Separation And Purification Of Crud Phenol From Phenol Oil

As the important raw materials during chemical synthesis,phenolic compounds were widely used in medicine,plastics,pesticides and other fields.Coal tar is one of the main sources of phenolic substances.Industrial method for separating crude phenol from coal tar is mainly acid and alkali solution elution methods,but because of some unavoidable shortcomings,it restricts its industrial widely used,such as the use of acid and alkali will cause serious corrosion of equipment in the elution process,a large number of phenol wastewater from elution process has brought great pressure to the environment,and by-product sodium sulfate due to entrainment of phenol from elution process was not acceptable for downstream users.In order to solve this problem,this paper adopts the green and solvent-recoverable double solvent extraction method and extractive distillation method to extract the crude phenol from phenol oil.At the later stage,the aspen Batch Modeler was used to simulate the separation process of the crude phenol.The main work is as follows:1.The effects of extraction agent,the mass fraction of water in the solvent,ratio of solvent to oil and mode of operation on the extraction efficiency were investigated in the double solvent extraction.The results showed that diethylene glycol was better than that of triacetate as polar extractant.The addition of a certain amount of water in the solvent is beneficial to the extraction of the crude phenol,and the higher the water content is,the better the extraction efficiency is.The octane is better than the petroleum ether as the light phase extraction agent.Compared with the intermittent extraction,the extraction efficiency of continuous extraction is high In the intermittent extraction.Increasing the ratio of oil to oil is beneficial to improve the extraction efficiency.2.The effects of extraction agent,ratio of solvent to oil,solvent feed mode and feed rate on the extraction efficiency were investigated.The results showed that the extraction efficiency of diethylene glycol was better than that of glycerol triacetate.Increasing the ratio of solvent to oil,using the feeding mode of increasing the solvent feed rate gradually were conducive to reducing the neutral oil and pyridine substances content in the crude phenol.Using water to recycle the solvent in neutral oil which can entrain some of the solvent by azeotropy after extractive distillation.The results show that increasing the concentration of water and lowering the temperature can reduce solvent entrainment.3.In this article,we choose NRTL-RK as property methods andUNIFAC to estimate unknown property.The effect of operating pressure,number of theoretical plate,reflux ratio,slop cut in batch distillation,impurities and other factors on the yield pf phenol,o-cresol,m-cresol was investigated under the the premise that the purity of the target products are as follows:Phenol 99.0%,O-cresol 96.0%and M-cresol 90.0%.The results show that the increase of the number of plates and reflux ratio can improve the product yield.The decrease of the operating pressure will decrease the yield of phenol slightly while increase the yield of o-cresol and m-cresol of the collection.Collection of slop cut in batch distillation can improve the purity of the composition and yield significantly.The simulation results are basically consistent with the separation of existing industrial plants.