efficiently extracted by n-hexane under subcritical/supercritical conditions with the yield of n-hexane extractives up to 19.5% ~24.2%（daf）.The extractives can not be used directly as liquid fuels for combustion,but as raw materials for refining,owning to its low O content and high S and N contents.The organic matters in the aqueous phase are primarily composed of alcohols and carboxylic acids,which are suitable to be recycled as the solvent for the hydrothermal liquefaction of the residue from extraction.The organic matters in extracted residues which can be dissolved in tetrahydrofuran are up to 74.1%~84.9%（daf）,which can be used to produce bio-oil by hydrothermal liquefaction.