页岩油含酚废水萃取过程的模拟研究

Simulation and study on extraction process of shale oil-phenolic wastewater

油页岩热解过程中产生大量的高质量浓度含酚废水无法排放,文中采用溶剂萃取法,以甲基叔戊基醚(TAME)为溶剂,针对页岩油含酚废水的处理进行初步研究。通过实验和Aspen P lus软件模拟相结合来考察TAME的萃取脱酚性能,研究了不同温度和相比条件下错、逆流萃取流程的分离性能。结果表明:TAME的脱酚能力很强,对苯酚的分配系数在40—60之间,pH值在2—10时萃取率达95%以上。此外比较了错、逆流3级萃取工艺,综合考虑萃取效果和溶剂用量,逆流多级萃取远远优于错流多级萃取,塔内3级萃取相比为2时出口废水酚质量浓度可降到1 mg/L以下,且受温度影响不明显。可见TAME的脱酚性能优异,在酸碱性体系中均适用,同时TAME原料易得,成本较低,可以作为含酚废水萃取工艺的萃取剂。

Shale oil-phenol wastewater produced in pyrogenation process of oil shale can not be discharged due to its high phenol mass concentration.The disposal of shale oil-phenol wastewater was researched by solvent extraction with methyl-tert-pentyl ether（TAME） as extractant.The experiment combined with Aspen Plus software simulation was carried out to investigate the phenol-absorbing capability of TAME and the separation properties of crosscurrent and countercurrent extraction at different temperatures or phase ratios.The results indicate that TAME possesses excellent capacity of extraction,the distribution coefficient of phenol is 40-60,and extraction efficiency is above 95% when pH value is 2-10.The countercurrent extraction is significantly superior to the crosscurrent extraction in the consideration of extraction efficiency and solvent dosage.When the phase ratio is 2,phenol mass concentration of final wastewater in 3-stage extraction tower is reduced to 1 mg/L,and it is insensitive to temperature.TAME has excellent performances to absorb the phenol,and also has other advantages such as abundant resources,low cost and applying to acid and alkaline system.TAME is perfect as an extractant for extracting phenol wastewater.