工业化生物质气化焦油中酚类化合物提纯工艺研究

Extraction of Phenolic Compounds from Industrial Biomass Gasification Tar

采用酸碱抽提法对5 MW工业化生物质气化焦油中的酚类化合物进行提纯。通过常压蒸馏装置将气化焦油切割为3个馏分并测定酚含量,选取酚含量最高的馏分I进行酚类化合物酸碱抽提工艺研究,并利用GC/MS对提纯粗酚进行分析。结果表明：3个馏分（110~180℃、180~210℃和210~235℃）的酚质量分数分别为51.86%、20.46%和12.86%。较优的馏分I酸碱抽提碱洗和酸洗工艺条件分别为：碱液质量分数20%、碱洗时间5min和碱洗温度50℃;硫酸质量分数20%、酸洗时间30 min和酸洗温度22℃。较优酸碱抽提工艺条件下,馏分I的粗酚收率为50.24%,GC/MS分析表明,粗酚中主要含有42种酚类化合物,质量分数合计为98.49%,低级酚质量分数为73.90%。

Phenolic compounds were separated from the 5 MW industrial biomass gasification tar by liquid-liquid extraction using alkali and acid. Three fractions were isolated from the tar by distillation and phenol content of each fraction was determined. The fraction 1 of the highest content of phenolic compounds was selected for alkali and acid extraction process. The crude phenol was analyzed by GC/MS. The mass fraction of phenols in 100--180 ℃, 180--210 ℃ and 210--235 ℃ fractions was 51. 86%, 20.46% and 12.86%, respectively. The optimum extraction process parameters of 100--180 ℃ fraction were as follows; alkali mass fraction of 20%, reaction time of 5 min, reaction temperature of 50 ℃ ; acid mass fraction of 20%, reaction time of 30 min and reaction temperature of 22 ℃. Meanwhile, the recovery yield of crude phenol was 50. 24%. There were 42 types of phenolic compounds in crude phenol, which contributed the 98.49% in quality, and the mass fraction of low-rank phenols was 73.90%. This research can provide reference for high value-added use of biomass gasification tar.