Development Of Extraction Solvent For Polyphenol From Wastewater With High Concentration The Phenols

Coal gasification usually adopt lurgi or BGL gasification technology.The technology will produce a large number of high concentrated phenol wastewater in the process gas washing.Extraction separation and biochemical treatment technique was used to realize phenolic recycling and waste water purification.The key to phenol extraction recovery technology is selecting efficient easy recycling extraction solvent.Now the most commonly used dephenolizing extractant are MIBK and diisopropyl ether,both are excellent dephenolizing extractant,especially MIBK extraction efficient is higher than diisopropyl ether,but all of existing extraction solvent's extraction efficient of polyphenol are far below than extraction efficient of phenol.The paper embarked from the extraction mechanism,studying the interaction between the components of extraction system,we try to break through the extraction solvent's weak force to polyphenol,and look for a kind of matter that can collaborate with MIBK to improve extraction efficient of polyphenol.At the same time,this novel composite extraction solvent can reduce the burden of biochemical treatment.we tested various kinds of extraction solvents in laboratory and selected MIBK as main component of new extraction,BE as synergistic component by mechanism analysis and experiment.Then we studied the effect of concentration on extraction efficient.Based on what was said above,we developed the new composite extraction solvent-SCUT-1.Its distribution coefficient of polyphenol is twice as high as MIBK's.The extractiom process condition and parameter such as temperature,pH,phase ratio and extraction stages were studied,and the suitable extraction condition and parameter were determined.According to the physical properties of extraction solvent,we used rectification to recycle solvent and the phenols.Operational process of stripping tower and rectification tower was simulated by Aspen plus.Taking into account the energy consumption,equipment cost,and recovery rates of extraction solvent,we set stage number,feed stage of stripping tower as 16 and 8 respectively,the distillation rate in solvent stripper was set as 2800kg/h.Stagenumber,feed stage of rectification tower was 40 and 18 respectively.The distillation rate in the bottom of rectification tower was set as 700kg/h.Finally,the paper provide the Liquid-liquid equilibrium data for the ternary system methyl isobutyl ketone(MIBK)+ polyphenol(hydroquinone,catechol,resorcinol)+ water.Then,the experimental data were correlated with the UNIQUAC and NRTL activity coefficient models,and the corresponding binary interaction parameters were regressed.These data can provide the fundamental data to design dephenoling process related to SCUT-1.